Molecular modeling and simulation of atactic polystyrene/amorphous silica nanocomposites

5th International Conference on Mathematical Modeling in Physical Sciences

物理学;数学

Mathioudakis, I.^1 ; Vogiatzis, G.G.^1 ; Tzoumanekas, C.^1 ; Theodorou, D.N.^1

Department of Materials Science and Engineering, School of Chemical Engineering, National Technical University of Athens, Athens, Greece^1

关键词: Atomistic molecular dynamics;    Atomistic simulations;    Entanglement networks;    Initial configuration;    Molecular modeling and simulations;    Molecular simulations;    Silica nanocomposites;    Topological analysis;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/738/1/012021/pdf
DOI  :  10.1088/1742-6596/738/1/012021

来源: IOP

【 摘 要 】

The local structure, segmental dynamics, topological analysis of entanglement networks and mechanical properties of atactic polystyrene - amorphous silica nanocomposites are studied via molecular simulations using two interconnected levels of representation: (a) A coarse - grained level. Equilibration at all length scales at this level is achieved via connectivity - altering Monte Carlo simulations. (b) An atomistic level. Initial configurations for atomistic Molecular Dynamics (MD) simulations are obtained by reverse mapping well- equilibrated coarse-grained configurations. By analyzing atomistic MD trajectories, the polymer density profile is found to exhibit layering in the vicinity of the nanoparticle surface. The dynamics of polystyrene (in neat and filled melt systems) is characterized in terms of bond orientation. Well-equilibrated coarse-grained long-chain configurations are reduced to entanglement networks via topological analysis with the CReTA algorithm. Atomistic simulation results for the mechanical properties are compared to the experimental measurements and other computational works.