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Indexed by:期刊论文

Date of Publication:2009-12-01

Journal:JOURNAL OF MEMBRANE SCIENCE

Included Journals:SCIE、EI、Scopus

Volume:345

Issue:1-2

Page Number:183-190

ISSN No.:0376-7388

Key Words:Silicalite-1 membrane; Counter-diffusion; Secondary growth; Permeance

Abstract:High performance silicalite-1 membranes on outer surface of macroprous alpha-Al(2)O(3) supports were synthesized by counter-diffusion secondary growth (CDSG). Different from the conventional synthesis methods by which the silica source (tetraethyl orthosilicate) and the template agent (tetra-propyl ammonium bromide) were mixed together to form the synthesis solution, this method introduced silica source and template agent from the opposite direction of a support wall, resulting in good membrane structures and properties as well as reduced chemical consumption. The correlation between particle size of seeds and the pore size of supports was optimized, and its influence on the morphology and permeation property of the as-prepared membranes was also investigated. Results showed the as-prepared membranes were typical silicalite-1 membranes without any other phase. The membranes were dense, continuous without obvious defects, displaying good permeation property. The H(2) permeance and H(2)/SF(6) ideal permselectivity for the membrane prepared under optimized parameters were up to 7.5 x 10(-7) mol m(-2) s(-1) Pa(-1) and 103 at 298 K under 0.1 MPa pressure drop, respectively. Moreover, by the CDSG method the consumption of the template can be greatly reduced. (C) 2009 Elsevier B.V. All rights reserved.