Fabrication of highly selective organosilica membrane for gas separation by mixing bis(triethoxysilyl)ethane with methyltriethoxysilane

Abstract

In the present study, the mixtures of bis(triethoxysilyl)ethane (BTESE) and methyltriethoxysilane (MTES) were proposed to design highly selective hybrid silica membranes for gas separation by the sol-gel method. The role of MTES in the hybrid membranes was investigated by changing the ratio of the two precursors. The membrane derived from mixture of 1 BTESE and 3 MTES exhibited the highest H2 and CO2 permeance with 7.99 × 10−7 mol m−2 s−1 Pa−1 and 3.53 × 10−7 mol m−2 s−1 Pa−1, respectively. In contrast, the superior selectivity was achieved on the membrane derived from mixture of 1 BTESE and 2 MTES, in which the H2/N2, H2/CH4, CO2/N2, and CO2/CH4 were found to be 64.4, 73.6, 28.5, and 32.6, respectively, which indicated that the structures of BTESE-MTES hybrid membranes can be adjusted by tuning the ratios of MTES to BTESE. Moreover, the membranes also performed well in the binary-component mixture gases and high-temperature test.