1
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Lang M, Scholz R. On the Swelling of Polymer Network Strands. Macromol Rapid Commun 2024; 45:e2400025. [PMID: 38323367 DOI: 10.1002/marc.202400025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Indexed: 02/08/2024]
Abstract
Large scale computer simulations are employed to analyze the conformations of network strands in polymer networks at preparation conditions (characterized by a polymer volume fraction of ϕ0) and when swollen to equilibrium (characterized by a polymer volume fraction ϕ < ϕ0). Network strands in end-linked model networks are weakly stretched and partially swollen at preparation conditions as compared to linear polymers in the same solvent at ϕ0. Equilibrium swelling causes non-ideal chain conformations characterized by an effective scaling exponent approaching 7/10 on intermediate length scales for increasing overlap of the chains. The chain size in a network consists of a fluctuating and a time average "elastic" contribution. The elastic contribution swells essentially affinely ∝(ϕ0/ϕ)2/3, whereas the swelling of the fluctuating part lies between the expected swelling of the entanglement constraints and the swelling of non-cross-linked chains in a comparable semi-dilute solution. The total swelling of chain size results from the changes of both fluctuating and non-fluctuating contributions.
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Affiliation(s)
- Michael Lang
- Leibniz Institute of Polymer Research Dresden, Hohe Straße 6, 01069, Dresden, Germany
| | - Reinhard Scholz
- Leibniz Institute of Polymer Research Dresden, Hohe Straße 6, 01069, Dresden, Germany
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2
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Ninarello A, Ruiz-Franco J, Zaccarelli E. Auxetic polymer networks: The role of crosslinking, density, and disorder. J Chem Phys 2023; 159:234902. [PMID: 38108485 DOI: 10.1063/5.0178409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 11/24/2023] [Indexed: 12/19/2023] Open
Abstract
Low-crosslinked polymer networks have recently been found to behave auxetically when subjected to small tensions, that is, their Poisson's ratio ν becomes negative. In addition, for specific state points, numerical simulations revealed that diamond-like networks reach the limit of mechanical stability, exhibiting values of ν = -1, a condition that we define as hyper-auxeticity. This behavior is interesting per se for its consequences in materials science but is also appealing for fundamental physics because the mechanical instability is accompanied by evidence of criticality. In this work, we deepen our understanding of this phenomenon by performing a large set of equilibrium and stress-strain simulations in combination with phenomenological elasticity theory. The two approaches are found to be in good agreement, confirming the above results. We also extend our investigations to disordered polymer networks and find that the hyper-auxetic behavior also holds in this case, still manifesting a similar critical-like behavior as in the diamond one. Finally, we highlight the role of the number density, which is found to be a relevant control parameter determining the elastic properties of the system. The validity of the results under disordered conditions paves the way for an experimental investigation of this phenomenon in real systems, such as hydrogels.
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Affiliation(s)
- Andrea Ninarello
- CNR Institute of Complex Systems, Uos Sapienza, Piazzale Aldo Moro 2, 00185 Roma, Italy
- Department of Physics, Sapienza University of Rome, Piazzale Aldo Moro 2, 00185 Roma, Italy
| | - José Ruiz-Franco
- CNR Institute of Complex Systems, Uos Sapienza, Piazzale Aldo Moro 2, 00185 Roma, Italy
- Physical Chemistry and Soft Matter, Wageningen University and Research, Stippeneng 4, 6708WE Wageningen, The Netherlands
| | - Emanuela Zaccarelli
- CNR Institute of Complex Systems, Uos Sapienza, Piazzale Aldo Moro 2, 00185 Roma, Italy
- Department of Physics, Sapienza University of Rome, Piazzale Aldo Moro 2, 00185 Roma, Italy
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3
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Salamanca FM, Zepeda-Rodríguez Z, Diñeiro L, Escrivá MM, Herrero R, Navarro R, Valentín JL. Introducing "MEW2" Software: A Tool to Analyze MQ-NMR Experiments for Elastomers. Polymers (Basel) 2023; 15:4058. [PMID: 37896302 PMCID: PMC10609784 DOI: 10.3390/polym15204058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 09/30/2023] [Accepted: 10/09/2023] [Indexed: 10/29/2023] Open
Abstract
Low-field time-domain proton Nuclear Magnetic Resonance (NMR) spectroscopy is an attractive and powerful tool for studying the structure and dynamics of elastomers. The existence of crosslinks and other topological constraints in rubber matrices (entanglements and filler-rubber interactions, among others) renders the fast segmental fluctuations of the polymeric chains non-isotropic, obtaining nonzero residual dipolar couplings, which is the main observable of MQ-NMR experiments. A new software, Multiple quantum nuclear magnetic resonance analyzer for Elastomeric Networks v2 (MEW2), provides a new tool to facilitate the study of the molecular structure of elastomeric materials. This program quantitatively analyzes two different sets of experimental data obtained in the same experiment, which are dominated by multiple-quantum coherence and polymer dynamics. The proper quantification of non-coupled network defects (dangling chain ends, loops, etc.) allows the analyzer to normalize the multiple quantum intensity, obtaining a build-up curve that contains the structural information without any influence from the rubber dynamics. Finally, it provides the spatial distribution of crosslinks using a fast Tikhonov regularization process based on a statistical criterion. As a general trend, this study provides an automatic solution to a tedious procedure of analysis, demonstrating a new tool that accelerates the calculations of network structure using 1H MQ-NMR low-field time-domain experiments for elastomeric compounds.
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Affiliation(s)
- Fernando M Salamanca
- Instituto de Ciencia y Tecnología de Polímeros (ICTP-CSIC), Juan de la Cierva 3, 28006 Madrid, Spain
| | - Zenen Zepeda-Rodríguez
- Instituto de Ciencia y Tecnología de Polímeros (ICTP-CSIC), Juan de la Cierva 3, 28006 Madrid, Spain
| | - Laura Diñeiro
- Instituto de Ciencia y Tecnología de Polímeros (ICTP-CSIC), Juan de la Cierva 3, 28006 Madrid, Spain
| | - Marina M Escrivá
- Instituto de Ciencia y Tecnología de Polímeros (ICTP-CSIC), Juan de la Cierva 3, 28006 Madrid, Spain
| | - Rebeca Herrero
- Instituto de Ciencia y Tecnología de Polímeros (ICTP-CSIC), Juan de la Cierva 3, 28006 Madrid, Spain
| | - Rodrigo Navarro
- Instituto de Ciencia y Tecnología de Polímeros (ICTP-CSIC), Juan de la Cierva 3, 28006 Madrid, Spain
| | - Juan L Valentín
- Instituto de Ciencia y Tecnología de Polímeros (ICTP-CSIC), Juan de la Cierva 3, 28006 Madrid, Spain
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4
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Beech HK, Johnson JA, Olsen BD. Conformation of Network Strands in Polymer Gels. ACS Macro Lett 2023; 12:325-330. [PMID: 36802508 DOI: 10.1021/acsmacrolett.3c00006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Small angle neutron scattering was used to measure single chain radii of gyration of end-linked polymer gels before and after cross-linking to calculate the prestrain, which is the ratio of the average chain size in a cross-linked network to that of a free chain in solution. The prestrain increased from 1.06 ± 0.01 to 1.16 ± 0.02 as gel synthesis concentration decreased near the overlap concentration, indicating that the chains are slightly more stretched in the network than in solution. Dilute gels with higher loop fractions were found to be spatially homogeneous. Form factor and volumetric scaling analyses independently confirmed that elastic strands stretch by 2-23% from Gaussian conformations to create a space-spanning network, with increased stretching as network synthesis concentration decreases. Prestrain measurements reported here serve as a point of reference for network theories that rely on this parameter for the calculation of mechanical properties.
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Affiliation(s)
- Haley K Beech
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Jeremiah A Johnson
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Bradley D Olsen
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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5
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Sorichetti V, Ninarello A, Ruiz-Franco J, Hugouvieux V, Zaccarelli E, Micheletti C, Kob W, Rovigatti L. Structure and elasticity of model disordered, polydisperse, and defect-free polymer networks. J Chem Phys 2023; 158:074905. [PMID: 36813705 DOI: 10.1063/5.0134271] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The elasticity of disordered and polydisperse polymer networks is a fundamental problem of soft matter physics that is still open. Here, we self-assemble polymer networks via simulations of a mixture of bivalent and tri- or tetravalent patchy particles, which result in an exponential strand length distribution analogous to that of experimental randomly cross-linked systems. After assembly, the network connectivity and topology are frozen and the resulting system is characterized. We find that the fractal structure of the network depends on the number density at which the assembly has been carried out, but that systems with the same mean valence and same assembly density have the same structural properties. Moreover, we compute the long-time limit of the mean-squared displacement, also known as the (squared) localization length, of the cross-links and of the middle monomers of the strands, showing that the dynamics of long strands is well described by the tube model. Finally, we find a relation connecting these two localization lengths at high density and connect the cross-link localization length to the shear modulus of the system.
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Affiliation(s)
- Valerio Sorichetti
- Laboratoire Charles Coulomb (L2C), Univ. Montpellier, CNRS, F-34095 Montpellier, France
| | | | | | | | | | - Cristian Micheletti
- SISSA-Scuola Internazionale Superiore di Studi Avanzati, Via Bonomea 265, 34136 Trieste, Italy
| | - Walter Kob
- Laboratoire Charles Coulomb (L2C), Univ. Montpellier, CNRS, F-34095 Montpellier, France
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6
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Lang M, Müller T. On the Reference Size of Chains in a Network and the Shear Modulus of Unentangled Networks Made of Real Chains. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c00660] [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)
- Michael Lang
- Institut Theorie der Polymere, Leibniz Institut für Polymerforschung Dresden, Hohe Straße 6, 01069 Dresden, Germany
| | - Toni Müller
- Institut Theorie der Polymere, Leibniz Institut für Polymerforschung Dresden, Hohe Straße 6, 01069 Dresden, Germany
- Institut für Theoretische Physik, Technische Universität Dresden, Zellescher Weg 17, 01069 Dresden, Germany
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7
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Müller T, Sommer JU, Lang M. Elasticity of Tendomer Gels. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c01229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Toni Müller
- Technische Universität Dresden, 01069 Dresden, Germany
| | | | - Michael Lang
- Leibniz-Institut für Polymerforschung Dresden e. V., Hohe Straße 6, 01069 Dresden, Germany
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8
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Bunk C, Löser L, Fribiczer N, Komber H, Jakisch L, Scholz R, Voit B, Seiffert S, Saalwächter K, Lang M, Böhme F. Amphiphilic Model Networks Based on PEG and PCL Tetra-arm Star Polymers with Complementary Reactivity. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c00693] [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)
- Carolin Bunk
- Leibniz-Institut für Polymerforschung Dresden e. V., Hohe Str. 6, 01069 Dresden, Germany
- Organic Chemistry of Polymers, Technische Universität Dresden, 01062 Dresden, Germany
| | - Lucas Löser
- Institut für Physik - NMR Group, Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str. 7, 06120 Halle, Germany
| | - Nora Fribiczer
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Hartmut Komber
- Leibniz-Institut für Polymerforschung Dresden e. V., Hohe Str. 6, 01069 Dresden, Germany
| | - Lothar Jakisch
- Leibniz-Institut für Polymerforschung Dresden e. V., Hohe Str. 6, 01069 Dresden, Germany
| | - Reinhard Scholz
- Leibniz-Institut für Polymerforschung Dresden e. V., Hohe Str. 6, 01069 Dresden, Germany
| | - Brigitte Voit
- Leibniz-Institut für Polymerforschung Dresden e. V., Hohe Str. 6, 01069 Dresden, Germany
- Organic Chemistry of Polymers, Technische Universität Dresden, 01062 Dresden, Germany
| | - Sebastian Seiffert
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Kay Saalwächter
- Institut für Physik - NMR Group, Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str. 7, 06120 Halle, Germany
| | - Michael Lang
- Leibniz-Institut für Polymerforschung Dresden e. V., Hohe Str. 6, 01069 Dresden, Germany
| | - Frank Böhme
- Leibniz-Institut für Polymerforschung Dresden e. V., Hohe Str. 6, 01069 Dresden, Germany
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9
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Lang M, Scholz R, Löser L, Bunk C, Fribiczer N, Seiffert S, Böhme F, Saalwächter K. Swelling and Residual Bond Orientations of Polymer Model Gels: The Entanglement-Free Limit. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c00589] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Michael Lang
- Leibniz Institut für Polymerforschung, Hohe Straße 6, 01069 Dresden, Germany
| | - Reinhard Scholz
- Leibniz Institut für Polymerforschung, Hohe Straße 6, 01069 Dresden, Germany
| | - Lucas Löser
- Martin-Luther Universität Halle-Wittenberg, Institute of Physics − NMR Group, Betty-Heimann-Straße 7, D-06120 Halle/Saale, Germany
| | - Carolin Bunk
- Leibniz Institut für Polymerforschung, Hohe Straße 6, 01069 Dresden, Germany
- Organic Chemistry of Polymers, Technische Universität Dresden, 01062 Dresden, Germany
| | - Nora Fribiczer
- Johannes Gutenberg University Mainz, Department of Chemistry, Duesbergweg 10−14, D-55128 Mainz, Germany
| | - Sebastian Seiffert
- Johannes Gutenberg University Mainz, Department of Chemistry, Duesbergweg 10−14, D-55128 Mainz, Germany
| | - Frank Böhme
- Leibniz Institut für Polymerforschung, Hohe Straße 6, 01069 Dresden, Germany
| | - Kay Saalwächter
- Martin-Luther Universität Halle-Wittenberg, Institute of Physics − NMR Group, Betty-Heimann-Straße 7, D-06120 Halle/Saale, Germany
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10
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Sotta P, Albouy PA, Abou Taha M, Moreaux B, Fayolle C. Crosslinked Elastomers: Structure-Property Relationships and Stress-Optical Law. Polymers (Basel) 2021; 14:polym14010009. [PMID: 35012035 PMCID: PMC8747717 DOI: 10.3390/polym14010009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/04/2021] [Accepted: 12/16/2021] [Indexed: 11/16/2022] Open
Abstract
We present a combination of independent techniques in order to characterize crosslinked elastomers. We combine well-established macroscopic methods, such as rheological and mechanical experiments and equilibrium swelling measurements, a more advanced technique such as proton multiple-quantum NMR, and a new method to measure stress-induced segmental orientation by in situ tensile X-ray scattering. All of these techniques give access to the response of the elastomer network in relation to the crosslinking of the systems. Based on entropic elasticity theory, all these quantities are related to segmental orientation effects through the so-called stress-optical law. By means of the combination of these techniques, we investigate a set of unfilled sulfur-vulcanized styrene butadiene rubber elastomers with different levels of crosslinking. We validate that the results of all methods correlate very well. The relevance of this approach is that it can be applied in any elastomer materials, including materials representative of various industrial application, without prerequisite as regards, e.g., optical transparency or simplified formulation. Moreover, the approach may be used to study reinforcement effects in filled elastomers with nanoparticles.
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Affiliation(s)
- Paul Sotta
- Laboratoire Polymères et Matériaux Avancés, CNRS, UMR 5268, Solvay, F-69192 Saint-Fons, France;
- Ingénierie des Matériaux Polymères, Université de Lyon, CNRS, UMR 5223, INSA Lyon, Université Lyon 1, UJM, F-69621 Villeurbanne, France
- Correspondence:
| | - Pierre-Antoine Albouy
- Laboratoire de Physique des Solides, Université Paris-Saclay, CNRS, UMR 8502, F-91405 Orsay, France;
| | - Mohammad Abou Taha
- Laboratoire Polymères et Matériaux Avancés, CNRS, UMR 5268, Solvay, F-69192 Saint-Fons, France;
- Ingénierie des Matériaux Polymères, Université de Lyon, CNRS, UMR 5223, INSA Lyon, Université Lyon 1, UJM, F-69621 Villeurbanne, France
| | - Benoit Moreaux
- Solvay Silica, F-69660 Collonges-au-Mont-d’Or, France; (B.M.); (C.F.)
| | - Caroline Fayolle
- Solvay Silica, F-69660 Collonges-au-Mont-d’Or, France; (B.M.); (C.F.)
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11
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Affiliation(s)
- Toni Müller
- Technical University Dresden, 01069 Dresden, Germany
- Leibniz Institute of Polymer Research Dresden, Hohe Str. 6, 01069 Dresden, Germany
| | - Jens-Uwe Sommer
- Technical University Dresden, 01069 Dresden, Germany
- Leibniz Institute of Polymer Research Dresden, Hohe Str. 6, 01069 Dresden, Germany
| | - Michael Lang
- Leibniz Institute of Polymer Research Dresden, Hohe Str. 6, 01069 Dresden, Germany
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12
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Danielsen SPO, Beech HK, Wang S, El-Zaatari BM, Wang X, Sapir L, Ouchi T, Wang Z, Johnson PN, Hu Y, Lundberg DJ, Stoychev G, Craig SL, Johnson JA, Kalow JA, Olsen BD, Rubinstein M. Molecular Characterization of Polymer Networks. Chem Rev 2021; 121:5042-5092. [PMID: 33792299 DOI: 10.1021/acs.chemrev.0c01304] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Polymer networks are complex systems consisting of molecular components. Whereas the properties of the individual components are typically well understood by most chemists, translating that chemical insight into polymer networks themselves is limited by the statistical and poorly defined nature of network structures. As a result, it is challenging, if not currently impossible, to extrapolate from the molecular behavior of components to the full range of performance and properties of the entire polymer network. Polymer networks therefore present an unrealized, important, and interdisciplinary opportunity to exert molecular-level, chemical control on material macroscopic properties. A barrier to sophisticated molecular approaches to polymer networks is that the techniques for characterizing the molecular structure of networks are often unfamiliar to many scientists. Here, we present a critical overview of the current characterization techniques available to understand the relation between the molecular properties and the resulting performance and behavior of polymer networks, in the absence of added fillers. We highlight the methods available to characterize the chemistry and molecular-level properties of individual polymer strands and junctions, the gelation process by which strands form networks, the structure of the resulting network, and the dynamics and mechanics of the final material. The purpose is not to serve as a detailed manual for conducting these measurements but rather to unify the underlying principles, point out remaining challenges, and provide a concise overview by which chemists can plan characterization strategies that suit their research objectives. Because polymer networks cannot often be sufficiently characterized with a single method, strategic combinations of multiple techniques are typically required for their molecular characterization.
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Affiliation(s)
- Scott P O Danielsen
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Haley K Beech
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Shu Wang
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Bassil M El-Zaatari
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Xiaodi Wang
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | | | | | - Zi Wang
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Patricia N Johnson
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Yixin Hu
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - David J Lundberg
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Georgi Stoychev
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Stephen L Craig
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Jeremiah A Johnson
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Julia A Kalow
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Bradley D Olsen
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Michael Rubinstein
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina 27599, United States.,Department of Chemistry, Duke University, Durham, North Carolina 27708, United States.,Departments of Biomedical Engineering and Physics, Duke University, Durham, North Carolina 27708, United States.,World Primer Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Kita 21 Nishi 10, Kita-ku, Sapporo, Hokkaido 001-0021, Japan
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13
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Martini F, Carignani E, Nardelli F, Rossi E, Borsacchi S, Cettolin M, Susanna A, Geppi M, Calucci L. Glassy and Polymer Dynamics of Elastomers by 1H Field-Cycling NMR Relaxometry: Effects of Cross-Linking. Macromolecules 2020; 53:10028-10039. [PMID: 33250523 PMCID: PMC7690040 DOI: 10.1021/acs.macromol.0c01439] [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] [Received: 06/19/2020] [Revised: 10/20/2020] [Indexed: 11/28/2022]
Abstract
![]()
1H spin lattice relaxation
rate (R1) dispersions were acquired by
field-cycling (FC) NMR relaxometry
between 0.01 and 35 MHz over a wide temperature range on polyisoprene
(IR), polybutadiene (BR), and poly(styrene-co-butadiene)
(SBR) rubbers, obtained by vulcanization under different conditions,
and on the corresponding uncured elastomers. By exploiting the frequency–temperature
superposition principle, χ″(ωτs) master curves were constructed by shifting the total FC NMR susceptibility,
χ″(ω) = ωR1(ω),
curves along the frequency axis by the correlation times for glassy
dynamics, τs. Longer τs values and,
correspondingly, higher glass transition temperatures were determined
for the sulfur-cured elastomers with respect to the uncured ones,
which increased by increasing the cross-link density, whereas no significant
changes were found for fragility. The contribution of polymer dynamics,
χpol″(ω), to χ″(ω)
was singled out by subtracting the contribution of glassy dynamics,
χglass″(ω), well represented using a
Cole–Davidson spectral density. For all elastomers, χpol″(ω) was found to represent a small fraction, on the order of
0.05–0.14, of the total χ″(ω), which did
not show a significant dependence on cross-link density. In the investigated
temperature and frequency ranges, polymer dynamics was found to encompass
regimes I (Rouse dynamics) and II (constrained Rouse dynamics) of
the tube reptation model for the uncured elastomers and only regime
I for the vulcanized ones. This is clear evidence that chemical cross-links
impose constraints on chain dynamics on a larger space and time scale
than free Rouse modes.
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Affiliation(s)
- Francesca Martini
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy.,Istituto di Chimica dei Composti OrganoMetallici, Consiglio Nazionale Delle Ricerche, Via G. Moruzzi 1, 56124 Pisa, Italy
| | - Elisa Carignani
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy.,Istituto di Chimica dei Composti OrganoMetallici, Consiglio Nazionale Delle Ricerche, Via G. Moruzzi 1, 56124 Pisa, Italy
| | - Francesca Nardelli
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy.,Istituto di Chimica dei Composti OrganoMetallici, Consiglio Nazionale Delle Ricerche, Via G. Moruzzi 1, 56124 Pisa, Italy
| | - Elena Rossi
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy
| | - Silvia Borsacchi
- Istituto di Chimica dei Composti OrganoMetallici, Consiglio Nazionale Delle Ricerche, Via G. Moruzzi 1, 56124 Pisa, Italy
| | | | | | - Marco Geppi
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy.,Istituto di Chimica dei Composti OrganoMetallici, Consiglio Nazionale Delle Ricerche, Via G. Moruzzi 1, 56124 Pisa, Italy
| | - Lucia Calucci
- Istituto di Chimica dei Composti OrganoMetallici, Consiglio Nazionale Delle Ricerche, Via G. Moruzzi 1, 56124 Pisa, Italy
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14
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Lang M, Müller T. Analysis of the Gel Point of Polymer Model Networks by Computer Simulations. Macromolecules 2020. [DOI: 10.1021/acs.macromol.9b02217] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- M. Lang
- Leibniz Institut für Polymerforschung Dresden, Hohe Straße 6, 01069 Dresden, Germany
| | - T. Müller
- Leibniz Institut für Polymerforschung Dresden, Hohe Straße 6, 01069 Dresden, Germany
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15
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Gusev AA, Schwarz F. Molecular Dynamics Validation and Applications of the Maximum Entropy Homogenization Procedure for Predicting the Elastic Properties of Gaussian Polymer Networks. Macromolecules 2019. [DOI: 10.1021/acs.macromol.9b01766] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Andrei A. Gusev
- Department of Materials, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Fabian Schwarz
- Department of Materials, ETH Zürich, CH-8093 Zürich, Switzerland
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16
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Affiliation(s)
- Michael Lang
- Leibniz Institute of Polymer Research Dresden, Hohe Str. 6, 01069 Dresden, Germany
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17
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Affiliation(s)
- Sergey Panyukov
- P. N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow 117924, Russia
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18
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Gusev AA. Numerical Estimates of the Topological Effects in the Elasticity of Gaussian Polymer Networks and Their Exact Theoretical Description. Macromolecules 2019. [DOI: 10.1021/acs.macromol.9b00262] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Andrei A. Gusev
- Institute of Polymers, Department of Materials, ETH Zürich, CH-8093 Zürich, Switzerland
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19
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Lin TS, Wang R, Johnson JA, Olsen BD. Revisiting the Elasticity Theory for Real Gaussian Phantom Networks. Macromolecules 2019. [DOI: 10.1021/acs.macromol.8b01676] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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20
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Abstract
The impact of finite cycles on the phantom modulus in an otherwise perfect network is computed exactly. It is shown that pending cycles reduce the phantom modulus of the network by kT/V independent of junction functionality. The correction for nonpending cycles is larger than estimated previously within this particular approximation of the surrounding network structure. It is discussed that loop formation inevitably leads to streched chain conformations, if the loops are built step by step as part of the network structure. All network loops tend to contract simultaneously to optimize conformations, which leads to an increasing stretch of chains in larger loops that can be observed in computer simulations. Possible other corrections to the phantom modulus that were left aside in previous work are discussed briefly.
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Affiliation(s)
- Michael Lang
- Leibniz Institute of Polymer Research Dresden, Hohe Straße 6, 01069 Dresden, Germany
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21
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Basterra-Beroiz B, Rommel R, Kayser F, Valentín JL, Westermann S, Heinrich G. Revisiting Segmental Order: A Simplified Approach for Sulfur-Cured Rubbers Considering Junction Fluctuations and Entanglements. Macromolecules 2018. [DOI: 10.1021/acs.macromol.8b00099] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
| | - Robert Rommel
- Goodyear
Innovation
Center Luxembourg, Avenue Gordon Smith, L-7750 Colmar-Berg, Luxembourg
| | - François Kayser
- Goodyear
Innovation
Center Luxembourg, Avenue Gordon Smith, L-7750 Colmar-Berg, Luxembourg
| | - Juan L. Valentín
- Institute of Polymer
Science and Technology (CSIC), c/Juan de la Cierva 3, 28006 Madrid, Spain
| | - Stephan Westermann
- Goodyear
Innovation
Center Luxembourg, Avenue Gordon Smith, L-7750 Colmar-Berg, Luxembourg
| | - Gert Heinrich
- Leibniz-Institut
für Polymerforschung Dresden e.V., Hohe Straβe 6, 01069 Dresden, Germany
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22
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Basterra-Beroiz B, Rommel R, Kayser F, Westermann S, Valentín JL, Heinrich G. NEW INSIGHTS INTO RUBBER NETWORK STRUCTURE BY A COMBINATION OF EXPERIMENTAL TECHNIQUES. RUBBER CHEMISTRY AND TECHNOLOGY 2017. [DOI: 10.5254/rct.16.83732] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
ABSTRACT
Robust quantitative cross-link density characterization becomes necessary for the complete understanding of the structure and optimization of final properties of rubber compounds for industrial applications. A combination of different experimental techniques have been used to establish the quantitative consistency on the correlations between the results obtained by the individual methods within a reliable unique (physically based) platform reclined on the concept of rubber elasticity that considers the impact of entanglements in technical rubbers. The contribution of cross-links and elastically active entanglements to mechanical properties has been quantified by the analysis of uniaxial stress–strain measurements by means of the extended tube model of rubber elasticity. In a complementary manner, rubber network structure has also been investigated by state-of-the-art multiple-quantum low-field NMR experiments and classical T1 and T2 relaxation measurements. In addition, equilibrium swelling data were analyzed by the classical phantom and Flory–Rehner limits as well as by applying the theoretical approach proposed by Helmis, Heinrich, and Straube that takes into account topological constraints during swelling. Correlations among these complementary techniques have been reported, and the interpretation of the obtained differences is addressed. The baseline study focuses on unfilled NR, setting the basis for the investigation of unfilled SBR matrices and filled rubbers.
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Affiliation(s)
| | - Robert Rommel
- Goodyear Innovation Center Luxembourg, Avenue Gordon Smith, L-7750 Colmar-Berg, Luxembourg
| | - Francois Kayser
- Goodyear Innovation Center Luxembourg, Avenue Gordon Smith, L-7750 Colmar-Berg, Luxembourg
| | - Stephan Westermann
- Goodyear Innovation Center Luxembourg, Avenue Gordon Smith, L-7750 Colmar-Berg, Luxembourg
| | - Juan López Valentín
- Instituto de Ciencia y Tecnología de Polímeros (CSIC), c/Juan de la Cierva 3, 28006 Madrid, Spain
| | - Gert Heinrich
- Leibniz-Institut für Polymerforschung Dresden E.V., Hohe Straβe 6, D-01069 Dresden, Germany
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23
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Lang M. Relation between Cross-Link Fluctuations and Elasticity in Entangled Polymer Networks. Macromolecules 2017. [DOI: 10.1021/acs.macromol.6b02690] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- M. Lang
- Leibniz-Institut für Polymerforschung, Hohe Straße 6, 01069 Dresden, Germany
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24
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Abstract
Different methods for creating Olympic gels are analyzed using computer simulations. First ideal reference samples are obtained from freely interpenetrating semi-dilute solutions and melts of cyclic polymers. The distribution of pairwise concatenations per cyclic molecule is given by a Poisson-distribution and can be used to describe the elastic structure of the gels. Several batches of linear chains decorated with different selectively binding groups at their ends are mixed in the "DNA Origami" technique and network formation is realized. While the formation of cyclic molecules follows mean field predictions below overlap of the precursor molecules, an enhanced ring formation above overlap is found that is not explained by mean field arguments. The "progressive construction" method allows to create Olympic gels with a single reaction step from a concentrated mixture of large compressed rings with a low weight fraction of short chains that are below overlap concentration. This method, however, is limited by the difficulty to obtain a sufficiently high degree of polymerization of the large rings.
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Affiliation(s)
- J Fischer
- Leibniz Institut für Polymerforschung Dresden, Hohe Straße 6, 01069 Dresden, Germany
| | - M Lang
- Leibniz Institut für Polymerforschung Dresden, Hohe Straße 6, 01069 Dresden, Germany
| | - J-U Sommer
- Leibniz Institut für Polymerforschung Dresden, Hohe Straße 6, 01069 Dresden, Germany
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25
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Amin D, Likhtman AE, Wang Z. Dynamics in Supramolecular Polymer Networks Formed by Associating Telechelic Chains. Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b00561] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Dipesh Amin
- School of Mathematical, Physical
and Computational Sciences, University of Reading, Whiteknights, Reading RG6 6AX, U.K
| | - Alexei E. Likhtman
- School of Mathematical, Physical
and Computational Sciences, University of Reading, Whiteknights, Reading RG6 6AX, U.K
| | - Zuowei Wang
- School of Mathematical, Physical
and Computational Sciences, University of Reading, Whiteknights, Reading RG6 6AX, U.K
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26
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Affiliation(s)
- M. Lang
- Leibniz-Institut für Polymerforschung
Dresden e.V., Hohe Str. 6, D-01069 Dresden, Germany
| | - M. Werner
- Leibniz-Institut für Polymerforschung
Dresden e.V., Hohe Str. 6, D-01069 Dresden, Germany
| | - R. Dockhorn
- Leibniz-Institut für Polymerforschung
Dresden e.V., Hohe Str. 6, D-01069 Dresden, Germany
| | - T. Kreer
- Leibniz-Institut für Polymerforschung
Dresden e.V., Hohe Str. 6, D-01069 Dresden, Germany
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27
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Wang H, Shentu B, Faller R. Refinement of a coarse-grained model of poly(2,6-dimethyl-1,4-phenylene ether) and its application to blends of PPE and PS. MOLECULAR SIMULATION 2016. [DOI: 10.1080/08927022.2015.1047368] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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28
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Lang M, John A, Sommer JU. Model simulations on network formation and swelling as obtained from cross-linking co-polymerization reactions. POLYMER 2016. [DOI: 10.1016/j.polymer.2015.10.061] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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29
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Lang M, Rubinstein M, Sommer JU. Conformations of a Long Polymer in a Melt of Shorter Chains: Generalizations of the Flory Theorem. ACS Macro Lett 2015; 4:177-181. [PMID: 26543675 PMCID: PMC4621164 DOI: 10.1021/mz500777r] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 01/05/2015] [Indexed: 11/28/2022]
Abstract
Large-scale simulations of the swelling of a long N-mer in a melt of chemically identical P-mers are used to investigate a discrepancy between theory and experiments. Classical theory predicts an increase of probe chain size R ∼ P-0.18 with decreasing degree of polymerization P of melt chains in the range of 1 < P < N1/2. However, both experiment and simulation data are more consistent with an apparently slower swelling R ∼ P-0.1 over a wider range of melt degrees of polymerization. This anomaly is explained by taking into account the recently discovered long-range bond correlations in polymer melts and corrections to excluded volume. We generalize the Flory theorem and demonstrate that it is in excellent agreement with experiments and simulations.
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Affiliation(s)
- Michael Lang
- Leibniz Institute of Polymer Research Dresden, Hohe Straße 6, 01069 Dresden, Germany
| | - Michael Rubinstein
- Department
of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599-3290, United States
| | - Jens-Uwe Sommer
- Leibniz Institute of Polymer Research Dresden, Hohe Straße 6, 01069 Dresden, Germany
- Institute
of Theoretical Physics, Technische Universität Dresden, Zellescher Weg
17, 01062 Dresden, Germany
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30
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Ott M, Pérez-Aparicio R, Schneider H, Sotta P, Saalwächter K. Microscopic Study of Chain Deformation and Orientation in Uniaxially Strained Polymer Networks: NMR Results versus Different Network Models. Macromolecules 2014. [DOI: 10.1021/ma5012655] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Maria Ott
- Institut
für Physik − NMR, Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str.
7, 06120 Halle, Germany
| | - Roberto Pérez-Aparicio
- Laboratoire
Polymères et Matériaux Avancés, UMR 5268, CNRS/Rhodia-Solvay, 85 avenue des Frères Perret, F-69192 Saint Fons, France
| | - Horst Schneider
- Institut
für Physik − NMR, Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str.
7, 06120 Halle, Germany
| | - Paul Sotta
- Laboratoire
Polymères et Matériaux Avancés, UMR 5268, CNRS/Rhodia-Solvay, 85 avenue des Frères Perret, F-69192 Saint Fons, France
| | - Kay Saalwächter
- Institut
für Physik − NMR, Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str.
7, 06120 Halle, Germany
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31
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Romeis D, Lang M. Excluded volume effects in polymer brushes at moderate chain stretching. J Chem Phys 2014; 141:104902. [DOI: 10.1063/1.4894503] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Dirk Romeis
- Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Strasse 6, 01069 Dresden, Germany
| | - Michael Lang
- Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Strasse 6, 01069 Dresden, Germany
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