Network Structure Engineering of Organosilica Membranes for Enhanced CO(2) Capture Performance

The membrane separation process for targeted CO(2) capture application has attracted much attention due to the significant advantages of saving energy and reducing consumption. High-performance separation membranes are a key factor in the membrane separation system. In the present study, we conducted a detailed examination of the effect of calcination temperatures on the network structures of organosilica membranes. Bis(triethoxysilyl)acetylene (BTESA) was selected as a precursor for membrane fabrication via the sol-gel strategy. Calcination temperatures affected the silanol density and the membrane pore size, which was evidenced by the characterization of FT-IR, TG, N(2) sorption, and molecular size dependent gas permeance. BTESA membrane fabricated at 500 °C showed a loose structure attributed to the decomposed acetylene bridges and featured an ultrahigh CO(2) permeance around 15,531 GPU, but low CO(2)/N(2) selectivity of 3.8. BTESA membrane calcined at 100 °C exhibited satisfactory CO(2) permeance of 3434 GPU and the CO(2)/N(2) selectivity of 22, displaying great potential for practical CO(2) capture application.