Macromolecules, Vol.29, No.27, 8922-8933, 1996
Conformation and Dynamics of Poly(Oxyethylene) in Benzene Solution - Solvent Effect from Molecular-Dynamics Simulation
The detailed analysis of the conformation and the dynamics of poly(oxyethylene) (POE) in benzene solution is presented in order to examine the solvent effect relative to a POE aqueous solution. The analysis is based on a 5 ns molecular dynamics simulation of a POE chain with 15 repeating units in a solution of 191 benzene molecules. The results are compared to the previous simulation of the same POE chain in aqueous solution. The helical conformation taken from the simulation in an aqueous solution transformed to a random coil in 0.5 ns in a benzene solution. Further, much faster conformational transition rates around the internal bonds have been found in a benzene solution than in an aqueous solution, indicating a significantly smaller solvent damping effect on the POE chain in benzene solution. The C-C-O pairwise conformational populations are also compared with those obtained from the recent POE melt simulation in light of the POE chain dimension in different states. The chain conformation, the conformational populations, and the relaxation time for the C-H vector reorientation are all in good accord with the experiments.
Keywords:ELECTRONIC-STRUCTURE CALCULATIONS;AQUEOUS SALT-SOLUTIONS;POLY(ETHYLENE OXIDE);LIQUID BENZENE;COMPUTER-SIMULATION;FORCE-FIELD;CHAIN;1;2-DIMETHOXYETHANE;APPROXIMATION;TRANSITIONS