STABILITY OF ORIENTED SILICALITE-1 FILMS IN VIEW OF ZEOLITE MEMBRANE PREPARATION

Silicalite-1 is grown as b- and (a, b)-oriented monolayers on silicon wafers and on silicon wafers containing low-stress silicon nitride win dows, aiming at two new membrane systems. The orientation of crystals determines the stability (crack formation), due to tensile or compress ive stress, imposed on the layer after removal of the organic template . By application of etching procedures, the nitride support can be rem oved, leaving the crystal layer undamaged. The latter makes preparatio n of oriented and nonsupported thin layers for gas separation purposes possible. (C) Elsevier Science Inc. 1997.