Preparation and Characterization of Microporous Sol-Gel Derived Ceramic Membranes for GAS Separation Applications

Abstract

ABSTRACTMesoporous alumina membranes were modified with microporous silica. The polymeric silica sols consist of very weakly branched polymeric molecules with a fractal dimension of 1.3 and Guinier radius of ≈ 2.0 nm. The resulting top layer material is microporous with a porosity of 40% and a layer thickness of 60 nm. Gas transport is activated with an activation energy of 11 kJ/mol for hydrogen and molecular sieve like separation factors have been obtained. From the mechanism of gas transport the conclusion can be drawn that the pores are of molecular dimensions (0.7 – 1 nm diameter).