摘要
Membrane separation is playing an increasingly critical role indiverse fields as a cost-efficient and energy-economic technology. Ultra-filtration and microfiltration based on the size-sieving mechanismof macroporous media have been clearly elucidated using classicaltheories of mass transfer. However, membrane processes includingpervaporation, gas separation, ion exchange, nanofiltration, reverseosmosis, etc., mainly involve mass transfer in narrow spaces whosesizes are comparable to the free distances of molecules mobility.