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Nagasaka M, Kumaki F, Yao Y, Adachi JI, Mochizuki K. Mechanism of poly( N-isopropylacrylamide) cononsolvency in aqueous methanol solutions explored via oxygen K-edge X-ray absorption spectroscopy. Phys Chem Chem Phys 2024; 26:13634-13638. [PMID: 38685819 DOI: 10.1039/d4cp00676c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
The cononsolvency mechanism of poly(N-isopropylacrylamide) (PNIPAM), dissolving in pure methanol (MeOH) and water (H2O) but being insoluble in MeOH-H2O mixtures, was investigated by O K-edge X-ray absorption spectroscopy (XAS). The cononsolvency emerges from the aggregation of PNIPAM with MeOH clusters, leading to the collapse of the hydrophobic hydration of PNIPAM.
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Affiliation(s)
- Masanari Nagasaka
- Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan.
- Molecular Science Program, Graduate Institute for Advanced Studies, SOKENDAI, Myodaiji, Okazaki 444-8585, Japan
| | - Fumitoshi Kumaki
- Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan
| | - Yifeng Yao
- Department of Chemistry, Zhejiang University, Hangzhou, 310028, P. R. China
| | - Jun-Ichi Adachi
- Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan
- Materials Structure Science Program, Graduate Institute for Advanced Studies, SOKENDAI, 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan
| | - Kenji Mochizuki
- Department of Chemistry, Zhejiang University, Hangzhou, 310028, P. R. China
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2
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Keshavarz MH, Shirazi Z, Jafari M, Jannesari F. The use of simple structural parameters of organic compounds to assess their PUF-air partition coefficients. CHEMOSPHERE 2024; 349:140855. [PMID: 38048827 DOI: 10.1016/j.chemosphere.2023.140855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 11/24/2023] [Accepted: 11/28/2023] [Indexed: 12/06/2023]
Abstract
A novel approach is introduced for the reliable prediction of PUF-air partition coefficients of organic compounds, which can determine the environmental fate of organic compounds during interactions with air, soil, and water. The biggest accessible measured data of PUF-air partition coefficients for 170 chemicals are used to develop and test the novel model. In comparison to available quantitative structure-property relationship (QSPR) methods for the prediction of PUF-air partition coefficients that need complex descriptors, the here used descriptors are simpler. The assessed various statistical factors of the simple method containing 147 (training) and 23 (test) organic compounds can verify the external and internal cross-validations. Various statistical parameters confirm the high reliability of the novel model as compared with the outputs of complex multiple linear regression (MLR), artificial neural network (ANN) and support vector machine (SVM) methods. The values of R-squared (R2), and root mean square error (RMSE) of the new model are for training/test sets are 0.924/0.894 and 0.374/0.318, respectively. Meanwhile, R2 and RMSE values for three comparative models training/test sets are (i) MLR: 0.848/0.670 (R2) and 0.531/0.573 (RMSE); (ii) ANN: 0.902/0.664 (R2) and 0.425/0.560 (RMSE); (iii) SVM: 0.935/0.794 (R2) and 0.351/0.419 (RMSE). Thus, the new model the simplest approach with higher reliability in comparison to the best available methods.
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Affiliation(s)
| | - Zeinab Shirazi
- Faculty of Applied Sciences, Malek Ashtar University of Technology, Iran
| | - Mohammad Jafari
- Faculty of Applied Sciences, Malek Ashtar University of Technology, Iran
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3
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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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4
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Tripathi K, Garg H, Rajesh R, Vemparala S. The conformational phase diagram of charged polymers in the presence of attractive bridging crowders. J Chem Phys 2023; 159:204903. [PMID: 38010332 DOI: 10.1063/5.0172696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 11/05/2023] [Indexed: 11/29/2023] Open
Abstract
Using extensive molecular dynamics simulations, we obtain the conformational phase diagram of a charged polymer in the presence of oppositely charged counterions and neutral attractive crowders for monovalent, divalent, and trivalent counterion valencies. We demonstrate that the charged polymer can exist in three phases: (1) an extended phase for low charge densities and weak polymer-crowder attractive interactions [Charged Extended (CE)]; (2) a collapsed phase for high charge densities and weak polymer-crowder attractive interactions, primarily driven by counterion condensation [Charged Collapsed due to Intra-polymer interactions [(CCI)]; and (3) a collapsed phase for strong polymer-crowder attractive interactions, irrespective of the charge density, driven by crowders acting as bridges or cross-links [Charged Collapsed due to Bridging interactions [(CCB)]. Importantly, simulations reveal that the interaction with crowders can induce collapse, despite the presence of strong repulsive electrostatic interactions, and can replace condensed counterions to facilitate a direct transition from the CCI and CE phases to the CCB phase.
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Affiliation(s)
- Kamal Tripathi
- The Institute of Mathematical Sciences, C.I.T. Campus, Taramani, Chennai 600113, India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India
- Univ. Grenoble Alpes, CNRS, Grenoble INP, 3SR, F-38000 Grenoble, France
| | - Hitesh Garg
- The Institute of Mathematical Sciences, C.I.T. Campus, Taramani, Chennai 600113, India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India
| | - R Rajesh
- The Institute of Mathematical Sciences, C.I.T. Campus, Taramani, Chennai 600113, India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India
| | - Satyavani Vemparala
- The Institute of Mathematical Sciences, C.I.T. Campus, Taramani, Chennai 600113, India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India
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Garg H, Rajesh R, Vemparala S. The conformational phase diagram of neutral polymers in the presence of attractive crowders. J Chem Phys 2023; 158:114903. [PMID: 36948827 DOI: 10.1063/5.0140721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023] Open
Abstract
Extensive coarse-grained molecular dynamics simulations are performed to investigate the conformational phase diagram of a neutral polymer in the presence of attractive crowders. We show that, for low crowder densities, the polymer predominantly shows three phases as a function of both intra-polymer and polymer-crowder interactions: (1) weak intra-polymer and weak polymer-crowder attractive interactions induce extended or coil polymer conformations (phase E), (2) strong intra-polymer and relatively weak polymer-crowder attractive interactions induce collapsed or globular conformations (phase CI), and (3) strong polymer-crowder attractive interactions, regardless of intra-polymer interactions, induce a second collapsed or globular conformation that encloses bridging crowders (phase CB). The detailed phase diagram is obtained by determining the phase boundaries delineating the different phases based on an analysis of the radius of gyration as well as bridging crowders. The dependence of the phase diagram on strength of crowder-crowder attractive interactions and crowder density is clarified. We also show that when the crowder density is increased, a third collapsed phase of the polymer emerges for weak intra-polymer attractive interactions. This crowder density-induced compaction is shown to be enhanced by stronger crowder-crowder attraction and is different from the depletion-induced collapse mechanism, which is primarily driven by repulsive interactions. We also provide a unified explanation of the observed re-entrant swollen/extended conformations of the earlier simulations of weak and strongly self-interacting polymers in terms of crowder-crowder attractive interactions.
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Affiliation(s)
- Hitesh Garg
- The Institute of Mathematical Sciences, C.I.T. Campus, Taramani, Chennai 600113, India
| | - R Rajesh
- The Institute of Mathematical Sciences, C.I.T. Campus, Taramani, Chennai 600113, India
| | - Satyavani Vemparala
- The Institute of Mathematical Sciences, C.I.T. Campus, Taramani, Chennai 600113, India
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6
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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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7
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Schmid F. Understanding and Modeling Polymers: The Challenge of Multiple Scales. ACS POLYMERS AU 2022. [DOI: 10.1021/acspolymersau.2c00049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Friederike Schmid
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 9, 55128Mainz, Germany
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8
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Pérez-Ramírez HA, Moncho-Jordá A, Odriozola G. Phenol release from pNIPAM hydrogels: scaling molecular dynamics simulations with dynamical density functional theory. SOFT MATTER 2022; 18:8271-8284. [PMID: 36278506 DOI: 10.1039/d2sm01083f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
We employed molecular dynamic simulations (MD) and the Bennett's acceptance ratio method to compute the free energy of transfer, ΔGtrans, of phenol, methane, and 5-fluorouracil (5-FU), between bulk water and water-pNIPAM mixtures of different polymer volume fractions, ϕp. For this purpose, we first calculate the solvation free energies in both media to obtain ΔGtrans. Phenol and 5-FU (a medication used to treat cancer) attach to the pNIPAM surface so that they show negative values of ΔGtrans irrespective of temperature (above or below the lower critical solution temperature of pNIPAM, Tc). Conversely, methane switches the ΔGtrans sign when considering temperatures below (positive) and above (negative) Tc. In all cases, and contrasting with some theoretical predictions, ΔGtrans maintains a linear behavior with the pNIPAM concentration up to large polymer densities. We have also employed MD to compute the diffusion coefficient, D, of phenol in water-pNIPAM mixtures as a function of ϕp in the diluted limit. Both ΔGtrans and D as a function of ϕp are required inputs to obtain the release halftime of hollow pNIPAM microgels through Dynamic Density Functional Theory (DDFT). Our scaling strategy captures the experimental value of 2200 s for 50 μm radius microgels with no cavity, for ϕp ≃ 0.83 at 315 K.
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Affiliation(s)
- H A Pérez-Ramírez
- Área de Física de Procesos Irreversibles, División de Ciencias Básicas e Ingeniería, Universidad Autónoma Metropolitana-Azcapotzalco, Avenida San Pablo 180, 02200 Ciudad de México, Mexico.
| | - A Moncho-Jordá
- Departamento de Física Aplicada, Universidad de Granada, Campus Fuentenueva S/N, 18071 Granada, Spain
| | - G Odriozola
- Área de Física de Procesos Irreversibles, División de Ciencias Básicas e Ingeniería, Universidad Autónoma Metropolitana-Azcapotzalco, Avenida San Pablo 180, 02200 Ciudad de México, Mexico.
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9
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Liu B, Yan X, Zhao Z, Wang J, Feng J. Distinctly different solvation behaviors of poly( N, N-diethylacrylamide) gels in water/acetone and water/DMSO mixtures. Phys Chem Chem Phys 2022; 24:23893-23902. [PMID: 36165400 DOI: 10.1039/d2cp02144g] [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
The solvation behaviors and intermolecular interactions of a poly(N,N-diethylacrylamide) (PDEA) gel network in water/DMSO and water/acetone mixtures have been investigated by variable-temperature high-resolution 1H MAS NMR. Unlike decreasing volume phase transition temperature (VPTT) of the typical thermosensitive poly(N-isopropylacrylamide) (PNIPAM) gel induced by both acetone and DMSO in a water-rich region, distinct phase transition behaviors are revealed for the PDEA gel. That is, acetone is found to increase the VPTT of PDEA directly in the water-rich region while DMSO is also found to increase the VPTT of PDEA at a very low concentration but then decrease the VPTT as the concentration further increases. The above distinctly different VPTT shifts of PDEA are attributed to the different polymer-cosolvent interactions in water/acetone and water/DMSO systems. DMSO molecules with a strong water affinity are preferentially excluded by the PDEA gel network, and can promote the volume phase transition by favoring the collapse of the PDEA gel network, while acetone molecules preferentially adsorbed on the polymer interact with PDEA via non-specific van der Waals interaction, which favors the swollen state of the PDEA gel.
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Affiliation(s)
- Biaolan Liu
- State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, Wuhan Center for Magnetic Resonance, Key Laboratory of Magnetic Resonance in Biological Systems, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China.
| | - Xiaoshuang Yan
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Zhihui Zhao
- State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, Wuhan Center for Magnetic Resonance, Key Laboratory of Magnetic Resonance in Biological Systems, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China. .,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Jian Wang
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Jiwen Feng
- State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, Wuhan Center for Magnetic Resonance, Key Laboratory of Magnetic Resonance in Biological Systems, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China.
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10
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Equilibrium Swelling of Thermo-Responsive Gels in Mixtures of Solvents. CHEMISTRY 2022. [DOI: 10.3390/chemistry4030049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Thermo-responsive (TR) gels of the LCST (lower critical solution temperature) type swell in water at temperatures below their volume phase transition temperature Tc and collapse above the critical temperature. When water is partially replaced with an organic liquid, these materials demonstrate three different types of equilibrium solvent uptake diagrams at temperatures below, above, in the close vicinity of Tc. A model is developed for equilibrium swelling of TR gels in binary mixtures of solvents. It takes into account three types of phase transitions in TR gels driven by (i) aggregation of hydrophobic side groups into clusters from which solvent molecules are expelled, (ii) replacement of water with cosolvent molecules in cage-like structures surrounding these groups, and (iii) replacement of water with cosolvent as the main element of hydration shells around backbone chains. The model involves a relatively small number of material constants that are found by matching observations on covalently cross-linked poly(N-isopropylacrylamide) macroscopic gels and microgels. Good agreement is demonstrated between the experimental data and results of numerical analysis. Classification is provided of the phase transition points on equilibrium swelling diagrams.
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11
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Drozdov A.D, Christiansen JD. Reentrant-Convex Swelling of Thermoresponsive Gels in Mixtures of Solvents. Ind Eng Chem Res 2022. [DOI: 10.1021/acs.iecr.2c01182] [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)
- A .D. Drozdov
- Department of Materials and Production, Aalborg University, Fibigerstraede 16, Aalborg 9220, Denmark
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12
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Co-solvent and temperature effect on conformation and hydration of polypropylene and polyethylene oxides in aqueous solutions. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119774] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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13
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Synthesis, characterization and application of dual thermo- and solvent-responsive double-hydrophilic diblock copolymers of N-acryloylmorpholine and N-isopropylacrylamide. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119053] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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14
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Wang P, Geiger C, Kreuzer LP, Widmann T, Reitenbach J, Liang S, Cubitt R, Henschel C, Laschewsky A, Papadakis CM, Müller-Buschbaum P. Poly(sulfobetaine)-Based Diblock Copolymer Thin Films in Water/Acetone Atmosphere: Modulation of Water Hydration and Co-nonsolvency-Triggered Film Contraction. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:6934-6948. [PMID: 35609178 DOI: 10.1021/acs.langmuir.2c00451] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The water swelling and subsequent solvent exchange including co-nonsolvency behavior of thin films of a doubly thermo-responsive diblock copolymer (DBC) are studied via spectral reflectance, time-of-flight neutron reflectometry, and Fourier transform infrared spectroscopy. The DBC consists of a thermo-responsive zwitterionic (poly(4-((3-methacrylamidopropyl) dimethylammonio) butane-1-sulfonate)) (PSBP) block, featuring an upper critical solution temperature transition in aqueous media but being insoluble in acetone, and a nonionic poly(N-isopropylmethacrylamide) (PNIPMAM) block, featuring a lower critical solution temperature transition in water, while being soluble in acetone. Homogeneous DBC films of 50-100 nm thickness are first swollen in saturated water vapor (H2O or D2O), before they are subjected to a contraction process by exposure to mixed saturated water/acetone vapor (H2O or D2O/acetone-d6 = 9:1 v/v). The affinity of the DBC film toward H2O is stronger than for D2O, as inferred from the higher film thickness in the swollen state and the higher absorbed water content, thus revealing a pronounced isotope sensitivity. During the co-solvent-induced switching by mixed water/acetone vapor, a two-step film contraction is observed, which is attributed to the delayed expulsion of water molecules and uptake of acetone molecules. The swelling kinetics are compared for both mixed vapors (H2O/acetone-d6 and D2O/acetone-d6) and with those of the related homopolymer films. Moreover, the concomitant variations of the local environment around the hydrophilic groups located in the PSBP and PNIPMAM blocks are followed. The first contraction step turns out to be dominated by the behavior of the PSBP block, whereas the second one is dominated by the PNIPMAM block. The unusual swelling and contraction behavior of the latter block is attributed to its co-nonsolvency behavior. Furthermore, we observe cooperative hydration effects in the DBC films, that is, both polymer blocks influence each other's solvation behavior.
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Affiliation(s)
- Peixi Wang
- Lehrstuhl für Funktionelle Materialien, Physik Department, Technische Universität München, James-Franck-Street 1, Garching 85748, Germany
| | - Christina Geiger
- Lehrstuhl für Funktionelle Materialien, Physik Department, Technische Universität München, James-Franck-Street 1, Garching 85748, Germany
| | - Lucas P Kreuzer
- Lehrstuhl für Funktionelle Materialien, Physik Department, Technische Universität München, James-Franck-Street 1, Garching 85748, Germany
| | - Tobias Widmann
- Lehrstuhl für Funktionelle Materialien, Physik Department, Technische Universität München, James-Franck-Street 1, Garching 85748, Germany
| | - Julija Reitenbach
- Lehrstuhl für Funktionelle Materialien, Physik Department, Technische Universität München, James-Franck-Street 1, Garching 85748, Germany
| | - Suzhe Liang
- Lehrstuhl für Funktionelle Materialien, Physik Department, Technische Universität München, James-Franck-Street 1, Garching 85748, Germany
| | - Robert Cubitt
- Institut-Laue-Langevin, 6 rue Jules Horowitz, Grenoble 38000, France
| | - Cristiane Henschel
- Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Street 24-25, Potsdam-Golm 14476, Germany
| | - André Laschewsky
- Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Street 24-25, Potsdam-Golm 14476, Germany
- Fraunhofer Institut für Angewandte Polymerforschung, Geiselberg Street 69, Potsdam-Golm 14476, Germany
| | - Christine M Papadakis
- Fachgebiet Physik weicher Materie, Physik Department, Technische Universität München, James-Franck-Street 1, Garching 85748, Germany
| | - Peter Müller-Buschbaum
- Lehrstuhl für Funktionelle Materialien, Physik Department, Technische Universität München, James-Franck-Street 1, Garching 85748, Germany
- Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Lichtenberg Street 1, Garching 85748, Germany
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15
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Folberth A, van der Vegt NFA. Temperature induced change of TMAO effects on hydrophobic hydration. J Chem Phys 2022; 156:184501. [DOI: 10.1063/5.0088388] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The effect of trimethylamine-N-oxide (TMAO) on hydrophobic solvation and hydrophobic interactions of methane has been studied with Molecular Dynamics simulations in the temperature range between 280 and 370 K at 1 bar ambient pressure. We observe a temperature transition in the effect of TMAO on the aqueous solubility of methane. At low temperature (280 K), methane is preferentially hydrated, causing TMAO to reduce its solubility in water, while above 320 K, methane preferentially interacts with TMAO, causing TMAO to promote its solubility in water. Based on a statistical-mechanical analysis of the excess chemical potential of methane, we find that the reversible work of creating a repulsive methane cavity opposes the solubility of methane in TMAO/water solution more than in pure water. Below 320 K, this solvent-excluded volume effect overcompensates the contribution of methane–TMAO van der Waals interactions, which promote the solvation of methane and are observed at all temperatures. These van der Waals interactions with the methyl groups of TMAO tip the balance above 320 K where the effect of TMAO on solvent-excluded volume is smaller. We furthermore find that the effective attraction between dissolved methane solutes increases with the increasing TMAO concentration. This observation correlates with a reduction in the methane solubility below 320 K but with an increase in methane solubility at higher temperatures.
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Affiliation(s)
- Angelina Folberth
- 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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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: 32] [Impact Index Per Article: 16.0] [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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17
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Tripathy M, Bharadwaj S, van der Vegt NFA. Solvation shell thermodynamics of extended hydrophobic solutes in mixed solvents. J Chem Phys 2022; 156:164901. [DOI: 10.1063/5.0090646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The ability of various cosolutes and cosolvents to enhance or quench solvent density fluctuations at solute–water interfaces has crucial implications on the conformational equilibrium of macromolecules such as polymers and proteins. Herein, we use an extended hydrophobic solute as a model system to study the effect of urea and methanol on the density fluctuations in the solute’s solvation shell and the resulting thermodynamics. On strengthening the solute–water/cosolute repulsive interaction, we observe distinct trends in the mutual affinities between various species in, and the thermodynamic properties of, the solvation shell. These trends strongly follow the respective trends in the preferential adsorption of urea and methanol: solute–water/cosolute repulsion strengthens, urea accumulation decreases, and methanol accumulation increases. Preferential accumulation of urea is found to quench the density fluctuations around the extended solute, leading to a decrease in the compressibility of the solvation shell. In contrast, methanol accumulation enhances the density fluctuations, leading to an increase in the compressibility. The mode of action of urea and methanol seems to be strongly coupled to their hydration behavior. The observations from this simple model is discussed in relation to urea driven swelling and methanol induced collapse of some well-known thermo-responsive polymers.
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Affiliation(s)
- Madhusmita Tripathy
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Swaminath Bharadwaj
- 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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18
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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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19
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Keshavarz MH, Shafiee M, Jazi BN. Simple Approach for Reliable Prediction of Solubility of Polymers in Environmentally Compatible Solvents. Ind Eng Chem Res 2022. [DOI: 10.1021/acs.iecr.1c04737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Mehdi Shafiee
- Faculty of Applied Sciences, Malek Ashtar University of Technology, Shahin-shahr 8315713115, Iran
| | - Bahareh Niroomand Jazi
- Faculty of Applied Sciences, Malek Ashtar University of Technology, Shahin-shahr 8315713115, Iran
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20
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Bharadwaj S, B SJ, van der Vegt NFA. Direct Calculation of Entropic Components in Cohesive Interaction Free Energies. J Phys Chem B 2021; 125:11026-11035. [PMID: 34570491 DOI: 10.1021/acs.jpcb.1c05748] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cohesive interaction free energies entail an entropic component related to fluctuations of the energy associated with the attractive portion of the solute-solvent potential. The corresponding "fluctuation entropy" is fundamental in the solvation thermodynamics of macromolecular solutes and is linked to interfacial solvent density fluctuations and hydrophobic effects. Since the direct calculation of fluctuation entropy in molecular simulations is hampered by the poor sampling of high-energy tails in the solute-solvent energy distribution, indirect, and often approximate, routes for the calculation of fluctuation entropy are usually required, involving the modeling of geometrically frozen repulsive solute cavities in thermodynamic integration approaches. Herein, we propose a method to directly compute the fluctuation entropy by employing indirect umbrella sampling (INDUS). To validate the method, we consider model systems consisting of subnanometer oil droplets in water for which the fluctuation entropy can be computed exactly using indirect methods. The fluctuation entropy calculated with the newly proposed direct method agrees with the indirect reference calculations. We also observe that the solvation free energy and the contribution of the fluctuation entropy to it are of comparable magnitudes, particularly for larger oil droplets (∼1 nm). The proposed method can readily be employed for flexible macromolecular solutes and systems with extended hydrophobic surfaces or in the vicinity of a dewetting transition.
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Affiliation(s)
- Swaminath Bharadwaj
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Shadrack Jabes B
- 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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21
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Ko CH, Henschel C, Meledam GP, Schroer MA, Guo R, Gaetani L, Müller-Buschbaum P, Laschewsky A, Papadakis CM. Co-Nonsolvency Effect in Solutions of Poly(methyl methacrylate)- b-poly( N-isopropylacrylamide) Diblock Copolymers in Water/Methanol Mixtures. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c00512] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Chia-Hsin Ko
- Physik-Department, Fachgebiet Physik Weicher Materie, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany
| | - Cristiane Henschel
- Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Golm, Germany
| | - Geethu P. Meledam
- Physik-Department, Fachgebiet Physik Weicher Materie, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany
| | - Martin A. Schroer
- European Molecular Biology Laboratory, Hamburg Outstation, c/o Deutsches Elektronen-Synchrotron, Notkestr. 85, 22607 Hamburg, Germany
| | - Renjun Guo
- Physik-Department, Lehrstuhl für Funktionelle Materialien, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany
| | - Luka Gaetani
- Physik-Department, Fachgebiet Physik Weicher Materie, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany
| | - Peter Müller-Buschbaum
- Physik-Department, Lehrstuhl für Funktionelle Materialien, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany
- Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Lichtenbergstr. 1, 85748 Garching, Germany
| | - André Laschewsky
- Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Golm, Germany
- Fraunhofer-Institut für Angewandte Polymerforschung, Geiselbergstraße 69, 14476 Potsdam, Golm, Germany
| | - Christine M. Papadakis
- Physik-Department, Fachgebiet Physik Weicher Materie, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany
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22
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Dhabal D, Jiang Z, Pallath A, Patel AJ. Characterizing the Interplay between Polymer Solvation and Conformation. J Phys Chem B 2021; 125:5434-5442. [PMID: 33978411 DOI: 10.1021/acs.jpcb.1c02191] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Conformational transitions of flexible molecules, especially those driven by hydrophobic effects, tend to be hindered by desolvation barriers. For such transitions, it is thus important to characterize and understand the interplay between solvation and conformation. Using specialized molecular simulations, here we perform such a characterization for a hydrophobic polymer solvated in water. We find that an external potential, which unfavorably perturbs the polymer hydration waters, can trigger a coil-to-globule or collapse transition, and that the relative stabilities of the collapsed and extended states can be quantified by the strength of the requisite potential. Our results also provide mechanistic insights into the collapse transition, highlighting that the bottleneck to polymer collapse is the formation of a sufficiently large cluster, and the collective dewetting of such a cluster. We also study the collapse of the hydrophobic polymer in octane, a nonpolar solvent, and interestingly, we find that the mechanistic details of the transition are qualitatively similar to that in water.
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Affiliation(s)
- Debdas Dhabal
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Zhitong Jiang
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Akash Pallath
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Amish J Patel
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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23
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Quoika PK, Fernández-Quintero ML, Podewitz M, Hofer F, Liedl KR. Implementation of the Freely Jointed Chain Model to Assess Kinetics and Thermodynamics of Thermosensitive Coil-Globule Transition by Markov States. J Phys Chem B 2021; 125:4898-4909. [PMID: 33942614 PMCID: PMC8154620 DOI: 10.1021/acs.jpcb.1c01946] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
![]()
We revived and implemented
a method developed by Kuhn in 1934,
originally only published in German, that is, the so-called “freely
jointed chain” model. This approach turned out to be surprisingly
useful for analyzing state-of-the-art computer simulations of the
thermosensitive coil–globule transition of N-Isopropylacrylamide 20-mer. Our atomistic computer simulations are
orders of magnitude longer than those of previous studies and lead
to a reliable description of thermodynamics and kinetics at many different
temperatures. The freely jointed chain model provides a coordinate
system, which allows us to construct a Markov state model of the conformational
transitions. Furthermore, this guarantees a reliable reconstruction
of the kinetics in back-and-forth directions. In addition, we obtain
a description of the high diversity and variability of both conformational
states. Thus, we gain a detailed understanding of the coil–globule
transition. Surprisingly, conformational entropy turns out to play
only a minor role in the thermodynamic balance of the process. Moreover,
we show that the radius of gyration is an unexpectedly unsuitable
coordinate to comprehend the transition kinetics because it does not
capture the high conformational diversity within the different states.
Consequently, the approach presented here allows for an exhaustive
description and resolution of the conformational ensembles of arbitrary
linear polymer chains.
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Affiliation(s)
- Patrick K Quoika
- Institute of General, Inorganic and Theoretical Chemistry, and Centre of Molecular Biosciences University of Innsbruck, A-6020 Innsbruck, Austria
| | - Monica L Fernández-Quintero
- Institute of General, Inorganic and Theoretical Chemistry, and Centre of Molecular Biosciences University of Innsbruck, A-6020 Innsbruck, Austria
| | - Maren Podewitz
- Institute of General, Inorganic and Theoretical Chemistry, and Centre of Molecular Biosciences University of Innsbruck, A-6020 Innsbruck, Austria
| | - Florian Hofer
- Institute of General, Inorganic and Theoretical Chemistry, and Centre of Molecular Biosciences University of Innsbruck, A-6020 Innsbruck, Austria
| | - Klaus R Liedl
- Institute of General, Inorganic and Theoretical Chemistry, and Centre of Molecular Biosciences University of Innsbruck, A-6020 Innsbruck, Austria
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24
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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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25
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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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26
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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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27
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Kreuzer LP, Lindenmeir C, Geiger C, Widmann T, Hildebrand V, Laschewsky A, Papadakis CM, Müller-Buschbaum P. Poly(sulfobetaine) versus Poly( N-isopropylmethacrylamide): Co-Nonsolvency-Type Behavior of Thin Films in a Water/Methanol Atmosphere. Macromolecules 2021. [DOI: 10.1021/acs.macromol.0c02281] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Lucas P. Kreuzer
- Lehrstuhl für Funktionelle Materialien, Physik Department, Technische Universität München, James-Franck-Str. 1, 85748 Garching, Germany
| | - Christoph Lindenmeir
- Lehrstuhl für Funktionelle Materialien, Physik Department, Technische Universität München, James-Franck-Str. 1, 85748 Garching, Germany
| | - Christina Geiger
- Lehrstuhl für Funktionelle Materialien, Physik Department, Technische Universität München, James-Franck-Str. 1, 85748 Garching, Germany
| | - Tobias Widmann
- Lehrstuhl für Funktionelle Materialien, Physik Department, Technische Universität München, James-Franck-Str. 1, 85748 Garching, Germany
| | - Viet Hildebrand
- Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam-Golm, Germany
| | - André Laschewsky
- Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam-Golm, Germany
- Fraunhofer Institut für Angewandte Polymerforschung, Geiselbergstr. 69, 14476 Potsdam-Golm, Germany
| | - Christine M. Papadakis
- Fachgebiet Physik weicher Materie, Physik Department, Technische Universität München, James-Franck-Str. 1, 85748 Garching, Germany
| | - Peter Müller-Buschbaum
- Lehrstuhl für Funktionelle Materialien, Physik Department, Technische Universität München, James-Franck-Str. 1, 85748 Garching, Germany
- Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Lichtenbergstr. 1, 85748 Garching, Germany
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28
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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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29
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Mochizuki K. On-Off of Co-non-solvency for Poly( N-vinylcaprolactam) in Alcohol-Water Mixtures: A Molecular Dynamics Study. J Phys Chem B 2020; 124:9951-9957. [PMID: 33086006 DOI: 10.1021/acs.jpcb.0c07188] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Poly(N-vinylcaprolactam) (PVCL) exhibits co-non-solvency in aqueous solutions of 2-propanol but not in methanol. What distinguishes the impact of these two cosolvents on the polymer conformational stability? We report a molecular dynamics simulation study on PVCL 50-mer and monomers dissolved in methanol-water and 2-propanol-water mixtures. We show that the alcohol-concentration dependence of the effective attraction between a pair of PVCL monomers closely resembles the conformational changes in a single PVCL 50-mer as well as the experimentally observed behavior for PVCL chains. We also found that, at the co-non-solvency maximum, the monomer-monomer attraction works over a long-range beyond the solvent-separated distance. Then, we correlate the long-range attraction to the appearance of a dense alcohol concentration accumulated between the monomers. Furthermore, we distinctly demonstrate that the co-non-solvency of PVCL monomers can be switched on/off by artificially tuning the alcohol size while keeping the energetic parameters. Thus, we conclude that the magnitude of the excluded volume effect in alcohol accompanying the gain in translational entropy of the solvent is crucial to the occurrence of PVCL polymer co-non-solvency.
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Affiliation(s)
- Kenji Mochizuki
- Department of Chemistry, Zhejiang University, 148 Tianmushan Road, Hangzhou, Zhejiang 310028, P. R. China
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30
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Quoika PK, Podewitz M, Wang Y, Kamenik AS, Loeffler JR, Liedl KR. Thermosensitive Hydration of Four Acrylamide-Based Polymers in Coil and Globule Conformations. J Phys Chem B 2020; 124:9745-9756. [PMID: 33054215 PMCID: PMC7604866 DOI: 10.1021/acs.jpcb.0c07232] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
![]()
To
characterize the thermosensitive coil–globule transition in
atomistic detail, the conformational dynamics of linear polymer chains
of acrylamide-based polymers have been investigated at multiple temperatures.
Therefore, molecular dynamic simulations of 30mers of polyacrylamide
(AAm), poly-N-methylacrylamide (NMAAm), poly-N-ethylacrylamide (NEAAm), and poly-N-isopropylacrylamide
(NIPAAm) have been performed at temperatures ranging from 250 to 360
K for 2 μs. While two of the polymers are known to exhibit thermosensitivity
(NEAAm, NIPAAm), no thermosensitivity is observed for AAm and NMAAm
in aqueous solution. Our computer simulations consistently reproduce
these properties. To understand the thermosensitivity of the respective
polymers, the conformational ensembles at different temperatures have
been separated according to the coil–globule transition. The
coil and globule conformational ensembles were exhaustively analyzed
in terms of hydrogen bonding with the solvent, the change of the solvent
accessible surface, and enthalpic contributions. Surprisingly, independent
of different thermosensitive properties of the four polymers, the
surface affinity to water of coil conformations is higher than for
globule conformations. Therefore, polymer–solvent interactions
stabilize coil conformations at all temperatures. Nevertheless, the
enthalpic contributions alone cannot explain the differences in thermosensitivity.
This clearly implies that entropy is the distinctive factor for thermosensitivity.
With increasing side chain length, the lifetime of the hydrogen bonds
between the polymer surface and water is extended. Thus, we surmise
that a longer side chain induces a larger entropic penalty due to
immobilization of water molecules.
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Affiliation(s)
- Patrick K Quoika
- Institute of General, Inorganic and Theoretical Chemistry, and Centre of Molecular Biosciences University of Innsbruck, Innsbruck, A-6020 Austria
| | - Maren Podewitz
- Institute of General, Inorganic and Theoretical Chemistry, and Centre of Molecular Biosciences University of Innsbruck, Innsbruck, A-6020 Austria
| | - Yin Wang
- Institute of General, Inorganic and Theoretical Chemistry, and Centre of Molecular Biosciences University of Innsbruck, Innsbruck, A-6020 Austria
| | - Anna S Kamenik
- Institute of General, Inorganic and Theoretical Chemistry, and Centre of Molecular Biosciences University of Innsbruck, Innsbruck, A-6020 Austria
| | - Johannes R Loeffler
- Institute of General, Inorganic and Theoretical Chemistry, and Centre of Molecular Biosciences University of Innsbruck, Innsbruck, A-6020 Austria
| | - Klaus R Liedl
- Institute of General, Inorganic and Theoretical Chemistry, and Centre of Molecular Biosciences University of Innsbruck, Innsbruck, A-6020 Austria
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31
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Raftopoulos KN, Kyriakos K, Nuber M, Niebuur BJ, Holderer O, Ohl M, Ivanova O, Pasini S, Papadakis CM. Co-nonsolvency in concentrated aqueous solutions of PNIPAM: effect of methanol on the collective and the chain dynamics. SOFT MATTER 2020; 16:8462-8472. [PMID: 32856669 DOI: 10.1039/d0sm01007c] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The polymer dynamics in concentrated solutions of poly(N-isopropyl acrylamide) (PNIPAM) in D2O/CD3OD mixtures is investigated in the one-phase region. Two polymer concentrations (9 and 25 wt%) and CD3OD contents in the solvent mixture of 0, 10 and 15 vol% are chosen. Temperature-resolved dynamic light scattering (DLS) reveals the collective dynamics. Two modes are observed, namely the fast relaxation of polymer segments within the blobs and the slow collective relaxation of the blobs. As the cloud point is approached, the correlation length related to the fast mode increases with CD3OD content. It features critical scaling behavior, which is consistent with mean-field behavior for the 9 wt% PNIPAM solution in pure D2O and with 3D Ising behavior for all other solutions. While the slow mode is not very strong in the 9 wt% PNIPAM solution in pure D2O, it is significantly more prominent as CD3OD is added and at all CD3OD contents in the 25 wt% solution, which may be attributed to enhanced interaction between the polymers. Neutron spin-echo spectroscopy (NSE) reveals a decay in the intermediate structure factor which indicates a diffusive process. For the polymer concentration of 9 wt%, the diffusion coefficients from NSE are similar to the ones from the fast relaxation observed in DLS. In contrast, they are significantly lower for the solutions having a polymer concentration of 25 wt%, which is attributed to the influence of the dominant large-scale dynamic heterogeneities. To summarize, addition of cosolvent leads to enhanced large-scale heterogeneities, which are reflected in the dynamic behavior at small length scales.
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Affiliation(s)
- Konstantinos N Raftopoulos
- Technische Universität München, Physik-Department, Fachgebiet Physik weicher Materie, James-Franck-Str. 1, 85748 Garching, Germany.
| | - Konstantinos Kyriakos
- Technische Universität München, Physik-Department, Fachgebiet Physik weicher Materie, James-Franck-Str. 1, 85748 Garching, Germany.
| | - Matthias Nuber
- Technische Universität München, Physik-Department, Fachgebiet Physik weicher Materie, James-Franck-Str. 1, 85748 Garching, Germany.
| | - Bart-Jan Niebuur
- Technische Universität München, Physik-Department, Fachgebiet Physik weicher Materie, James-Franck-Str. 1, 85748 Garching, Germany.
| | - Olaf Holderer
- Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, 85747 Garching, Germany
| | - Michael Ohl
- Jülich Centre for Neutron Science JCNS-1, Forschungszentrum Jülich GmbH, Wilhelm-Johnen-Str., 52425 Jülich, Germany
| | - Oxana Ivanova
- Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, 85747 Garching, Germany
| | - Stefano Pasini
- Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, 85747 Garching, Germany
| | - Christine M Papadakis
- Technische Universität München, Physik-Department, Fachgebiet Physik weicher Materie, James-Franck-Str. 1, 85748 Garching, Germany.
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Drozdov AD, deClaville Christiansen J. The effect of saccharides on equilibrium swelling of thermo-responsive gels. RSC Adv 2020; 10:30723-30733. [PMID: 35547557 PMCID: PMC9088206 DOI: 10.1039/d0ra05845a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Accepted: 08/10/2020] [Indexed: 11/21/2022] Open
Abstract
Mechanical and optical properties of thermo-responsive (TR) gels change drastically at their volume phase transition temperature. As the critical temperature is strongly affected by the presence of small amounts of additives in aqueous solutions, TR gels can be employed as sensors for detection and recognition of multiple analytes (from specific ions to hazardous biochemicals to pathogenic proteins) and actuators for biomedical applications. A simplified mean-field model is developed for equilibrium swelling of TR gels in aqueous solutions of additives. Its advantage is that the model involves a relatively small (compared with the conventional approaches) number of material constants and accounts for changes in the thermo-mechanical response at transition from the swollen to collapsed state. The ability of the model to describe experimental swelling diagrams and to predict the influence of additives on the equilibrium degree of swelling and the volume phase transition temperature of TR gels is confirmed by comparison of observations on poly(N-isopropylacrylamide) gel in aqueous solutions of saccharides (glucose, sucrose and galactose) with results of numerical analysis.
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Affiliation(s)
- A D Drozdov
- Department of Materials and Production, Aalborg University Fibigerstraede 16 Aalborg 9220 Denmark
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Niebuur BJ, Ko CH, Zhang X, Claude KL, Chiappisi L, Schulte A, Papadakis CM. Pressure Dependence of the Cononsolvency Effect in Aqueous Poly(N-isopropylacrylamide) Solutions: A SANS Study. Macromolecules 2020. [DOI: 10.1021/acs.macromol.0c00489] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Bart-Jan Niebuur
- Physik-Department, Fachgebiet Physik weicher Materie, Technische Universität München, James-Franck-Str. 1, 85748 Garching, Germany
| | - Chia-Hsin Ko
- Physik-Department, Fachgebiet Physik weicher Materie, Technische Universität München, James-Franck-Str. 1, 85748 Garching, Germany
| | - Xiaohan Zhang
- Physik-Department, Fachgebiet Physik weicher Materie, Technische Universität München, James-Franck-Str. 1, 85748 Garching, Germany
| | - Kora-Lee Claude
- Physik-Department, Fachgebiet Physik weicher Materie, Technische Universität München, James-Franck-Str. 1, 85748 Garching, Germany
| | - Leonardo Chiappisi
- Large Scale Structures Group, Institut Laue-Langevin, 71, Avenue des Martyrs, CS 20 156, 38042 Grenoble, France
- Stranski Laboratorium für Physikalische Chemie und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 124, Sekr. TC7, D-10623 Berlin, Germany
| | - Alfons Schulte
- Department of Physics and College of Optics and Photonics, University of Central Florida, 4111 Libra Drive, Orlando, Florida 32816, 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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Zhang YY, Jia XM, Shi R, Li SJ, Zhao H, Qian HJ, Lu ZY. Synthesis of Polymer Single-Chain Nanoparticle with High Compactness in Cosolvent Condition: A Computer Simulation Study. Macromol Rapid Commun 2020; 41:e1900655. [PMID: 32134543 DOI: 10.1002/marc.201900655] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/21/2020] [Accepted: 01/28/2020] [Indexed: 01/27/2023]
Abstract
Polymeric single-chain nanoparticles (SCNPs) are soft nano-objects synthesized by intramolecular crosslinking of isolated single polymer chains. Syntheses of such SCNPs usually need to be performed in a dilute solution. In such a condition, the bonding probability of the two active crosslinking units at a short contour distance along the chain backbone is much higher than those which are far away from each other. Such a reaction condition often results in local spheroidization and, therefore, the formation of loosely packed structures. How to inhibit the local spheroidization and improve the compactness of SCNPs is thus a major challenge for the syntheses of SCNPs. In this study, computer simulations are performed and the fact that a precollapse of the polymer chain conformation in a cosolvent condition can largely improve the probability of the crosslinking reactions at large contour distances is demonstrated, favoring the formations of closely packed globular structures. As a result, the formed SCNPs can be more spherical and have higher compactness than those fabricated in ultradilute good solvent solution in a conventional way. It is believed this simulation work can provide a insight into the effective syntheses of SCNPs with spherical conformations and high compactness.
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Affiliation(s)
- Yue-Yuan Zhang
- State Key Laboratory of Supramolecular Structure and Materials, International Joint Research Laboratory of Nano-Micro Architecture Chemistry, Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun, 130021, China
| | - Xiang-Meng Jia
- State Key Laboratory of Supramolecular Structure and Materials, International Joint Research Laboratory of Nano-Micro Architecture Chemistry, Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun, 130021, China
| | - Rui Shi
- State Key Laboratory of Supramolecular Structure and Materials, International Joint Research Laboratory of Nano-Micro Architecture Chemistry, Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun, 130021, China
| | - Shu-Jia Li
- State Key Laboratory of Supramolecular Structure and Materials, International Joint Research Laboratory of Nano-Micro Architecture Chemistry, Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun, 130021, China
| | - Huanyu Zhao
- State Key Laboratory of Supramolecular Structure and Materials, International Joint Research Laboratory of Nano-Micro Architecture Chemistry, Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun, 130021, China
| | - Hu-Jun Qian
- State Key Laboratory of Supramolecular Structure and Materials, International Joint Research Laboratory of Nano-Micro Architecture Chemistry, Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun, 130021, China
| | - Zhong-Yuan Lu
- State Key Laboratory of Supramolecular Structure and Materials, International Joint Research Laboratory of Nano-Micro Architecture Chemistry, Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun, 130021, China
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Lazarev A, Tatarenko K, Trubnikov D, Gordienko V. Controlled transition of microcapsules from coil conformation to globule during the expansion of the pulse jet of nanoparticle suspension of TiO2 in supercritical (CO2) polyethylene glycol solution. Chem Phys 2020. [DOI: 10.1016/j.chemphys.2019.110581] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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36
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Molecular description of the coil-to-globule transition of Poly(N-isopropylacrylamide) in water/ethanol mixture at low alcohol concentration. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2019.111928] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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37
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Conformational transitions of poly(ethylene oxide) in supersonic jets of supercritical CO2. J Supercrit Fluids 2019. [DOI: 10.1016/j.supflu.2019.104557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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38
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Pooch F, Teltevskij V, Karjalainen E, Tenhu H, Winnik FM. Poly(2-propyl-2-oxazoline)s in Aqueous Methanol: To Dissolve or not to Dissolve. Macromolecules 2019; 52:6361-6368. [PMID: 31543552 PMCID: PMC6748674 DOI: 10.1021/acs.macromol.9b01234] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 08/01/2019] [Indexed: 11/30/2022]
Abstract
![]()
At
room temperature, poly(N-isopropylacrylamide)
(PNIPAM) is soluble in water and methanol, but it is not soluble in
certain water/methanol mixtures. This phenomenon, known as cononsolvency,
has been explored in great detail experimentally and theoretically
in an attempt to understand the complex interactions occurring in
the ternary PNIPAM/water/co-nonsolvent system. Yet little is known
about the effects of the polymer structure on cononsolvency. To address
this point, we investigated the temperature-dependent solution properties
in water, methanol, and mixtures of the two solvents of poly(2-cyclopropyl-2-oxazoline)
(PcyPOx) and two structural isomers of PNIPAM (Mn ∼ 11 kg/mol): poly(2-isopropyl-2-oxazoline) (PiPOx)
and poly(2-n-propyl-2-oxazoline) (PnPOx). The phase
diagram of the ternary water/methanol/poly(2-propyl-2-oxazolines)
(PPOx) systems, constructed based on cloud point (TCP) measurements, revealed that PnPOx exhibits cononsolvency
in water/methanol mixtures. In contrast, methanol acts as a cosolvent
for PiPOx and PcyPOx in water. The enthalpy, ΔH, and temperature, Tmax, of the coil-to-globule
transition of the three polymers in various water/methanol mixtures
were measured by high-sensitivity differential scanning calorimetry. Tmax follows the same trends as TCP, confirming the cononsolvency of PnPOx and the cosolvency
of PiPOx and PcyPOx. ΔH decreases linearly
as a function of the methanol content for all PPOx systems. Ancillary
high-resolution 1H NMR spectroscopy studies of PPOx solutions
in D2O and methanol-d4, coupled
with DOSY and NOESY experiments revealed that the n-propyl group of PnPOx rotates freely in D2O, whereas
the rotation of the isopropyl and cyclopropyl groups of PiPOx and
PcyPOx, respectively, is limited due to steric restriction. This factor
appears to play an important role in the case of the PPOxs/water/methanol
ternary system.
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Affiliation(s)
- Fabian Pooch
- Department of Chemistry, University of Helsinki, P.O. Box 55, Helsinki 00014, Finland
| | - Valerij Teltevskij
- Department of Chemistry, University of Helsinki, P.O. Box 55, Helsinki 00014, Finland
| | - Erno Karjalainen
- Department of Chemistry, University of Helsinki, P.O. Box 55, Helsinki 00014, Finland
| | - Heikki Tenhu
- Department of Chemistry, University of Helsinki, P.O. Box 55, Helsinki 00014, Finland
| | - Françoise M Winnik
- Department of Chemistry, University of Helsinki, P.O. Box 55, Helsinki 00014, Finland.,International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
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39
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Bruce EE, van der Vegt NFA. Molecular Scale Solvation in Complex Solutions. J Am Chem Soc 2019; 141:12948-12956. [DOI: 10.1021/jacs.9b03469] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Ellen E. Bruce
- Eduard-Zintl-Institut für Anorganische und
Physikalische Chemie, Technische Universität Darmstadt, D-64287 Darmstadt, Germany
| | - Nico F. A. van der Vegt
- Eduard-Zintl-Institut für Anorganische und
Physikalische Chemie, Technische Universität Darmstadt, D-64287 Darmstadt, Germany
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40
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Affiliation(s)
- Swaminath Bharadwaj
- 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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41
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Dalgicdir C, van der Vegt NFA. Improved Temperature Behavior of PNIPAM in Water with a Modified OPLS Model. J Phys Chem B 2019; 123:3875-3883. [PMID: 30990715 DOI: 10.1021/acs.jpcb.9b01644] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We test the OPLS/AA force field for a single PNIPAM 40-mer in aqueous solution using replica exchange molecular dynamics simulations and find that the force field fails to reproduce the experimental temperature behavior. To resolve this issue, we apply a modification on the partial charges previously suggested to reproduce the liquid-liquid phase separation of NIPAM aqueous solutions. The modified force field features stronger amide-water electrostatic interactions than the original OPLS model, predicts a weaker water-mediated monomer-monomer attraction, and reproduces the experimental coil-globule collapse enthalpy of PNIPAM in water. We revisit the cononsolvency problem of PNIPAM in methanol/water mixtures with the modified model and show that the dependence of the coil-globule collapse enthalpy on methanol concentration follows the experimental trend of the lower critical solution temperature. The calculations with the modified force field confirm that polymer dehydration is the determining factor for chain collapse in the cononsolvency regime.
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Affiliation(s)
- Cahit Dalgicdir
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie , Technische Universität Darmstadt , D-64287 Darmstadt , Germany
| | - Nico F A van der Vegt
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie , Technische Universität Darmstadt , D-64287 Darmstadt , Germany
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42
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Jiang Z, Remsing RC, Rego NB, Patel AJ. Characterizing Solvent Density Fluctuations in Dynamical Observation Volumes. J Phys Chem B 2019; 123:1650-1661. [PMID: 30682885 DOI: 10.1021/acs.jpcb.8b11423] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Hydrophobic effects drive diverse aqueous assemblies, such as micelle formation or protein folding, wherein the solvent plays an important role. Consequently, characterizing the free energetics of solvent density fluctuations can lead to important insights into these processes. Although techniques such as the indirect umbrella sampling (INDUS) method can be used to characterize solvent fluctuations in static observation volumes of various sizes and shapes, characterizing how the solvent mediates inherently dynamic processes, such as self-assembly or conformational change, remains a challenge. In this work, we generalize the INDUS method to facilitate the enhanced sampling of solvent fluctuations in dynamical observation volumes, whose positions and shapes can evolve. We illustrate the usefulness of this generalization by characterizing water density fluctuations in dynamical volumes pertaining to the hydration of flexible solutes, the assembly of small hydrophobes, and conformational transitions in a model peptide. We also use the method to probe the dynamics of hard spheres.
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Affiliation(s)
| | - Richard C Remsing
- Institute for Computational Molecular Science , Temple University , Philadelphia , Pennsylvania 19122 , United States
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43
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Nothdurft K, Müller DH, Brands T, Bardow A, Richtering W. Enrichment of methanol inside pNIPAM gels in the cononsolvency-induced collapse. Phys Chem Chem Phys 2019; 21:22811-22818. [DOI: 10.1039/c9cp04383g] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
From Raman, we determined an enrichment of methanol inside the polymer in the cononsolvency-induced collapse and donor-type hydrogen-bonding of methanol with pNIPAM.
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Affiliation(s)
- Katja Nothdurft
- Institute of Physical Chemistry
- RWTH Aachen University
- 52056 Aachen
- Germany
| | - David H. Müller
- Institute of Technical Thermodynamics
- RWTH Aachen University
- 52062 Aachen
- Germany
| | - Thorsten Brands
- Institute of Technical Thermodynamics
- RWTH Aachen University
- 52062 Aachen
- Germany
| | - André Bardow
- Institute of Technical Thermodynamics
- RWTH Aachen University
- 52062 Aachen
- Germany
| | - Walter Richtering
- Institute of Physical Chemistry
- RWTH Aachen University
- 52056 Aachen
- Germany
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44
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Milster S, Chudoba R, Kanduč M, Dzubiella J. Cross-linker effect on solute adsorption in swollen thermoresponsive polymer networks. Phys Chem Chem Phys 2019; 21:6588-6599. [DOI: 10.1039/c8cp07601d] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Molecular dynamics study on the solute adsorption to thermoresponsive polymers estimating the cross-link impact on particle partitioning in swollen hydrogels.
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Affiliation(s)
- Sebastian Milster
- Research Group for Simulations of Energy Materials
- Helmholtz-Zentrum Berlin für Materialien und Energie
- D-14109 Berlin
- Germany
- Institut für Physik
| | - Richard Chudoba
- Research Group for Simulations of Energy Materials
- Helmholtz-Zentrum Berlin für Materialien und Energie
- D-14109 Berlin
- Germany
- Institut für Physik
| | - Matej Kanduč
- Research Group for Simulations of Energy Materials
- Helmholtz-Zentrum Berlin für Materialien und Energie
- D-14109 Berlin
- Germany
- Jožef Stefan Institute
| | - Joachim Dzubiella
- Research Group for Simulations of Energy Materials
- Helmholtz-Zentrum Berlin für Materialien und Energie
- D-14109 Berlin
- Germany
- Applied Theoretical Physics – Computational Physics
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Lopez CG, Scotti A, Brugnoni M, Richtering W. The Swelling of Poly(Isopropylacrylamide) Near the θ Temperature: A Comparison between Linear and Cross‐Linked Chains. MACROMOL CHEM PHYS 2018. [DOI: 10.1002/macp.201800421] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Carlos G. Lopez
- Dr. C. G. Lopez, Dr. A. Scotti, M. Brugnoni, Prof. W. RichteringInstitute of Physical ChemistryRWTH Aachen University Landoltweg 2 52056 Aachen Germany
| | - Andrea Scotti
- Dr. C. G. Lopez, Dr. A. Scotti, M. Brugnoni, Prof. W. RichteringInstitute of Physical ChemistryRWTH Aachen University Landoltweg 2 52056 Aachen Germany
| | - Monia Brugnoni
- Dr. C. G. Lopez, Dr. A. Scotti, M. Brugnoni, Prof. W. RichteringInstitute of Physical ChemistryRWTH Aachen University Landoltweg 2 52056 Aachen Germany
| | - Walter Richtering
- Dr. C. G. Lopez, Dr. A. Scotti, M. Brugnoni, Prof. W. RichteringInstitute of Physical ChemistryRWTH Aachen University Landoltweg 2 52056 Aachen Germany
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46
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Nian S, Pu L. Racemic Fluorescence Probe for Enantiomeric Excess Determination: Application of Cononsolvency of a Polymer in Sensing. J Org Chem 2018; 84:909-913. [DOI: 10.1021/acs.joc.8b02793] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Shifeng Nian
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904-4319, United States
| | - Lin Pu
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904-4319, United States
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47
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Budkov YA, Kolesnikov AL. Models of the Conformational Behavior of Polymers in Mixed Solvents. POLYMER SCIENCE SERIES C 2018. [DOI: 10.1134/s1811238218020030] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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48
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Keidel R, Ghavami A, Lugo DM, Lotze G, Virtanen O, Beumers P, Pedersen JS, Bardow A, Winkler RG, Richtering W. Time-resolved structural evolution during the collapse of responsive hydrogels: The microgel-to-particle transition. SCIENCE ADVANCES 2018; 4:eaao7086. [PMID: 29740608 PMCID: PMC5938240 DOI: 10.1126/sciadv.aao7086] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 02/20/2018] [Indexed: 05/19/2023]
Abstract
Adaptive hydrogels, often termed smart materials, are macromolecules whose structure adjusts to external stimuli. Responsive micro- and nanogels are particularly interesting because the small length scale enables very fast response times. Chemical cross-links provide topological constraints and define the three-dimensional structure of the microgels, whereas their porous structure permits fast mass transfer, enabling very rapid structural adaption of the microgel to the environment. The change of microgel structure involves a unique transition from a flexible, swollen finite-size macromolecular network, characterized by a fuzzy surface, to a colloidal particle with homogeneous density and a sharp surface. In this contribution, we determine, for the first time, the structural evolution during the microgel-to-particle transition. Time-resolved small-angle x-ray scattering experiments and computer simulations unambiguously reveal a two-stage process: In a first, very fast process, collapsed clusters form at the periphery, leading to an intermediate, hollowish core-shell structure that slowly transforms to a globule. This structural evolution is independent of the type of stimulus and thus applies to instantaneous transitions as in a temperature jump or to slower stimuli that rely on the uptake of active molecules from and/or exchange with the environment. The fast transitions of size and shape provide unique opportunities for various applications as, for example, in uptake and release, catalysis, or sensing.
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Affiliation(s)
- Rico Keidel
- Chair of Technical Thermodynamics, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Schinkelstrasse 8, 52062 Aachen, Germany
| | - Ali Ghavami
- Institute for Advanced Simulation, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Dersy M. Lugo
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52056 Aachen, Germany
| | - Gudrun Lotze
- European Synchrotron Radiation Facility (ESRF), ID02–Time-Resolved Ultra Small-Angle X-Ray Scattering, 71 Avenue des Martyrs, CS 40220, 38043 Grenoble Cedex 9, France
| | - Otto Virtanen
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52056 Aachen, Germany
| | - Peter Beumers
- Chair of Technical Thermodynamics, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Schinkelstrasse 8, 52062 Aachen, Germany
| | - Jan Skov Pedersen
- Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University, 8000 Aarhus, Denmark
| | - Andre Bardow
- Chair of Technical Thermodynamics, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Schinkelstrasse 8, 52062 Aachen, Germany
- Institute of Energy and Climate Research: Energy Systems Engineering (IEK-10), Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Roland G. Winkler
- Institute for Advanced Simulation, Forschungszentrum Jülich, 52425 Jülich, Germany
- Corresponding author. (W.R.); (R.G.W.)
| | - Walter Richtering
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52056 Aachen, Germany
- DWI–Leibniz Institute for Interactive Materials, Forckenbeckstrasse 50, D-52056 Aachen, Germany
- Corresponding author. (W.R.); (R.G.W.)
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Fukai T, Shinyashiki N, Yagihara S, Kita R, Tanaka F. Phase Behavior of Co-Nonsolvent Systems: Poly( N-isopropylacrylamide) in Mixed Solvents of Water and Methanol. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:3003-3009. [PMID: 29412671 DOI: 10.1021/acs.langmuir.7b03815] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Cloud points of poly( N-isopropylacrylamide) in aqueous mixed solvents, with methanol as the cosolvent, are experimentally measured for polymer concentrations varied up to as high as the weight fraction 0.25. They are shown to form closed loops on the ternary phase plane in the temperature region between 5 and 30 °C, and hence co-nonsolvency is complete. Miscibility loops shrink by cooling, or equivalently, they exhibit lower critical solution temperature behavior. For a fixed polymer concentration, there is a composition of the mixed solvent at which the cloud-point temperature takes the lowest value. This minimum cloud-point temperature composition of the mixed solvent turned out to be almost independent of the polymer concentration, at least within the measured dilute region below the weight fraction 0.25. On the basis of the assumption that the phase separation is closely related to the preferential adsorption of the solvents by hydrogen bonding, we employ a model solution of Flory-Huggins type, augmented with direct and cooperative polymer-solvent hydrogen bonds, to construct the ternary phase diagrams. Theoretical calculation of the spinodal curves is performed, and the results are compared with the obtained experimental cloud-point data. The effect of molecular volume of the cosolvent is also studied within the same theoretical framework. Possibility for a upper critical solution temperature co-nonsolvency to appear for cosolvents with larger molecular volume is discussed.
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Affiliation(s)
| | | | | | | | - Fumihiko Tanaka
- Department of Polymer Chemistry , Kyoto University , Katsura , Kyoto 615-8510 , Japan
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Kanduč M, Chudoba R, Palczynski K, Kim WK, Roa R, Dzubiella J. Selective solute adsorption and partitioning around single PNIPAM chains. Phys Chem Chem Phys 2018; 19:5906-5916. [PMID: 28176999 DOI: 10.1039/c6cp08366h] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Thermoresponsive polymer architectures have become integral building blocks of 'smart' functional materials in modern applications. For a large range of developments, e.g. for drug delivery or nanocatalytic carrier systems, the selective adsorption and partitioning of molecules (ligands or reactants) inside the polymeric matrix are key processes that have to be controlled and tuned for the desired material function. In order to gain insights into the nanoscale structure and binding details in such systems, we here employ molecular dynamics simulations of the popular poly(N-isopropylacrylamide) (PNIPAM) polymer in explicit water in the presence of various representative solute types with a focus on aromatic model reactants. We study a single polymer chain and explore the influence of its elongation, stereochemistry, and temperature on the solute binding affinities. While we find that the excess adsorption generally increases with the size of the solute, the temperature-dependent affinity to the chain is highly solute specific and has a considerable dependence on the polymer elongation (i.e. polymer swelling state). We elucidate the molecular mechanisms of the selective binding in detail and eventually present how the results can be extrapolated to macroscopic partitioning of the solutes in swollen polymer architectures, such as hydrogels.
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Affiliation(s)
- Matej Kanduč
- Soft Matter and Functional Materials, Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, D-14109 Berlin, Germany.
| | - Richard Chudoba
- Soft Matter and Functional Materials, Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, D-14109 Berlin, Germany. and Institut für Physik, Humboldt-Universität zu Berlin, Newtonstr. 15, D-12489 Berlin, Germany
| | - Karol Palczynski
- Soft Matter and Functional Materials, Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, D-14109 Berlin, Germany.
| | - Won Kyu Kim
- Soft Matter and Functional Materials, Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, D-14109 Berlin, Germany.
| | - Rafael Roa
- Soft Matter and Functional Materials, Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, D-14109 Berlin, Germany.
| | - Joachim Dzubiella
- Soft Matter and Functional Materials, Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, D-14109 Berlin, Germany. and Institut für Physik, Humboldt-Universität zu Berlin, Newtonstr. 15, D-12489 Berlin, Germany
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