Molecular dynamics study of the effect of solvent types on the dynamic properties of polymer chains in solution
Journal
Desalination
Journal Volume
192
Journal Issue
1-3
Pages
380-390
Date Issued
2006
Author(s)
Abstract
The effect of types of solvent on the dynamic properties of atactic poly(methyl methacrylate)s (a-PMMA)s chains in solution was studied by a molecular dynamics simulation technique with the condensed-phase optimized molecular potentials for atomistic simulation studies (COMPASS) force field. Five kinds of casting solvent molecules were randomly embedded into the a-PMMA matrix to construct various types of simulated a-PMMA solutions based upon experimentally obtained densities. The dynamic properties of polymer chains such as mean-square end-to-end distance <R2>, mean-square radius of gyration <S2>, and asphericity ratio <R2>/<S2> of polymer chains were analyzed. Simulated results revealed that the <R2> of the a-PMMA chains increased with the increase of the dipole moment of the surrounded solvent molecules. The asphericity ratio of polymer chains showed a high correlation to the molecular weight of solvents. Furthermore, the simulated radial distribution function of H-H atomic pairs in the system of a-PMMA solutions indicated that the expansion of a polymer chain depends mainly on the conformation of solvent molecules instead of the interaction between the polymer chain and the functional group on solvent molecules. ? 2006.
Subjects
COMPASS force field
Molecular dynamics simulation
PMMA membrane
Polymeric solution
Solvent effect
Type
journal article