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Simulation of United Atom Model of Atactic Polystyrene

Nobahar Shahidi
Department of Chemical Engineering, University of Tennessee

This page shows the visualizations of diffusion of gas ethane in polystyrene melt. These structures were created by Nobahar Shahidi, using united atom models developed by Martin et al.

The diffusion of gas ethane in polystyrene melt was studied with molecular dynamics simulations. The system consists of 20 ethane molecules and 20 atactic polystyren chains with chain length of 20 monomers at 500 K and 1 atm. For both componeonets, united atom models were used with TraPPE forcefiled wich significantly decreased the computation time. After equilibration, both components showed Fickian diffusion in the mixture. Due to the low volume of ethane, the PDF of polystyrene and desnity of mixture were close to pure polystyrene melt. 1

Interactive Structures

Interactive Structures

Color Legend:

  • white = CH3


1. Martin, Marcus G., and J. Ilja Siepmann. "Transferable potentials for phase equilibria. 1. United-atom description of n-alkanes." The Journal of Physical Chemistry B 102.14 (1998): 2569-2577. doi: 10.1021/jp972543+

posted: March 2018.
updated: March 2018.