Polymer Cavities Research Articles

Diffusion between cells with semipermeable walls

A model is presented for the diffusion of noninteracting particles in a lattice of cubic cells with semipermeable walls. This model describes the type A Fickian diffusion of low concentrations of small molecules in molecular sieves or polymer cavities. Exact formulas are presented for the average mean-square displacement as a function of time and for the diffusion constant. The jump frequency of the jump diffusional model is related to the probability of transmission through the cell walls.