Influence of the synthesis conditions and growth environment on MFI zeolite film orientation

Zeolite powders and films were prepared from six published synthesis recipes claimed to produce zeolite film coatings and membranes with (2 0 0), (0 2 0), (0 0 2) and (1 0 1) orientations. The morphology and orientation of the zeolite films prepared from each synthesis recipe were characterized and compared to determine the influence of synthesis composition and crystallization conditions. The zeolite growth environment was manipulated by changing the seed concentration on the substrate. The experimental results indicate that the synthesis chemistry and crystallization conditions affect the crystal grain morphology, whereas the growth environment influences the crystal habit. A simple method for predicting the orientation of the zeolite film based on the morphology of the zeolite crystal and the growth environment is also presented. (C) 2002 Elsevier Science Inc. All rights reserved.