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Mandin S, Metilli L, Karrouch M, Lancelon-Pin C, Putaux JL, Chèvremont W, Paineau E, Hengl N, Jean B, Pignon F. Chiral nematic nanocomposites with pitch gradient elaborated by filtration and ultraviolet curing of cellulose nanocrystal suspensions. Carbohydr Polym 2024; 337:122162. [PMID: 38710556 DOI: 10.1016/j.carbpol.2024.122162] [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: 01/23/2024] [Revised: 03/15/2024] [Accepted: 04/11/2024] [Indexed: 05/08/2024]
Abstract
An innovative method combining frontal filtration with ultraviolet (UV) curing has been implemented to design cellulosic nanocomposite films with controlled anisotropic textures from nanometric to micrometric length scales. Namely, an aqueous suspension containing poly (ethylene glycol) diacrylate polymer (PEGDA) as a photocurable polymer and cellulose nanocrystals (CNCs) at a 70/30 mass ratio was processed by frontal filtration, followed by in-situ UV-curing in a dedicated cell. This procedure allowed designing nanocomposite films with highly oriented and densely-packed CNCs, homogeneously distributed in a PEGDA matrix over a thickness of ca. 500 μm. The nanocomposite films were investigated with small-angle X-ray scattering (SAXS), by raster-scanning along their height with a 25 μm vertically-collimated X-ray beam. The CNCs exhibited a high degree of orientation, with their director aligned parallel to the membrane surface, combined with an increase in the degree of alignment as concentration increased towards the membrane surface. Scanning electron microscopy images of fractured films showed the presence of regularly spaced bands lying perpendicular to the applied transmembrane pressure, highlighting the presence of a chiral nematic (cholesteric) organization of the CNCs with a pitch gradient that increased from the membrane surface to the bulk.
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Affiliation(s)
- S Mandin
- Univ. Grenoble Alpes, CNRS, Grenoble INP (Institute of Engineering Univ. Grenoble Alpes), LRP, F-38000 Grenoble, France
| | - L Metilli
- Univ. Grenoble Alpes, CNRS, CERMAV, F-38000 Grenoble, France
| | - M Karrouch
- Univ. Grenoble Alpes, CNRS, Grenoble INP (Institute of Engineering Univ. Grenoble Alpes), LRP, F-38000 Grenoble, France
| | - C Lancelon-Pin
- Univ. Grenoble Alpes, CNRS, CERMAV, F-38000 Grenoble, France
| | - J-L Putaux
- Univ. Grenoble Alpes, CNRS, CERMAV, F-38000 Grenoble, France
| | - W Chèvremont
- ESRF, The European Synchrotron, CS 40220, F-38043 Grenoble Cedex 9, France
| | - E Paineau
- Université Paris Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay Cedex, France
| | - N Hengl
- Univ. Grenoble Alpes, CNRS, Grenoble INP (Institute of Engineering Univ. Grenoble Alpes), LRP, F-38000 Grenoble, France
| | - B Jean
- Univ. Grenoble Alpes, CNRS, CERMAV, F-38000 Grenoble, France
| | - F Pignon
- Univ. Grenoble Alpes, CNRS, Grenoble INP (Institute of Engineering Univ. Grenoble Alpes), LRP, F-38000 Grenoble, France.
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Pignon F, Guilbert E, Mandin S, Hengl N, Karrouch M, Jean B, Putaux JL, Gibaud T, Manneville S, Narayanan T. Orthotropic organization of a cellulose nanocrystal suspension realized via the combined action of frontal ultrafiltration and ultrasound as revealed by in situ SAXS. J Colloid Interface Sci 2024; 659:914-925. [PMID: 38219310 DOI: 10.1016/j.jcis.2023.12.164] [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: 10/03/2023] [Revised: 12/21/2023] [Accepted: 12/28/2023] [Indexed: 01/16/2024]
Abstract
HYPOTHESIS Rodlike cellulose nanocrystals (CNCs) exhibit significant potential as building blocks for creating uniform, sustainable materials. However, a critical hurdle lies in the need to enhance existing or devise novel processing that provides improved control over the alignment and arrangement of CNCs across a wide spatial range. Specifically, the challenge is to achieve orthotropic organization in a single-step processing, which entails creating non-uniform CNC orientations to generate spatial variations in anisotropy. EXPERIMENTS A novel processing method combining frontal ultrafiltration (FU) and ultrasound (US) has been developed. A dedicated channel-cell was designed to simultaneously generate (1) a vertical acoustic force thanks to a vibrating blade at the top and (2) a transmembrane pressure force at the bottom. Time-resolved in situ small-angle X-ray scattering permitted to probe the dynamical structural organization/orientation of CNCs during the processing. FINDINGS For the first time, a typical three-layer orthotropic structure that resembles the articular cartilage organization was achieved in one step during the FU/US process: a first layer composed of CNCs having their director aligned parallel to the horizontal membrane surface, a second intermediate isotropic layer, and a third layer of CNCs with their director vertically oriented along the direction of US wave propagation direction.
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Affiliation(s)
- Frédéric Pignon
- Univ. Grenoble Alpes, CNRS, Grenoble INP (Institute of Engineering Univ. Grenoble Alpes), LRP, F-38000 Grenoble, France.
| | - Emilie Guilbert
- Univ. Grenoble Alpes, CNRS, Grenoble INP (Institute of Engineering Univ. Grenoble Alpes), LRP, F-38000 Grenoble, France
| | - Samuel Mandin
- Univ. Grenoble Alpes, CNRS, Grenoble INP (Institute of Engineering Univ. Grenoble Alpes), LRP, F-38000 Grenoble, France
| | - Nicolas Hengl
- Univ. Grenoble Alpes, CNRS, Grenoble INP (Institute of Engineering Univ. Grenoble Alpes), LRP, F-38000 Grenoble, France
| | - Mohamed Karrouch
- Univ. Grenoble Alpes, CNRS, Grenoble INP (Institute of Engineering Univ. Grenoble Alpes), LRP, F-38000 Grenoble, France
| | - Bruno Jean
- Univ. Grenoble Alpes, CNRS, CERMAV, F-38000 Grenoble, France
| | - Jean-Luc Putaux
- Univ. Grenoble Alpes, CNRS, CERMAV, F-38000 Grenoble, France
| | - Thomas Gibaud
- ENSL, CNRS, Laboratoire de Physique, F-69342 Lyon, France
| | - Sebastien Manneville
- ENSL, CNRS, Laboratoire de Physique, F-69342 Lyon, France; Institut Universitaire de France, France
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Metilli L, Ugo H, Chèvremont W, Picard C, Pignon F. Self-supported MOF/cellulose-nanocrystals materials designed from ultrafiltration. SOFT MATTER 2023; 19:8228-8239. [PMID: 37861338 DOI: 10.1039/d3sm00798g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2023]
Abstract
Metal-organic-frameworks (MOFs) are promising materials for addressing critical issues such as petrochemical separation, water purification, energy storage and drug delivery. Their large-scale deployment, however, is hampered by a limited processability due to their powdery nature. Recently, the hybridization of MOFs with biopolymers has emerged as a greener, biocompatible strategy to shape MOFs composites into more processable membranes, films, and porous materials. In this work, cellulose nanocrystals (CNCs) were used in combination with ZIF-8 (a widely used synthetic zeolite) to produce hybrid composites through ultrafiltration. Results showed that small quantities of CNCs (1 to 20 CNC:ZIF-8 volume ratio) were sufficient to form a self-supported, dense deposit with high ZIF-8 loadings. Compared to classical MOF in situ growth strategies, this approach allowed the tuning of the composition of the final nanocomposite by controlling the nature and quantities of particles in the suspension. The fabrication of the deposit was strongly dependent on the physiochemical properties of the suspension, which were fully characterized with a set of complementary techniques, including in situ SAXS. This technique was employed to investigate the filtration process, which exhibited a homogeneous deposition of ZIF-8 particles mediated by CNC self-assembly. Finally, the available pore volume and integrity of the internal porosity of ZIF-8 were characterized by water porosimetry, demonstrating that the presence of CNCs did not alter the properties of the supported ZIF-8.
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Affiliation(s)
- Lorenzo Metilli
- University Grenoble Alpes, CNRS, Grenoble INP (Institute of Engineering Univ. Grenoble Alpes), LRP, Grenoble F-38000, France.
| | - Héloïse Ugo
- Univ. Grenoble Alpes, CNRS, LIPhy, 38000 Grenoble, France
| | | | - Cyril Picard
- Univ. Grenoble Alpes, CNRS, LIPhy, 38000 Grenoble, France
| | - Frédéric Pignon
- University Grenoble Alpes, CNRS, Grenoble INP (Institute of Engineering Univ. Grenoble Alpes), LRP, Grenoble F-38000, France.
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Pignon F, Challamel M, De Geyer A, Elchamaa M, Semeraro EF, Hengl N, Jean B, Putaux JL, Gicquel E, Bras J, Prevost S, Sztucki M, Narayanan T, Djeridi H. Breakdown and buildup mechanisms of cellulose nanocrystal suspensions under shear and upon relaxation probed by SAXS and SALS. Carbohydr Polym 2021; 260:117751. [DOI: 10.1016/j.carbpol.2021.117751] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 01/27/2021] [Accepted: 01/29/2021] [Indexed: 11/27/2022]
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Prévost S, Krickl S, Marčelja S, Kunz W, Zemb T, Grillo I. Spontaneous Ouzo Emulsions Coexist with Pre-Ouzo Ultraflexible Microemulsions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:3817-3827. [PMID: 33724851 DOI: 10.1021/acs.langmuir.0c02935] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Even in the absence of surfactants, polymers, or particles, spontaneous emulsions produced by dilution with water can be stable over days. This "Ouzo effect" used by the industry is obtained by rapid dilution from an identified "pre-Ouzo" domain of composition where weak aggregates are present: nanometer-sized clusters covered by a surface layer enriched in a hydrotrope such as ethanol. In these systems, Ostwald ripening is not an effective destabilizing mechanism. Using in situ autodilution small-angle X-ray scattering (SAXS), we follow the morphological transitions occurring in a ternary mixture of water/n-octanol/ethanol throughout the monophasic and biphasic regions. This allows for the first time an online characterization of the multiscale coexisting microstructures. Small-angle neutron scattering (SANS) profiles on metastable emulsions as well as phase-separated samples complete the SAXS data, taking advantage of contrast variation via isotopic substitution. After crossing the phase boundary into the two-phase region, coexisting phases are both ternary solutions structured at the nanometer scale when the emulsion is stable. The transition from single phase to two phases is asymmetric around the plait point. When the initial concentration of the hydrotrope is below the minimum hydrotrope concentration (MHC), emulsification failure occurs, i.e., emulsions cream within seconds. Beyond MHC, the low interfacial tension between coexisting ternary fluids results in a Laplace pressure below 100 Pa, explaining the puzzling resilience of spontaneous emulsion to the universal mechanism of Ostwald ripening.
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Affiliation(s)
- Sylvain Prévost
- Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, France
| | - Sebastian Krickl
- Institute of Physical and Theoretical Chemistry, University of Regensburg, 93053 Regensburg, Germany
| | - Stjepan Marčelja
- Department of Applied Mathematics, Research School of Physics & Engineering, Australian National University, Canberra, ACT 2601, Australia
| | - Werner Kunz
- Institute of Physical and Theoretical Chemistry, University of Regensburg, 93053 Regensburg, Germany
| | - Thomas Zemb
- Institut de Chimie Séparative de Marcoule, CEA, CNRS, ENSCM, Univ Montpellier, 30207 Marcoule, France
| | - Isabelle Grillo
- Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, France
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Rezaeyan A, Pipich V, Busch A. MATSAS: a small-angle scattering computing tool for porous systems. J Appl Crystallogr 2021; 54:697-706. [PMID: 33953661 PMCID: PMC8056760 DOI: 10.1107/s1600576721000674] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 01/20/2021] [Indexed: 11/26/2022] Open
Abstract
MATSAS analyses X-ray and neutron small-angle scattering data obtained from porous systems. MATSAS delivers a full suite of pore characterizations, including specific surface area, porosity, pore size distribution and fractal dimensions. MATSAS is a script-based MATLAB program for analysis of X-ray and neutron small-angle scattering (SAS) data obtained from various facilities. The program has primarily been developed for sedimentary rock samples but is equally applicable to other porous media. MATSAS imports raw SAS data from .xls(x) or .csv files, combines small-angle and very small angle scattering data, subtracts the sample background, and displays the processed scattering curves in log–log plots. MATSAS uses the polydisperse spherical (PDSP) model to obtain structural information on the scatterers (scattering objects); for a porous system, the results include specific surface area (SSA), porosity (Φ), and differential and logarithmic differential pore area/volume distributions. In addition, pore and surface fractal dimensions (Dp and Ds, respectively) are obtained from the scattering profiles. The program package allows simultaneous and rapid analysis of a batch of samples, and the results are then exported to .xlsx and .csv files with separate spreadsheets for individual samples. MATSAS is the first SAS program that delivers a full suite of pore characterizations for sedimentary rocks. MATSAS is an open-source package and is freely available at GitHub (https://github.com/matsas-software/MATSAS).
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Affiliation(s)
- Amirsaman Rezaeyan
- Lyell Centre, Institute of GeoEnergy Engineering, Heriot-Watt University, Research Avenue South, Edinburgh EH14 4AS, United Kingdom
| | - Vitaliy Pipich
- Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS), Lichtenbergstrasse 1, Garching 85748, Germany
| | - Andreas Busch
- Lyell Centre, Institute of GeoEnergy Engineering, Heriot-Watt University, Research Avenue South, Edinburgh EH14 4AS, United Kingdom
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Contrast variation of micelles composed of Ca2+ and block copolymers of two negatively charged polyelectrolytes. Colloid Polym Sci 2020. [DOI: 10.1007/s00396-019-04596-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
AbstractBlock copolymers were prepared with two anionic polyelectrolyte blocks: sodium polyacrylate (PA) and sodium polystyrene sulfonate (PSS), in order to investigate their phase behavior in aqueous solution in the presence of Ca2+ cations. Depending on the concentration of polymer and Ca2+ and on the ratio of the block lengths in the copolymer, spherical micelles were observed. Micelle formation arises from the specific interaction of Ca2+ with the PA block only. An extensive small-angle scattering study was performed in order to unravel the structure and dimensions of the block copolymer micelles. Deuteration of the PA block enabled us to perform contrast variation experiments using small-angle neutron scattering at variable ratios of light and heavy water which were combined with information from small-angle X-ray scattering and dynamic light scattering.
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Del Sorbo GR, Prévost S, Schneck E, Gradzielski M, Hoffmann I. On the Mechanism of Shear-Thinning in Viscous Oppositely Charged Polyelectrolyte Surfactant Complexes (PESCs). J Phys Chem B 2020; 124:909-913. [PMID: 31935087 DOI: 10.1021/acs.jpcb.9b10467] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Semidilute mixtures of the cationically modified cellulose-based polyelectrolyte JR 400 and the anionic surfactant sodium dodecyl sulfate (SDS) form highly viscous solutions if a slight excess of charges from the polyelectrolyte is present. The reason for this is the formation of mixed rodlike aggregates in which the surfactant cross-links several polyelectrolyte chains. The same solutions also show shear-thinning behavior. In this paper, we use rheoSANS to investigate the structural evolution of the rodlike aggregates under steady shear and thereby elucidate the mechanism of shear-thinning in these viscous oppositely charged polyelectrolyte surfactant complexes.
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Affiliation(s)
- Giuseppe Rosario Del Sorbo
- Max Planck Institute of Colloids and Interfaces , Am Mühlenberg 1 , 14476 Potsdam , Germany.,Institut Max von Laue-Paul Langevin (ILL) , 71 avenue des Martyrs, CS 20156 , F-38042 Grenoble Cedex 9, France
| | - Sylvain Prévost
- Institut Max von Laue-Paul Langevin (ILL) , 71 avenue des Martyrs, CS 20156 , F-38042 Grenoble Cedex 9, France
| | - Emanuel Schneck
- Max Planck Institute of Colloids and Interfaces , Am Mühlenberg 1 , 14476 Potsdam , Germany.,Soft Matter Biophysics, Department of Physics , TU Darmstadt , Hochschulstraße 8 , D-64289 Darmstadt , Germany
| | - 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
| | - Ingo Hoffmann
- Institut Max von Laue-Paul Langevin (ILL) , 71 avenue des Martyrs, CS 20156 , F-38042 Grenoble Cedex 9, France
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9
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Semeraro EF, Hengl N, Karrouch M, Michot LJ, Paineau E, Jean B, Putaux JL, Lancelon-Pin C, Sharpnack L, Pignon F. Layered organization of anisometric cellulose nanocrystals and beidellite clay particles accumulated near the membrane surface during cross-flow ultrafiltration: In situ SAXS and ex situ SEM/WAXD characterization. Colloids Surf A Physicochem Eng Asp 2020. [DOI: 10.1016/j.colsurfa.2019.124030] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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10
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Carl N, Prévost S, Schweins R, Houston JE, Morfin I, Huber K. Invertible Micelles Based on Ion-Specific Interactions of Sr 2+ and Ba 2+ with Double Anionic Block Copolyelectrolytes. Macromolecules 2019. [DOI: 10.1021/acs.macromol.9b01924] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Nico Carl
- Large Scale Structures Group, DS, Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20 156, 38042 Grenoble, France
- Chemistry Departement, University of Paderborn, Warburger Str. 100, 33098 Paderborn, North Rhine-Westphalia, Germany
| | - Sylvain Prévost
- Large Scale Structures Group, DS, Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20 156, 38042 Grenoble, France
| | - Ralf Schweins
- Large Scale Structures Group, DS, Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20 156, 38042 Grenoble, France
| | - Judith E. Houston
- Jülich Centre for Neutron Science, Forschungszentrum Jülich GmbH, 85747 Garching, Bavaria, Germany
| | | | - Klaus Huber
- Chemistry Departement, University of Paderborn, Warburger Str. 100, 33098 Paderborn, North Rhine-Westphalia, Germany
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A Small-Angle Neutron Scattering Environment for In-Situ Observation of Chemical Processes. Sci Rep 2018; 8:7299. [PMID: 29740024 PMCID: PMC5940810 DOI: 10.1038/s41598-018-24718-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 04/03/2018] [Indexed: 12/18/2022] Open
Abstract
A new sample environment for the observation of ongoing chemical reactions is introduced for small-angle neutron scattering (SANS) experiments which enables structural changes to be followed continuously across a wide Q-range in response to changes in the chemical environment. The approach is demonstrated and validated by performing single and multiple potentiometric titrations on an aqueous anionic surfactant solution (oligo-oxyethylene alkylether carboxylic acid in D2O) with addition times varying from 1 s to 2 h. It is shown that the continuous flow set-up offers considerable advantages over classical ‘static’ measurements with regards to sample throughput, compositional precision and the ability to observe fast structural transitions. Finally, the capabilities and ongoing optimisation of the sample environment are discussed with reference to potential applications in the fields of biology, colloidal systems and complex soft matter.
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12
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Buchold P, Schweins R, Di Z, Gradzielski M. Structural behaviour of sodium hyaluronate in concentrated oppositely charged surfactant solutions. SOFT MATTER 2017; 13:2253-2263. [PMID: 28261739 DOI: 10.1039/c6sm02742c] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
This work discusses the polyelectrolyte sodium hyaluronate (HA) and its polyelectrolyte/surfactant complexes (PESCs) with tetradecyltrimethylammonium bromide (TTAB) in the semi-dilute regime of HA and at high concentrations of TTAB. The structure and flow properties in the surfactant excess region were studied by light scattering and small angle neutron scattering (SANS) as well as by rheology. The unique behaviour of HA to maintain its high viscosity was observed even at very high TTAB concentrations of 496 mM and this effect was systematically studied in the concentration range from 1 to 25 mM HA. From the data, it could be concluded that: (1) extended rod-like structures of the PESCs prevent molecular dissolution of HA by TTAB. (2) HA and TTAB micelles interact rather weakly as seen by a low fraction of bound micelles. (3) At very high TTAB concentrations a decompaction of PESCs (fractal dimension Df going from 2.0 to 1.2) occurs with increasing HA concentration but (4) both the entanglement of HA and the structure of the micelles are not affected.
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Affiliation(s)
- Philipp Buchold
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin, D-10623 Berlin, Germany. and Institut Laue-Langevin (ILL), DS/LSS, 71 Avenue des Martyrs, CS 20 156, F-38042 Grenoble CEDEX 9, France
| | - Ralf Schweins
- Institut Laue-Langevin (ILL), DS/LSS, 71 Avenue des Martyrs, CS 20 156, F-38042 Grenoble CEDEX 9, France
| | - Zhenyu Di
- Jülich Centre for Neutron Science JCNS, Forschungszentrum Jülich GmbH, Outstation at MLZ, Lichtenbergstrasse 1, 85747 Garching, Germany
| | - Michael Gradzielski
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin, D-10623 Berlin, Germany.
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13
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Carl N, Prévost S, Fitzgerald JPS, Karg M. Salt-induced cluster formation of gold nanoparticles followed by stopped-flow SAXS, DLS and extinction spectroscopy. Phys Chem Chem Phys 2017; 19:16348-16357. [DOI: 10.1039/c7cp01807j] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The salt-induced cluster formation of negatively charged gold nanoparticles was studied by time-resolved DLS, stopped-flow SAXS and in-situ extinction spectroscopy.
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Affiliation(s)
- Nico Carl
- Physical Chemistry I
- University of Bayreuth
- 95447 Bayreuth
- Germany
| | - Sylvain Prévost
- ESRF-The European Synchrotron
- CS40220
- 38043 Grenoble Cedex 9
- France
| | | | - Matthias Karg
- Physical Chemistry I
- University of Bayreuth
- 95447 Bayreuth
- Germany
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14
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Prevost S, Lopian T, Pleines M, Diat O, Zemb T. Small-angle scattering and morphologies of ultra-flexible microemulsions. J Appl Crystallogr 2016; 49:2063-2072. [PMID: 27980512 PMCID: PMC5139994 DOI: 10.1107/s1600576716016150] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 10/11/2016] [Indexed: 11/23/2022] Open
Abstract
Three-component fluids can exhibit structured density fluctuations, and their small-angle scattering patterns present similarities to those of classical microemulsions. One general analytical expression with two additive contributions (one for the two immiscible fluids and a smaller one for a structured fluid) allows the whole phase diagram to be mapped in the single-phase domain. The phase diagrams of ternary mixtures of partly miscible solvents containing a hydrotropic co-solvent exhibit a variable miscibility gap and one critical point. This work investigates the entire monophasic region far from and near to the miscibility gap in octan-1-ol/ethanol/water, for which ultra-flexible microemulsions (UFMEs) are observed by small-angle scattering techniques. SWAXS (combined small- and wide-angle X-ray scattering) allows the elucidation of these types of structure. Three distinct areas can be identified in the phase diagram, with scattering data resembling those from direct, bicontinuous and reverse local structures. These UFMEs are far more polydisperse than their surfactant-based counterparts. Water-rich and solvent-rich domains are only delimited by a small excess of hydrotrope, instead of a well defined surfactant layer of fixed area per molecule. It is shown that all scattering spectra obtained for the nanostructured compositions can be modelled by a simple unified analytical model composed of two uncorrelated contributions. The main one is the Ornstein–Zernike formula for composition fluctuations which gives information about the pseudo-phase domain size. The second is a Lorentzian that captures the structure of at least one of the coexisting pseudo-phases. No Porod law can be measured in the SAXS domain. The proposed expression gives access to two characteristic sizes as well as one inter-aggregate distance.
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Affiliation(s)
- Sylvain Prevost
- ESRF - The European Synchrotron, 71 avenue des Martyrs, 38000 Grenoble, France
| | - Tobias Lopian
- Institut de Chimie Séparative de Marcoule (ICSM), UMR 5257 (CEA/CNRS/UM2/ENCSM), 30207 Bagnols-sur-Cèze, France; Institute of Physical and Theoretical Chemistry, University of Regensburg, 93040 Regensburg, Germany
| | - Maximilian Pleines
- Institut de Chimie Séparative de Marcoule (ICSM), UMR 5257 (CEA/CNRS/UM2/ENCSM), 30207 Bagnols-sur-Cèze, France; Institute of Physical and Theoretical Chemistry, University of Regensburg, 93040 Regensburg, Germany
| | - Olivier Diat
- Institut de Chimie Séparative de Marcoule (ICSM), UMR 5257 (CEA/CNRS/UM2/ENCSM), 30207 Bagnols-sur-Cèze, France
| | - Thomas Zemb
- Institut de Chimie Séparative de Marcoule (ICSM), UMR 5257 (CEA/CNRS/UM2/ENCSM), 30207 Bagnols-sur-Cèze, France
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Gurnon AK, Lopez-Barron CR, Eberle APR, Porcar L, Wagner NJ. Spatiotemporal stress and structure evolution in dynamically sheared polymer-like micellar solutions. SOFT MATTER 2014; 10:2889-2898. [PMID: 24668232 DOI: 10.1039/c3sm53113a] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The complex, nonlinear flow behavior of soft materials transcends industrial applications, smart material design and non-equilibrium thermodynamics. A long-standing, fundamental challenge in soft-matter science is establishing a quantitative connection between the deformation field, local microstructure and macroscopic dynamic flow properties i.e., the rheology. Here, a new experimental method is developed using simultaneous small angle neutron scattering (SANS) and nonlinear oscillatory shear rheometry to investigate the spatiotemporal microstructure evolution of a polymer-like micellar (PLM) solution. We demonstrate the novelty of nonlinear oscillatory shear experimental methods to create and interrogate metastable material states. These include a precursory state to the shear banded condition as well as a disentangled, low viscosity state with an inhomogeneous supra-molecular microstructure flowing at high shear rates. This new experimental evidence provides insight into the complexities of the shear banding phenomenon often observed in sheared complex fluids and provides valuable data for quantitatively testing non-equilibrium theory.
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Affiliation(s)
- A Kate Gurnon
- Center for Neutron Science, Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE, USA.
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