The diffusion of benzene

toluene and ethylbenzene in amorphous polyethylene(PE) membrane was studied in this paper

and their diffusion coefficients were analyzed and calculated by molecular dynamics simulation.The diffusion coefficients were calculated with the clustering method.The calculated results have the same trend with experimental results: the diffusion coefficient decreases with increasing molecular weight of organic molecules at the same temperature and increases with temperature for the same organic molecule.It is shown that the diffusion coefficients are reasonable and reliable.The diffusion behavior of three kinds of molecules in polyethylene membrane in a long time(300 ps) scale was simulated and the tracks of molecules were obtained

which show that the molecule movement in the membrane is local vibration combined with prancing diffusion.