Study on the diffusion of small molecule penetrants in dense polymer membranes

摘要

An equation describing the diffusion of small molecular penetrants in dense polymer membranes was deduced. The sorption equation in the initial sorption stage and the steady permeation equation were derived. The dynamci sorption and permeation data of CH_2Cl_2, CH_3OH, CH_3CH_3OH and H_2O in polyimide(PI) membranes were measured. The anomalous diffusion factor d_w and the fractal dimension d_f in these equations were calculated.