Surface-modified Zeolite-filled Chitosan Membranes For Pervaporation Dehydration Of Ethanol

摘要

Surface-modified zeolite-filled chitosan (CS) membranes were prepared by incorporating 3-mercapto-propyltrimethoxysilane (MPTMS)-modified H-ZSM-5 zeolite into chitosan for pervaporation dehydration of aqueous ethanol solution. The physicochemical characterization by XPS, FT-IR, XRD, DMA and SEM showed that -SO_3H group was readily grafted on the surface of H-ZSM-5 with the mediation of MPTMS and hydrogen peroxide, and the accompanying ion-ion interaction between -SO_3H group on surface-modified H-ZSM-5 and -NH_3~+ group on chitosan substantially eliminated the nonselective voids at the chitosan-H-ZSM-5 interface of the filled membranes. The experimental results also revealed that H-ZSM-5 exhibited desirable size-selective and preferential adsorption effects for aqueous ethanol solution. As a result, modified H-ZSM-5 filled membranes showed higher swelling degree and permeation flux, and improved selectivity for aqueous ethanol solution. In comparison between chitosan control membrane (permeation flux 54.18 g/(m~2 h) and separation factor 158.02 for 90 wt.% aqueous ethanol solution at 80 ℃), the modified H-ZSM-5 filled membrane with 8 wt.% filling content exhibited a remarkably improved pervaporation performance with permeation flux 278.54 g/(m~2 h) and separation factor 274.46 under the identical experimental condition.