1
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Xu H, Qi K, Zong C, Deng J, Zhou P, Hu X, Ma X, Wang D, Wang M, Zhang J, King SM, Rogers SE, Lu JR, Yang J, Wang J. Controlling 1D Nanostructures and Handedness by Polar Residue Chirality of Amphiphilic Peptides. Small 2024; 20:e2304424. [PMID: 37726235 DOI: 10.1002/smll.202304424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 08/17/2023] [Indexed: 09/21/2023]
Abstract
Peptide assemblies are promising nanomaterials, with their properties and technological applications being highly hinged on their supramolecular architectures. Here, how changing the chirality of the terminal charged residues of an amphiphilic hexapeptide sequence Ac-I4 K2 -NH2 gives rise to distinct nanostructures and supramolecular handedness is reported. Microscopic imaging and neutron scattering measurements show thin nanofibrils, thick nanofibrils, and wide nanotubes self-assembled from four stereoisomers. Spectroscopic and solid-state nuclear magnetic resonance (NMR) analyses reveal that these isomeric peptides adopt similar anti-parallel β-sheet secondary structures. Further theoretical calculations demonstrate that the chiral alterations of the two C-terminal lysine residues cause the formation of diverse single β-strand conformations, and the final self-assembled nanostructures and handedness are determined by the twisting direction and degree of single β-strands. This work not only lays a useful foundation for the fabrication of diverse peptide nanostructures by manipulating the chirality of specific residues but also provides a framework for predicting the supramolecular structures and handedness of peptide assemblies from single molecule conformations.
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Affiliation(s)
- Hai Xu
- State Key Laboratory of Heavy Oil Processing and Department of Biological and Energy Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China
| | - Kai Qi
- State Key Laboratory of Heavy Oil Processing and Department of Biological and Energy Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China
| | - Cheng Zong
- State Key Laboratory of Heavy Oil Processing and Department of Biological and Energy Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China
| | - Jing Deng
- National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Peng Zhou
- State Key Laboratory of Heavy Oil Processing and Department of Biological and Energy Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Science, Beijing, 100190, China
| | - Xuzhi Hu
- Biological Physics Group, Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK
| | - Xiaoyue Ma
- State Key Laboratory of Heavy Oil Processing and Department of Biological and Energy Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China
| | - Dong Wang
- State Key Laboratory of Heavy Oil Processing and Department of Biological and Energy Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China
| | - Muhan Wang
- Department of Civil Engineering, Qingdao University of Technology, Qingdao, 266033, China
| | - Jun Zhang
- School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao, 266033, China
| | - Stephen M King
- ISIS Pulsed Neutron & Muon Source, Didcot, Oxon, OX11 0QX, UK
| | - Sarah E Rogers
- ISIS Pulsed Neutron & Muon Source, Didcot, Oxon, OX11 0QX, UK
| | - Jian Ren Lu
- Biological Physics Group, Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK
| | - Jun Yang
- National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Jiqian Wang
- State Key Laboratory of Heavy Oil Processing and Department of Biological and Energy Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China
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2
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Elstone N, Shimizu K, Shaw EV, Lane PD, D’Andrea L, Demé B, Mahmoudi N, Rogers SE, Youngs S, Costen ML, McKendrick KG, Canongia Lopes JN, Bruce DW, Slattery JM. Understanding the Liquid Structure in Mixtures of Ionic Liquids with Semiperfluoroalkyl or Alkyl Chains. J Phys Chem B 2023; 127:7394-7407. [PMID: 37555779 PMCID: PMC10461228 DOI: 10.1021/acs.jpcb.3c02647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 06/15/2023] [Indexed: 08/10/2023]
Abstract
By mixing ionic liquids (ILs), it is possible to fine-tune their bulk and interfacial structure. This alters their physical properties and solvation behavior and is a simple way to prepare a collection of ILs whose properties can be tuned to optimize a specific application. In this study, mixtures of perfluorinated and alkylated ILs have been prepared, and links between composition, properties, and nanostructure have been investigated. These different classes of ILs vary substantially in the flexibility and polarizability of their chains. Thus, a range of useful structural and physical property variations are accessible through mixing that will expand the library of IL mixtures available in an area that to this point has received relatively little attention. In the experiments presented herein, the physical properties and bulk structure of mixtures of 1-methyl-3-octylimidazolium bis(trifluoromethylsulfonyl)imide [C8MIM][Tf2N] and 1-(1H,1H,2H,2H-perfluorooctyl)-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [C8MIM-F13][Tf2N] have been prepared. The bulk liquid structure was investigated using a combination of small-angle X-ray and neutron scattering (SAXS and SANS, respectively) experiments in combination with atomistic molecular dynamics simulations and the measurement of density and viscosity. We observed that the addition of [C8MIM-F13][Tf2N] to [C8MIM][Tf2N] causes changes in the nanostructure of the IL mixtures that are dependent on composition so that variation in the characteristic short-range correlations is observed as a function of composition. Thus, while the length scales associated with the apolar regions (polar non-polar peak─PNPP) increase with the proportion of [C8MIM-F13][Tf2N] in the mixtures, perhaps surprisingly given the greater volume of the fluorocarbon chains, the length scale of the charge-ordering peak decreases. Interestingly, consideration of the contact peak shows that its origins are both in the direct anion···cation contact length scale and the nature (and hence volume) of the chains appended to the imidazolium cation.
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Affiliation(s)
- Naomi
S. Elstone
- Department
of Chemistry, University of York, Heslington, York YO10
5DD, U.K.
| | - Karina Shimizu
- Centro
de Química Estrutural, Institute of Molecular Sciences, Instituto
Superior Técnico, Universidade de
Lisboa, Av. Rovisco Pais, Lisboa 1049 001, Portugal
| | - Emily V. Shaw
- Department
of Chemistry, University of York, Heslington, York YO10
5DD, U.K.
| | - Paul D. Lane
- Institute
of Chemical Sciences, School of Engineering and Physical Sciences, Heriot−Watt University, Edinburgh EH14 4AS, U.K.
| | - Lucía D’Andrea
- Department
of Chemistry, University of York, Heslington, York YO10
5DD, U.K.
| | - Bruno Demé
- Institut
Laue−Langevin, Grenoble 38000, France
| | - Najet Mahmoudi
- ISIS
Neutron Source Facility, Harwell Science and Innovation Campus, Didcot OX11 0DE, U.K.
| | - Sarah E. Rogers
- ISIS
Neutron Source Facility, Harwell Science and Innovation Campus, Didcot OX11 0DE, U.K.
| | - Sarah Youngs
- ISIS
Neutron Source Facility, Harwell Science and Innovation Campus, Didcot OX11 0DE, U.K.
| | - Matthew L. Costen
- Institute
of Chemical Sciences, School of Engineering and Physical Sciences, Heriot−Watt University, Edinburgh EH14 4AS, U.K.
| | - Kenneth G. McKendrick
- Institute
of Chemical Sciences, School of Engineering and Physical Sciences, Heriot−Watt University, Edinburgh EH14 4AS, U.K.
| | - Jose N. Canongia Lopes
- Centro
de Química Estrutural, Institute of Molecular Sciences, Instituto
Superior Técnico, Universidade de
Lisboa, Av. Rovisco Pais, Lisboa 1049 001, Portugal
| | - Duncan W. Bruce
- Department
of Chemistry, University of York, Heslington, York YO10
5DD, U.K.
| | - John M. Slattery
- Department
of Chemistry, University of York, Heslington, York YO10
5DD, U.K.
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3
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Guan Q, McAulay K, Xu T, Rogers SE, Edwards-Gayle C, Schweins R, Cui H, Seddon AM, Adams DJ. Self-Sorting in Diastereomeric Mixtures of Functionalized Dipeptides. Biomacromolecules 2023. [PMID: 37257089 DOI: 10.1021/acs.biomac.3c00246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Self-sorting in functionalized dipeptide systems can be driven by the chirality of a single amino acid, both at a high pH in the micellar state and at a low pH in the gel state. The structures formed are affected to some degree by the relative concentrations of each component showing the complexity of such an approach. The structures underpinning the gel network are predefined by the micellar structures at a high pH. Here, we describe the systems prepared from two dipeptide-based gelators that differ only by the chirality of one of the amino acids. We provide firm evidence for self-sorting in the micellar and gel phases using small-angle neutron scattering and cryo-transmission electron microscopy (cryo-TEM), showing that complete self-sorting occurs across a range of relative concentrations.
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Affiliation(s)
- Qingwen Guan
- School of Chemistry, University of Glasgow, Glasgow G12 8QQ, U.K
| | - Kate McAulay
- School of Chemistry, University of Glasgow, Glasgow G12 8QQ, U.K
| | - Tian Xu
- Department of Chemical and Biomolecular Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Sarah E Rogers
- ISIS Pulsed Neutron Source, Rutherford Appleton Laboratory, Didcot, OX11 0QX, U.K
| | | | - Ralf Schweins
- Large Scale Structures Group, Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20156, F-38042 Grenoble,CEDEX 9, France
| | - Honggang Cui
- Department of Chemical and Biomolecular Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Annela M Seddon
- School of Physics, HH Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, U.K
| | - Dave J Adams
- School of Chemistry, University of Glasgow, Glasgow G12 8QQ, U.K
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4
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Li Z, Carter J, Santos L, Webster C, van der Walle CF, Li P, Rogers SE, Lu JR. Acidification-Induced Structure Evolution of Lipid Nanoparticles Correlates with Their In Vitro Gene Transfections. ACS Nano 2023; 17:979-990. [PMID: 36608273 PMCID: PMC9878718 DOI: 10.1021/acsnano.2c06213] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 12/21/2022] [Indexed: 06/17/2023]
Abstract
The rational design of lipid nanoparticles (LNPs) for enhanced gene delivery remains challenging because of incomplete knowledge of their formulation-structure relationship that impacts their intracellular behavior and consequent function. Small-angle neutron scattering has been used in this work to investigate the structure of LNPs encapsulating plasmid DNA upon their acidification (from pH 7.4 to 4.0), as would be encountered during endocytosis. The results revealed the acidification-induced structure evolution (AISE) of the LNPs on different dimension scales, involving protonation of the ionizable lipid, volume expansion and redistribution of aqueous and lipid components. A similarity analysis using an LNP's structural feature space showed a strong positive correlation between function (measured by intracellular luciferase expression) and the extent of AISE, which was further enhanced by the fraction of unsaturated helper lipid. Our findings reveal molecular and nanoscale changes occurring during AISE that underpin the LNPs' formulation-nanostructure-function relationship, aiding the rational design of application-directed gene delivery vehicles.
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Affiliation(s)
- Zongyi Li
- Biological
Physics Laboratory, School of Physics and Astronomy, University of Manchester, Oxford Road, Schuster Building, ManchesterM13 9PL, U.K.
| | - Jessica Carter
- Biological
Physics Laboratory, School of Physics and Astronomy, University of Manchester, Oxford Road, Schuster Building, ManchesterM13 9PL, U.K.
| | - Luis Santos
- Dosage
Form Design Development, Biopharmaceuticals Development, AstraZeneca, Gaithersburg, Maryland20878, United States
| | - Carl Webster
- Discovery
Sciences, R&D, AstraZeneca, CambridgeCB21 6GH, U.K.
| | - Christopher F. van der Walle
- The
Cell and Gene Therapy Catapult, The Centre
for Regenerative Medicine, 5 Little France Drive, EdinburghEH16 4UU, U.K.
| | - Peixun Li
- ISIS
Neutron Facility, STFC, Chilton, DidcotOX11 0QZ, U.K.
| | | | - Jian Ren Lu
- Biological
Physics Laboratory, School of Physics and Astronomy, University of Manchester, Oxford Road, Schuster Building, ManchesterM13 9PL, U.K.
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5
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Zhou P, Hu X, Li J, Wang Y, Yu H, Chen Z, Wang D, Zhao Y, King SM, Rogers SE, Wang J, Lu JR, Xu H. Peptide Self-Assemblies from Unusual α-Sheet Conformations Based on Alternation of d/ l Amino Acids. J Am Chem Soc 2022; 144:21544-21554. [DOI: 10.1021/jacs.2c08425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Peng Zhou
- State Key Laboratory of Heavy Oil Processing and Department of Biological and Energy Chemical Engineering, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao 266580, China
| | - Xuzhi Hu
- Biological Physics Group, Department of Physics and Astronomy, The University of Manchester, Manchester M13 9PL, U.K
| | - Jie Li
- State Key Laboratory of Heavy Oil Processing and Department of Biological and Energy Chemical Engineering, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao 266580, China
| | - Yan Wang
- State Key Laboratory of Heavy Oil Processing and Department of Biological and Energy Chemical Engineering, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao 266580, China
| | - Henghao Yu
- State Key Laboratory of Heavy Oil Processing and Department of Biological and Energy Chemical Engineering, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao 266580, China
| | - Zhaoyu Chen
- State Key Laboratory of Heavy Oil Processing and Department of Biological and Energy Chemical Engineering, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao 266580, China
| | - Dong Wang
- State Key Laboratory of Heavy Oil Processing and Department of Biological and Energy Chemical Engineering, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao 266580, China
| | - Yurong Zhao
- State Key Laboratory of Heavy Oil Processing and Department of Biological and Energy Chemical Engineering, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao 266580, China
| | - Stephen M. King
- ISIS Pulsed Neutron & Muon Source, STFC Rutherford Appleton Laboratory, Didcot, Oxon OX11 0QX, U.K
| | - Sarah E. Rogers
- ISIS Pulsed Neutron & Muon Source, STFC Rutherford Appleton Laboratory, Didcot, Oxon OX11 0QX, U.K
| | - Jiqian Wang
- State Key Laboratory of Heavy Oil Processing and Department of Biological and Energy Chemical Engineering, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao 266580, China
| | - Jian Ren Lu
- Biological Physics Group, Department of Physics and Astronomy, The University of Manchester, Manchester M13 9PL, U.K
| | - Hai Xu
- State Key Laboratory of Heavy Oil Processing and Department of Biological and Energy Chemical Engineering, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao 266580, China
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6
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Costa T, Knaapila M, Stewart B, Ramos ML, Justino LLG, Valente AJM, Dalgliesh R, Rogers SE, Kraft M, Allard S, Scherf U, Burrows HD. Nanostructuring with Surfactants: The Self-Assembly of a New Poly(thiophene-phenylene) Conjugated Polymer Bearing Azacrown Ether Pendant Groups. Langmuir 2022; 38:11845-11859. [PMID: 36121768 DOI: 10.1021/acs.langmuir.2c01246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
We report the synthesis of a new conjugated polymer bearing crown ether moieties, poly[(N(1-aza-[18]crown-6)carbamido)thiophene-2,5-diyl-alt-1,4-phenylene] (BG2). In water, BG2 forms a dispersion with a slightly cloudy appearance. We have studied the effect of adding surfactants, with different polar head groups, on these polymer-polymer aggregates. Special attention is given to the system with the anionic surfactant, sodium dodecyl sulfate (SDS). The combination of photophysical techniques with electrical conductivity, NMR (1H, 13C, and 27Na), DFT calculations, molecular dynamics simulations, and small-angle neutron scattering (SANS) provides a detailed picture on the behavior of the SDS/BG2 system in aqueous solution and in thin films. NMR, electric conductivity, and DFT results suggest that hydrophilic interactions occur between the polar headgroup of the surfactant (OSO3- Na+) and the aza-[18]-crown-6 moiety. DFT calculations confirmed the capability of BG2 to form stable complexes with the Na+ cations, where the cation can be either inside the azacrown cavity or sandwiched between the cavity and the polymer chain, which seem to determine the position of the surfactant hydrocarbon chain and, therefore, be responsible for the disruption of the BG2 aggregates and subsequent increase in the photoluminescence quantum yields. SANS measurements, made with hydrogenated and deuterated SDS in D2O, clearly show how micron-sized aggregates of BG2 are broken down by SDS and then how BG2 becomes preferentially incorporated within joint colloidal particles of BG2 and SDS with increasing [SDS]/[BG2] molar ratio.
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Affiliation(s)
- Telma Costa
- Department of Chemistry, University of Coimbra, CQC-IMS, Coimbra P-3004-535, Portugal
| | - Matti Knaapila
- Department of Physics, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Beverly Stewart
- Polymer and Biomaterials Chemistry Laboratories, School of Chemistry and Biosciences, University of Bradford, Bradford BD7 1DP, United Kingdom
| | - M Luísa Ramos
- Department of Chemistry, University of Coimbra, CQC-IMS, Coimbra P-3004-535, Portugal
| | - Licinia L G Justino
- Department of Chemistry, University of Coimbra, CQC-IMS, Coimbra P-3004-535, Portugal
| | - Artur J M Valente
- Department of Chemistry, University of Coimbra, CQC-IMS, Coimbra P-3004-535, Portugal
| | - Robert Dalgliesh
- Rutherford Appleton Laboratory, ISIS STFC, Chilton, Oxfordshire OX11 0QX, United Kingdom
| | - Sarah E Rogers
- Rutherford Appleton Laboratory, ISIS STFC, Chilton, Oxfordshire OX11 0QX, United Kingdom
| | - Mario Kraft
- Macromolecular Chemistry Group (buwmacro), Bergische Universität Wuppertal, Gauß-Strasse. 20, 42097 Wuppertal, Germany
| | - Sybille Allard
- Macromolecular Chemistry Group (buwmacro), Bergische Universität Wuppertal, Gauß-Strasse. 20, 42097 Wuppertal, Germany
| | - Ullrich Scherf
- Macromolecular Chemistry Group (buwmacro), Bergische Universität Wuppertal, Gauß-Strasse. 20, 42097 Wuppertal, Germany
| | - Hugh D Burrows
- Department of Chemistry, University of Coimbra, CQC-IMS, Coimbra P-3004-535, Portugal
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7
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Cabry CP, D'Andrea L, Elstone NS, Kirchhecker S, Riccobono A, Khazal I, Li P, Rogers SE, Bruce DW, Slattery JM. Small-angle neutron scattering from mixtures of long- and short-chain 3-alkyl-1-methyl imidazolium bistriflimides. Phys Chem Chem Phys 2022; 24:15811-15823. [PMID: 35762383 DOI: 10.1039/d2cp01528e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The preparation of mixtures of ionic liquids (ILs) represents an attractive strategy to tune their properties, an important aspect of which is to understand how the structure of the bulk varies with composition. In this study, small-angle neutron scattering (SANS) was used to probe mixtures of methylimidazolium-based ionic liquids [Cnmim][Tf2N] with [C2mim][Tf2N]) (n = 4, 6, 8 and 10) and of [Cmmim][Tf2N] with [C12mim][Tf2N] (m = 2, 4, 6 and 8). Mixtures were prepared in both contrasts, which is to say that one component would be fully hydrogenated while the other was fully deuterated, and vice versa. Data were fitted using a range of appropriate models, of which the Teubner-Strey model provided most useful information and the pure materials showed a nascent Polar Non-polar Peak (PNPP) for n = 6, which became more evident as n increased. In the mixtures [Cnmim]x[C2mim]1-x[Tf2N], the PNPP was evident for n = 10 and 8, nascent for n = 6 and absent for n = 4, with percolation showing a very strong dependence on the chain length of the added IL, [Cnmim][Tf2N]. In contrast, while the ability of [C12mim][Tf2N] to form percolated structures was damped when mixed with [Cmmim][Tf2N], as m increased from 2 to 6, this effect was less strong. However, data obtained for mixtures of [C12mim][Tf2N] and [C8mim][Tf2N], both of which percolate as pure materials, did not fit easily in any of the models applied to the previous systems and gave results that depended on the contrast used. Complementary small-angle X-ray scattering (SAXS) data, however, showed the expected evolution and behaviour of the PNPP, COP and CP, revealing that the unexpected observations were due to an adventitious matching out of isotopic contrasts. As well as revealing details of the structures of these IL mixtures, the results also point to complementary strategies for generating bulk percolated structures as a function of cation chain length.
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Affiliation(s)
| | - Lucía D'Andrea
- Department of Chemistry, University of York, Heslington, York YO10 5DD, UK.
| | - Naomi S Elstone
- Department of Chemistry, University of York, Heslington, York YO10 5DD, UK.
| | - Sarah Kirchhecker
- Department of Chemistry, University of York, Heslington, York YO10 5DD, UK.
| | - Alessio Riccobono
- Department of Chemistry, University of York, Heslington, York YO10 5DD, UK.
| | - Iman Khazal
- Department of Chemistry, University of York, Heslington, York YO10 5DD, UK.
| | - Peixun Li
- ISIS, Science & Technology Facilities Council, Rutherford Appleton Laboratory, Chilton, UK
| | - Sarah E Rogers
- ISIS, Science & Technology Facilities Council, Rutherford Appleton Laboratory, Chilton, UK
| | - Duncan W Bruce
- Department of Chemistry, University of York, Heslington, York YO10 5DD, UK.
| | - John M Slattery
- Department of Chemistry, University of York, Heslington, York YO10 5DD, UK.
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8
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Simon OB, Rojas DC, Ghosh D, Yang X, Rogers SE, Martin CS, Holden SK, Kluger BM, Buard I. Profiling Parkinson's disease cognitive phenotypes via resting-state magnetoencephalography. J Neurophysiol 2022; 127:279-289. [PMID: 34936515 PMCID: PMC8782645 DOI: 10.1152/jn.00316.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Aberrant brain oscillations are a hallmark of Parkinson's disease (PD) pathophysiology and may be related to both motor and nonmotor symptoms. Mild cognitive impairment (MCI) affects many people with PD even at the time of diagnosis and conversion risks to PD dementia (PDD) are very high. Unfortunately, pharmacotherapies are not addressing cognitive symptoms in PD. Profiling PD cognitive phenotypes (e.g., MCI, PDD, etc.) may therefore help inform future treatments. Neurophysiological methods, such as magnetoencephalography (MEG), offer the advantage of observing oscillatory patterns, whose regional and temporal profiles may elucidate how cognitive changes relate to neural mechanisms. We conducted a resting-state MEG cross-sectional study of 89 persons with PD stratified into three phenotypic groups: normal cognition, MCI, and PDD, to identify brain regions and frequencies most associated with each cognitive profile. In addition, a neuropsychological battery was administered to assess each domain of cognition. Our data showed higher power in lower frequency bands (delta and theta) observed along with more severe cognitive impairment and associated with memory, language, attention, and global cognition. Of the total 119 brain parcels assessed during source analysis, widespread group differences were found in the beta band, with significant changes mostly occurring between the normal cognition and MCI groups. Moreover, bilateral frontal and left-hemispheric regions were particularly affected in the other frequencies as cognitive decline becomes more pronounced. Our results suggest that MCI and PDD may be qualitatively distinct cognitive phenotypes, and most dramatic changes seem to have happened when the PD brain shows mild cognitive decline.NEW & NOTEWORTHY Can we better stage cognitive decline in patients with Parkinson's disease (PD)? Here, we provide evidence that mild cognitive impairment, rather than being simply a milder form of dementia, may be a qualitatively distinct phase in its development. We suggest that the most dramatic neurophysiological changes may occur during the time the PD brain transitions from normal cognition to MCI, then compensatory changes further occur as the brain "switches" to a dementia state.
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Affiliation(s)
- Olivier B. Simon
- 1Department of Biostatistics and Informatics, University of Colorado Denver, Aurora, Colorado
| | - Donald C. Rojas
- 2Department of Psychology, Colorado State University, Fort Collins, Colorado
| | - Debashis Ghosh
- 1Department of Biostatistics and Informatics, University of Colorado Denver, Aurora, Colorado
| | - Xinyi Yang
- 1Department of Biostatistics and Informatics, University of Colorado Denver, Aurora, Colorado
| | - Sarah E. Rogers
- 3Department of Neurology, University of Colorado Denver, Aurora, Colorado
| | | | - Samantha K. Holden
- 3Department of Neurology, University of Colorado Denver, Aurora, Colorado
| | - Benzi M. Kluger
- 4Department of Neurology, University of Rochester Medical Center Rochester, Rochester, New York
| | - Isabelle Buard
- 3Department of Neurology, University of Colorado Denver, Aurora, Colorado
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9
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Jamaluddin NA, Mohamed A, Bakar SA, Ardyani T, Sagisaka M, Saito H, Mamat MH, Ahmad MK, Abdul Khalil HPS, King SM, Rogers SE, Eastoe J. Fabrication and application of composite adsorbents made by one-pot electrochemical exfoliation of graphite in surfactant ionic liquid/nanocellulose mixtures. Phys Chem Chem Phys 2021; 23:19313-19328. [PMID: 34524298 DOI: 10.1039/d1cp02206g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Previously, surfactant-assisted exfoliated graphene oxide (sEGO) formed with the triple-chain surfactant TC14 (sodium 1,4-bis(neopentyloxy)-3-(neopentylcarbonyl)-1,4-dioxobutane-2-sulfonate) was applied in wastewater treatment. The extent of dye-removal and the adsorption capacity of the sEGO formed with this triple-chain surfactant outperformed those of two other systems, namely, the di-chain version of TC14 (AOT14; sodium 1,2-bis-(2,2-dimethyl-propoxycarbonyl)-ethanesulfonate) and the single-chain surfactant sodium n-dodecylsulfate. In the present study, to further optimise the surfactant chemical structure, the sodium ion of TC14 was substituted with 1-butyl-3-methyl-imidazolium (BMIM) generating surfactant ionic liquids (SAILs; 1-butyl-3-imidazolium 1,4-bis(neopentyloxy)-3-(neopentyloxycarbonyl)-1,4-dioxobutane-2-sulfonate), hereafter denoted as BMIM-TC14. This SAIL, together with nanofibrillated kenaf cellulose (NFC), was used to electrochemically exfoliate graphite, yielding BMIM-TC14 sEGO/NFC composites. These highly hydrophobic polymer composites were then used for the removal of methylene blue (MB) from aqueous solution. 1H NMR spectroscopy was used to elucidate the structure of the synthesised SAILs. The morphologies of the resulting nanocomposites were investigated using Raman spectroscopy, field-emission scanning electron microscopy, and high-resolution transmission electron microscopy. Analysis using small-angle neutron scattering was performed to examine the aggregation behaviour of sEGO and custom-made SAILs. Zeta potential, surface tension, and dynamic light-scattering measurements were used to study the aqueous properties and colloidal stability of the suspension. Amongst the surfactants tested, BMIM-TC14 sEGO/NFC exhibited the highest MB adsorption ability, achieving 99% dye removal under optimum conditions. These results highlight the importance of modifying the hydrophilic moieties of amphiphilic compounds to improve the performance of sEGO/NFC composites as effective adsorbents for wastewater treatment.
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Affiliation(s)
- Nur Amirah Jamaluddin
- Department of Chemistry, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, 35900 Tanjong Malim, Perak, Malaysia.
| | - Azmi Mohamed
- Department of Chemistry, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, 35900 Tanjong Malim, Perak, Malaysia. .,Nanotechnology Research Centre, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, 35900 Tanjong Malim, Perak, Malaysia
| | - Suriani Abu Bakar
- Nanotechnology Research Centre, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, 35900 Tanjong Malim, Perak, Malaysia
| | - Tretya Ardyani
- Department of Chemistry, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, 35900 Tanjong Malim, Perak, Malaysia.
| | - Masanobu Sagisaka
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University, Bunkyo-cho 3, Hirosaki, Aomori 036-8561, Japan
| | - Haruka Saito
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University, Bunkyo-cho 3, Hirosaki, Aomori 036-8561, Japan
| | - Mohamad Hafiz Mamat
- NANO-ElecTronic Centre (NET), School of Electrical Engineering, College of Engineering, Universiti Teknologi MARA, 40450 Shah Alam, Selangor, Malaysia
| | - Mohd Khairul Ahmad
- Microelectronic and Nanotechnology - Shamsuddin Research Centre (MiNT-SRC), Faculty of Electrical and Electronic Engineering, Universiti Tun Hussein Onn Malaysia, 86400 Parit Raja, Batu Pahat, Johor, Malaysia
| | - H P S Abdul Khalil
- School of Industrial Technology, Universiti Sains Malaysia, 11700, Gelugor, Penang, Malaysia
| | - Stephen M King
- ISIS Pulsed Neutron & Muon Source, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxfordshire, OX11 0QT, UK
| | - Sarah E Rogers
- ISIS Pulsed Neutron & Muon Source, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxfordshire, OX11 0QT, UK
| | - Julian Eastoe
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
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10
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Matthews L, Ruscigno S, Rogers SE, Bartlett P, Johnson AJ, Sochon R, Briscoe WH. Fracto-eutectogels: SDS fractal dendrites via counterion condensation in a deep eutectic solvent. Phys Chem Chem Phys 2021; 23:11672-11683. [PMID: 33978002 DOI: 10.1039/d1cp01370j] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Glyceline, a deep eutectic solvent comprising glycerol and choline chloride, is a green nonaqueous solvent with potential industrial applications. Molecular mechanisms of surfactant self-assembly in deep eutectic solvents are expected to differ from those in their constituent polar components and are not well understood. Here we report the observation of self-assembled SDS fractal dendrites with dimensions up to ∼mm in glyceline at SDS concentrations as low as cSDS ∼ 0.1 wt%. The prevalence of these dendritic fractal aggregates led to the formation of a gel phase at SDS concentrations above ≥1.9 wt% (the critical gelation concentration cCGC). The gel microscopic structure was visualised using polarised light microscopy (PLM); rheology measurements confirmed the formation of a colloidal gel, where the first normal stress difference was negative and the elastic modulus was dominant. Detailed nano-structural characterisation by small-angle neutron scattering (SANS) further confirmed the presence of fractal aggregates. Such SDS aggregation or gelation has not been observed in water at such low surfactant concentrations, whereas SDS has been reported to form lamellar aggregates in glycerol (a component of glyceline). We attribute the formation of the SDS fractal dendrites to the condensation of counterions (i.e. the choline ions) around the SDS aggregates - a diffusion-controlled process, leading to the aggregate morphology observed. These unprecedented results shed light on the molecular mechanisms of surfactant self-assembly in deep eutectic solvents, important to their application in industrial formulation.
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Affiliation(s)
- Lauren Matthews
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK. and Bristol Centre for Functional Nanomaterials, HH Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK
| | - Silvia Ruscigno
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK.
| | - Sarah E Rogers
- ISIS Muon and Neutron Source, Rutherford Appleton Laboratory, Harwell Oxford, Didcot, OX11 0QX, UK
| | - Paul Bartlett
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK.
| | | | - Robert Sochon
- GlaxoSmithKline, St George's Avenue, Weybridge, KT13 0DE, UK
| | - Wuge H Briscoe
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK.
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11
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Sharratt WN, Lopez CG, Sarkis M, Tyagi G, O’Connell R, Rogers SE, Cabral JT. Ionotropic Gelation Fronts in Sodium Carboxymethyl Cellulose for Hydrogel Particle Formation. Gels 2021; 7:44. [PMID: 33921260 PMCID: PMC8167666 DOI: 10.3390/gels7020044] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 04/06/2021] [Accepted: 04/08/2021] [Indexed: 11/17/2022] Open
Abstract
Hydrogel microparticles (HMPs) find numerous practical applications, ranging from drug delivery to tissue engineering. Designing HMPs from the molecular to macroscopic scales is required to exploit their full potential as functional materials. Here, we explore the gelation of sodium carboxymethyl cellulose (NaCMC), a model anionic polyelectrolyte, with Fe3+ cations in water. Gelation front kinetics are first established using 1D microfluidic experiments, and effective diffusive coefficients are found to increase with Fe3+ concentration and decrease with NaCMC concentrations. We use Fourier Transform Infrared Spectroscopy (FTIR) to elucidate the Fe3+-NaCMC gelation mechanism and small angle neutron scattering (SANS) to spatio-temporally resolve the solution-to-network structure during front propagation. We find that the polyelectrolyte chain cross-section remains largely unperturbed by gelation and identify three hierarchical structural features at larger length scales. Equipped with the understanding of gelation mechanism and kinetics, using microfluidics, we illustrate the fabrication of range of HMP particles with prescribed morphologies.
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Affiliation(s)
- William N. Sharratt
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK; (M.S.); (G.T.); (R.O.)
| | - Carlos G. Lopez
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52056 Aachen, Germany;
| | - Miriam Sarkis
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK; (M.S.); (G.T.); (R.O.)
| | - Gunjan Tyagi
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK; (M.S.); (G.T.); (R.O.)
| | - Róisín O’Connell
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK; (M.S.); (G.T.); (R.O.)
| | - Sarah E. Rogers
- ISIS, Rutherford Appleton Laboratory, Harwell, Didcot OX11 0QX, UK;
| | - João T. Cabral
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK; (M.S.); (G.T.); (R.O.)
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12
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Zhao Y, Hu X, Zhang L, Wang D, King SM, Rogers SE, Wang J, Lu JR, Xu H. Monolayer wall nanotubes self-assembled from short peptide bolaamphiphiles. J Colloid Interface Sci 2021; 583:553-562. [DOI: 10.1016/j.jcis.2020.09.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 09/07/2020] [Accepted: 09/07/2020] [Indexed: 12/29/2022]
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13
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Bharatiya B, Wang G, Rogers SE, Pedersen JS, Mann S, Briscoe WH. Mixed liposomes containing gram-positive bacteria lipids: Lipoteichoic acid (LTA) induced structural changes. Colloids Surf B Biointerfaces 2021; 199:111551. [PMID: 33387794 DOI: 10.1016/j.colsurfb.2020.111551] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 12/18/2020] [Accepted: 12/19/2020] [Indexed: 11/26/2022]
Abstract
Lipoteichoic acid (LTA), a surface associated polymer amphiphile tethered directly to the Gram-positive bacterial cytoplasmic membrane, is a key structural and functional membrane component. Its composition in the membrane is regulated by bacteria under different physiological conditions. How such LTA compositional variations modulate the membrane structural stability and integrity is poorly understood. Here, we have investigated structural changes in mixed liposomes mimicking the lipid composition of Gram-positive bacteria membranes, in which the concentration of Bacillus Subtilis LTA was varied between 0-15 mol%. Small-angle neutron scattering (SANS) and dynamic light scattering (DLS) measurements indicated formation of mixed unilamellar vesicles, presumably stabilized by the negatively charged LTA polyphosphates. The vesicle size increased with the LTA molar concentration up to ∼6.5 mol%, accompanied by a broadened size distribution, and further increasing the LTA concentration led to a decrease in the vesicle size. At 80 °C, SANS analyses showed the formation of larger vesicles with thinner shells. Complementary Cryo-TEM imaging confirmed the vesicle formation and the size increase with LTA addition, as well as the presence of interconnected spherical aggregates of smaller size at higher LTA concentrations. The results are discussed in light of the steric and electrostatic interactions of the bulky LTA molecules with increased chain fluidity at the higher temperature, which affect the molecular packing and interactions, and thus depend on the LTA composition, in the membrane.
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Affiliation(s)
- Bhavesh Bharatiya
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Gang Wang
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Sarah E Rogers
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Harwell Oxford, Didcot, OX11 0QX, UK
| | - Jan Skov Pedersen
- Department of Chemistry and Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, Building 1590-252, 8000, Aarhus C, Denmark
| | - Stephen Mann
- Max Planck Bristol Centre for Minimal Biology, Centre for Protolife Research and Centre for Organized Matter Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, UK
| | - Wuge H Briscoe
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK.
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14
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Riccobono A, Lazzara G, Rogers SE, Pibiri I, Pace A, Slattery JM, Bruce DW. Synthesis and mesomorphism of related series of triphilic ionic liquid crystals based on 1,2,4-triazolium cations. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2020.114758] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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15
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Hill C, Umetsu Y, Fujita K, Endo T, Sato K, Yoshizawa A, Rogers SE, Eastoe J, Sagisaka M. Design of Surfactant Tails for Effective Surface Tension Reduction and Micellization in Water and/or Supercritical CO 2. Langmuir 2020; 36:14829-14840. [PMID: 33228361 DOI: 10.1021/acs.langmuir.0c02835] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The interfacial properties and water-in-CO2 (W/CO2) microemulsion (μE) formation with double- and novel triple-tail surfactants bearing trimethylsilyl (TMS) groups in the tails are investigated. Comparisons of these properties are made with those for analogous hydrocarbon (HC) and fluorocarbon (FC) tail surfactants. Surface tension measurements allowed for critical micelle concentrations (CMC) and surface tensions at the CMC (γCMC) to be determined, resulting in the following trend in surface activity FC > TMS > HC. Addition of a third surfactant tail gave rise to increased surface activity, and very low γCMC values were recorded for the double/triple-tail TMS and HC surfactants. Comparing effective tail group densities (ρlayer) of the respective surfactants allowed for an understanding of how γCMC is affected by both the number of surfactant tails and the chemistry of the tails. These results highlight the important role of tail group chemical structure on ρlayer for double-tail surfactants. For triple-tail surfactants, however, the degree to which ρlayer is affected by tail group architecture is harder to discern due to formation of highly dense layers. Stable W/CO2 μEs were formed by both the double- and the triple-tail TMS surfactants. High-pressure small-angle neutron scattering (HP-SANS) has been used to characterize the nanostructures of W/CO2 μEs formed by the double- and triple-tail surfactants, and at constant pressure and temperature, the aqueous cores of the microemulsions were found to swell with increasing water-to-surfactant ratio (W0). A maximum W0 value of 25 was recorded for the triple-tail TMS surfactant, which is very rare for nonfluorinated surfactants. These data therefore highlight important parameters required to design fluorine-free environmentally responsible surfactants for stabilizing W/CO2 μEs.
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Affiliation(s)
- Christopher Hill
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Yasushi Umetsu
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Kazuki Fujita
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Takumi Endo
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Kodai Sato
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Atsushi Yoshizawa
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Sarah E Rogers
- ISIS-CCLRC, Rutherford Appleton Laboratory, Chilton, Oxon OX11 0QX, United Kingdom
| | - Julian Eastoe
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Masanobu Sagisaka
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
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16
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Michel SES, Rogers SE, Briscoe WH, Galan MC. Tunable Thiol-Ene Photo-Cross-Linked Chitosan-Based Hydrogels for Biomedical Applications. ACS Appl Bio Mater 2020; 3:8075-8083. [PMID: 35019547 DOI: 10.1021/acsabm.0c01171] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Access to biocompatible hydrogels with tunable properties is of great interest in biomedical applications. Here we report the synthesis and characterization of a series of photo-cross-linked chitosan hydrogels from norbornene-functionalized chitosan (CS-nb) and various thiolated cross-linkers. The resulting materials were characterized by NMR, swelling ratio, rheology, SEM, and small angle neutron scattering (SANS) measurements. The hydrogels exhibited pH- and salt-dependent swelling, while the macro- and microscale properties could be modulated by the choice and degree of cross-linker or the polymer concentration. The materials could be molded in situ and loaded with small molecules that can be released overtime. Moreover, the incorporation of collagen in the hydrogels drastically improved cell adhesion, with excellent viabilities of human dermofibroblast cells on the hydrogels observed for up to 6 days, highlighting the potential use of these materials in the biomedical area.
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Affiliation(s)
- Sarah E S Michel
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
| | - Sarah E Rogers
- ISIS Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Didcot, OX11 0QX, U.K
| | - Wuge H Briscoe
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
| | - M Carmen Galan
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
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17
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Li J, Zhao Y, Zhou P, Hu X, Wang D, King SM, Rogers SE, Wang J, Lu JR, Xu H. Ordered Nanofibers Fabricated from Hierarchical Self-Assembling Processes of Designed α-Helical Peptides. Small 2020; 16:e2003945. [PMID: 33015967 DOI: 10.1002/smll.202003945] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/15/2020] [Indexed: 06/11/2023]
Abstract
Peptide self-assembly is fast evolving into a powerful method for the development of bio-inspired nanomaterials with great potential for many applications, but it remains challenging to control the self-assembling processes and nanostrucutres because of the intricate interplay of various non-covalent interactions. A group of 28-residue α-helical peptides is designed including NN, NK, and HH that display distinct hierarchical events. The key of the design lies in the incorporation of two asparagine (Asn) or histidine (His) residues at the a positions of the second and fourth heptads, which allow one sequence to pack into homodimers with sticky ends through specific interhelical Asn-Asn or metal complexation interactions, followed by their longitudinal association into ordered nanofibers. This is in contrast to classical self-assembling helical peptide systems consisting of two complementary peptides. The collaborative roles played by the four main non-covalent interactions, including hydrogen-bonding, hydrophobic interactions, electrostatic interactions, and metal ion coordination, are well demonstrated during the hierarchical self-assembling processes of these peptides. Different nanostructures, for example, long and short nanofibers, thin and thick fibers, uniform metal ion-entrapped nanofibers, and polydisperse globular stacks, can be prepared by harnessing these interactions at different levels of hierarchy.
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Affiliation(s)
- Jie Li
- State Key Laboratory of Heavy Oil Processing and Centre for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao, 266580, China
| | - Yurong Zhao
- State Key Laboratory of Heavy Oil Processing and Centre for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao, 266580, China
| | - Peng Zhou
- State Key Laboratory of Heavy Oil Processing and Centre for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao, 266580, China
| | - Xuzhi Hu
- Biological Physics Group, School of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK
| | - Dong Wang
- State Key Laboratory of Heavy Oil Processing and Centre for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao, 266580, China
| | - Stephen M King
- ISIS Pulsed Neutron & Muon Source, STFC Rutherford Appleton Laboratory, Didcot, Oxon, OX11 0QX, UK
| | - Sarah E Rogers
- ISIS Pulsed Neutron & Muon Source, STFC Rutherford Appleton Laboratory, Didcot, Oxon, OX11 0QX, UK
| | - Jiqian Wang
- State Key Laboratory of Heavy Oil Processing and Centre for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao, 266580, China
| | - Jian R Lu
- Biological Physics Group, School of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK
| | - Hai Xu
- State Key Laboratory of Heavy Oil Processing and Centre for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao, 266580, China
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18
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Sanchez-Fernandez A, Diehl C, Houston JE, Leung AE, Tellam JP, Rogers SE, Prevost S, Ulvenlund S, Sjögren H, Wahlgren M. An integrative toolbox to unlock the structure and dynamics of protein-surfactant complexes. Nanoscale Adv 2020; 2:4011-4023. [PMID: 36132802 PMCID: PMC9417085 DOI: 10.1039/d0na00194e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Accepted: 07/11/2020] [Indexed: 05/06/2023]
Abstract
The interactions between protein and surfactants play an important role in the stability and performance of formulated products. Due to the high complexity of such interactions, multi-technique approaches are required to study these systems. Here, an integrative approach is used to investigate the various interactions in a model system composed of human growth hormone and sodium dodecyl sulfate. Contrast variation small-angle neutron scattering was used to obtain information on the structure of the protein, surfactant aggregates and surfactant-protein complexes. 1H and 1H-13C HSQC nuclear magnetic resonance spectroscopy was employed to probe the local structure and dynamics of specific amino acids upon surfactant addition. Through the combination of these advanced methods with fluorescence spectroscopy, circular dichroism and isothermal titration calorimetry, it was possible to identify the interaction mechanisms between the surfactant and the protein in the pre- and post-micellar regimes, and interconnect the results from different techniques. As such, the protein was revealed to evolve from a partially unfolded conformation at low SDS concentration to a molten globule at intermediate concentrations, where the protein conformation and local dynamics of hydrophobic amino acids are partially affected compared to the native state. At higher surfactant concentrations the local structure of the protein appears disrupted, and a decorated micelle structure is observed, where the protein is wrapped around a surfactant assembly. Importantly, this integrative approach allows for the identification of the characteristic fingerprints of complex transitions as seen by each technique, and establishes a methodology for an in-detail study of surfactant-protein systems.
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Affiliation(s)
| | - Carl Diehl
- SARomics Biostructures AB Medicon Village, Scheelevägen 2 223 81 Lund Sweden
| | | | - Anna E Leung
- European Spallation Source Box 176 221 00 Lund Sweden
| | - James P Tellam
- ISIS Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory Didcot OX11 0QX UK
| | - Sarah E Rogers
- ISIS Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory Didcot OX11 0QX UK
| | - Sylvain Prevost
- Institut Laue-Langevin 71 Avenue des Martyrs 38000 Grenoble France
| | - Stefan Ulvenlund
- Food Technology, Engineering and Nutrition, Lund University Box 124 221 00 Lund Sweden
- EnzaBiotech AB Scheelevägen 22 223 63 Lund Sweden
| | - Helen Sjögren
- Ferring Pharmaceuticals A/S Kay Fiskers Plads 11 2300 Copenhagen S Denmark
| | - Marie Wahlgren
- Food Technology, Engineering and Nutrition, Lund University Box 124 221 00 Lund Sweden
- EnzaBiotech AB Scheelevägen 22 223 63 Lund Sweden
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19
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Michel SSE, Kilner A, Eloi JC, Rogers SE, Briscoe WH, Galan MC. Norbornene-Functionalized Chitosan Hydrogels and Microgels via Unprecedented Photoinitiated Self-Assembly for Potential Biomedical Applications. ACS Appl Bio Mater 2020; 3:5253-5262. [PMID: 35021700 DOI: 10.1021/acsabm.0c00629] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Access to biocompatible self-assembled gels and microgels is of great interests for a variety of biological applications from tissue engineering to drug delivery. Here, the facile synthesis of supramolecular hydrogels of norbornene (nb)-functionalized chitosan (CS-nb) via UV-triggered self-assembly in the presence of Irgacure 2959 (IRG) is reported. The in vitro stable hydrogels are injectable and showed pH-responsive swelling behavior, while their structure and mechanical properties could be tuned by tailoring the stereochemistry of the norbornene derivative (e.g., endo- or -exo). Interestingly, unlike other nb-type hydrogels, the gels possess nanopores within their structure, which might lead to potential drug delivery applications. A gelation mechanism was proposed based on hydrophobic interactions following the combination of IRG on norbornene, as supported by 1H NMR. This self-assembly mechanism was used to access microgels of size 100-150 nm, which could be further functionalized and showed no significant toxicity to human dermofibroblast cells.
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Affiliation(s)
- Sarah S E Michel
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS81TS, U.K
| | - Alice Kilner
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS81TS, U.K
| | - Jean-Charles Eloi
- Chemical Imaging Facility, School of Chemistry, University of Bristol, Cantock's Close, Bristol BS81TS, U.K
| | - Sarah E Rogers
- ISIS Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Didcot OX11 0QX, U.K
| | - Wuge H Briscoe
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS81TS, U.K
| | - M Carmen Galan
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS81TS, U.K
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20
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Sagisaka M, Saito T, Abe M, Yoshizawa A, Blesic M, Rogers SE, Alexander S, Guittard F, Hill C, Eastoe J. Water-in-CO 2 Microemulsions Stabilized by an Efficient Catanionic Surfactant. Langmuir 2020; 36:7418-7426. [PMID: 32532155 DOI: 10.1021/acs.langmuir.0c00970] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
To facilitate potential applications of water-in-supercritical CO2 microemulsions (W/CO2 μEs) efficient and environmentally responsible surfactants are required with low levels of fluorination. As well as being able to stabilize water-CO2 interfaces, these surfactants must also be economical, prevent bioaccumulation and strong adhesion, deactivation of enzymes, and be tolerant to high salt environments. Recently, an ion paired catanionic surfactant with environmentally acceptable fluorinated C6 tails was found to be very effective at stabilizing W/CO2 μEs with high water-to-surfactant molar ratios (W0) up to ∼50 (Sagisaka, M.; et al. Langmuir 2019, 35, 3445-3454). As the cationic and anionic constituent surfactants alone did not stabilize W/CO2 μEs, this was the first demonstration of surfactant synergistic effects in W/CO2 microemulsions. The aim of this new study is to understand the origin of these intriguing effects by detailed investigations of nanostructure in W/CO2 microemulsions using high-pressure small-angle neutron scattering (HP-SANS). These HP-SANS experiments have been used to determine the headgroup interfacial area and volume, aggregation number, and effective packing parameter (EPP). These SANS data suggest the effectiveness of this surfactant originates from increased EPP and decreased hydrophilic/CO2-philic balance, related to a reduced effective headgroup ionicity. This surfactant bears separate C6F13 tails and oppositely charged headgroups, and was found to have a EPP value similar to that of a double C4F9-tail anionic surfactant (4FG(EO)2), which was previously reported to be one of most efficient stabilizers for W/CO2 μEs (maximum W0 = 60-80). Catanionic surfactants based on this new design will be key for generating superefficient W/CO2 μEs with high stability and water solubilization.
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Affiliation(s)
- Masanobu Sagisaka
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Tatsuya Saito
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Masashi Abe
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Atsushi Yoshizawa
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Marijana Blesic
- School of Chemistry and Chemical Engineering, Queen's University Belfast, University Road, Belfast BT7 1NN, U.K
| | - Sarah E Rogers
- ISIS-CCLRC, Rutherford Appleton Laboratory, Chilton, Oxfordshire OX11 0QX, U.K
| | - Shirin Alexander
- Energy Safety Research Institute (ESRI), Swansea University, Bay Campus, Swansea SA1 8EN, U.K
| | - Frédéric Guittard
- NICE-Lab, Université Côte d'Azur, 61-63 avenue S. Viel, 06200 Nice, France
| | - Christopher Hill
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
| | - Julian Eastoe
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
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21
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Matthews L, Przybyłowicz Ż, Rogers SE, Bartlett P, Johnson AJ, Sochon R, Briscoe WH. The curious case of SDS self-assembly in glycerol: Formation of a lamellar gel. J Colloid Interface Sci 2020; 572:384-395. [DOI: 10.1016/j.jcis.2020.03.102] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Revised: 03/26/2020] [Accepted: 03/27/2020] [Indexed: 01/09/2023]
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22
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Dicko C, Engberg A, Houston JE, Jackson AJ, Pettersson A, Dalgliesh RM, Akeroyd FA, Venero DA, Rogers SE, Martel A, Porcar L, Rennie AR. NUrF-Optimization of in situ UV-vis and fluorescence and autonomous characterization techniques with small-angle neutron scattering instrumentation. Rev Sci Instrum 2020; 91:075111. [PMID: 32752852 DOI: 10.1063/5.0011325] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 06/15/2020] [Indexed: 06/11/2023]
Abstract
We have designed, built, and validated a (quasi)-simultaneous measurement platform called NUrF, which consists of neutron small-angle scattering, UV-visible, fluorescence, and densitometry techniques. In this contribution, we illustrate the concept and benefits of the NUrF setup combined with high-performance liquid chromatography pumps to automate the preparation and measurement of a mixture series of Brij35 nonionic surfactants with perfluorononanoic acid in the presence of a reporter fluorophore (pyrene).
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Affiliation(s)
- Cedric Dicko
- Chemistry Department, Lund University, Lund 221 00, Sweden
| | - Adam Engberg
- Centre for Neutron Scattering, Uppsala University, Uppsala 751 20, Sweden
| | | | | | | | - Robert M Dalgliesh
- ISIS Neutron and Muon Source-STFC Rutherford Appleton Laboratory, Didcot OX11 0QX, United Kingdom
| | - Frederick A Akeroyd
- ISIS Neutron and Muon Source-STFC Rutherford Appleton Laboratory, Didcot OX11 0QX, United Kingdom
| | - Diego Alba Venero
- ISIS Neutron and Muon Source-STFC Rutherford Appleton Laboratory, Didcot OX11 0QX, United Kingdom
| | - Sarah E Rogers
- ISIS Neutron and Muon Source-STFC Rutherford Appleton Laboratory, Didcot OX11 0QX, United Kingdom
| | - Anne Martel
- Institut Laue Langevin, Grenoble 38000, France
| | | | - Adrian R Rennie
- Centre for Neutron Scattering, Uppsala University, Uppsala 751 20, Sweden
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23
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Jamaluddin NA, Mohamed A, Abu Bakar S, Ardyani T, Sagisaka M, Suhara S, Hafiz Mamat M, Ahmad MK, King SM, Rogers SE, Eastoe J. Highly branched triple-chain surfactant-mediated electrochemical exfoliation of graphite to obtain graphene oxide: colloidal behaviour and application in water treatment. Phys Chem Chem Phys 2020; 22:12732-12744. [PMID: 32462145 DOI: 10.1039/d0cp01243b] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The generation of surfactant-assisted exfoliated graphene oxide (sEGO) by electrochemical exfoliation is influenced by the presence of surfactants, and in particular the hydrophobic tail molecular-architecture. Increasing surfactant chain branching may improve the affinity for the graphite surfaces to provide enhanced intersheet separation and stabilisation of exfoliated sheets. The resulting sEGO composites can be readily used to remove of a model pollutant, the dye, methylene blue (MB), from aqueous solutions by providing abundant sites for dye adsorption. This article explores relationships between surfactant structure and the performance of sEGO for MB adsorption. Double-branched and highly branched triple-chain graphene-compatible surfactants were successfully synthesised and characterised by 1H NMR spectroscopy. These surfactants were used to produce sEGO via electrochemical exfoliation of graphite, and the sEGOs generated were further utilised in batch adsorption studies of MB from aqueous solutions. The properties of these synthesised surfactants were compared with those of a common single-chain standard surfactant, sodium dodecyl-sulfate (SDS). The structural morphology of sEGO was assessed using Raman spectroscopy and field emission scanning electron microscopy (FESEM). To reveal the links between the hydrophobic chain structure and the sEGO adsorption capacity, UV-visible spectroscopy, zeta potential, and air-water (a/w) surface tension measurements were conducted. The aggregation behaviour of the surfactants was studied using small-angle neutron scattering (SANS). The highly branched triple-chain surfactant sodium 1,4-bis(neopentyloxy)-3-(neopentylcarbonyl)-1,4-dioxobutane-2-sulfonate (TC14) displayed enhanced exfoliating efficiency compared to those of the single-and double-chain surfactants, leading to ∼83% MB removal. The findings suggest that highly branched triple-chain surfactants are able to offer more adsorption sites, by expanding the sEGO interlayer gap for MB adsorption, compared to standard single-chain surfactants.
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Affiliation(s)
- Nur Amirah Jamaluddin
- Department of Chemistry, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, 35900 Tanjong Malim, Perak, Malaysia.
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24
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Cornel EJ, Smith GN, Rogers SE, Hallett JE, Growney DJ, Smith T, O'Hora PS, van Meurs S, Mykhaylyk OO, Armes SP. Time-resolved small-angle neutron scattering studies of the thermally-induced exchange of copolymer chains between spherical diblock copolymer nanoparticles prepared via polymerization-induced self-assembly. Soft Matter 2020; 16:3657-3668. [PMID: 32227048 DOI: 10.1039/c9sm02425e] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Sterically-stabilized diblock copolymer nanoparticles (a.k.a. micelles) are prepared directly in non-polar media via polymerization-induced self-assembly (PISA). More specifically, a poly(lauryl methacrylate) chain transfer agent is chain-extended via reversible addition-fragmentation chain transfer (RAFT) dispersion polymerization of methyl methacrylate (MMA) to form sterically-stabilized spheres at 20% w/w solids in n-dodecane at 90 °C. Both fully hydrogenous (PLMA39-PMMA55 and PLMA39-PMMA94) and core-deuterated (PLMA39-d8PMMA57 and PLMA39-d8PMMA96) spherical nanoparticles with mean core diameters of approximately 20 nm were prepared using this protocol. After diluting each dispersion in turn to 1.0% w/w with n-dodecane, small-angle X-ray scattering studies confirmed essentially no change in spherical nanoparticle diameter after thermal annealing at 150 °C. Time-resolved small angle neutron scattering was used to examine whether copolymer chain exchange occurs between such nanoparticles at elevated temperatures. Copolymer chain exchange for a binary mixture of PLMA39-PMMA55 and PLMA39-d8PMMA57 nanoparticles produced hybrid (mixed) cores containing both PMMA55 and d8PMMA57 blocks within 3 min at 150 °C. In contrast, a binary mixture of PLMA39-PMMA94 and PLMA39-d8PMMA96 nanoparticles required 8 min at this temperature before no further reduction in neutron scattering intensity could be observed. These observations suggest that the rate of copolymer chain exchange depends on the degree of polymerization of the core-forming block. Relatively slow copolymer chain exchange was also observed at 80 °C, which is below the Tg of the core-forming PMMA block as determined by DSC studies. These observations confirm rapid exchange of individual copolymer chains between sterically-stabilized nanoparticles at elevated temperature. The implications of these findings are briefly discussed in the context of PISA, which is a powerful technique for the synthesis of sterically-stabilized nanoparticles.
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Affiliation(s)
- Erik J Cornel
- Department of Chemistry, University of Sheffield, Brook Hill, Dainton Building, Sheffield, South Yorkshire S3 7HF, UK.
| | - Gregory N Smith
- Department of Chemistry, University of Sheffield, Brook Hill, Dainton Building, Sheffield, South Yorkshire S3 7HF, UK. and Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø, Denmark
| | - Sarah E Rogers
- Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX, UK
| | - James E Hallett
- H.H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK
| | - David J Growney
- Lubrizol Ltd, Nether Lane, Hazelwood, Derbyshire DE56 4AN, UK
| | - Timothy Smith
- Lubrizol Ltd, Nether Lane, Hazelwood, Derbyshire DE56 4AN, UK
| | - Paul S O'Hora
- Lubrizol Ltd, Nether Lane, Hazelwood, Derbyshire DE56 4AN, UK
| | - Sandra van Meurs
- Department of Chemistry, University of Sheffield, Brook Hill, Dainton Building, Sheffield, South Yorkshire S3 7HF, UK.
| | - Oleksandr O Mykhaylyk
- Department of Chemistry, University of Sheffield, Brook Hill, Dainton Building, Sheffield, South Yorkshire S3 7HF, UK.
| | - Steven P Armes
- Department of Chemistry, University of Sheffield, Brook Hill, Dainton Building, Sheffield, South Yorkshire S3 7HF, UK.
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25
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Sharratt WN, O’Connell R, Rogers SE, Lopez CG, Cabral JT. Conformation and Phase Behavior of Sodium Carboxymethyl Cellulose in the Presence of Mono- and Divalent Salts. Macromolecules 2020. [DOI: 10.1021/acs.macromol.9b02228] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- William N. Sharratt
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, U.K
| | - Róisín O’Connell
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, U.K
| | - Sarah E. Rogers
- ISIS, Rutherford Appleton Laboratory, Harwell, Didcot OX11 0QX, U.K
| | - Carlos G. Lopez
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52056 Aachen, Germany
| | - João T. Cabral
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, U.K
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26
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Fuentes-Caparrós AM, McAulay K, Rogers SE, Dalgliesh RM, Adams DJ. On the Mechanical Properties of N-Functionalised Dipeptide Gels. Molecules 2019; 24:E3855. [PMID: 31731551 PMCID: PMC6864704 DOI: 10.3390/molecules24213855] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 10/21/2019] [Accepted: 10/21/2019] [Indexed: 11/16/2022] Open
Abstract
The properties of a hydrogel are controlled by the underlying network that immobilizes the solvent. For gels formed by the self-assembly of a small molecule, it is common to show the primary fibres that entangle to form the network by microscopy, but it is difficult to access information about the network. One approach to understand the network is to examine the effect of the concentration on the rheological properties, such that G'∝ cx, where G' is the storage modulus and c is the concentration. A number of reports link the exponent x to a specific type of network. Here, we discuss a small library of gels formed using functionalized dipeptides, and describe the underlying networks of these gels, using microscopy, small angle scattering and rheology. We show that apparently different networks can give very similar values of x.
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Affiliation(s)
| | - Kate McAulay
- School of Chemistry, University of Glasgow, Glasgow G12 8QQ, UK; (A.M.F.-C.); (K.M.)
| | - Sarah E. Rogers
- Rutherford Appleton Laboratory, ISIS Pulsed Neutron Source, Didcot OX11 0QX, UK; (S.E.R.); (R.M.D.)
| | - Robert M. Dalgliesh
- Rutherford Appleton Laboratory, ISIS Pulsed Neutron Source, Didcot OX11 0QX, UK; (S.E.R.); (R.M.D.)
| | - Dave J. Adams
- School of Chemistry, University of Glasgow, Glasgow G12 8QQ, UK; (A.M.F.-C.); (K.M.)
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27
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Ardyani T, Mohamed A, Abu Bakar S, Sagisaka M, Umetsu Y, Hafiz Mamat M, Khairul Ahmad M, Abdul Khalil HPS, King SM, Rogers SE, Eastoe J. Electrochemical exfoliation of graphite in nanofibrillated kenaf cellulose (NFC)/surfactant mixture for the development of conductive paper. Carbohydr Polym 2019; 228:115376. [PMID: 31635739 DOI: 10.1016/j.carbpol.2019.115376] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 09/23/2019] [Accepted: 09/23/2019] [Indexed: 12/19/2022]
Abstract
The effect of incorporating common dodecyl anionic and cationic surfactants such as dodecyltrimethylammonium bromide (DTAB), dodecylethyldimethylammonium bromide (DDAB), and sodium dodecylsulfate (SDS) in nanocomposites of reduced graphene oxide and nanocellulose are described. The stabilization and electrical properties of the nanocomoposites of reduced graphene oxide (RGO) and nanofibrillated kenaf cellulose (NFC) were characterized using four-point probe electrical conductivity measurements. Raman spectroscopy, field emission scanning electron microscopy, and high-resolution transmission electron microscopy were used to investigate dispersion morphology and the quality of RGO inside the NFC matrices. Small-angle neutron scattering (SANS) was used to study the aggregation behavior of the aqueous surfactant systems and RGO dispersions. The cationic surfactant DTAB proved to be the best choice for stabilization of RGO in NFC, giving enhanced electrical conductivity five orders of magnitude higher than the neat NFC. The results highlight the effects of hydrophilic surfactant moieties on the structure, stability and properties of RGO/NFC composites.
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Affiliation(s)
- Tretya Ardyani
- Department of Chemistry, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, 35900, Tanjong Malim, Perak, Malaysia
| | - Azmi Mohamed
- Department of Chemistry, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, 35900, Tanjong Malim, Perak, Malaysia; Nanotechnology Research Centre, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, 35900, Tanjong Malim, Perak, Malaysia.
| | - Suriani Abu Bakar
- Nanotechnology Research Centre, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, 35900, Tanjong Malim, Perak, Malaysia
| | - Masanobu Sagisaka
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University, Bunkyo-cho 3, Hirosaki, Aomori, 036-8561, Japan
| | - Yasushi Umetsu
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University, Bunkyo-cho 3, Hirosaki, Aomori, 036-8561, Japan
| | - Mohamad Hafiz Mamat
- NANO-ElecTronic Centre (NET), Faculty of Electrical Engineering, Universitas Teknologi MARA, 40450, Shah Alam, Selangor, Malaysia
| | - Mohd Khairul Ahmad
- Microelectronic and Nanotechnology - Shamsuddin Research Centre (MiNT-SRC), Faculty of Electrical and Electronic Engineering, Universiti Tun Hussein Onn Malaysia, 86400, Parit Raja, Batu Pahat, Johor, Malaysia
| | - H P S Abdul Khalil
- School of Industrial Technology, Universiti Sains Malaysia, 11700, Gelugor, Penang, Malaysia
| | - Stephen M King
- ISIS Pulsed Neutron & Muon Source, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxfordshire, OX11 0QT, United Kingdom
| | - Sarah E Rogers
- ISIS Pulsed Neutron & Muon Source, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxfordshire, OX11 0QT, United Kingdom
| | - Julian Eastoe
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, United Kingdom
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28
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Koshkina O, Lajoinie G, Bombelli FB, Swider E, Cruz LJ, White PB, Schweins R, Dolen Y, van Dinther EAW, van Riessen NK, Rogers SE, Fokkink R, Voets IK, van Eck ERH, Heerschap A, Versluis M, de Korte CL, Figdor CG, de Vries IJM, Srinivas M. Multicore Liquid Perfluorocarbon-Loaded Multimodal Nanoparticles for Stable Ultrasound and 19F MRI Applied to In Vivo Cell Tracking. Adv Funct Mater 2019; 29:1806485. [PMID: 32132881 PMCID: PMC7056356 DOI: 10.1002/adfm.201806485] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Indexed: 05/22/2023]
Abstract
Ultrasound is the most commonly used clinical imaging modality. However, in applications requiring cell-labeling, the large size and short active lifetime of ultrasound contrast agents limit their longitudinal use. Here, 100 nm radius, clinically applicable, polymeric nanoparticles containing a liquid perfluorocarbon, which enhance ultrasound contrast during repeated ultrasound imaging over the course of at least 48 h, are described. The perfluorocarbon enables monitoring the nanoparticles with quantitative 19F magnetic resonance imaging, making these particles effective multimodal imaging agents. Unlike typical core-shell perfluorocarbon-based ultrasound contrast agents, these nanoparticles have an atypical fractal internal structure. The nonvaporizing highly hydrophobic perfluorocarbon forms multiple cores within the polymeric matrix and is, surprisingly, hydrated with water, as determined from small-angle neutron scattering and nuclear magnetic resonance spectroscopy. Finally, the nanoparticles are used to image therapeutic dendritic cells with ultrasound in vivo, as well as with 19F MRI and fluorescence imaging, demonstrating their potential for long-term in vivo multimodal imaging.
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Affiliation(s)
- Olga Koshkina
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences (RIMLS), Geert Grooteplein Zuid 28, 6525 GA, Nijmegen, The Netherlands; Physical Chemistry of Polymers, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Guillaume Lajoinie
- Physics of Fluids Group, Technical Medical (TechMed) Centre and MESA+ Institute for, Nanotechnology, University of Twente, Drienerlolaan 5, 7522 NB, Enschede, The Netherlands
| | - Francesca Baldelli Bombelli
- Laboratory of Supramolecular and BioNano Materials, (SupraBioNanoLab), Department of Chemistry, Materials, and Chemical Engineering, "Giulio Natta,", Politecnico di Milano, Via Luigi Mancinelli 7, 20131 Milan, Italy
| | - Edyta Swider
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences (RIMLS), Geert Grooteplein Zuid 28, 6525 GA, Nijmegen, The Netherlands
| | - Luis J Cruz
- Translational Nanobiomaterials and Imaging, Department of Radiology, Leiden University Medical Centre, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Paul B White
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - Ralf Schweins
- Institut Laue - Langevin, DS/LSS, 71 Avenue des Martyrs, CS 20 156, 38042 Grenoble CEDEX 9, France
| | - Yusuf Dolen
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences (RIMLS), Geert Grooteplein Zuid 28, 6525 GA, Nijmegen, The Netherlands
| | - Eric A W van Dinther
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences (RIMLS), Geert Grooteplein Zuid 28, 6525 GA, Nijmegen, The Netherlands
| | - N Koen van Riessen
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences (RIMLS), Geert Grooteplein Zuid 28, 6525 GA, Nijmegen, The Netherlands
| | - Sarah E Rogers
- ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell, Oxford OX11 0QX, UK
| | - Remco Fokkink
- Department of Agrotechnology and Food Sciences, Physical Chemistry and Soft Matter, Wageningen University, 6708 WE, Wageningen, Netherlands
| | - Ilja K Voets
- Laboratory of Self-Organizing Soft Matter, Laboratory of Macromolecular and Organic Chemistry, Department of Chemical Engineering and Chemistry and Institute for Complex Molecular Systems, Eindhoven University of Technology, De Rondom 70, 5612 AP, Eindhoven, The Netherlands
| | - Ernst R H van Eck
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - Arend Heerschap
- Department of Radiology and Nuclear Medicine, Radboudumc, Geert Grooteplein Zuid 10, 6525 GA, Nijmegen, The Netherlands
| | - Michel Versluis
- Physics of Fluids Group, Technical Medical (TechMed) Centre and MESA+ Institute for, Nanotechnology, University of Twente, Drienerlolaan 5, 7522 NB, Enschede, The Netherlands
| | - Chris L de Korte
- Physics of Fluids Group, Technical Medical (TechMed) Centre and MESA+ Institute for, Nanotechnology, University of Twente, Drienerlolaan 5, 7522 NB, Enschede, The Netherlands; Department of Radiology and Nuclear Medicine, Radboudumc, Geert Grooteplein Zuid 10, 6525 GA, Nijmegen, The Netherlands
| | - Carl G Figdor
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences (RIMLS), Geert Grooteplein Zuid 28, 6525 GA, Nijmegen, The Netherlands
| | - I Jolanda M de Vries
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences (RIMLS), Geert Grooteplein Zuid 28, 6525 GA, Nijmegen, The Netherlands
| | - Mangala Srinivas
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences (RIMLS), Geert Grooteplein Zuid 28, 6525 GA, Nijmegen, The Netherlands
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29
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Martín-Fabiani I, Makepeace DK, Richardson PG, Lesage de la Haye J, Venero DA, Rogers SE, D'Agosto F, Lansalot M, Keddie JL. In Situ Monitoring of Latex Film Formation by Small-Angle Neutron Scattering: Evolving Distributions of Hydrophilic Stabilizers in Drying Colloidal Films. Langmuir 2019; 35:3822-3831. [PMID: 30777761 DOI: 10.1021/acs.langmuir.8b04251] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The distribution of hydrophilic species, such as surfactants, in latex films is of critical importance for the performance of adhesives, coatings, and inks, among others. However, the evolution of this distribution during the film formation process and in the resulting dried films remains insufficiently elucidated. Here, we present in situ (wet) and ex situ (dry) small-angle neutron scattering (SANS) experiments that follow the film formation of two types of latex particles, which differ in their stabilizer: either a covalently bonded poly(methacrylic acid) (PMAA) segment or a physically adsorbed surfactant (sodium dodecyl sulfate, SDS). By fitting the experimental SANS data and combining with gravimetry experiments, we have ascertained the hydrophilic species distribution within the drying film and followed its evolution by correlating the size and shape of stabilizer clusters with the drying time. The evolution of the SDS distribution over drying time is being driven by a reduction in the interfacial free energy. However, the PMAA-based stabilizer macromolecules are restricted by their covalent bonding to core polymer chains and hence form high-surface area disclike phases at the common boundary between particles and PMAA micelles. Contrary to an idealized view of film formation, PMAA does not remain in the walls of a continuous honeycomb structure. The results presented here shed new light on the nanoscale distribution of hydrophilic species in drying and ageing latex films. We provide valuable insights into the influence of the stabilizer mobility on the final structure of latex films.
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Affiliation(s)
- Ignacio Martín-Fabiani
- Department of Materials , Loughborough University , Loughborough LE11 3TU , Leicestershire , U.K
| | - David K Makepeace
- Department of Physics , University of Surrey , Guildford GU2 7XH , U.K
| | | | - Jennifer Lesage de la Haye
- Université Lyon, Université Claude Bernard Lyon 1, CPE Lyon, CNRS, UMR 5265, Chemistry, Catalysis, Polymers and Processes (C2P2) , 43 Bd du 11 Novembre 1918 , 69616 Villeurbanne , France
| | - Diego Alba Venero
- Science and Technology Facilities Council, Rutherford Appleton Laboratory , ISIS Pulsed Neutron and Muon Source , Harwell , Didcot, Oxford OX11 0QX , U.K
| | - Sarah E Rogers
- Science and Technology Facilities Council, Rutherford Appleton Laboratory , ISIS Pulsed Neutron and Muon Source , Harwell , Didcot, Oxford OX11 0QX , U.K
| | - Franck D'Agosto
- Université Lyon, Université Claude Bernard Lyon 1, CPE Lyon, CNRS, UMR 5265, Chemistry, Catalysis, Polymers and Processes (C2P2) , 43 Bd du 11 Novembre 1918 , 69616 Villeurbanne , France
| | - Muriel Lansalot
- Université Lyon, Université Claude Bernard Lyon 1, CPE Lyon, CNRS, UMR 5265, Chemistry, Catalysis, Polymers and Processes (C2P2) , 43 Bd du 11 Novembre 1918 , 69616 Villeurbanne , France
| | - Joseph L Keddie
- Department of Physics , University of Surrey , Guildford GU2 7XH , U.K
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Sagisaka M, Saito T, Yoshizawa A, Rogers SE, Guittard F, Hill C, Eastoe J, Blesic M. Water-in-CO 2 Microemulsions Stabilized by Fluorinated Cation-Anion Surfactant Pairs. Langmuir 2019; 35:3445-3454. [PMID: 30739456 DOI: 10.1021/acs.langmuir.8b03942] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
High-water-content water-in-supercritical CO2 (W/CO2) microemulsions are considered to be green, universal solvents, having both polar and nonpolar domains. Unfortunately, these systems generally require environmentally unacceptable stabilizers like long and/or multifluorocarbon-tail surfactants. Here, a series of catanionic surfactants having more environmentally friendly fluorinated C4-C6 tails have been studied in terms of interfacial properties, aggregation behavior, and solubilizing power in water and/or CO2. Surface tensions and critical micelle concentrations of these catanionic surfactants are, respectively, lowered by ∼9 mN/m and 100 times than those of the constituent single fluorocarbon-tail surfactants. Disklike micelles in water were observed above the respective critical micelle concentrations, implying the catanionic surfactants have a high critical packing parameter, which should be suitable for the formation of reverse micelles. Based on visual observation of phase behavior and Fourier transform infrared spectroscopic and small-angle neutron scattering studies, one of the three catanionic surfactants tested was found to form transparent single-phase W/CO2 microemulsions with a water-to-surfactant molar ratio of up to ∼50. This is the first successful demonstration of the formation of W/CO2 microemulsions by synergistic ion-pairing of anionic and cationic single-tail surfactants. This indicates that catanionic surfactants offer a promising approach to generate high-water-content W/CO2 microemulsions.
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Affiliation(s)
- Masanobu Sagisaka
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology , Hirosaki University , 3 Bunkyo-cho , Hirosaki , Aomori 036-8561 , Japan
| | - Tatsuya Saito
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology , Hirosaki University , 3 Bunkyo-cho , Hirosaki , Aomori 036-8561 , Japan
| | - Atsushi Yoshizawa
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology , Hirosaki University , 3 Bunkyo-cho , Hirosaki , Aomori 036-8561 , Japan
| | - Sarah E Rogers
- ISIS-CCLRC, Rutherford Appleton Laboratory , Chilton OX11 0QX , Oxon , U.K
| | - Frédéric Guittard
- Univ. Cote d'Azur, NICE-Lab , 61-63 av. S. Viel , 06200 Nice , France
| | - Christopher Hill
- School of Chemistry , University of Bristol , Cantock's Close , Bristol BS8 1TS , U.K
| | - Julian Eastoe
- School of Chemistry , University of Bristol , Cantock's Close , Bristol BS8 1TS , U.K
| | - Marijana Blesic
- School of Chemistry and Chemical Engineering , Queen's University Belfast , University Road , Belfast BT7 1NN , U.K
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Hill C, Czajka A, Hazell G, Grillo I, Rogers SE, Skoda MW, Joslin N, Payne J, Eastoe J. Surface and bulk properties of surfactants used in fire-fighting. J Colloid Interface Sci 2018; 530:686-694. [DOI: 10.1016/j.jcis.2018.07.023] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 07/04/2018] [Accepted: 07/06/2018] [Indexed: 11/26/2022]
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Zielbauer BI, Jackson AJ, Maurer S, Waschatko G, Ghebremedhin M, Rogers SE, Heenan RK, Porcar L, Vilgis TA. Soybean oleosomes studied by small angle neutron scattering (SANS). J Colloid Interface Sci 2018; 529:197-204. [PMID: 29894938 DOI: 10.1016/j.jcis.2018.05.080] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Revised: 05/21/2018] [Accepted: 05/22/2018] [Indexed: 11/29/2022]
Abstract
HYPOTHESIS Oleosomes are stabilized by a complex outer phospholipid-protein-layer. To improve understanding of its structure and stabilization mechanism, this shell has to be studied in extracellular native conditions. This should be possible by SANS using contrast variation. Oleosomes are expected to be highly temperature stable, with molecular changes occurring first in the protein shell. Direct measurements of changes in the shell structure are also important for processing methods, e.g. encapsulation. EXPERIMENTS Extracted soybean oleosomes were studied directly and after encapsulation with pectin by SANS using contrast variation. In order to determine structure and size, a shell model of oleosomes was developed. The method was tested against a simple phospholipid-stabilized emulsion. The oleosomes' temperature stability was investigated by performing SANS at elevated temperatures. FINDINGS Size (Rg = 1380 Å) and shell thickness of native and encapsulated oleosomes have been determined. This is the first report measuring the shell thickness of oleosomes directly. For native oleosomes, a shell of 9 nm thickness surrounds the oil core, corresponding to a layer of phospholipids and proteins. Up to 90 °C, no structural change was observed, confirming the oleosomes' high temperature stability. Successful coavervation of oleosomes was shown by an increase in shell thickness of 10 nm after electrostatic deposition of pectin.
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Affiliation(s)
- Birgitta I Zielbauer
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
| | - Andrew J Jackson
- European Spallation Source, Box 176, Lund 221 00, Sweden; Physical Chemistry, Lund University, Box 124, Lund 221 00, Sweden.
| | - Sania Maurer
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
| | - Gustav Waschatko
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
| | - Marta Ghebremedhin
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
| | - Sarah E Rogers
- ISIS Facility, STFC Rutherford Appleton Laboratory, Didcot OX11 0QX, United Kingdom.
| | - Richard K Heenan
- ISIS Facility, STFC Rutherford Appleton Laboratory, Didcot OX11 0QX, United Kingdom.
| | | | - Thomas A Vilgis
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
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Sagisaka M, Ono S, James C, Yoshizawa A, Mohamed A, Guittard F, Enick RM, Rogers SE, Czajka A, Hill C, Eastoe J. Anisotropic reversed micelles with fluorocarbon-hydrocarbon hybrid surfactants in supercritical CO 2. Colloids Surf B Biointerfaces 2018; 168:201-210. [PMID: 29276082 DOI: 10.1016/j.colsurfb.2017.12.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Revised: 11/28/2017] [Accepted: 12/09/2017] [Indexed: 11/19/2022]
Abstract
Previous work (M. Sagisaka, et al. Langmuir 31 (2015) 7479-7487), showed the most effective fluorocarbon (FC) and hydrocarbon (HC) chain lengths in the hybrid surfactants FCm-HCn (sodium 1-oxo-1-[4-(perfluoroalkyl)phenyl]alkane-2-sulfonates, where m = FC length and n = HC length) were m and n = 6 and 4 for water solubilization, whereas m 6 and n 6, or m 6 and n 5, were optimal chain lengths for reversed micelle elongation in supercritical CO2. To clarify why this difference of only a few methylene chain units is so effective at tuning the solubilizing power and reversed micelle morphology, nanostructures of water-in-CO2 (W/CO2) microemulsions were investigated by high-pressure small-angle neutron scattering (SANS) measurements at different water-to-surfactant molar ratios (W0) and surfactant concentrations. By modelling SANS profiles with cylindrical and ellipsoidal form factors, the FC6-HCn/W/CO2 microemulsions were found to increase in size with increasing W0 and surfactant concentration. Ellipsoidal cross-sectional radii of the FC6-HC4/W/CO2 microemulsion droplets increased linearly with W0, and finally reached ∼39 Å and ∼78 Å at W0 = 85 (close to the upper limit of solubilizing power). These systems appear to be the largest W/CO2 microemulsion droplets ever reported. The aqueous domains of FC6-HC6 rod-like reversed micelles increased in size by 3.5 times on increasing surfactant concentration from 35 mM to 50 mM: at 35 mM, FC6-HC5 formed rod-like reversed micelles 5.3 times larger than FC6-HC6. Interestingly, these results suggest that hybrid HC-chains partition into the microemulsion aqueous cores with the sulfonate headgroups, or at the W/CO2 interfaces, and so play important roles for tuning the W/CO2 interfacial curvature. The super-efficient W/CO2-type solubilizer FC6-HC4, and the rod-like reversed micelle forming surfactant FC6-HC5, represent the most successful cases of low fluorine content additives. These surfactants facilitate VOC-free, effective and energy-saving CO2 solvent systems for applications such as extraction, dyeing, dry cleaning, metal-plating, enhanced oil recovery and organic/inorganic or nanomaterial synthesis.
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Affiliation(s)
- Masanobu Sagisaka
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan.
| | - Shinji Ono
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Craig James
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Atsushi Yoshizawa
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Azmi Mohamed
- Department of Chemistry, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, 35900 Tanjong Malim, Perak, Malaysia; Nanotechnology Research Centre, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, 35900 Tanjong Malim, Perak, Malaysia
| | | | - Robert M Enick
- Department of Chemical and Petroleum Engineering, University of Pittsburgh, 940 Benedum Hall, 3700 O'Hara Street, Pittsburgh, PA 15261, United States
| | - Sarah E Rogers
- ISIS-CCLRC, Rutherford Appleton Laboratory, Chilton, Oxon OX11 0QX, UK
| | - Adam Czajka
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Christopher Hill
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Julian Eastoe
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK.
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Mansfield EDH, Hartlieb M, Catrouillet S, Rho JY, Larnaudie SC, Rogers SE, Sanchis J, Brendel JC, Perrier S. Systematic study of the structural parameters affecting the self-assembly of cyclic peptide-poly(ethylene glycol) conjugates. Soft Matter 2018; 14:6320-6326. [PMID: 30019044 DOI: 10.1039/c8sm01133h] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Self-assembling cyclic peptides (CP) consisting of amino acids with alternating d- and l-chirality form nanotubes by hydrogen bonding, hydrophobic interactions, and π-π stacking in solution. These highly dynamic materials are emerging as promising supramolecular systems for a wide range of biomedical applications. Herein, we discuss how varying the polymer conformation (linear vs. brush), as well as the number of polymer arms per peptide unimer affects the self-assembly of PEGylated cyclic peptides in different solvents, using small angle neutron scattering. Using the derived information, strong correlations were drawn between the size of the aggregates, solvent polarity, and its ability to compete for hydrogen bonding interactions between the peptide unimers. Using these data, it could be possible to engineer cyclic peptide nanotubes of a controlled length.
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Affiliation(s)
- Edward D H Mansfield
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK.
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35
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Terakosolphan W, Trick JL, Royall PG, Rogers SE, Lamberti O, Lorenz CD, Forbes B, Harvey RD. Glycerol Solvates DPPC Headgroups and Localizes in the Interfacial Regions of Model Pulmonary Interfaces Altering Bilayer Structure. Langmuir 2018; 34:6941-6954. [PMID: 29738253 DOI: 10.1021/acs.langmuir.8b00866] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The inclusion of glycerol in formulations for pulmonary drug delivery may affect the bioavailability of inhaled steroids by retarding their transport across the lung epithelium. The aim of this study was to evaluate whether the molecular interactions of glycerol with model pulmonary interfaces provide a biophysical basis for glycerol modifying inhaled drug transport. Dipalmitoylphosphatidylcholine (DPPC) monolayers and liposomes were used as model pulmonary interfaces, in order to examine the effects of bulk glycerol (0-30% w/w) on their structures and dynamics using complementary biophysical measurements and molecular dynamics (MD) simulations. Glycerol was found to preferentially interact with the carbonyl groups in the interfacial region of DPPC and with phosphate and choline in the headgroup, thus causing an increase in the size of the headgroup solvation shell, as evidenced by an expansion of DPPC monolayers (molecular area increased from 52 to 68 Å2) and bilayers seen in both Langmuir isotherms and MD simulations. Both small angle neutron scattering and MD simulations indicated a reduction in gel phase DPPC bilayer thickness by ∼3 Å in 30% w/w glycerol, a phenomenon consistent with the observation from FTIR data, that glycerol caused the lipid headgroup to remain oriented parallel to the membrane plane in contrast to its more perpendicular conformation adopted in pure water. Furthermore, FTIR measurements suggested that the terminal methyl groups of the DPPC acyl chains were constrained in the presence of glycerol. This observation is supported by MD simulations, which predict bridging between adjacent DPPC headgroups by glycerol as a possible source of its putative membrane stiffening effect. Collectively, these data indicate that glycerol preferentially solvates DPPC headgroups and localizes in specific areas of the interfacial region, resulting in structural changes to DPPC bilayers which may influence cell permeability to drugs.
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Affiliation(s)
- Wachirun Terakosolphan
- School of Cancer and Pharmaceutical Sciences , King's College London , London SE1 9NH , United Kingdom
| | - Jemma L Trick
- Department of Physics , King's College London , London WC2R 2LS , United Kingdom
| | - Paul G Royall
- School of Cancer and Pharmaceutical Sciences , King's College London , London SE1 9NH , United Kingdom
| | - Sarah E Rogers
- Rutherford Appleton Laboratory , ISIS Facility , Chilton , Oxfordshire OX11 0QX , United Kingdom
| | - Olimpia Lamberti
- Department of Physics , King's College London , London WC2R 2LS , United Kingdom
| | - Christian D Lorenz
- Department of Physics , King's College London , London WC2R 2LS , United Kingdom
| | - Ben Forbes
- School of Cancer and Pharmaceutical Sciences , King's College London , London SE1 9NH , United Kingdom
| | - Richard D Harvey
- Institute of Pharmacy , Martin-Luther-University Halle-Wittenberg , Halle (Saale) , 06099 , Germany
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36
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Lyu W, Alotaibi M, Bell OA, Watanabe K, Harniman R, Mills BM, Seddon AM, Rogers SE, King SM, Yan W, Faul CFJ. An addressable packing parameter approach for reversibly tuning the assembly of oligo(aniline)-based supra-amphiphiles. Chem Sci 2018; 9:4392-4401. [PMID: 29896380 PMCID: PMC5956978 DOI: 10.1039/c8sc00068a] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Accepted: 04/01/2018] [Indexed: 11/25/2022] Open
Abstract
An addressable packing parameter approach was developed for reversibly tuning the self-assembly of oligo(aniline)-based supra-amphiphiles.
We present a newly developed approach to non-covalently address the packing parameter of an electroactive amphiphile. The pH-responsive reversible switching of a tetra(aniline)-based cationic amphiphile, TANI-pentyl trimethylammonium bromide (TANI-PTAB), between self-assembled vesicles and nanowires by acid/base chemistry in aqueous solution is used to exemplify this approach. Trifluoroacetic acid (TFA) was selected as a prototypical acid to form emeraldine salt (ES) state (TANI(TFA)2-PTAB) vesicles for this new class of small-molecule supramolecular amphiphiles. UV-vis-NIR spectroscopy, transmission electron microscopy (TEM), tapping-mode atomic force microscopy (AFM), and fluorescence spectroscopy were used to investigate the reversible structural transformation from vesicles to nanowires. We show that utilising different protonic acid-dopants for TANI-PTAB can regulate the packing parameter, and thus the final self-assembled structures, in a predictable fashion. We envisage potential application of this concept as smart and switchable delivery systems.
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Affiliation(s)
- Wei Lyu
- School of Chemistry , University of Bristol , Bristol , BS8 1TS , UK . .,Department of Environmental Science and Engineering , Xi'an Jiaotong University , 710049 , Xi'an , P. R. China
| | - Maha Alotaibi
- School of Chemistry , University of Bristol , Bristol , BS8 1TS , UK . .,Chemistry Department , Faculty of Science , King Abdul Aziz University , Jeddah , Kingdom of Saudi Arabia
| | - O Alexander Bell
- School of Chemistry , University of Bristol , Bristol , BS8 1TS , UK .
| | | | - Robert Harniman
- School of Chemistry , University of Bristol , Bristol , BS8 1TS , UK .
| | - Benjamin M Mills
- School of Chemistry , University of Bristol , Bristol , BS8 1TS , UK .
| | - Annela M Seddon
- School of Physics , H. H. Wills Physics Laboratory , University of Bristol , Tyndall Avenue , Bristol , BS8 1FD , UK.,Bristol Centre for Functional Nanomaterials , H. H. Wills Physics Laboratory , University of Bristol , Tyndall Avenue , Bristol , BS8 1FD , UK
| | - Sarah E Rogers
- ISIS Pulsed Neutron & Muon Source , STFC Rutherford Appleton Laboratory , Harwell Campus , Didcot , OX11 0QX , UK
| | - Stephen M King
- ISIS Pulsed Neutron & Muon Source , STFC Rutherford Appleton Laboratory , Harwell Campus , Didcot , OX11 0QX , UK
| | - Wei Yan
- Department of Environmental Science and Engineering , Xi'an Jiaotong University , 710049 , Xi'an , P. R. China
| | - Charl F J Faul
- School of Chemistry , University of Bristol , Bristol , BS8 1TS , UK .
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Houghton DC, DeWalt RE, Pytel AJ, Brandin CM, Rogers SE, Ruiter DE, Bright E, Hudson PL, Armitage BJ. Updated checklist of the Michigan (USA) caddisflies, with regional and habitat affinities. Zookeys 2018:57-74. [PMID: 29416396 PMCID: PMC5799788 DOI: 10.3897/zookeys.730.21776] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 12/06/2017] [Indexed: 11/12/2022] Open
Abstract
Based on examination of ~180,000 specimens from 695 collections of 443 localities collected from the 1930s to 2015 we report 295 species of caddisflies from Michigan. Of these, 41 are reported from the state for the first time. Another 18 species previously reported from Michigan are listed as doubtful. The 11 most abundant species collectively represented over half of all specimens collected. Conversely, 80 species were known from <10 specimens, and 27 species from a single specimen. The Michigan fauna is similar to those of Minnesota and Ohio, adjacent states with comparable recent collecting effort. Regional and habitat affinities for each Michigan species are reported herein. Due to the high level of species discovery over the last few years, despite a >80-year collecting history, it is likely that additional species remain undiscovered in the state.
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Affiliation(s)
- David C Houghton
- Department of Biology, Hillsdale College, 33 East College Street, Hillsdale, MI 49242, USA
| | - R Edward DeWalt
- Illinois Natural History Survey, 1816 South Oak Street, Champaign IL 61820, USA
| | - Angelica J Pytel
- Department of Biology, Hillsdale College, 33 East College Street, Hillsdale, MI 49242, USA
| | - Constance M Brandin
- Department of Biology, Hillsdale College, 33 East College Street, Hillsdale, MI 49242, USA
| | - Sarah E Rogers
- Department of Biology, Hillsdale College, 33 East College Street, Hillsdale, MI 49242, USA
| | | | - Ethan Bright
- Museum of Zoology, University of Michigan, Ann Arbor, MI 48103, USA
| | - Patrick L Hudson
- Great Lakes Science Center, US Geological Survey, 1451 Green Road, Ann Arbor, MI 48105, USA
| | - Brian J Armitage
- Instituto Conmemorativo Gorgas de Estudio de la Salud, Ave. Justo Arosemena y Calle 35, Apartado Postal No 0816-02593, Ciudad de Panamá, Republic of Panamá
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38
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Mansfield EDH, Pandya Y, Mun EA, Rogers SE, Abutbul-Ionita I, Danino D, Williams AC, Khutoryanskiy VV. Structure and characterisation of hydroxyethylcellulose–silica nanoparticles. RSC Adv 2018; 8:6471-6478. [PMID: 35540425 PMCID: PMC9078266 DOI: 10.1039/c7ra08716k] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 01/29/2018] [Indexed: 12/01/2022] Open
Abstract
Functionalising nanoparticles with polymers has gained much interest in recent years, as it aids colloidal stability and manipulation of surface properties. Here, polymer-coated thiolated silica nanoparticles were synthesised by self-condensation of 3-mercaptopropyltrimethoxysilane in the presence of hydroxyethylcellulose. These nanoparticles were characterised by dynamic light scattering, small angle neutron scattering, Nanoparticle Tracking Analysis, Raman spectroscopy, FT-IR spectroscopy, thermogravimetric analysis, Ellman's assay, transmission electron microscopy and cryo-transmission electron microscopy. It was found that increasing the amount of hydroxyethylcellulose in the reaction mixture increased the nanoparticle size and reduced the number of thiol groups on their surface. Additionally, by utilising small angle neutron scattering and dynamic light scattering, it was demonstrated that higher concentrations of polymer in the reaction mixture (0.5–2% w/v) resulted in the formation of aggregates, whereby several silica nanoparticles are bridged together with macromolecules of hydroxyethylcellulose. A correlation was identified between the aggregate size and number of particles per aggregate based on size discrepancies observed between DLS and SANS measurements. This information makes it possible to control the size of aggregates during a simple one-pot synthesis; a prospect highly desirable in the design of potential drug delivery systems. Polymer-coated thiolated silica nanoparticles were synthesised by self-condensation of 3-mercaptopropyltrimethoxysilane in the presence of hydroxyethylcellulose.![]()
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Affiliation(s)
| | - Yash Pandya
- School of Pharmacy
- University of Reading
- Reading
- UK
| | | | - Sarah E. Rogers
- ISIS Spallation Neutron Source
- Science and Technology Facilities Council
- Rutherford Appleton Laboratory
- Harwell Science and Innovation Campus
- Didcot
| | - Inbal Abutbul-Ionita
- Technion – Israel Institute of Technology
- Faculty of Biotechnology and Food Engineering
- Israel
| | - Dganit Danino
- Technion – Israel Institute of Technology
- Faculty of Biotechnology and Food Engineering
- Israel
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Smith GN, Ahualli S, Delgado ÁV, Gillespie DAJ, Kemp R, Peach J, Pegg JC, Rogers SE, Shebanova O, Smith N, Eastoe J. Charging Poly(methyl Methacrylate) Latexes in Nonpolar Solvents: Effect of Particle Concentration. Langmuir 2017; 33:13543-13553. [PMID: 29064706 DOI: 10.1021/acs.langmuir.7b02257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The electrophoresis of a well-established model system of charged colloids in nonpolar solvents has been studied as a function of particle volume fraction at constant surfactant concentration. Dispersions of poly(12-hydroxystearic acid)-stabilized poly(methyl methacrylate) (PMMA) latexes in dodecane were prepared with added Aerosol OT surfactant as the charging agent. The electrophoretic mobility (μ) of the PMMA latexes is found to decrease with particle concentration. The particles are charged by a small molecule charging agent (AOT) at finite concentration, and this makes the origin of this decrease in μ unclear. There are two suggested explanations. The decrease could either be due to the reservoir of available surfactant being exhausted at high particle concentrations or the interactions between the charged particles at high particle number concentrations. Contrast-variation small-angle neutron scattering measurements of PMMA latexes and deuterated AOT-d34 surfactant in latex core contrast-matched solvent were used to study the former, and electrokinetic modeling was used to study the latter. As the same amount of AOT-d34 is found to be incorporated with the latexes at all volume fractions, the solvodynamic and electrical interactions between particles are determined to be the explanation for the decrease in mobility. These measurements show that, for small latexes, there are interactions between the charged particles at all accessible particle volume fractions and that it is necessary to account for this to accurately determine the electrokinetic ζ potential.
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Affiliation(s)
- Gregory N Smith
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Silvia Ahualli
- Department of Applied Physics, School of Science, University of Granada , 18071 Granada, Spain
| | - Ángel V Delgado
- Department of Applied Physics, School of Science, University of Granada , 18071 Granada, Spain
| | - David A J Gillespie
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Roger Kemp
- Merck Chemicals Ltd, University Parkway , Chilworth, Southampton SO16 7QD, United Kingdom
| | - Jocelyn Peach
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Jonathan C Pegg
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Sarah E Rogers
- ISIS-STFC, Rutherford Appleton Laboratory , Chilton, Oxon OX11 0QX, United Kingdom
| | - Olga Shebanova
- Diamond Light Source Ltd, Diamond House, Harwell Science and Innovation Campus , Chilton, Didcot OX11 0DE, United Kingdom
| | - Nathan Smith
- Merck Chemicals Ltd, University Parkway , Chilworth, Southampton SO16 7QD, United Kingdom
| | - Julian Eastoe
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom
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Smith GN, Mears LLE, Rogers SE, Armes SP. Synthesis and electrokinetics of cationic spherical nanoparticles in salt-free non-polar media. Chem Sci 2017; 9:922-934. [PMID: 29629159 PMCID: PMC5874696 DOI: 10.1039/c7sc03334f] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 11/16/2017] [Indexed: 01/29/2023] Open
Abstract
Cationic diblock copolymer nanoparticles have been prepared in n-dodecane via polymerization-induced self-assembly (PISA). A previously reported poly(stearyl methacrylate)-poly(benzyl methacrylate) (PSMA-PBzMA) PISA formulation (Chem. Sci. 2016, 7, 5078-5090) was modified by statistically copolymerizing an oil-soluble cationic methacrylic monomer, (2-(methacryloyloxy)ethyl)trimethylammonium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate, with either SMA or BzMA, to produce either charged shell or charged core nanoparticles. The electrokinetics were studied as a function of many variables (function of volume function, particle size, solvent viscosity, and number of ions per chain). These data are consistent with electrophoresis controlled by counterion condensation, which is typically observed in salt-free media. However, there are several interesting and unexpected features of interest. In particular, charged shell nanoparticles have a lower electrophoretic mobility than the equivalent charged core nanoparticles, and the magnitude of the electrophoretic mobility increases as the fraction of cationic stabilizer chains in the shell layer is reduced. These results show that cationic PSMA-PBzMA spheres provide an interesting new example of electrophoretic nanoparticles in non-polar solvents. Moreover, they should provide an ideal model system to evaluate new electrokinetic theories.
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Affiliation(s)
- Gregory N Smith
- Department of Chemistry , University of Sheffield , Brook Hill , Sheffield , South Yorkshire S3 7HF , UK . ;
| | - Laura L E Mears
- Department of Chemistry , University of Liverpool , Liverpool L69 7ZD , UK
| | - Sarah E Rogers
- ISIS-STFC , Rutherford Appleton Laboratory , Chilton , Oxon OX11 0QX , UK
| | - Steven P Armes
- Department of Chemistry , University of Sheffield , Brook Hill , Sheffield , South Yorkshire S3 7HF , UK . ;
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Smith GN, Finlayson SD, Rogers SE, Bartlett P, Eastoe J. Electrolyte-induced Instability of Colloidal Dispersions in Nonpolar Solvents. J Phys Chem Lett 2017; 8:4668-4672. [PMID: 28853903 DOI: 10.1021/acs.jpclett.7b01685] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Dispersions of poly(methyl methacrylate) (PMMA) latexes were prepared in a low dielectric, nonpolar solvent (dodecane) both with and without the oil-soluble electrolyte, tetradodecylammonium-tetrakis(3,5-bis(trifluoromethyl)phenyl)borate. For dispersions with a high concentration of background electrolyte, the latexes become colloidally unstable and sediment in a short period of time (<1 h). This is completely reversible upon dilution. Instability of the dispersions is due to an apparent attraction between the colloids, directly observed using optical tweezers by bringing optically trapped particles into close proximity. Simple explanations generally used by colloid scientists to explain loss of stability (charge screening or stabilizer collapse) are insufficient to explain this observation. This unexpected interaction seems, therefore, to be a consequence of the materials that can be dispersed in low dielectric media and is expected to have ramifications for studying colloids in such solvents.
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Affiliation(s)
- Gregory N Smith
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Samuel D Finlayson
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Sarah E Rogers
- ISIS-STFC, Rutherford Appleton Laboratory , Chilton, Oxon OX11 0QX, United Kingdom
| | - Paul Bartlett
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Julian Eastoe
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom
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Pegg JC, Czajka A, Hazell G, Hill C, Peach J, Rogers SE, Eastoe J. Solubilisation of oils in aqueous solutions of a random cationic copolymer. J Colloid Interface Sci 2017; 502:210-218. [DOI: 10.1016/j.jcis.2017.04.093] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 04/27/2017] [Accepted: 04/28/2017] [Indexed: 02/02/2023]
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Peach J, Czajka A, Hazell G, Hill C, Mohamed A, Pegg JC, Rogers SE, Eastoe J. Tuning Micellar Structures in Supercritical CO 2 Using Surfactant and Amphiphile Mixtures. Langmuir 2017; 33:2655-2663. [PMID: 28215094 DOI: 10.1021/acs.langmuir.7b00324] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
For equivalent micellar volume fraction (ϕ), systems containing anisotropic micelles are generally more viscous than those comprising spherical micelles. Many surfactants used in water-in-CO2 (w/c) microemulsions are fluorinated analogues of sodium bis(2-ethylhexyl) sulfosuccinate (AOT): here it is proposed that mixtures of CO2-philic surfactants with hydrotropes and cosurfactants may generate elongated micelles in w/c systems at high-pressures (e.g., 100-400 bar). A range of novel w/c microemulsions, stabilized by new custom-synthesized CO2-phillic, partially fluorinated surfactants, were formulated with hydrotropes and cosurfactant. The effects of water content (w = [water]/[surfactant]), surfactant structure, and hydrotrope tail length were all investigated. Dispersed water domains were probed using high pressure small-angle neutron scattering (HP-SANS), which provided evidence for elongated reversed micelles in supercritical CO2. These new micelles have significantly lower fluorination levels than previously reported (6-29 wt % cf. 14-52 wt %), and furthermore, they support higher water dispersion levels than other related systems (w = 15 cf. w = 5). The intrinsic viscosities of these w/c microemulsions were estimated based on micelle aspect ratio; from this value a relative viscosity value can be estimated through combination with the micellar volume fraction (ϕ). Combining these new results with those for all other reported systems, it has been possible to "map" predicted viscosity increases in CO2 arising from elongated reversed micelles, as a function of surfactant fluorination and micellar aspect ratio.
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Affiliation(s)
- Jocelyn Peach
- School of Chemistry, University of Bristol , Bristol, BS8 1TS, United Kingdom
| | - Adam Czajka
- School of Chemistry, University of Bristol , Bristol, BS8 1TS, United Kingdom
| | - Gavin Hazell
- School of Chemistry, University of Bristol , Bristol, BS8 1TS, United Kingdom
| | - Christopher Hill
- School of Chemistry, University of Bristol , Bristol, BS8 1TS, United Kingdom
| | - Azmi Mohamed
- Faculty of Science and Mathematics, Department of Chemistry, University Pendidikan Sultan Idris , Tanjong Malim 35900, Perak, Malaysia
| | - Jonathan C Pegg
- School of Chemistry, University of Bristol , Bristol, BS8 1TS, United Kingdom
| | - Sarah E Rogers
- Rutherford Appleton Laboratory, ISIS Spallation Source, Chilton, Oxfordshire, OX11 0QT, United Kingdom
| | - Julian Eastoe
- School of Chemistry, University of Bristol , Bristol, BS8 1TS, United Kingdom
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Pegg JC, Czajka A, Hill C, James C, Peach J, Rogers SE, Eastoe J. Alternative Route to Nanoscale Aggregates with a pH-Responsive Random Copolymer. Langmuir 2017; 33:2628-2638. [PMID: 28219244 DOI: 10.1021/acs.langmuir.6b04559] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A random copolymer, poly(methyl methacrylate-co-2-dimethylaminoethyl methacrylate) (poly(MMA-co-DMAEMA)) is shown to form nanoscale aggregates (NAs) (∼20 nm) at copolymer concentrations ≥10% w/w, directly from the preformed surfactant-stabilized latex (∼120 nm) in aqueous solution. The copolymer is prepared by conventional emulsion polymerization. Introducing a small mole fraction of DMAEMA (∼10%) allows the copolymer hydrophilicity to be adjusted by the pH and external temperature, generating NAs with tuneable sizes and a defined weight-average aggregation number, as observed by dynamic light scattering (DLS) and small-angle neutron scattering (SANS). These NAs are different from the so-called mesoglobular systems and are insensitive to temperature at fixed pH. The relatively broad chemical composition distribution of the copolymer and lumpy (or blocky but not diblock) incorporation of DMAEMA mean that the NAs cannot be simply thought of as conventional polymer micelles. In the acidic pH regime, the amphiphilic copolymer exhibits a defined critical assembly concentration (CAC) and a minimum air-water surface tension of 45.2 mN m-1. This copolymer represents a convenient route to self-assembled NAs, which form directly in aqueous dispersions after pH and temperature triggers, rather than the typically applied (and time-consuming) water-induced micellization approach for common polymer micelles.
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Affiliation(s)
- Jonathan C Pegg
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, U.K
| | - Adam Czajka
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, U.K
| | - Christopher Hill
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, U.K
| | - Craig James
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, U.K
| | - Jocelyn Peach
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, U.K
| | - Sarah E Rogers
- ISIS-STFC, Rutherford Appleton Laboratory, Chilton, Oxon OX11 0QX, U.K
| | - Julian Eastoe
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, U.K
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Smith GN, Brown P, James C, Rogers SE, Eastoe J. Corrigendum to “The effect of solvent and counterion variation on inverse micelle CMCs in hydrocarbon solvents” [Colloids Surf. A: Physicochem. Eng. Asp. 494 (2016) 194–200]. Colloids Surf A Physicochem Eng Asp 2017. [DOI: 10.1016/j.colsurfa.2016.12.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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46
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Czajka A, Hill C, Peach J, Pegg JC, Grillo I, Guittard F, Rogers SE, Sagisaka M, Eastoe J. Trimethylsilyl hedgehogs – a novel class of super-efficient hydrocarbon surfactants. Phys Chem Chem Phys 2017; 19:23869-23877. [DOI: 10.1039/c7cp02570j] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Presented here are the results for a novel class of hydrocarbon surfactants, termed trimethylsilyl hedgehogs (TMS-hedgehogs), due to the presence of silicon in the tails.
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Affiliation(s)
- Adam Czajka
- School of Chemistry
- University of Bristol
- Bristol
- UK
| | | | | | | | | | - Frédéric Guittard
- University of Nice Sophia Antipolis
- CNRS
- LPMC
- Group surfaces & interfaces
- 06100 Nice
| | - Sarah E. Rogers
- ISIS Neutron and Muon Source
- Rutherford Appleton Laboratory
- Didcot
- UK
| | - Masanobu Sagisaka
- Department of Frontier Materials Chemistry
- Hirosaki University
- Hirosaki
- Japan
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47
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Sagisaka M, Ogiwara S, Ono S, James C, Yoshizawa A, Mohamed A, Rogers SE, Heenan RK, Yan C, Peach JA, Eastoe J. New Class of Amphiphiles Designed for Use in Water-in-Supercritical CO 2 Microemulsions. Langmuir 2016; 32:12413-12422. [PMID: 27448717 DOI: 10.1021/acs.langmuir.6b01670] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Water-in-supercritical CO2 microemulsions formed using the hybrid F-H surfactant sodium 1-oxo-1-[4-(perfluorohexyl)phenyl]hexane-2-sulfonate, FC6-HC4, have recently been shown to have the highest water-solubilizing power ever reported. FC6-HC4 demonstrated the ability to outperform not only other surfactants but also other FCm-HCn analogues containing different fluorocarbon and hydrocarbon chain lengths (Sagisaka, M. et al. Langmuir 2015, 31, 7479-7487). With the aim of clarifying the key structural features of this surfactant, this study examined the phase behavior and water/supercritical CO2 aggregate formation of 1-oxo-1-[4-(perfluorohexyl)phenyl]hexane (Nohead FC6-HC4), which is an FC6-HC4 analogue but now, interestingly, without the sulfonate headgroup. Surprisingly, Nohead FC6-HC4, which would not normally be identified as a classic surfactant, yielded transparent single-phase W/CO2 microemulsions with polar cores able to solubilize a water-soluble dye, even at pressures and temperatures so low as to approach the critical point of CO2 (e.g., ∼100 bar at 35 °C). High-pressure small-angle scattering (SANS) measurements revealed the transparent phases to consist of ellipsoidal nanodroplets of water. The morphology of these droplets was shown to be dependent on the pressure, Nohead FC6-HC4 concentration, and water-to-surfactant molar ratio. Despite having almost the same structure as Nohead FC6-HC4, analogues containing both shorter and longer hydrocarbons were unable to form W/CO2 microemulsion droplets. This shows the importance of the role of the hydrocarbon chain in the stabilization of W/CO2 microemulsions. A detailed examination of the mechanism of Nohead FC6-HC4 adsorption onto the water surface suggests that the hexanoyl group protrudes into the aqueous core, allowing for association between the carbonyl group and water.
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Affiliation(s)
- Masanobu Sagisaka
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University , 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Shunsuke Ogiwara
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University , 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Shinji Ono
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University , 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Craig James
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University , 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Atsushi Yoshizawa
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University , 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | | | - Sarah E Rogers
- ISIS-CCLRC, Rutherford Appleton Laboratory , Chilton, Oxon OX11 0QX, U.K
| | - Richard K Heenan
- ISIS-CCLRC, Rutherford Appleton Laboratory , Chilton, Oxon OX11 0QX, U.K
| | - Ci Yan
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, U.K
| | - Jocelyn Alice Peach
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, U.K
| | - Julian Eastoe
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, U.K
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48
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Hoffmann I, Simon M, Hörmann A, Gravert T, Heunemann P, Rogers SE, Gradzielski M. Kinetics of Oil Exchange in Nanoemulsions Prepared with the Phase Inversion Concentration Method. Langmuir 2016; 32:12084-12090. [PMID: 27776212 DOI: 10.1021/acs.langmuir.6b03009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Nanoemulsions (NEs) are metastable emulsions with droplet sizes between 20 and 100 nm and with a wide range of applications, for example, in polymerization, in pharmaceutical and cosmetic formulations, and as drug delivery systems. Even though they are not in thermodynamic equilibrium, they can be metastable over relatively long times and have the advantage that they can be formed easily by low energy input methods. In particular, the phase inversion concentration (PIC) method allows the formation of NEs by the dilution of a suitable mixture of oil and surfactants with water. In this paper, we investigate the kinetics of the oil exchange process of NEs formed by the PIC method by looking at the exchange of different hydrophobic oils and by employing contrast variation stopped flow small-angle neutron scattering. These experiments demonstrate that this exchange becomes substantially slower by increasing the chain length of the alkane. This indicates a mechanism where monomer exchange is relevant, which would indicate also that for aging one would expect Ostwald ripening to be the determining factor. Such investigations can be carried out in a unique fashion by means of neutron scattering, and the results have important implications for the optimization of NE formulations.
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Affiliation(s)
- Ingo Hoffmann
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin , Straße des 17. Juni 124, Sekr. TC 7, D-10623, Berlin, Germany
- Institut Max von Laue-Paul Langevin (ILL) , F-38042 Grenoble Cedex 9, France
| | - Miriam Simon
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin , Straße des 17. Juni 124, Sekr. TC 7, D-10623, Berlin, Germany
| | - Anja Hörmann
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin , Straße des 17. Juni 124, Sekr. TC 7, D-10623, Berlin, Germany
| | - Thorsten Gravert
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin , Straße des 17. Juni 124, Sekr. TC 7, D-10623, Berlin, Germany
| | - Peggy Heunemann
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin , Straße des 17. Juni 124, Sekr. TC 7, D-10623, Berlin, Germany
- Institut Max von Laue-Paul Langevin (ILL) , F-38042 Grenoble Cedex 9, France
| | - Sarah E Rogers
- ISIS , Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX, U.K
| | - Michael Gradzielski
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin , Straße des 17. Juni 124, Sekr. TC 7, D-10623, Berlin, Germany
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Knaapila M, Stewart B, Costa T, Rogers SE, Pragana J, Fonseca SM, Valente AJM, Ramos ML, Murtinho D, Pereira JC, Mallavia R, Burrows HD. Incorporation of a Cationic Conjugated Polyelectrolyte CPE within an Aqueous Poly(vinyl alcohol) Sol. Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b01895] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Matti Knaapila
- Department
of Physics, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Beverly Stewart
- Department
of Chemistry and Coimbra Chemistry Centre, University of Coimbra, 3004-535 Coimbra, Portugal
| | - Telma Costa
- Department
of Chemistry and Coimbra Chemistry Centre, University of Coimbra, 3004-535 Coimbra, Portugal
| | - Sarah E. Rogers
- Rutherford
Appleton
Laboratory, ISIS STFC, Chilton OX11 0QX, Oxon, U.K
| | - Joana Pragana
- Department
of Chemistry and Coimbra Chemistry Centre, University of Coimbra, 3004-535 Coimbra, Portugal
| | - Sofia M. Fonseca
- Department
of Chemistry and Coimbra Chemistry Centre, University of Coimbra, 3004-535 Coimbra, Portugal
| | - Artur J. M. Valente
- Department
of Chemistry and Coimbra Chemistry Centre, University of Coimbra, 3004-535 Coimbra, Portugal
| | - M. Luisa Ramos
- Department
of Chemistry and Coimbra Chemistry Centre, University of Coimbra, 3004-535 Coimbra, Portugal
| | - Dina Murtinho
- Department
of Chemistry and Coimbra Chemistry Centre, University of Coimbra, 3004-535 Coimbra, Portugal
| | - Jorge Costa Pereira
- Department
of Chemistry and Coimbra Chemistry Centre, University of Coimbra, 3004-535 Coimbra, Portugal
| | - Ricardo Mallavia
- Instituto
de Biología Molecular y Celular, Universidad Miquel Hernandez de Elche, Avda. de la Universidad s/n, 03202 Elche, Spain
| | - Hugh D. Burrows
- Department
of Chemistry and Coimbra Chemistry Centre, University of Coimbra, 3004-535 Coimbra, Portugal
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Smith GN, Finlayson SD, Gillespie DA, Peach J, Pegg JC, Rogers SE, Shebanova O, Terry AE, Armes SP, Bartlett P, Eastoe J. The internal structure of poly(methyl methacrylate) latexes in nonpolar solvents. J Colloid Interface Sci 2016; 479:234-243. [DOI: 10.1016/j.jcis.2016.06.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 06/08/2016] [Accepted: 06/08/2016] [Indexed: 11/26/2022]
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