Deposition of continuous silicalite-1 films on inorganic fibers

Silicalite-fiber composites were prepared by a new method for the synthesis of molecular sieve films. The method consists of two steps: in the first one, the surface charge of the support is reversed by treatment with a cationic polymer solution and a monolayer of negatively charged colloidal molecular sieve seed crystals is adsorbed on the surface. The second step consists of hydrothermal treatment of the support in a molecular sieve precursor solution resulting in the formation of a continuous film of molecular sieve. The method was applied to carbon, ZrO₂, Al₂O₃, mullite, ceramic and pyrex glass fibers. The crystallization of continuous silicalite-1 films on all types of fibers was confirmed by SEM, XRD, FTIR, DTA analyses and BET surface area measurements.