Mesoscale model of polymer melt structure: Self-consistent mapping of molecular correlations to coarse-grained potentials

2005 ◽  
Vol 122 (10) ◽  
pp. 104908 ◽  
Author(s):  
Henry S. Ashbaugh ◽  
Harshit A. Patel ◽  
Sanat K. Kumar ◽  
Shekhar Garde
Keyword(s):  
Mesoscale Model ◽  
Polymer Melt ◽  
Coarse Grained ◽  
Melt Structure ◽  
Self Consistent ◽  
Consistent Mapping

scholarly journals RuSseL: A Self-Consistent Field Theory Code for Inhomogeneous Polymer Interphases

Computation ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 57
Author(s):  
Constantinos J. Revelas ◽  
Aristotelis P. Sgouros ◽  
Apostolos T. Lakkas ◽  
Doros N. Theodorou
Keyword(s):  
Field Theory ◽  
Polymer Melt ◽  
Polymer Chains ◽  
Solid Polymer ◽  
One Dimensional ◽  
Consistent Field ◽  
Adsorbed Polymer ◽  
Self Consistent ◽  
Self Consistent Field ◽  
Self Consistent Field Theory

In this article, we publish the one-dimensional version of our in-house code, RuSseL, which has been developed to address polymeric interfaces through Self-Consistent Field calculations. RuSseL can be used for a wide variety of systems in planar and spherical geometries, such as free films, cavities, adsorbed polymer films, polymer-grafted surfaces, and nanoparticles in melt and vacuum phases. The code includes a wide variety of functional potentials for the description of solid–polymer interactions, allowing the user to tune the density profiles and the degree of wetting by the polymer melt. Based on the solution of the Edwards diffusion equation, the equilibrium structural properties and thermodynamics of polymer melts in contact with solid or gas surfaces can be described. We have extended the formulation of Schmid to investigate systems comprising polymer chains, which are chemically grafted on the solid surfaces. We present important details concerning the iterative scheme required to equilibrate the self-consistent field and provide a thorough description of the code. This article will serve as a technical reference for our works addressing one-dimensional polymer interphases with Self-Consistent Field theory. It has been prepared as a guide to anyone who wishes to reproduce our calculations. To this end, we discuss the current possibilities of the code, its performance, and some thoughts for future extensions.

Coarse-grained dynamics of one chain in a polymer melt

2000 ◽  
Vol 113 (15) ◽  
pp. 6409-6422 ◽  
Author(s):  
Reinier L. C. Akkermans ◽  
W. J. Briels
Keyword(s):  
Polymer Melt ◽  
Coarse Grained

scholarly journals Why we need to look beyond the glass transition temperature to characterize the dynamics of thin supported polymer films

2018 ◽  
Vol 115 (22) ◽  
pp. 5641-5646 ◽  
Author(s):  
Wengang Zhang ◽  
Jack F. Douglas ◽  
Francis W. Starr
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Polymer Films ◽  
Interaction Strength ◽  
Polymer Melt ◽  
Dynamic Structure ◽  
Coarse Grained ◽  
Implicit Assumption ◽  
Simple Method ◽  
Thin Polymer

There is significant variation in the reported magnitude and even the sign of Tg shifts in thin polymer films with nominally the same chemistry, film thickness, and supporting substrate. The implicit assumption is that methods used to estimate Tg in bulk materials are relevant for inferring dynamic changes in thin films. To test the validity of this assumption, we perform molecular simulations of a coarse-grained polymer melt supported on an attractive substrate. As observed in many experiments, we find that Tg based on thermodynamic criteria (temperature dependence of film height or enthalpy) decreases with decreasing film thickness, regardless of the polymer–substrate interaction strength ε. In contrast, we find that Tg based on a dynamic criterion (relaxation of the dynamic structure factor) also decreases with decreasing thickness when ε is relatively weak, but Tg increases when ε exceeds the polymer–polymer interaction strength. We show that these qualitatively different trends in Tg reflect differing sensitivities to the mobility gradient across the film. Apparently, the slowly relaxing polymer segments in the substrate region make the largest contribution to the shift of Tg in the dynamic measurement, but this part of the film contributes less to the thermodynamic estimate of Tg. Our results emphasize the limitations of using Tg to infer changes in the dynamics of polymer thin films. However, we show that the thermodynamic and dynamic estimates of Tg can be combined to predict local changes in Tg near the substrate, providing a simple method to infer information about the mobility gradient.

scholarly journals Dual responsive PMEEECL–PAE block copolymers: a computational self-assembly and doxorubicin uptake study

RSC Advances ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 3233-3245 ◽  
Author(s):  
Amin Koochaki ◽  
Mohammad Reza Moghbeli ◽  
Sousa Javan Nikkhah ◽  
Alessandro Ianiro ◽  
Remco Tuinier
Keyword(s):  
Block Copolymers ◽  
Self Assembly ◽  
The Self ◽  
Coarse Grained ◽  
Dual Responsive ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field ◽  
Self Consistent Field Theory ◽  
Dynamics Simulations

The self-assembly behaviour of dual-responsive block copolymers and their ability to solubilize the drug doxorubicin is demonstrated using molecular dynamics simulations, coarse-grained force field simulations and self-consistent field theory.

Mesoscale Simulation of Morphology in Hydrated Perfluorosulfonic Acid Membranes

2005 ◽  
Vol 885 ◽  
Author(s):  
James T. Wescott ◽  
Yue Qi ◽  
Lalitha Subramanian ◽  
T. Weston Capehart
Keyword(s):  
Mesoscale Model ◽  
Random Network ◽  
Mean Field Theory ◽  
Mean Field ◽  
Domain Size ◽  
Proton Exchange ◽  
Coarse Grained ◽  
Perfluorosulfonic Acid ◽  
Perfluorosulfonic Acid Membranes ◽  
Hydrophilic Domain

ABSTRACTCurrent fuel cell proton exchange membranes (PEM) rely on a random network of conducting hydrophilic domains to transport protons across the membrane. Despite extensive investigation, details of the structure of the hydrophilic domains in these membranes remain unresolved. In this study a dynamic self-consistent mean field theory has been applied to obtain the morphologies of hydrated Perfluorosulfonic Acid (PFSA) (equivalent weight of 1100) as a model for Nafion® at several water contents. A coarse-grained mesoscale model was developed by dividing the system into three components: backbone, side chain, and water. The interaction parameters for this model were generated using classical molecular dynamics. The simulated morphology shows phase separated micelles filled with water, surrounded by side chains containing sulfonic groups, and embedded in the fluorocarbon matrix. For λ<6 (λ gives the ratio of water molecules to sulfonic groups), the isolated domains obtained from simulation are nearly spherical with a domain size smaller than that fitted to experimental SANS data. For λ>8; the domains deform into elliptical and barbell shapes as they merge. The simulated morphology, hydrophilic domain size and shape are generally consistent with some experimental observations.

scholarly journals Quantitative relations between cooperative motion, emergent elasticity, and free volume in model glass-forming polymer materials

2015 ◽  
Vol 112 (10) ◽  
pp. 2966-2971 ◽  
Author(s):  
Beatriz A. Pazmiño Betancourt ◽  
Paul Z. Hanakata ◽  
Francis W. Starr ◽  
Jack F. Douglas
Keyword(s):  
Free Volume ◽  
Glass Formation ◽  
Collective Motion ◽  
Configurational Entropy ◽  
Polymer Melt ◽  
Polymer Materials ◽  
Coarse Grained ◽  
Glass Forming ◽  
Cooperative Motion ◽  
Glass Forming Materials

The study of glass formation is largely framed by semiempirical models that emphasize the importance of progressively growing cooperative motion accompanying the drop in fluid configurational entropy, emergent elasticity, or the vanishing of accessible free volume available for molecular motion in cooled liquids. We investigate the extent to which these descriptions are related through computations on a model coarse-grained polymer melt, with and without nanoparticle additives, and for supported polymer films with smooth or rough surfaces, allowing for substantial variation of the glass transition temperature and the fragility of glass formation. We find quantitative relations between emergent elasticity, the average local volume accessible for particle motion, and the growth of collective motion in cooled liquids. Surprisingly, we find that each of these models of glass formation can equally well describe the relaxation data for all of the systems that we simulate. In this way, we uncover some unity in our understanding of glass-forming materials from perspectives formerly considered as distinct.

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