| 초록 |
Facilitated transport(FT) membranes with fixed site carriers have attracted much attention lately, because it is capable of increasing permeability and permselectivity simultaneously. Recently, Kang and co-workers reported that the transport of olefin molecules through FT membranes using Ag carrier is much higher than that of paraffin molecules. However, despite the observation of these unique transport phenomena, the understanding of the molecular mechanism with respect to FT is far less completed. In the present work, the origin of FT is studied by using a modified dual sorption theory and a numerical simulation. When compared to the traditional dual sorption model which fails to predict FT, the dual sorption model modified by adding a contribution from coupling between Henry and Langmuir mode successfully explains the enhanced permeability when the concentration of carrier increases. In order to confirm this, a numerical simulation based on Kawasaki Ising model is performed and various molecular factors affecting the diffusion of penetrants in the FT membrane are investigated. From these results, it is shown that the coupling contribution due to the association and dissociation between carriers and penetrants plays an important role in the transport of penetrant, particularly when the concentration of carriers is low. |
