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Papadakis CM, Niebuur BJ, Schulte A. Thermoresponsive Polymers under Pressure with a Focus on Poly( N-isopropylacrylamide) (PNIPAM). LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:1-20. [PMID: 38149782 DOI: 10.1021/acs.langmuir.3c02398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2023]
Abstract
Pressure is a key variable in the phase behavior of responsive polymers, both for applications and from a fundamental point of view. In this feature article, we review recent developments, particularly applications of neutron techniques such as small-angle neutron scattering (SANS) and quasi-elastic neutron scattering (QENS), across the temperature-pressure phase diagram. These are complemented by kinetic SANS experiments following pressure jumps. In the prototype system poly(N-isopropylacrylamide) (PNIPAM), QENS revealed the pressure-dependent characteristics of hydration water around the lower critical solution temperature transition. The size, water content, and inner structure of the mesoglobules formed in the two-phase region depend strongly on pressure, as shown by SANS. Beside these changes at the phase transition, the mesoglobule formation at low pressure is determined by kinetic factors, namely the formation of a polymer-rich, rigid shell, which hampers further growth by coalescence. At high pressure, in contrast, the growth proceeds by diffusion-limited coalescence without any kinetic hindrance. The disintegration of the mesoglobules evolves either via chain release from their surface or via swelling, depending on the osmotic pressure of the water. Moreover, we report on the profound influence of pressure on the cononsolvency effect. In the temperature-pressure frame, the one-phase region is hugely expanded upon the addition of the cosolvent methanol. SANS experiments unveil the enthalpic and entropic contributions to the effective Flory-Huggins interaction parameter between the segments and the solvent mixture. QENS experiments demonstrate an increase in polymer associated water with pressure, whereas methanol is released. Correspondingly, the solvent phase becomes enriched in methanol, providing a mechanism for the breakdown of cononsolvency at a high pressure. Finally, we outline future opportunities for high-pressure studies of thermoresponsive polymers, with a focus on neutron methods.
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Affiliation(s)
- Christine M Papadakis
- TUM School of Natural Sciences, Physics Department, Soft Matter Physics Group, Technical University of Munich, James-Franck-Str. 1, 85748 Garching, Germany
| | - Bart-Jan Niebuur
- TUM School of Natural Sciences, Physics Department, Soft Matter Physics Group, Technical University of Munich, James-Franck-Str. 1, 85748 Garching, Germany
| | - Alfons Schulte
- Department of Physics and College of Optics and Photonics, University of Central Florida, 4111 Libra Drive, Orlando, Florida 32816-2385, United States
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2
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Mukherji D, Kremer K. Smart Polymers for Soft Materials: From Solution Processing to Organic Solids. Polymers (Basel) 2023; 15:3229. [PMID: 37571124 PMCID: PMC10421237 DOI: 10.3390/polym15153229] [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: 07/05/2023] [Revised: 07/26/2023] [Accepted: 07/27/2023] [Indexed: 08/13/2023] Open
Abstract
Polymeric materials are ubiquitous in our everyday life, where they find a broad range of uses-spanning across common household items to advanced materials for modern technologies. In the context of the latter, so called "smart polymers" have received a lot of attention. These systems are soluble in water below their lower critical solution temperature Tℓ and often exhibit counterintuitive solvation behavior in mixed solvents. A polymer is known as smart-responsive when a slight change in external stimuli can significantly change its structure, functionm and stability. The interplay of different interactions, especially hydrogen bonds, can also be used for the design of lightweight high-performance organic solids with tunable properties. Here, a general scheme for establishing a structure-property relationship is a challenge using the conventional simulation techniques and also in standard experiments. From the theoretical side, a broad range of all-atom, multiscale, generic, and analytical techniques have been developed linking monomer level interaction details with macroscopic material properties. In this review, we briefly summarize the recent developments in the field of smart polymers, together with complementary experiments. For this purpose, we will specifically discuss the following: (1) the solution processing of responsive polymers and (2) their use in organic solids, with a goal to provide a microscopic understanding that may be used as a guiding tool for future experiments and/or simulations regarding designing advanced functional materials.
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Affiliation(s)
- Debashish Mukherji
- Quantum Matter Institute, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Kurt Kremer
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany;
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3
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Henschel C, Schanzenbach D, Laschewsky A, Ko CH, Papadakis CM, Müller-Buschbaum P. Thermoresponsive and co-nonsolvency behavior of poly(N-vinyl isobutyramide) and poly(N-isopropyl methacrylamide) as poly(N-isopropyl acrylamide) analogs in aqueous media. Colloid Polym Sci 2023. [DOI: 10.1007/s00396-023-05083-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
Abstract
Abstract
Sets of the nonionic polymers poly(N-vinyl isobutyramide) (pNVIBAm) and poly(N-isopropyl methacrylamide) (pNIPMAm) are synthesized by radical polymerization covering the molar mass range from about 20,000 to 150,000 kg mol−1, and their thermoresponsive and solvent-responsive behaviors in aqueous solution are studied. Both polymers feature a lower critical solution temperature (LCST) apparently of the rare so-called type II, as characteristic for their well-studied analogue poly(N-isopropyl acrylamide) (pNIPAm). Moreover, in analogy to pNIPAm, both polymers exhibit co-nonsolvency behavior in mixtures of water with several co-solvents, including short-chain alcohols as well as a range of polar aprotic solvents. While the cloud points of the aqueous solutions are a few degrees higher than those for pNIPAm and increase in the order pNIPAm < pNVIBAm < pNIPMAm, the co-nonsolvency behavior becomes less pronounced in the order pNIPAm > pNVIBAm > pNIPMAm. Exceptionally, pNIPMAm does not show co-nonsolvency in mixtures of water and N,N-dimethylformamide.
Graphical Abstract
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4
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Xiang J, Hao C, Pan Q, Li Z, Ma Q. Investigation on the aggregation structure of poly(1-vinyl-2-pyrrolidone) concentrated solution in mixed solvents of water/N,N-dimethylformamide. Colloid Polym Sci 2023. [DOI: 10.1007/s00396-023-05057-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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5
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Zhang P, Wang Z, Wang ZG. Conformation Transition of a Homopolymer Chain in Binary Mixed Solvents. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c01896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Pengfei Zhang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Center for Advanced Low-Dimension Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620, China
| | - Zheng Wang
- School of Physics, Nankai University, Tianjin 300071, China
| | - Zhen-Gang Wang
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
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6
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Yong H, Sommer JU. Cononsolvency Effect: When the Hydrogen Bonding between a Polymer and a Cosolvent Matters. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c01428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Huaisong Yong
- School of New Energy and Materials, Southwest Petroleum University, 610500Chengdu, China
- Sichuan Engineering Technology Research Center of Basalt Fiber Composites Development and Application, Southwest Petroleum University, 610500Chengdu, China
- Institute Theory of Polymers, Leibniz-Institut für Polymerforschung Dresden e.V., D-01069Dresden, Germany
| | - Jens-Uwe Sommer
- Institute Theory of Polymers, Leibniz-Institut für Polymerforschung Dresden e.V., D-01069Dresden, Germany
- Institute for Theoretical Physics, Technische Universität Dresden, D-01069Dresden, Germany
- Cluster of Excellence Physics of Life, Technische Universität Dresden, D-01307Dresden, Germany
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7
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Glišić I, Ritsema van Eck GC, Smook LA, de Beer S. Enhanced vapor sorption in block and random copolymer brushes. SOFT MATTER 2022; 18:8398-8405. [PMID: 36259991 PMCID: PMC9667471 DOI: 10.1039/d2sm00868h] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 10/05/2022] [Indexed: 06/16/2023]
Abstract
Polymer brushes in gaseous environments absorb and adsorb vapors of favorable solvents, which makes them potentially relevant for sensing applications and separation technologies. Though significant amounts of vapor are sorbed in homopolymer brushes at high vapor pressures, at low vapor pressures sorption remains limited. In this work, we vary the structure of two-component polymer brushes and investigate the enhancement in vapor sorption at different relative vapor pressures compared to homopolymer brushes. We perform molecular dynamics simulations on two-component block and random copolymer brushes and investigate the influence of monomer miscibility and formation of high-energy interfaces between immiscible monomers on vapor sorption. Additionally, we present absorption isotherms of pure homopolymer, mixed binary brush and 2-block, 4-block, and random copolymer brushes. Based on these isotherms, we finally show that random copolymer brushes absorb more vapor than any other architecture investigated thus far. Random brushes display enhanced sorption at both high and low vapor pressures, with the largest enhancement in sorption at low vapor pressures.
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Affiliation(s)
- Ivona Glišić
- Sustainable Polymer Chemistry Group, Department of Molecules & Materials, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
| | - Guido C Ritsema van Eck
- Sustainable Polymer Chemistry Group, Department of Molecules & Materials, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
| | - Leon A Smook
- Sustainable Polymer Chemistry Group, Department of Molecules & Materials, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
| | - Sissi de Beer
- Sustainable Polymer Chemistry Group, Department of Molecules & Materials, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
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8
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Mohammadyarloo Z, Sommer JU. Co-nonsolvency Transition in Polymer Solutions: A Simulation Study. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c01280] [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)
- Zahra Mohammadyarloo
- Leibniz-Institute fur Polymerforschung Dresden, Institute Theory of Polymers, Hohe Strasse 6, 01069Dresden, Germany
- Institute for Theoretical Physics, TU Dresden, Zellescher Weg 17, 01069Dresden, Germany
| | - Jens-Uwe Sommer
- Leibniz-Institute fur Polymerforschung Dresden, Institute Theory of Polymers, Hohe Strasse 6, 01069Dresden, Germany
- Institute for Theoretical Physics, TU Dresden, Zellescher Weg 17, 01069Dresden, Germany
- Cluster of Excellence Physics of Life, TU Dresden, 01307Dresden, Germany
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9
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Ritsema van Eck G, Chiappisi L, de Beer S. Fundamentals and Applications of Polymer Brushes in Air. ACS APPLIED POLYMER MATERIALS 2022; 4:3062-3087. [PMID: 35601464 PMCID: PMC9112284 DOI: 10.1021/acsapm.1c01615] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 01/03/2022] [Indexed: 05/22/2023]
Abstract
For several decades, high-density, end-tethered polymers, forming so-called polymer brushes, have inspired scientists to understand their properties and to translate them to applications. While earlier research focused on polymer brushes in liquids, it was recently recognized that these brushes can find application in air as well. In this review, we report on recent progress in unraveling fundamental concepts of brushes in air, such as their vapor-swelling and solvent partitioning. Moreover, we provide an overview of the plethora of applications in air (e.g., in sensing, separations or smart adhesives) where brushes can be key components. To conclude, we provide an outlook by identifying open questions and issues that, when solved, will pave the way for the large scale application of brushes in air.
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Affiliation(s)
- Guido
C. Ritsema van Eck
- Sustainable
Polymer Chemistry Group, Department of Molecules & Materials,
MESA+ Institute for Nanotechnology, University
of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Leonardo Chiappisi
- Institut
Max von Laue - Paul Langevin, 71 avenue des Martyrs, 38042 Grenoble, France
| | - Sissi de Beer
- Sustainable
Polymer Chemistry Group, Department of Molecules & Materials,
MESA+ Institute for Nanotechnology, University
of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
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10
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Bharadwaj S, Niebuur BJ, Nothdurft K, Richtering W, van der Vegt NFA, Papadakis CM. Cononsolvency of thermoresponsive polymers: where we are now and where we are going. SOFT MATTER 2022; 18:2884-2909. [PMID: 35311857 DOI: 10.1039/d2sm00146b] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Cononsolvency is an intriguing phenomenon where a polymer collapses in a mixture of good solvents. This cosolvent-induced modulation of the polymer solubility has been observed in solutions of several polymers and biomacromolecules, and finds application in areas such as hydrogel actuators, drug delivery, compound detection and catalysis. In the past decade, there has been a renewed interest in understanding the molecular mechanisms which drive cononsolvency with a predominant emphasis on its connection to the preferential adsorption of the cosolvent. Significant efforts have also been made to understand cononsolvency in complex systems such as micelles, block copolymers and thin films. In this review, we will discuss some of the recent developments from the experimental, simulation and theoretical fronts, and provide an outlook on the problems and challenges which are yet to be addressed.
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Affiliation(s)
- Swaminath Bharadwaj
- Technical University of Darmstadt, Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Computational Physical Chemistry Group, 64287 Darmstadt, Germany.
| | - Bart-Jan Niebuur
- Technical University of Munich, Physics Department, Soft Matter Physics Group, James-Franck-Str. 1, 85748 Garching, Germany
| | - Katja Nothdurft
- RWTH Aachen University, Institut für Physikalische Chemie, Landoltweg 2, 52056 Aachen, Germany, European Union
| | - Walter Richtering
- RWTH Aachen University, Institut für Physikalische Chemie, Landoltweg 2, 52056 Aachen, Germany, European Union
| | - Nico F A van der Vegt
- Technical University of Darmstadt, Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Computational Physical Chemistry Group, 64287 Darmstadt, Germany.
| | - Christine M Papadakis
- Technical University of Munich, Physics Department, Soft Matter Physics Group, James-Franck-Str. 1, 85748 Garching, Germany
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11
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Wang L, Liu F, Qian J, Wu Z, Xiao R. Multi-responsive PNIPAM-PEGDA hydrogel composite. SOFT MATTER 2021; 17:10421-10427. [PMID: 34605528 DOI: 10.1039/d1sm01178b] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Hydrogels are widely used in applications such as soft robots and flexible sensors due to their sensitivity to environmental stimuli. It is highly demanded to develop multiple-responsive hydrogel structures. In this work, we employ the 3D printing technique to fabricate a PNIPAM-PEGDA hydrogel bilayer that can change shape through controlling the temperature, solvent mixture and magnetic field. The PNIPAM gel is a typical thermo-responsive gel, showing a decrease in swelling ratio with increasing temperature. Meanwhile, the PNIPAM gels also exhibit the cononsolvency effect in ethanol-water mixtures with a smaller swelling ratio in the mixture compared with that in each pure solvent. In comparison, the swelling ratio of PEGDA gels is insensitive to changes in both the temperature and solvent composition. Thus, the bilayer structure of PNIPAM-PEGDA can bend in different directions and with different angles with changing the temperature and solvent composition. Finally, Fe3O4 nanoparticles are incorporated into the matrix of PEGDA gels, endowing the whole structure with deformation and motion in response to an external magnetic field.
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Affiliation(s)
- Liqian Wang
- State Key Laboratory of Fluid Power & Mechatronic System, Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province, Department of Engineering Mechanics, Zhejiang University, Hangzhou 310027, China.
| | - Fengrui Liu
- State Key Laboratory of Fluid Power & Mechatronic System, Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province, Department of Engineering Mechanics, Zhejiang University, Hangzhou 310027, China.
| | - Jin Qian
- State Key Laboratory of Fluid Power & Mechatronic System, Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province, Department of Engineering Mechanics, Zhejiang University, Hangzhou 310027, China.
| | - Ziliang Wu
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Rui Xiao
- State Key Laboratory of Fluid Power & Mechatronic System, Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province, Department of Engineering Mechanics, Zhejiang University, Hangzhou 310027, China.
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12
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Zhu PW. Effects of cosolvent partitioning on conformational transitions and tethered chain flexibility in spherical polymer brushes. SOFT MATTER 2021; 17:6817-6832. [PMID: 34223603 DOI: 10.1039/d1sm00523e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In this work, based on the framework of preferential adsorption concept and analytical self-consistent field (SCF) theory, a model is proposed to investigate the reentrant transition experimentally observed from the thermoresponsive spherical brush in a series of aqueous alcohol solutions. The interaction between monomers is incorporated into the model. Conformational transitions of the spherical brush are quantitatively correlated to the physical parameters, including the number of adsorbed cosolvents which facilitates the solvent quality, the number of cosolvent bridges which drives the brush collapse, as well as their partition coefficients between the brush and the bulk solution. An analytical formula for the number of Kuhn segments per tethered chain is obtained based on the analytical SCF theory, which elucidates the flexibility of tethered chains in the intricate system of multicomponents involving the conformational transitions. Under the experimental conditions associated with the cosolvent-brush interaction, the variation of the monomer chemical potential with the monomer concentration indicates that the monomer distribution of the spherical brush remains continuous. The analysis based on the SFC theory also reveals that the distribution of adsorbed cosolvents is a positive parabola while the distribution of cosolvent bridges appears to be an exponential decay function, implying that the intervening space between tethered chains, rather than the number of adsorbed cosolvents, plays a crucial role in forming the cosolvent bridge. We demonstrate that the model formulated for the reentrant transition under weaker cosolvent-brush interactions provides guidelines for the one under stronger nanoparticle-brush interactions.
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Affiliation(s)
- Peng Wei Zhu
- Department of Materials Science and Engineering, Monash University, Clayton, VIC 3800, Australia.
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13
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Yong H, Molcrette B, Sperling M, Montel F, Sommer JU. Regulating the Translocation of DNA through Poly( N-isopropylacrylamide)-Decorated Switchable Nanopores by Cononsolvency Effect. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c00215] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Huaisong Yong
- Leibniz-Institut für Polymerforschung Dresden e.V., Dresden 01069, Germany
- Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Dresden 01069, Germany
| | - Bastien Molcrette
- Université de Lyon, École Normale Supérieure de Lyon, Université Claude Bernard, CNRS, Laboratoire de Physique, Lyon F-69342, France
| | - Marcel Sperling
- Fraunhofer-Institut für Angewandte Polymerforschung, Potsdam-Golm 14476, Germany
| | - Fabien Montel
- Université de Lyon, École Normale Supérieure de Lyon, Université Claude Bernard, CNRS, Laboratoire de Physique, Lyon F-69342, France
| | - Jens-Uwe Sommer
- Leibniz-Institut für Polymerforschung Dresden e.V., Dresden 01069, Germany
- Institute for Theoretical Physics, Technische Universität Dresden, Dresden 01069, Germany
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14
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Niebuur BJ, Lohstroh W, Ko CH, Appavou MS, Schulte A, Papadakis CM. Pressure Dependence of Water Dynamics in Concentrated Aqueous Poly( N-isopropylacrylamide) Solutions with a Methanol Cosolvent. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c00111] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Bart-Jan Niebuur
- Physik-Department, Fachgebiet Physik weicher Materie, Technische Universität München, James-Franck-Str. 1, 85748 Garching, Germany
| | - Wiebke Lohstroh
- Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Lichtenbergstr. 1, 85748 Garching, Germany
| | - Chia-Hsin Ko
- Physik-Department, Fachgebiet Physik weicher Materie, Technische Universität München, James-Franck-Str. 1, 85748 Garching, Germany
| | - Marie-Sousai Appavou
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, 85748 Garching, Germany
| | - Alfons Schulte
- Department of Physics and College of Optics and Photonics, University of Central Florida, 4111 Libra Drive, Orlando, Florida 32816-2385, United States
| | - Christine M. Papadakis
- Physik-Department, Fachgebiet Physik weicher Materie, Technische Universität München, James-Franck-Str. 1, 85748 Garching, Germany
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15
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Bharadwaj S, Nayar D, Dalgicdir C, van der Vegt NFA. An interplay of excluded-volume and polymer-(co)solvent attractive interactions regulates polymer collapse in mixed solvents. J Chem Phys 2021; 154:134903. [PMID: 33832270 DOI: 10.1063/5.0046746] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Cosolvent effects on the coil-globule transitions in aqueous polymer solutions are not well understood, especially in the case of amphiphilic cosolvents that preferentially adsorb on the polymer and lead to both polymer swelling and collapse. Although a predominant focus in the literature has been placed on the role of polymer-cosolvent attractive interactions, our recent work has shown that excluded-volume interactions (repulsive interactions) can drive both preferential adsorption of the cosolvent and polymer collapse via a surfactant-like mechanism. Here, we further study the role of polymer-(co)solvent attractive interactions in two kinds of polymer solutions, namely, good solvent (water)-good cosolvent (alcohol) (GSGC) and poor solvent-good cosolvent (PSGC) solutions, both of which exhibit preferential adsorption of the cosolvent and a non-monotonic change in the polymer radius of gyration with the addition of the cosolvent. Interestingly, at low concentrations, the polymer-(co)solvent energetic interactions oppose polymer collapse in the GSGC solutions and contrarily support polymer collapse in the PSGC solutions, indicating the importance of the underlying polymer chemistry. Even though the alcohol molecules are preferentially adsorbed on the polymer, the trends of the energetic interactions at low cosolvent concentrations are dominated by the polymer-water energetic interactions in both the cases. Therefore, polymer-(co)solvent energetic interactions can either reinforce or compensate the surfactant-like mechanism, and it is this interplay that drives coil-to-globule transitions in polymer solutions. These results have implications for rationalizing the cononsolvency transitions in real systems such as polyacrylamides in aqueous alcohol solutions where the understanding of microscopic driving forces is still debatable.
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Affiliation(s)
- Swaminath Bharadwaj
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Divya Nayar
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Cahit Dalgicdir
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Nico F A van der Vegt
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, 64287 Darmstadt, Germany
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16
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Yu Y, Brió Pérez M, Cao C, de Beer S. Switching (bio-) adhesion and friction in liquid by stimulus responsive polymer coatings. Eur Polym J 2021. [DOI: 10.1016/j.eurpolymj.2021.110298] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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17
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A cosolvent surfactant mechanism affects polymer collapse in miscible good solvents. Commun Chem 2020; 3:165. [PMID: 36703319 PMCID: PMC9814688 DOI: 10.1038/s42004-020-00405-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 10/14/2020] [Indexed: 01/29/2023] Open
Abstract
The coil-globule transition of aqueous polymers is of profound significance in understanding the structure and function of responsive soft matter. In particular, the remarkable effect of amphiphilic cosolvents (e.g., alcohols) that leads to both swelling and collapse of stimuli-responsive polymers has been hotly debated in the literature, often with contradictory mechanisms proposed. Using molecular dynamics simulations, we herein demonstrate that alcohols reduce the free energy cost of creating a repulsive polymer-solvent interface via a surfactant-like mechanism which surprisingly drives polymer collapse at low alcohol concentrations. This hitherto neglected role of interfacial solvation thermodynamics is common to all coil-globule transitions, and rationalizes the experimentally observed effects of higher alcohols and polymer molecular weight on the coil-to-globule transition of thermoresponsive polymers. Polymer-(co)solvent attractive interactions reinforce or compensate this mechanism and it is this interplay which drives polymer swelling or collapse.
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