Water vapor sorption and desorption by human callus I: Anomalous diffusion

The rates of sorption and desorption of water in membranes of varying thickness of excised human callus were determined for several relative vapor pressures and temperatures. Under the conditions studied, the diffusion of water in these membranes was interpreted as non-Fickian in nature. It was concluded that at low water concentration this type of membrane exists in the glassy state. The effect of the relative vapor pressure on the water sorption rates was examined in the context of the free volume theory.