Dehydration of an Ethanol/Water Azeotrope by Novel Organic-Inorganic Hybrid Membranes Based on Quaternized Chitosan and Tetraethoxysilane

摘要

To control swelling of quaternized chitosan(q-Chito)membranes,mixtures of q-Chito as an organic component and tetraethoxysilane(TEOS)as an inorganic component were prepared using the sol-gel reaction,and novel q-Chito/TEOS hybrid membranes were formed.In the separation of an ethanol/water azeotrope by pervaporation,the effect of TEOS content on the water/ethanol selectivity of q-Chito/TEOS hybrid membranes was investigated.Hybrid membranes containing up to 45 mol % TEOS exhibited higher water/ ethanol selectivity than the q-Chito membrane.This resulted from depressed swelling of the membranes by formation of a cross-linked structure.However,introduction of excess TEOS led to greater swelling of the hybrid membranes.Therefore,the water/ethanol selectivity of the hybrid membranes containing more than 45 mol % TEOS was lower than that of the q-Chito membrane.The relationship between the structure of q-Chito/TEOS hybrid membranes and their permeation and separation characteristics during pervaporation of an ethanol/water azeotrope is discussed in detail.