Mesoscopic Simulations of Free Surfaces of Molten Polyethylene: Brownian Dynamics/Kinetic Monte Carlo Coupled with Square Gradient Theory and Compared to Atomistic Calculations and Experiment
| Autor: | Apostolos T. Lakkas, Grigorios Megariotis, A. P. Sgouros, Doros N. Theodorou |
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| Rok vydání: | 2018 |
| Předmět: |
chemistry.chemical_classification
Quantitative Biology::Biomolecules Mesoscopic physics Equation of state Materials science Molar mass 010304 chemical physics Polymers and Plastics Organic Chemistry Polymer 010402 general chemistry 01 natural sciences 0104 chemical sciences Condensed Matter::Soft Condensed Matter Inorganic Chemistry Linear low-density polyethylene chemistry Chemical physics 0103 physical sciences Materials Chemistry Brownian dynamics Particle Kinetic Monte Carlo |
| Zdroj: | Macromolecules. 51:9798-9815 |
| ISSN: | 1520-5835 0024-9297 |
| DOI: | 10.1021/acs.macromol.8b01873 |
| Popis: | A mesoscopic simulation approach is developed for liquid–gas interfaces of weakly and strongly entangled polymer melts and implemented for linear polyethylene at 450 K. A combined particle and field-theoretic treatment is adopted based on aggressive coarse-graining, each polymer bead representing ∼50 carbon atoms, with effective bonded interactions extracted from atomistic simulations. Nonbonded interactions in the mesoscopic model are dictated by an equation of state (here the Sanchez–Lacombe) in conjunction with a variant of gradient theory—the discrete square gradient theory. The dynamics of free films is examined in the presence and in the absence of topological constraints (modeled by slip-springs) to unveil the impact of the latter on chain self-diffusion, to assess their contribution to the interfacial free energy, and to explore how this contribution can be removed by invoking a compensating potential. The molar mass dependence of surface tension—which arises from bonded contributions among beads ... |
| Databáze: | OpenAIRE |
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