Thin films of molecular sieves synthesis and applications

Sammanfattning: The seed film method for synthesis of ultra thin and thin molecular sieve films was developed. The versatility of the method was demonstrated by successful preparation of films of a number of molecular sieves (silicate-1, ZSM-5, NA) on various supports (silicon, alumina, gold, etc.). The preferred orientation of the crystalline material could be controlled. Silicate-1 films on silicon wafers were evaluated as optical gas sensors. Sorption isotherms of water, toluene, 1-propanol and n-hexane were recorded. ZSM-5 films with a thickness of 1.5 um were crystallized on a porous support and the membranes were evaluated in permeation experiments. The flux in single gas experiments decreased in the series H2O, H2, CO2, O2, N2 and CH4. The difference in flux between each molecule was about 1 order of magnitude which indicated the high quality of the membranes. The measured separation factors for binary mixtures of N2/SF6 and H2/i-C4 were 99 and 66.