Synthesis of thin molecular sieve films

A method to synthesize thin films of various molecular sieves on a number o f substrates employing pre-seeding has been developed, The substrate is mod ified to enable adsorption of seed crystals. Substrates with an originally negative surface charge are charge reversed by adsorption of cationic polym er molecules. Nobel metal substrates are first silanized to obtain a negati ve surface charge. Nano seed crystals are adsorbed on the modified substrat es from a sol and induced to grow in a synthesis solution to form a dense f ilm with controlled thickness. The versatility of the method may be of grea t value in the development of novel applications, Films have been tested in membrane and sensor applications with successful results, (C) 1999 Acta Me tallurgica Inc.