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Milster S, Darwish A, Göth N, Dzubiella J. Synergistic chemomechanical dynamics of feedback-controlled microreactors. Phys Rev E 2023; 108:L042601. [PMID: 37978612 DOI: 10.1103/physreve.108.l042601] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 09/06/2023] [Indexed: 11/19/2023]
Abstract
The experimental control of synergistic chemomechanical dynamics of catalytically active microgels (microreactors) is a key prerequisite for the design of adaptive and biomimetic materials. Here, we report a minimalistic model of feedback-controlled microreactors based on the coupling between the hysteretic polymer volume phase transition and a volume-controlled permeability for the internal chemical conversion. We categorize regimes of mono- and bistability, excitability, damped oscillations, as well as sustained oscillatory states with tunable amplitude, as indicated by experiments and representable by the FitzHugh-Nagumo dynamics for neurons. We summarize the features of such a "colloidal neuron" in bifurcation diagrams with respect to microgel design parameters, such as permeability and relaxation times, as a guide for experimental synthesis.
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Affiliation(s)
- Sebastian Milster
- Applied Theoretical Physics - Computational Physics, Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, D-79104 Freiburg, Germany
| | - Abeer Darwish
- Applied Theoretical Physics - Computational Physics, Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, D-79104 Freiburg, Germany
| | - Nils Göth
- Applied Theoretical Physics - Computational Physics, Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, D-79104 Freiburg, Germany
| | - Joachim Dzubiella
- Applied Theoretical Physics - Computational Physics, Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, D-79104 Freiburg, Germany
- Cluster of Excellence livMatS @ FIT - Freiburg Center for Interactive Materials and Bioinspired Technologies, Albert-Ludwigs-Universität Freiburg, D-79110 Freiburg, Germany
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2
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Akgonullu DZ, Murray BS, Connell SD, Fang Y, Linter B, Sarkar A. Synthetic and biopolymeric microgels: Review of similarities and difference in behaviour in bulk phases and at interfaces. Adv Colloid Interface Sci 2023; 320:102983. [PMID: 37690329 DOI: 10.1016/j.cis.2023.102983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 08/12/2023] [Accepted: 08/14/2023] [Indexed: 09/12/2023]
Abstract
This review discusses the current knowledge of interfacial and bulk interactions of biopolymeric microgels in relation to the well-established properties of synthetic microgels for applications as viscosity modifiers and Pickering stabilisers. We present a timeline showing the key milestones in designing microgels and their bulk/ interfacial performance. Poly(N-isopropylacrylamide) (pNIPAM) microgels have remained as the protagonist in the synthetic microgel domain whilst proteins or polysaccharides have been primarily used to fabricate biopolymeric microgels. Bulk properties of microgel dispersions are dominated by the volume fraction (ϕ) of the microgel particles, but ϕ is difficult to pinpoint, as addressed by many theoretical models. By evaluating recent experimental studies over the last five years, we find an increasing focus on the analysis of microgel elasticity as a key parameter in modulating their packing at the interfaces, within the provinces of both synthetic and biopolymeric systems. Production methods and physiochemical factors shown to influence microgel swelling in the aqueous phase can have a significant impact on their bulk as well as interfacial performance. Compared to synthetic microgels, biopolymer microgels show a greater tendency for polydispersity and aggregation and do not appear to have a core-corona structure. Comprehensive studies of biopolymeric microgels are still lacking, for example, to accurately determine their inter- and intra- particle interactions, whilst a wider variety of techniques need to be applied in order to allow comparisons to real systems of practical usage.
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Affiliation(s)
- Daisy Z Akgonullu
- Food Colloids and Bioprocessing Group, School of Food Science and Nutrition, University of Leeds, UK
| | - Brent S Murray
- Food Colloids and Bioprocessing Group, School of Food Science and Nutrition, University of Leeds, UK
| | - Simon D Connell
- Molecular and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, UK
| | - Yuan Fang
- PepsiCo, Valhalla, New York, NY, USA
| | | | - Anwesha Sarkar
- Food Colloids and Bioprocessing Group, School of Food Science and Nutrition, University of Leeds, UK.
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3
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Hu C, van Bonn P, Demco DE, Bolm C, Pich A. Mechanochemical Synthesis of Stimuli Responsive Microgels. Angew Chem Int Ed Engl 2023; 62:e202305783. [PMID: 37177824 DOI: 10.1002/anie.202305783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 05/12/2023] [Accepted: 05/12/2023] [Indexed: 05/15/2023]
Abstract
Mechanochemical approaches are widely used for the efficient, solvent-free synthesis of organic molecules, however their applicability to the synthesis of functional polymers has remained underexplored. Herein, we demonstrate for the first time that mechanochemically triggered free-radical polymerization allows solvent- and initiator-free syntheses of structurally and morphologically well-defined complex functional macromolecular architectures, namely stimuliresponsive microgels. The developed mechanochemical polymerization approach is applicable to a variety of monomers and allows synthesizing microgels with tunable chemical structure, variable size, controlled number of crosslinks and reactive functional end-groups.
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Affiliation(s)
- Chaolei Hu
- DWI-Leibniz Institute for Interactive Materials e.V., Forckenbeckstraße 50, 52074, Aachen, Germany
- Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Forckenbeckstraße 50, 52074, Aachen, Germany
| | - Pit van Bonn
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074, Aachen, Germany
| | - Dan E Demco
- DWI-Leibniz Institute for Interactive Materials e.V., Forckenbeckstraße 50, 52074, Aachen, Germany
| | - Carsten Bolm
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074, Aachen, Germany
| | - Andrij Pich
- DWI-Leibniz Institute for Interactive Materials e.V., Forckenbeckstraße 50, 52074, Aachen, Germany
- Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Forckenbeckstraße 50, 52074, Aachen, Germany
- Aachen Maastricht Institute for Biobased Materials (AMIBM), Maastricht University, Urmonderbaan 22, 6167 RD, Geleen, The Netherlands
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4
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Rudov AA, Portnov IV, Bogdanova AR, Potemkin II. Structure of swollen hollow polyelectrolyte nanogels with inhomogeneous cross-link distribution. J Colloid Interface Sci 2023; 640:1015-1028. [PMID: 36921382 DOI: 10.1016/j.jcis.2023.02.090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 01/31/2023] [Accepted: 02/16/2023] [Indexed: 02/23/2023]
Abstract
HYPOTHESIS Recently, it has become possible to synthesize hollow polyelectrolyte nano- and microgels. The shell permeability can be controlled by external stimuli, while the cavity can serve as a storage place for guest molecules. However, there is a lack of a detailed understanding at the molecular level regarding the role of the network topology, inhomogeneities of the distribution of cross-links, and the impact of the electrostatics on the structural response of hollow microgel to external stimuli. To bridge these gaps, molecular dynamics (MD) of computer simulations are used. EXPERIMENTS Here, we propose a fresh methodology to create realistic hollow microgel particles in silico. The technique involves a gradual change in the average local length of subchains depending on the distance to the center of mass of the microgel particles resulting in the microgels with a non-uniform distribution of cross-linking species. In particular, a series of microgels with (i) a highly cross-linked inner part of the shell and gradually decreased cross-linker concentration towards the periphery, (ii) microgels with loosely cross-linked inner and outer parts, as well as (iii) microgels with a more-or-less homogeneous structure, have been created and validated. Counterions and salt ions are taken into account explicitly, and electrostatic interactions are described by the Coulomb potential. FINDINGS Our studies reveal a strong dependence of the microgel swelling response on the network topology. Simple redistribution of cross-links plays a significant role in the structure of the microgels, including cavity size, microgel size, fuzziness, and extension of the inner and outer parts of the microgels. Our results indicate the possibilities of qualitative justification of the structure of the hollow microgels in the experiments by measuring the relative change in the size of the sacrificial core to the size of the cavity and by estimation of a power law function, [Formula: see text] , of the hydrodynamic radius of the hollow microgels as a function of added salt concentration.
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Affiliation(s)
- Andrey A Rudov
- Physics Department, Lomonosov Moscow State University, Moscow, Russian Federation
| | - Ivan V Portnov
- Physics Department, Lomonosov Moscow State University, Moscow, Russian Federation; A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Moscow 119991, Russian Federation
| | - Alisa R Bogdanova
- Physics Department, Lomonosov Moscow State University, Moscow, Russian Federation
| | - Igor I Potemkin
- Physics Department, Lomonosov Moscow State University, Moscow, Russian Federation.
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5
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Shu Z, Li HZ, Shi Y, Zuo DY, Yi Z, Gao CJ. Dual sugar and temperature responsive isoporous membranes for protein sieving with improved separation coefficient and decreased denaturation. J Memb Sci 2023. [DOI: 10.1016/j.memsci.2023.121450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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6
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Ranganathan VT, Bazmi S, Wallin S, Liu Y, Yethiraj A. Is Ficoll a Colloid or Polymer? A Multitechnique Study of a Prototypical Excluded-Volume Macromolecular Crowder. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c00677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Saman Bazmi
- Department of Physics and Physical Oceanography, Memorial University, St. John’s, NLA1B 3X7, Canada
| | - Stefan Wallin
- Department of Physics and Physical Oceanography, Memorial University, St. John’s, NLA1B 3X7, Canada
| | - Yun Liu
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland20899, United States
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware19716, United States
| | - Anand Yethiraj
- Department of Physics and Physical Oceanography, Memorial University, St. John’s, NLA1B 3X7, Canada
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7
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Feller D, Karg M. Fluid interface-assisted assembly of soft microgels: recent developments for structures beyond hexagonal packing. SOFT MATTER 2022; 18:6301-6312. [PMID: 35993260 DOI: 10.1039/d2sm00872f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Microgels adsorb to air/water and oil/water interfaces - a process driven by a significant reduction in interfacial tension. Depending on the available interface area per microgel, strong lateral deformation can be observed. Typically, hexagonally ordered structures appear spontaneously upon contact of the microgel shells. Transfer from the interface to solid substrates gives access to macroscopically sized microgel monolayers that are interesting for photonic and plasmonic studies as well as colloid-based lithography, for example. Significant efforts have been made to understand the phase behavior of microgels at different interfaces and to explore the available parameter space for achieving complex tessellations. In this review, we will discuss the most recent developments in the realization of microgel monolayers with structures beyond hexagonal packing.
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Affiliation(s)
- Déborah Feller
- Institut für Physikalische Chemie I: Kolloide und Nanooptik, Heinrich-Heine-Universität Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany.
| | - Matthias Karg
- Institut für Physikalische Chemie I: Kolloide und Nanooptik, Heinrich-Heine-Universität Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany.
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8
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Wilms D, Müller J, Urach A, Schröer F, Schmidt S. Specific Binding of Ligand-Functionalized Thermoresponsive Microgels: Effect of Architecture, Ligand Density, and Hydrophobicity. Biomacromolecules 2022; 23:3899-3908. [PMID: 35930738 DOI: 10.1021/acs.biomac.2c00725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The biomolecular interaction of ligand-presenting switchable microgels is studied with respect to the polymer type, composition, and structure of the microgels. Monodisperse microgels are prepared through precipitation polymerization of N-isopropylacrylamide (PNIPAM microgels) or oligo(ethylene glycol methacrylamide)s (POEGMA microgels) in the presence of crosslinkers or in their absence (self-crosslinked). Functionalization with mannose or biotin as model ligands and affinity measurements upon heating/cooling are conducted to obtain mechanistic insights into how the microgel phase transition affects the specific interactions. In particular, we are interested in adjusting the crosslinking, swelling degree, and ligand density of mannose-functionalized microgels to reversibly catch and release mannose binding Escherichia coli by setting the temperature below or above the microgels' volume phase transition temperature (VPTT). The increased mannose density for collapsed microgels above the VPTT results in stronger E. coli binding. Detachment of E. coli by reswelling the microgels below the VPTT is achieved only for self-crosslinked microgels showing a stronger decrease in ligand density compared to microgels with dedicated crosslinkers. Owing to a reduced mannose density in the shell of POEGMA microgels, their E. coli binding was lower compared to PNIPAM microgels, as supported by ultraresolution microscopy. Importantly, an inverse temperature-controlled binding of microgels decorated with hydrophilic mannose and hydrophobic biotin ligands is observed. This indicates that hydrophobic ligands are inaccessible in the collapsed hydrophobic network above the VPTT, whereas hydrophilic mannose units are then enriched at the microgel-water interface and thus are more accessible.
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Affiliation(s)
- Dimitri Wilms
- Institute for Organic Chemistry and Macromolecular Chemistry, Heinrich-Heine-University, Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Janita Müller
- Institute for Organic Chemistry and Macromolecular Chemistry, Heinrich-Heine-University, Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Anselm Urach
- Institute for Organic Chemistry and Macromolecular Chemistry, Heinrich-Heine-University, Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Fabian Schröer
- Institute for Organic Chemistry and Macromolecular Chemistry, Heinrich-Heine-University, Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Stephan Schmidt
- Institute for Organic Chemistry and Macromolecular Chemistry, Heinrich-Heine-University, Universitätsstraße 1, 40225 Düsseldorf, Germany
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9
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Buratti E, Tavagnacco L, Zanatta M, Chiessi E, Buoso S, Franco S, Ruzicka B, Angelini R, Orecchini A, Bertoldo M, Zaccarelli E. The role of polymer structure on water confinement in poly(N-isopropylacrylamide) dispersions. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.118924] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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10
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Ponomareva E, Tadgell B, Hildebrandt M, Krüsmann M, Prévost S, Mulvaney P, Karg M. The fuzzy sphere morphology is responsible for the increase in light scattering during the shrinkage of thermoresponsive microgels. SOFT MATTER 2022; 18:807-825. [PMID: 34939641 DOI: 10.1039/d1sm01473k] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Thermoresponsive microgels undergo a volume phase transition from a swollen state under good solvent conditions to a collapsed state under poor solvent conditions. The most prominent examples of such responsive systems are based on poly-(N-isopropylacrylamide). When cross-linked with N,N'-methylenebisacrylamide, such microgels typically possess a fuzzy-spherelike morphology with a higher cross-linked core and a loosely cross-linked fuzzy shell. Despite the efforts devoted to understanding the internal structure of microgels and their kinetics during collapse/swelling, the origins of the accompanying changes in light scattering intensity have barely been addressed. In this work, we study core-shell microgels that contain small gold nanoparticle cores with microgel shells of different thicknesses and cross-linker densities. All microgels are small enough to fulfill the Rayleigh-Debye-Gans criterion at all stages of swelling. Due to the high X-ray contrast of the gold cores, we can use absolute intensity small-angle X-ray scattering to determine the number density in the dilute dispersions. This allows us to extract polymer volume fractions of the microgels at different stages of swelling from form factor analysis of small-angle neutron scattering data. We match our findings to results from temperature-dependent absorbance measurements. The increase in absorbance during the shrinkage of the microgels is related to the transition from fuzzy spheres to hard sphere-like scattering objects with a rather homogeneous density profile. We provide a first attempt to model experimental spectra using finite difference time domain simulations that take into account the structural changes during the volume phase transition. Our findings significantly contribute to the understanding of the optical properties of thermoresponsive microgels. Further, we provide polymer volume fractions and microgel refractive indices as a function of the swelling state.
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Affiliation(s)
- Ekaterina Ponomareva
- Institut für Physikalische Chemie I: Kolloide und Nanooptik, Heinrich-Heine-Universität Düsseldorf, Universitätsstrase 1, D-40225 Düsseldorf, Germany.
| | - Ben Tadgell
- ARC Centre of Excellence in Exciton Science, The University of Melbourne, School of Chemistry, Parkville, VIC 3010, Australia
| | - Marco Hildebrandt
- Institut für Physikalische Chemie I: Kolloide und Nanooptik, Heinrich-Heine-Universität Düsseldorf, Universitätsstrase 1, D-40225 Düsseldorf, Germany.
| | - Marcel Krüsmann
- Institut für Physikalische Chemie I: Kolloide und Nanooptik, Heinrich-Heine-Universität Düsseldorf, Universitätsstrase 1, D-40225 Düsseldorf, Germany.
| | - Sylvain Prévost
- Large Scale Structures, Institut Laue-Langevin, 71 avenue des Martyrs, CS 20156, 38042, Grenoble Cedex 9, France
| | - Paul Mulvaney
- ARC Centre of Excellence in Exciton Science, The University of Melbourne, School of Chemistry, Parkville, VIC 3010, Australia
| | - Matthias Karg
- Institut für Physikalische Chemie I: Kolloide und Nanooptik, Heinrich-Heine-Universität Düsseldorf, Universitätsstrase 1, D-40225 Düsseldorf, Germany.
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11
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Sbeih S, Mohanty PS, Yethiraj A, Morrow MR. 2H NMR Study of Polymer Segmental Dynamics at Varying Cross-Linking in Poly( N-isopropylacrylamide) Microgels. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:13664-13675. [PMID: 34767370 DOI: 10.1021/acs.langmuir.1c02269] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
A microscopic understanding of the internal structure and dynamics of poly(N-isopropylacrylamide) (PNIPAM) chains, in microgel colloids, is developed using deuterium NMR (2H NMR) to study deuterated PNIPAM suspensions as functions of temperature and pressure for four cross-linker molar fractions (f). The PNIPAM polymers were labeled with deuterons at the backbone (d3-PNIPAM) or on side chains (d7-PNIPAM). 2H NMR spectra of the d3-PNIPAM suspensions for all cross-linker molar fractions indicated freely moving chains at low temperature and a nearly immobilized fraction above ∼35 °C. Polymer segments in the collapsed phase of the d3-PNIPAM suspension were more mobile than those in the dry powder. This is direct microscopic evidence that the polymer remains significantly hydrated in the collapsed phase, consistent with strong, indirect evidence from recent light scattering and rheology measurements from our laboratory. However, the observation of a small fraction of immobilized segments in the swollen phase for higher cross-linker molar fraction suggests that, particularly for high levels of cross-linking, some polymer is nonhydrated even in the swollen phase. Finally, variable-pressure NMR (up to 90 MPa) showed a slight increase in transition temperature with pressure for lower cross-linker molar fractions and a larger increase in transition temperature with pressure for higher cross-linker molar fractions. This is consistent with a previously reported dependence of collapse transition enthalpy on cross-linker molar fraction.
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Affiliation(s)
- Suhad Sbeih
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada A1B 3X7
- School of Basic Sciences and Humanities, German Jordanian University, P.O. Box 35247, Amman 11180, Jordan
| | - Priti S Mohanty
- School of Chemical Technology, Kalinga Institute of Industrial Technology (KIIT), Bhubaneswar 751024, India
| | - Anand Yethiraj
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada A1B 3X7
| | - Michael R Morrow
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada A1B 3X7
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12
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Jose M, Basavaraj MG, Satapathy DK. Evaporative self-assembly of soft colloidal monolayers: the role of particle softness. SOFT MATTER 2021; 17:7921-7931. [PMID: 34373885 DOI: 10.1039/d1sm00841b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We investigate the sessile drop evaporation aided self-assembly of microgel particles by varying their softness. Evaporation of sessile drops containing amphiphilic microgel particles at suitable concentrations results in uniform monolayer deposits that span the entire drop area. At lower concentrations, the deposits are in the form of monolayer coffee rings whose width scales with particle concentration. Using softer microgels synthesised with a lower quantity of crosslinker, we show that the monolayer coffee rings do not form at low particle concentrations. The microgels adsorbed at the interface deform, and the extent of deformation depends on the softness of the microgels as well as their concentration at the interface. Upon complete evaporation of the solvent, the microgel-laden interface is transferred to the substrate. The final deposit shows hexagonal particle arrays where the interparticle separation increases with increasing microgel softness and decreases with particle concentration in the drop. Further insight into the role of microgel softness in the microstructure of the particulate deposits is obtained by measuring the viscoelasticity of the particle-laden interface. Interestingly, the interface loaded with lesser crosslinked microgels exhibits viscoelastic nature even at lower particle concentrations, whereas the higher crosslinked microgels show viscous behaviour.
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Affiliation(s)
- Merin Jose
- Soft Materials Laboratory, Department of Physics, IIT Madras, Chennai, India.
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13
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Chaudhary G, Ghosh A, Kang JG, Braun PV, Ewoldt RH, Schweizer KS. Linear and nonlinear viscoelasticity of concentrated thermoresponsive microgel suspensions. J Colloid Interface Sci 2021; 601:886-898. [PMID: 34186277 DOI: 10.1016/j.jcis.2021.05.111] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 04/26/2021] [Accepted: 05/19/2021] [Indexed: 11/25/2022]
Abstract
We present an integrated experimental and theoretical study of the dynamics and rheology of self-crosslinked, slightly charged, temperature responsive soft poly(N-isopropylacrylamide) (pNIPAM) microgels over a wide range of concentration and temperature spanning the sharp change in particle size and intermolecular interactions across the lower critical solution temperature (LCST). Dramatic, non-monotonic changes in viscoelasticity are observed as a function of temperature, with distinct concentration dependence in the dense fluid, glassy, and soft-jammed regimes. Motivated by our experimental observations, we formulate a minimalistic model for the size dependence of a single microgel particle and the change of the interparticle interaction from purely repulsive to attractive upon heating. Using microscopic equilibrium and time-dependent statistical mechanical theories, theoretical predictions are quantitatively compared with experimental measurements of the shear modulus. Good agreement is found for the nonmonotonic temperature behavior that originates as a consequence of the competition between reduced microgel packing fraction and increasing interparticle attractions. Testable predictions are made for nonlinear rheological properties such as the yield stress and strain. To our knowledge, this is the first attempt to quantitatively understand in a unified manner the viscoelasticity of dense, temperature-responsive microgel suspensions spanning a wide range of temperatures and concentrations.
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Affiliation(s)
- Gaurav Chaudhary
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Ashesh Ghosh
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Jin Gu Kang
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Paul V Braun
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Randy H Ewoldt
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
| | - Kenneth S Schweizer
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Chemical & Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
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14
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Song X, Zhou J, Qiao C, Xu X, Zhao S, Liu H. Engulfing Behavior of Nanoparticles into Thermoresponsive Microgels: A Mesoscopic Simulation Study. J Phys Chem B 2021; 125:2994-3004. [PMID: 33720720 DOI: 10.1021/acs.jpcb.1c00817] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The engulfing of nanoparticles into microgels provides a versatile platform to design nano- and microstructured materials with various shape anisotropies and multifunctional properties. Manipulating the spontaneous engulfment process remains elusive. Herein, we report a mesoscopic simulation study on the engulfing behavior of nanoparticles into thermoresponsive microgels. The effects of the multiple parameters, including binding strength, temperature, and nanoparticle size, are examined systematically. Our simulation results disclose three engulfing states at different temperatures, namely full-engulfing, half-engulfing, and surface contact. The engulfing depth is determined by the complementary balance of interfacial elastocapillarity. Specifically, the van der Waals interaction of hybrid microgel-nanoparticle offers the capillary force while the internally networked structure of microgel reinforces the elasticity repulsion. Our study, validated by relevant experimental results, provides a mechanistic understanding of the interfacial elastocapillarity for nanoparticle-microgels.
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Affiliation(s)
- Xianyu Song
- State Key Laboratory of Chemical Engineering and School of Chemical Engineering, East China University of Science and Technology, Shanghai, 200237, China.,Chongqing Key Laboratory of Water Environment Evolution and Pollution Control in Three Gorges Reservoir, Chongqing Three Gorges University, Wanzhou 404020, China
| | - Jianzhuang Zhou
- State Key Laboratory of Chemical Engineering and School of Chemical Engineering, East China University of Science and Technology, Shanghai, 200237, China
| | - Chongzhi Qiao
- State Key Laboratory of Chemical Engineering and School of Chemical Engineering, East China University of Science and Technology, Shanghai, 200237, China
| | - Xiaofei Xu
- State Key Laboratory of Chemical Engineering and School of Chemical Engineering, East China University of Science and Technology, Shanghai, 200237, China
| | - Shuangliang Zhao
- State Key Laboratory of Chemical Engineering and School of Chemical Engineering, East China University of Science and Technology, Shanghai, 200237, China.,Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, Guangxi University, Nanning, 530004, China
| | - Honglai Liu
- State Key Laboratory of Chemical Engineering and School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, 200237, China
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15
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Pérez-Chávez NA, Albesa AG, Longo GS. Thermodynamic Theory of Multiresponsive Microgel Swelling. Macromolecules 2021. [DOI: 10.1021/acs.macromol.0c02885] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Néstor A. Pérez-Chávez
- Instituto de Investigaciones Fisicoquímicas, Teóricas y Aplicadas (INIFTA), UNLP-CONICET, La Plata 1900, Argentina
| | - Alberto G. Albesa
- Instituto de Investigaciones Fisicoquímicas, Teóricas y Aplicadas (INIFTA), UNLP-CONICET, La Plata 1900, Argentina
| | - Gabriel S. Longo
- Instituto de Investigaciones Fisicoquímicas, Teóricas y Aplicadas (INIFTA), UNLP-CONICET, La Plata 1900, Argentina
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16
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Kurt SB, Ayyala RS, Sahiner N. Versatile poly(maltose) micro/nanoparticles with tunable surface functionality as a biomaterial. J Appl Polym Sci 2021. [DOI: 10.1002/app.49906] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Saliha B. Kurt
- Department of Chemistry & Nanoscience and Technology Research and Application Center Canakkale Onsekiz Mart University Terzioglu Campus Canakkale Turkey
| | - Ramesh S. Ayyala
- Department of Ophthalmology, Morsani College of Medicine University of South Florida Tampa Florida USA
| | - Nurettin Sahiner
- Department of Chemistry & Nanoscience and Technology Research and Application Center Canakkale Onsekiz Mart University Terzioglu Campus Canakkale Turkey
- Department of Ophthalmology, Morsani College of Medicine University of South Florida Tampa Florida USA
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17
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Lu D, Zhu M, Jin J, Saunders BR. Triply-responsive OEG-based microgels and hydrogels: regulation of swelling ratio, volume phase transition temperatures and mechanical properties. Polym Chem 2021. [DOI: 10.1039/d1py00695a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Facile methods to coordinate swelling ratio, volume-phase transition temperatures and mechanical properties for pH-, thermal-, and cationic-responsive microgels and hydrogels.
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Affiliation(s)
- Dongdong Lu
- Department of Materials
- University of Manchester
- Manchester
- UK
| | - Mingning Zhu
- Department of Materials
- University of Manchester
- Manchester
- UK
| | - Jing Jin
- Department of Materials
- University of Manchester
- Manchester
- UK
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18
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Microgel Particles with Distinct Morphologies and Common Chemical Compositions: a Unified Description of the Responsivity to Temperature and Osmotic Stress. Gels 2020; 6:gels6040034. [PMID: 33081416 PMCID: PMC7709680 DOI: 10.3390/gels6040034] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/13/2020] [Accepted: 10/16/2020] [Indexed: 11/30/2022] Open
Abstract
Poly(N-isopropylacrylamide) (PNIPAM) hydrogel microparticles with different core–shell morphologies have been designed, while maintaining an unvaried chemical composition: a morphology with (i) an un-crosslinked core with a crosslinked shell of PNIPAM chains and (ii) PNIPAM chains crosslinked to form the core with a shell consisting of tethered un-crosslinked PNIPAM chains to the core. Both morphologies with two different degrees of crosslinking have been assessed by confocal microscopy and tested with respect to their temperature responsivity and deformation by applying an osmotic stress. The thermal and mechanical behavior of these architectures have been framed within a Flory–Rehner modified model in order to describe the microgel volume shrinking occurring as response to a temperature increase or an osmotic perturbation. This study provides a background for assessing to what extent the mechanical features of the microgel particle surface affect the interactions occurring at the interface of a microgel particle with a cell, in addition to the already know ligand/receptor interaction. These results have direct implications in triggering a limited phagocytosis of microdevices designed as injectable drug delivery systems.
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19
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Kawaguchi H. On Going to a New Era of Microgel Exhibiting Volume Phase Transition. Gels 2020; 6:gels6030026. [PMID: 32824458 PMCID: PMC7559898 DOI: 10.3390/gels6030026] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 08/03/2020] [Accepted: 08/10/2020] [Indexed: 12/14/2022] Open
Abstract
The discovery of phenomena of volume phase transition has had a great impact not only on bulk gels but also on the world of microgels. In particular, research on poly(N-isopropylacrylamide) (PNIPAM) microgels, whose transition temperature is close to body temperature, has made remarkable progress in almost 35 years. This review presents some breakthrough findings in microgels that exhibit volume phase transitions and outlines recent works on the synthesis, structural analysis, and research direction of microgels.
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Affiliation(s)
- Haruma Kawaguchi
- Faculty of Science and Technology, Keio University, Hiyoshi, Yokohama 241-0814, Japan
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20
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Lopez CG, Lohmeier T, Wong JE, Richtering W. Electrostatic expansion of polyelectrolyte microgels: Effect of solvent quality and added salt. J Colloid Interface Sci 2020; 558:200-210. [DOI: 10.1016/j.jcis.2019.07.042] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 07/05/2019] [Accepted: 07/16/2019] [Indexed: 11/24/2022]
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21
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Fussell SL, Bayliss K, Coops C, Matthews L, Li W, Briscoe WH, Faers MA, Royall CP, van Duijneveldt JS. Reversible temperature-controlled gelation in mixtures of pNIPAM microgels and non-ionic polymer surfactant. SOFT MATTER 2019; 15:8578-8588. [PMID: 31642834 DOI: 10.1039/c9sm01299k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We investigate the reversible gelation of poly(N-isopropylacrylamide) (pNIPAM) microgels in the presence of triblock-copolymer (PEO-PPO-PEO type) surfactant. We demonstrate that the association of these polymers with the microgel particles at elevated temperature is responsible for the gelation, due to the temperature responsive nature of the components. This is highlighted by an increase in the apparent hydrodynamic diameter of the particles in dynamic light scattering experiments, which only occurs above the volume phase transition temperature of pNIPAM. The gels that result shrink over a time period much larger than that of the collapse of pNIPAM microgels, and retain the shape of the container they form in. We investigate the mechanism that leads to this gelation and the structure of the gels that result. Confocal microscopy experiments show that both polymers are present in the gel network, indicating that an associative mechanism is responsible for the gelation. We vary the pNIPAM particle architecture to further investigate the gelation process, and find that the cross-link distribution plays a key role in the gelation mechanism, where for uniformly cross-linked particles the gelation is not observed. This shows that the fuzzy corona of the pNIPAM microgels is involved in the association of the polymers, allowing the triblock-copolymer to penetrate the outer corona of the microgels and bridge the particles. The phase transition observed is close to physiological conditions, so these gels have the potential for use in biomedical applications, including tissue engineering.
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Affiliation(s)
- S L Fussell
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK.
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