SYNTHESIS OF AN A-TYPE ZEOLITE MEMBRANE ON SILICON-OXIDE FILM-SILICON, QUARTZ PLATE AND QUARTZ FIBER FILTER

A-type zeolite membranes were prepared on three kinds of substrates with different characters: silicon plate, the surface of which was oxidized; quartz glass plate; and a filter of quartz glass fiber. The membrane syntheses were successfully performed by using the liquid phase separated from the hydrogel of the reactants. A well crystallized tight membrane was synthesized on silicon oxide film-silicon and quartz plates. However, the former substrate was often corroded, which induced instability for the prepared membrane. A multi-fold crystallization by using A-type zeolite powder as a seed was very effective to obtain a tight and compact membrane on the quartz fiber filter. A formation mechanism of the A-type zeolite membrane on the substrate is also discussed.