Permeation of small penetrants in hydrogels

Molecular dynamics (MD) simulations are performed to investigate permeation processes of oxygen and nitrogen in PVA hydrogels. Permeabilities of oxygen and nitrogen are calculated from diffusion coefficients and solubilities, which are obtained by molecular simulations. Separation factors agree semiquantitatively with experiments. Diffusion process of the gases is examined in connection with the mobility of polymer chains and with the reorganization of hydrogen-bond networks.