High-performance molecular-separation ceramic membranes derived from oxidative cross-linked polytitanocarbosilane |
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Authors: | Qing Wang Liang Yu Hiroki Nagasawa Masakoto Kanezashi Toshinori Tsuru |
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Affiliation: | Department of Chemical Engineering, Hiroshima University, Higashi-Hiroshima, Japan |
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Abstract: | Polytitanocarbosilane (TiPCS)-derived ceramic membranes were fabricated using a pre-ceramic polymer. Special attention was focused on a process of thermal-oxidative curing that was used to induce cross-linking and the effect of this process on the ceramic yield, thermal stability, oxidation resistance, and microstructure of TiPCS. The cross-linked TiPCS powders showed a ceramic yield and thermal stability that were higher than that from the non-cross-linked version. In addition, the cross-linked TiPCS with uniform micropores showed higher levels of N2 and CO2 adsorption capacity, BET surface area, and micropore volume than the non-cross-linked versions, and the cross-linking process enhanced the stability of the pore structure at high temperature. The cross-linked TiPCS membranes showed high H2 permeance (1.49 × 10−6 mol/(m2 s Pa)) with sub-nanopores (H2/SF6 selectivity: 12 000, H2/N2: 10), and in addition higher oxidation resistance than their non-cross-linked counterparts. Furthermore, the influence of the concentration of the TiPCS precursor coating solution was optimized and the hydrothermal stability of the membranes at high temperatures was also evaluated. The optimized membrane demonstrated great performance for the pervaporation removal of methanol in binary azeotropic systems of either MeOH/butyl acetate or MeOH/toluene, and it also showed high hydrothermal stability with excellent dehumidification performance under high temperatures. |
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Keywords: | cross-linking hydrothermal stability methanol removal pervaporation polytitanocarbosilane |
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