Molecular dynamics simulation of tracer diffusion of acetonitril in polyacrylamide hydrogels

Abstract

AbstractThe diffusional motion of individual acetonitril molecules in polyacrylamide hydrogels has been investigated by molecular dynamics simulation. The mobility and the reorientation of the probe particles depend on their location within the polymer network. It can be separated between slow bound molecules and faster unbound molecules. To uncover the change in diffusion mechanism, we have followed the motion of individual probe molecules. Strong polymer‐solute interactions, which are dominated by hydrogen bonding, result in a significant retardation of the transport properties. In the solvent‐rich pores of the polymer matrix the acetonitril molecules can move freely as in pure water. A comparison of calculated diffusion coefficients reveals good agreement of the MD simulation results with experimental data.