Microstructural Optimization of a Zeolite Membrane for Organic Vapor Separation

• DOI: 10.1126/science.1082169
• Publication Date: 2003-04-17T20:04:03Z
• Authors: Zhiping Lai; Griselda Bonilla; Isabel Diaz; Jose Geraldo Nery; Khristina Sujaoti; Miguel A. Amat; Efrosini Kokkoli; Osamu Terasaki; Robert W. Thompson; Michael Tsapatsis; Dionisios G. Vlachos
• Keywords: Permeance; Micrometer; Crystal (programming language); Seed crystal

A seeded growth method for the fabrication of high-permeance, high-separation-factor zeolite (siliceous ZSM-5, [Si96O192]-MFI) membranes is reported. The consists growing crystals an oriented seed layer to a well-intergrown film by avoiding events that lead loss preferred orientation, such as twin overgrowths and random nucleation. Organic polycations are used crystal shape modifiers enhance relative rates along desirable out-of-plane direction. polycrystalline films thin (approximately 1 micrometer) with single grains extending thickness large in-plane grain size micrometer). orientation straight channels open diameter approximately 5.5 angstroms run down membrane thickness. Comparison previously reported shows these microstructurally optimized have superior performance separation organic mixtures components small differences in shape, xylene isomers.