1
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Phillies GDJ. Simulational Tests of the Rouse Model. Polymers (Basel) 2023; 15:2615. [PMID: 37376261 DOI: 10.3390/polym15122615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 05/24/2023] [Accepted: 06/03/2023] [Indexed: 06/29/2023] Open
Abstract
An extensive review of literature simulations of quiescent polymer melts is given, considering results that test aspects of the Rouse model in the melt. We focus on Rouse model predictions for the mean-square amplitudes ⟨(Xp(0))2⟩ and time correlation functions ⟨Xp(0)Xp(t)⟩ of the Rouse mode Xp(t). The simulations conclusively demonstrate that the Rouse model is invalid in polymer melts. In particular, and contrary to the Rouse model, (i) mean-square Rouse mode amplitudes ⟨(Xp(0))2⟩ do not scale as sin-2(pπ/2N), N being the number of beads in the polymer. For small p (say, p≤3) ⟨(Xp(0))2⟩ scales with p as p-2; for larger p, it scales as p-3. (ii) Rouse mode time correlation functions ⟨Xp(t)Xp(0)⟩ do not decay with time as exponentials; they instead decay as stretched exponentials exp(-αtβ). β depends on p, typically with a minimum near N/2 or N/4. (iii) Polymer bead displacements are not described by independent Gaussian random processes. (iv) For p≠q, ⟨Xp(t)Xq(0)⟩ is sometimes non-zero. (v) The response of a polymer coil to a shear flow is a rotation, not the affine deformation predicted by Rouse. We also briefly consider the Kirkwood-Riseman polymer model.
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2
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Ohkuma T, Hagita K, Murashima T, Deguchi T. Miscibility and exchange chemical potential of ring polymers in symmetric ring-ring blends. SOFT MATTER 2023; 19:3818-3827. [PMID: 37191220 DOI: 10.1039/d3sm00108c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Generally, differences of polymer topologies may affect polymer miscibility even with the same repeated units. In this study, the topological effect of ring polymers on miscibility was investigated by comparing symmetric ring-ring and linear-linear polymer blends. To elucidate the topological effect of ring polymers on mixing free energy, the exchange chemical potential of binary blends was numerically evaluated as a function of composition ϕ by performing semi-grand canonical Monte Carlo and molecular dynamics simulations of a bead-spring model. For ring-ring blends, an effective miscibility parameter was evaluated by comparing the exchange chemical potential with that of the Flory-Huggins model for linear-linear polymer blends. It was confirmed that in the mixed states satisfying χN > 0, ring-ring blends are more miscible and stable than the linear-linear blends with the same molecular weight. Furthermore, we investigated finite molecular weight dependence on the miscibility parameter, which reflected the statistical probability of interchain interactions in the blends. The simulation results revealed that the molecular weight dependence on the miscibility parameter was smaller in ring-ring blends. The effect of the ring polymers on miscibility was verified to be consistent with the change in the interchain radial distribution function. In ring-ring blends, it was indicated that the topology affected miscibility by reducing the effect of the direct interaction between the components of the blends.
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Affiliation(s)
- Takahiro Ohkuma
- Digital Engineering Division, Bridgestone Corporation, Kodaira, 187-8531, Japan.
| | - Katsumi Hagita
- Department of Applied Physics, National Defense Academy, 1-10-20, Hashirimizu, Yokosuka, 239-8686, Japan
| | - Takahiro Murashima
- Department of Physics, Tohoku University, 6-3, Aramaki-aza-Aoba, Aoba-ku, Sendai, 980-8578, Japan
| | - Tetsuo Deguchi
- Department of Physics, Faculty of Core Research, Ochanomizu University, 2-1-1 Ohtsuka, Bunkyo-ku, Tokyo 112-8610, Japan
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3
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Choi JH, Kwon T, Sung BJ. Relative Chain Flexibility Determines the Spatial Arrangement and the Diffusion of a Single Ring Chain in Linear Chain Films. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c01937] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Jong Ho Choi
- Department of Chemistry, Sogang University, Seoul 04107, Republic of Korea
| | - Taejin Kwon
- Department of Chemistry, Sogang University, Seoul 04107, Republic of Korea
| | - Bong June Sung
- Department of Chemistry, Sogang University, Seoul 04107, Republic of Korea
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4
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Hagita K, Murashima T. Molecular Dynamics Simulations of Ring Shapes on a Ring Fraction in Ring–Linear Polymer Blends. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c00656] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Katsumi Hagita
- Department of Applied Physics, National Defense Academy, 1-10-20, Hashirimizu, Yokosuka 239-8686, Japan
| | - Takahiro Murashima
- Department of Physics, Tohoku University, 6-3, Aramaki-aza-Aoba, Aoba-ku, Sendai 980-8578, Japan
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5
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Liebetreu M, Likos CN. Cluster prevalence in concentrated ring-chain mixtures under shear. SOFT MATTER 2020; 16:8710-8719. [PMID: 32996544 DOI: 10.1039/d0sm01309a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Semiflexible ring polymers are known to exhibit clustering behavior and form stacks in concentrated solutions. Recently, weak shear was suggested to re-orient these stacks with flow, a phenomenon more easily visible in more concentrated solutions [Liebetreu et al., ACS Appl. Polym. Mater., 2020, 2(8), 3505-3517, DOI: 10.1021/acsapm.0c00522]. In this work, we investigate the impact of mixing linear chains and rings in a similar system under shear, studying clustering in the presence of semiflexible, rod-like chains. We present a correlation between chain monomer fraction and clustering behavior as linear chains take up less space, thus decreasing the system's effective density and, subsequently, clustering. However, we suggest mixtures with a low chain concentration to maintain or potentially enhance clustering at equilibrium while this effect is destroyed under shear. The mixing of chains and rings may therefore be used to create more strongly organized structures susceptible to reorientation via weak shear.
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Affiliation(s)
- Maximilian Liebetreu
- Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna, Austria.
| | - Christos N Likos
- Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna, Austria.
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6
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Local Effects of Ring Topology Observed in Polymer Conformation and Dynamics by Neutron Scattering-A Review. Polymers (Basel) 2020; 12:polym12091884. [PMID: 32825628 PMCID: PMC7563567 DOI: 10.3390/polym12091884] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 08/14/2020] [Accepted: 08/17/2020] [Indexed: 11/24/2022] Open
Abstract
The physical properties of polymers depend on a range of both structural and chemical parameters, and in particular, on molecular topology. Apparently simple changes such as joining chains at a point to form stars or simply joining the two ends to form a ring can profoundly alter molecular conformation and dynamics, and hence properties. Cyclic polymers, as they do not have free ends, represent the simplest model system where reptation is completely suppressed. As a consequence, there exists a considerable literature and several reviews focused on high molecular weight cyclics where long range dynamics described by the reptation model comes into play. However, this is only one area of interest. Consideration of the conformation and dynamics of rings and chains, and of their mixtures, over molecular weights ranging from tens of repeat units up to and beyond the onset of entanglements and in both solution and melts has provided a rich literature for theory and simulation. Experimental work, particularly neutron scattering, has been limited by the difficulty of synthesizing well-characterized ring samples, and deuterated analogues. Here in the context of the broader literature we review investigations of local conformation and dynamics of linear and cyclic polymers, concentrating on poly(dimethyl siloxane) (PDMS) and covering a wide range of generally less high molar masses. Experimental data from small angle neutron scattering (SANS) and quasi-elastic neutron scattering (QENS), including Neutron Spin Echo (NSE), are compared to theory and computational predictions.
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7
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Rauscher PM, Schweizer KS, Rowan SJ, de Pablo JJ. Dynamics of poly[n]catenane melts. J Chem Phys 2020; 152:214901. [PMID: 32505155 DOI: 10.1063/5.0007573] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Inspired by advances in the chemical synthesis of interlocking polymer architectures, extensive molecular dynamics simulations have been conducted to study the dynamical properties of poly[n]catenanes-polymers composed entirely of interlocking rings-in the melt state. Both the degree of polymerization (number of links) and the number of beads per ring are systematically varied, and the results are compared to linear and ring polymers. A simple Rouse-like model is presented, and its analytical solution suggests a decomposition of the dynamics into "ring-like" and "linear-like" regimes at short and long times, respectively. In agreement with this picture, multiple sub-diffusive regimes are observed in the monomer mean-squared-displacements even though interchain entanglement is not prevalent in the system. However, the Rouse-type model does not account for the topological effects of the mechanical bonds, which significantly alter the dynamics at intermediate length scales both within the rings and at the chain segment scales. The stress relaxation in the system is extremely rapid and may be conveniently separated into ring-like and linear-like contributions, again in agreement with the Rouse picture. However, the viscosity has a non-monotonic dependence on the ring size for long chains, which disagrees strongly with theoretical predictions. This unexpected observation cannot be explained in terms of chain disentanglement and is inconsistent with other measures of polymer relaxation. Possible mechanisms for this behavior are proposed and implications for materials design are discussed.
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Affiliation(s)
- Phillip M Rauscher
- Pritzker School of Molecular Engineering, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637, USA
| | - Kenneth S Schweizer
- Department of Materials Science, University of Illinois, 1304 West Green Street, Urbana, Illinois 61801-3028, USA
| | - Stuart J Rowan
- Pritzker School of Molecular Engineering, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637, USA
| | - Juan J de Pablo
- Pritzker School of Molecular Engineering, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637, USA
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8
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Lee E, Paul W. Additional Entanglement Effect Imposed by Small Sized Ring Aggregates in Supramolecular Polymer Melts: Molecular Dynamics Simulation Study. Macromolecules 2020. [DOI: 10.1021/acs.macromol.9b02209] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Eunsang Lee
- Institut für Physik, Martin-Luther Universität Halle-Wittenberg, Halle 06120, Germany
| | - Wolfgang Paul
- Institut für Physik, Martin-Luther Universität Halle-Wittenberg, Halle 06120, Germany
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9
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Tsalikis DG, Mavrantzas VG. Size and Diffusivity of Polymer Rings in Linear Polymer Matrices: The Key Role of Threading Events. Macromolecules 2020. [DOI: 10.1021/acs.macromol.9b02099] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Dimitrios G. Tsalikis
- Department of Chemical Engineering, University of Patras and FORTH-ICE/HT, GR 26504 Patras, Greece
| | - Vlasis G. Mavrantzas
- Department of Chemical Engineering, University of Patras and FORTH-ICE/HT, GR 26504 Patras, Greece
- Particle Technology Laboratory, Department of Mechanical and Process Engineering, ETH Zürich, CH-8092 Zürich, Switzerland
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10
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Wang W, Biswas CS, Huang C, Zhang H, Liu CY, Stadler FJ, Du B, Yan ZC. Topological Effect on Effective Local Concentration and Dynamics in Linear/Linear, Ring/Ring, and Linear/Ring Miscible Polymer Blends. Macromolecules 2020. [DOI: 10.1021/acs.macromol.9b02105] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Wei Wang
- Shenzhen Key Laboratory of Polymer Science and Technology, Guangdong Research Center for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, China
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Chandra Sekhar Biswas
- Shenzhen Key Laboratory of Polymer Science and Technology, Guangdong Research Center for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, China
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Congcong Huang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Engineering Plastics, Institute of Chemistry, the Chinese Academy of Sciences, Beijing 100190, China
| | - Hui Zhang
- Shenzhen Key Laboratory of Polymer Science and Technology, Guangdong Research Center for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, China
| | - Chen-Yang Liu
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Engineering Plastics, Institute of Chemistry, the Chinese Academy of Sciences, Beijing 100190, China
| | - Florian J. Stadler
- Shenzhen Key Laboratory of Polymer Science and Technology, Guangdong Research Center for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, China
| | - Bing Du
- Shenzhen Key Laboratory of Polymer Science and Technology, Guangdong Research Center for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, China
| | - Zhi-Chao Yan
- Shenzhen Key Laboratory of Polymer Science and Technology, Guangdong Research Center for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, China
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11
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Tsamopoulos AJ, Katsarou AF, Tsalikis DG, Mavrantzas VG. Shear Rheology of Unentangled and Marginally Entangled Ring Polymer Melts from Large-Scale Nonequilibrium Molecular Dynamics Simulations. Polymers (Basel) 2019; 11:E1194. [PMID: 31319474 PMCID: PMC6680584 DOI: 10.3390/polym11071194] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 06/29/2019] [Accepted: 07/05/2019] [Indexed: 11/24/2022] Open
Abstract
We present results for the steady state shear rheology of non-concatenated, unentangled and marginally entangled ring poly(ethylene oxide) (PEO) melts from detailed, atomistic nonequilibrium molecular dynamics (NEMD) simulations, and compare them to the behavior of the corresponding linear melts. The applied flow field spans a wide range of shear rates, from the linear (Newtonian) to the highly non-linear (described by a power law) regime. For all melts studied, rings are found to exhibit shear thinning but to a lesser degree compared to linear counterparts, mostly due to their reduced deformability and stronger resistance to alignment in the direction of flow. These features are attributed to the more compact structure of ring molecules compared to linear chains; the latter are capable of adopting wider and more open conformations even under shear due to the freedom provided by the free ends. Similar to linear melts, rings also exhibit a first and a second normal stress coefficient; the latter is negative. The ratio of the magnitude of the two coefficients remains practically constant with shear rate and is systematically higher than the corresponding one for linear melts. Emphasis was also given to the statistics of terminal (re-orientational) relaxation times which we computed by analyzing all chains in the simulated systems one by one; it was demonstrated that long time dynamics are strongly heterogeneous both for rings and (especially) linears. Repeating the analysis under flow conditions, and as expected, we found that the applied flow field significantly suppresses dynamic heterogeneity, especially for high shear rates well beyond the Newtonian plateau. Finally, a detailed geometrical analysis revealed that the average population of ring-ring threading events in the longest melt studied here (the PEO-5k ring) remains practically unaffected by the imposed flow rate even at strong shear rates, except for multi-threadings which disappear. To further analyze this peculiar and rather unexpected effect, we computed the corresponding survival times and penetration lengths, and found that the overwhelming majority of threadings under shear are extremely weak constraints, as they are characterized by very small penetration lengths, thus also by short survival times. They are expected therefore to play only a minor (if any) role on chain dynamics.
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Affiliation(s)
- Alexandros J Tsamopoulos
- Department of Chemical Engineering, University of Patras and FORTH-ICE/HT, GR 26504 Patras, Greece
| | - Anna F Katsarou
- Department of Chemical Engineering, University of Patras and FORTH-ICE/HT, GR 26504 Patras, Greece
| | - Dimitrios G Tsalikis
- Department of Chemical Engineering, University of Patras and FORTH-ICE/HT, GR 26504 Patras, Greece.
| | - Vlasis G Mavrantzas
- Department of Chemical Engineering, University of Patras and FORTH-ICE/HT, GR 26504 Patras, Greece.
- Particle Technology Laboratory, Department of Mechanical and Process Engineering, ETH Zürich, CH-8092 Zürich, Switzerland.
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12
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Dabrowski-Tumanski P, Gren B, Sulkowska JI. Statistical Properties of Lasso-Shape Polymers and Their Implications for Complex Lasso Proteins Function. Polymers (Basel) 2019; 11:E707. [PMID: 30999683 PMCID: PMC6523798 DOI: 10.3390/polym11040707] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 04/11/2019] [Accepted: 04/12/2019] [Indexed: 12/19/2022] Open
Abstract
The shape and properties of closed loops depend on various topological factors. One of them is loop-threading, which is present in complex lasso proteins. In this work, we analyze the probability of loop-threading by the tail and its influence on the shape of the loop measured by the radius of gyration, distention, asphericity, and prolateness. In particular, we show that the probability of a trivial lasso for phantom polymer is non-zero even for an infinite structure, as well as that the threading flattens the loop by restricting its motion in one dimension. These results are further used to show that there are fewer non-trivial protein lassos than expected and select potentially functional complex lasso proteins.
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Affiliation(s)
- Pawel Dabrowski-Tumanski
- Centre of New Technologies, University of Warsaw, 02-097 Warsaw, Poland.
- Faculty of Chemistry, University of Warsaw, 02-093 Warsaw, Poland.
| | - Bartosz Gren
- Centre of New Technologies, University of Warsaw, 02-097 Warsaw, Poland.
- Faculty of Physics, University of Warsaw, 02-093 Warsaw, Poland.
| | - Joanna I Sulkowska
- Centre of New Technologies, University of Warsaw, 02-097 Warsaw, Poland.
- Faculty of Chemistry, University of Warsaw, 02-093 Warsaw, Poland.
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13
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Lee E, Jung Y. Slow Dynamics of Ring Polymer Melts by Asymmetric Interaction of Threading Configuration: Monte Carlo Study of a Dynamically Constrained Lattice Model. Polymers (Basel) 2019; 11:E516. [PMID: 30960500 PMCID: PMC6473489 DOI: 10.3390/polym11030516] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 03/11/2019] [Accepted: 03/14/2019] [Indexed: 12/03/2022] Open
Abstract
Abnormally slower diffusional processes than its internal structure relaxation have been observed in ring polymeric melt systems recently. A key structural feature in ring polymer melts is topological constraints which allow rings to assume a threading configuration in the melt phase. In this work, we constructed a lattice model under the assumption of asymmetric diffusivity between two threading rings, and investigated a link between the structural correlation and its dynamic behavior via Monte Carlo simulations. We discovered that the hierarchical threading configurations render the whole system to exhibit abnormally slow dynamics. By analyzing statistical distributions of timescales of threading configurations, we found that the decoupling between internal structure relaxation and diffusion is crucial to understand the threading effects on the dynamics of a ring melt. In particular, in the limit of small but threaded rings, scaling exponents of the diffusion coefficient D and timescale τ diff with respect to the degree of polymerization N agree well with that of the annealed tree model as well as our mean-field analysis. As N increases, however, the ring diffusion abruptly slows down to the glassy behavior, which is supported by a breakdown of the Stokes⁻Einstein relation.
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Affiliation(s)
- Eunsang Lee
- Department of Chemistry, Seoul National University, Seoul 08826, Korea.
| | - YounJoon Jung
- Department of Chemistry, Seoul National University, Seoul 08826, Korea.
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14
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Yan ZC, Hossain MD, Monteiro MJ, Vlassopoulos D. Viscoelastic Properties of Unentangled Multicyclic Polystyrenes. Polymers (Basel) 2018; 10:E973. [PMID: 30960898 PMCID: PMC6403732 DOI: 10.3390/polym10090973] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 08/10/2018] [Accepted: 08/28/2018] [Indexed: 11/16/2022] Open
Abstract
We report on the viscoelastic properties of linear, monocyclic, and multicyclic polystyrenes with the same low molecular weight. All polymers investigated were found to exhibit unentangled dynamics. For monocyclic polymers without inner loops, a cyclic-Rouse model complemented by the contribution of unlinked chains (whose fraction was determined experimentally) captured the observed rheological response. On the other hand, multicyclic polymers with inner loops were shown to follow a hierarchical cyclic-Rouse relaxation with the outer loops relaxing first, followed by the inner loop relaxation. The influence of unlinked linear chains was less significant in multicyclic polymers with inner loops. The isofrictional zero-shear viscosity decreased with increasing number of constrained segments on the coupling sites, which was attributed to the decreasing loop size and the dilution effect due to the hierarchical relaxation.
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Affiliation(s)
- Zhi-Chao Yan
- Institute of Electronic Structure & Laser, Foundation for Research & Technology Hellas (FORTH), 70013 Heraklion, Greece.
- College of Materials Science and Engineering, Shenzhen Key Laboratory of Polymer Science and Technology, Guangdong Research Center for Interfacial Engineering of Functional Materials, Nanshan District Key Lab for Biopolymers and Safety Evaluation, Shenzhen University, Shenzhen 518060, China.
| | - Md D Hossain
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia.
- School of Chemical and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia.
| | - Michael J Monteiro
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia.
- School of Chemical and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia.
| | - Dimitris Vlassopoulos
- Institute of Electronic Structure & Laser, Foundation for Research & Technology Hellas (FORTH), 70013 Heraklion, Greece.
- Department of Materials Science & Technology, University of Crete, 70013 Heraklion, Greece.
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15
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Rauscher PM, Rowan SJ, de Pablo JJ. Topological Effects in Isolated Poly[ n]catenanes: Molecular Dynamics Simulations and Rouse Mode Analysis. ACS Macro Lett 2018; 7:938-943. [PMID: 35650969 DOI: 10.1021/acsmacrolett.8b00393] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Poly[n]catenanes are mechanically interlocked polymers consisting of interlocking ring molecules. Over the years, researchers have speculated that the permanent topological interactions within the poly[n]catenane backbone could lead to unique dynamical behaviors. To investigate these unusual polymers, molecular dynamics simulations of isolated poly[n]catenanes have been conducted, along with a Rouse mode analysis. Owing to the mechanical bonds within the molecule, the dynamics of poly[n]catenanes at short length scales are significantly slowed and the distribution of relaxation times is broadened; these same behaviors have been observed in melts of linear polymers and are associated with entanglement. Despite these entanglement-like effects, at large length scales poly[n]catenanes do not relax much slower than isolated linear polymers and are less strongly impacted by increased segmental stiffness.
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16
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Tsalikis DG, Alatas PV, Peristeras LD, Mavrantzas VG. Scaling Laws for the Conformation and Viscosity of Ring Polymers in the Crossover Region around Me from Detailed Molecular Dynamics Simulations. ACS Macro Lett 2018; 7:916-920. [PMID: 35650965 DOI: 10.1021/acsmacrolett.8b00437] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
We present results from detailed, atomistic molecular dynamics (MD) simulations of pure, strictly monodisperse linear and ring poly(ethylene oxide) (PEO) melts under equilibrium and nonequilibrium (shear flow) conditions. The systems examined span the regime of molecular weights (Mw) from sub-Rouse (Mw < Me) to reptation (Mw ∼ 10 Me), where Me denotes the characteristic entanglement molecular weight of linear PEO. For both PEO architectures (ring and linear), the predicted chain center-of-mass self-diffusion coefficients DG as a function of PEO Mw are in remarkable agreement with experimental data. From the flow simulations under shear, we have extracted and analyzed the zero-shear viscosity of ring and linear PEO melts as a function of Mw.
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Affiliation(s)
- Dimitrios G. Tsalikis
- Department of Chemical Engineering, University of Patras and FORTH/ICE-HT, Patras, GR 26504, Greece
| | - Panagiotis V. Alatas
- Department of Chemical Engineering, University of Patras and FORTH/ICE-HT, Patras, GR 26504, Greece
| | - Loukas D. Peristeras
- Molecular Thermodynamics and Modeling of Material Laboratory, Institute of Nanoscience and Nanotechnology, National Center of Scientific Research “Demokritos”, GR-15310 Aghia Paraskevi, Greece
| | - Vlasis G. Mavrantzas
- Department of Chemical Engineering, University of Patras and FORTH/ICE-HT, Patras, GR 26504, Greece
- Particle Technology Laboratory, Department of Mechanical and Process Engineering, ETH Zürich, CH-8092 Zürich, Switzerland
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17
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Kruteva M, Allgaier J, Richter D. Direct Observation of Two Distinct Diffusive Modes for Polymer Rings in Linear Polymer Matrices by Pulsed Field Gradient (PFG) NMR. Macromolecules 2017. [DOI: 10.1021/acs.macromol.7b01850] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Margarita Kruteva
- Jülich Centre for
Neutron Science (JCNS-1) and Institute for Complex Systems (ICS-1), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Jürgen Allgaier
- Jülich Centre for
Neutron Science (JCNS-1) and Institute for Complex Systems (ICS-1), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Dieter Richter
- Jülich Centre for
Neutron Science (JCNS-1) and Institute for Complex Systems (ICS-1), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
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18
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Yin F, Tang C, Li X, Wang X. Effect of Moisture on Mechanical Properties and Thermal Stability of Meta-Aramid Fiber Used in Insulating Paper. Polymers (Basel) 2017; 9:E537. [PMID: 30965841 PMCID: PMC6418652 DOI: 10.3390/polym9100537] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 10/13/2017] [Accepted: 10/18/2017] [Indexed: 11/17/2022] Open
Abstract
Seven composite models of meta-aramid fibers with different moisture contents were studied using molecular dynamics simulation. The effects of moisture on the thermal stability and mechanical properties of the fibers and their mechanisms were analyzed, considering characteristics such as hydrogen bonding, free volume, mean square displacement, and mechanical parameters. The simulation results showed that the large number of hydrogen bonds between water molecules and meta-aramid fibers destroyed the original hydrogen-bond network. Hydrogen bonds between the molecular chains of meta-aramid fibers were first destroyed, and their number decreased with increasing moisture content. The free volume of the fibers thereby increased, the interactions between fiber chains weakened with increasing moisture content, and the fiber chain movement intensified accordingly. The ratio of diffusion coefficients of the water molecules to moisture contents of the composite models increased linearly, and the water molecule diffusion increased, which accelerated the rate of damage to the original hydrogen-bond network of the meta-aramid fibers and further reduced their thermal stability. In general, the mechanical properties of the composites were negatively related to their moisture content.
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Affiliation(s)
- Fei Yin
- College of Engineering and Technology, Southwest University, Chongqing 400715, China.
| | - Chao Tang
- College of Engineering and Technology, Southwest University, Chongqing 400715, China.
- School of Electronics and Computer Science, University of Southampton, SO171BJ Southampton, UK.
| | - Xu Li
- College of Engineering and Technology, Southwest University, Chongqing 400715, China.
| | - Xiaobo Wang
- College of Engineering and Technology, Southwest University, Chongqing 400715, China.
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Jeong C, Douglas JF. Relation between Polymer Conformational Structure and Dynamics in Linear and Ring Polyethylene Blends. MACROMOL THEOR SIMUL 2017. [DOI: 10.1002/mats.201700045] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Cheol Jeong
- Materials Science and Engineering Division; National Institute of Standards and Technology; Gaithersburg MD 20899 USA
| | - Jack F. Douglas
- Materials Science and Engineering Division; National Institute of Standards and Technology; Gaithersburg MD 20899 USA
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20
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Tsalikis DG, Koukoulas T, Mavrantzas VG, Pasquino R, Vlassopoulos D, Pyckhout-Hintzen W, Wischnewski A, Monkenbusch M, Richter D. Microscopic Structure, Conformation, and Dynamics of Ring and Linear Poly(ethylene oxide) Melts from Detailed Atomistic Molecular Dynamics Simulations: Dependence on Chain Length and Direct Comparison with Experimental Data. Macromolecules 2017. [DOI: 10.1021/acs.macromol.6b02495] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Dimitrios G. Tsalikis
- Department
of Chemical Engineering, University of Patras and FORTH-ICE/HT, GR 26504, Patras, Greece
| | - Thanasis Koukoulas
- Department
of Chemical Engineering, University of Patras and FORTH-ICE/HT, GR 26504, Patras, Greece
| | - Vlasis G. Mavrantzas
- Department
of Chemical Engineering, University of Patras and FORTH-ICE/HT, GR 26504, Patras, Greece
- Particle
Technology Laboratory, Department of Mechanical and Process Engineering, ETH-Z, CH-8092 Zürich, Switzerland
| | - Rossana Pasquino
- FORTH, Institute
for Electronic Structure and Laser, Heraklion 71110, Greece
- Department
of Chemical, Materials and Industrial Engineering, University of Napoli Federico II, P.le Tecchio 80, 80125 Napoli, Italy
| | - Dimitris Vlassopoulos
- FORTH, Institute
for Electronic Structure and Laser, Heraklion 71110, Greece
- Department of Materials Science & Technology, University of Crete, Heraklion 71003, Greece
| | - Wim Pyckhout-Hintzen
- Jülich
Centre for Neutron Science (JCNS-1) and Institute for Complex Systems
(ICS-1), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Andreas Wischnewski
- Jülich
Centre for Neutron Science (JCNS-1) and Institute for Complex Systems
(ICS-1), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Michael Monkenbusch
- Jülich
Centre for Neutron Science (JCNS-1) and Institute for Complex Systems
(ICS-1), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Dieter Richter
- Jülich
Centre for Neutron Science (JCNS-1) and Institute for Complex Systems
(ICS-1), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
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21
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Crysup B, Shanbhag S. What Happens When Threading is Suppressed in Blends of Ring and Linear Polymers? Polymers (Basel) 2016; 8:E409. [PMID: 30974687 PMCID: PMC6432297 DOI: 10.3390/polym8120409] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 11/15/2016] [Accepted: 11/18/2016] [Indexed: 11/16/2022] Open
Abstract
Self-diffusivity of a large tracer ring polymer, D r , immersed in a matrix of linear polymers with N l monomers each shows unusual length dependence. D r initially increases, and then decreases with increasing N l . To understand the relationship between the nonmonotonic variation in D r and threading by matrix chains, we perform equilibrium Monte Carlo simulations of ring-linear blends in which the uncrossability of ring and linear polymer contours is switched on (non-crossing), or artificially turned off (crossing). The D r ≈ 6 . 2 × 10 - 7 N l 2 / 3 obtained from the crossing simulations, provides an upper bound for the D r obtained for the regular, non-crossing simulations. The center-of-mass mean-squared displacement ( g 3 ( t ) ) curves for the crossing simulations are consistent with the Rouse model; we find g 3 ( t ) = 6 D r t . Analysis of the polymer structure indicates that the smaller matrix chains are able to infiltrate the space occupied by the ring probe more effectively, which is dynamically manifested as a larger frictional drag per ring monomer.
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Affiliation(s)
- Benjamin Crysup
- Department of Scientific Computing, Florida State University, Tallahassee, FL 32306, USA.
| | - Sachin Shanbhag
- Department of Scientific Computing, Florida State University, Tallahassee, FL 32306, USA.
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