18 April 2003
Vol 300, Issue 5618

About The Cover

Cover image expansion

COVER Scanning electron micrograph of a polycrystalline molecular sieve membrane. The membrane was prepared from an oriented monolayer of seed crystals, but the orientation was lost during growth because of undesirable nucleation and growth events. A method that preserves the preferred orientation and other microstructural characteristics of a zeolite film, yielding improved membrane performance, is reported on page 456. [Image: M. Tsapatsis]