MEL zeolite films with various orientations were prepared on the surface of single crystal silicon by a seeding method, and the influences of the synthesis conditions upon the orientation for the zeolite crystallites in the films were investigated. It suggests that the crystal orientation strongly depends on the water content in the reactants and the crystallization periods. The concentrated reactant in a shorter crystallization time forms favorably the zeolite film with (101) orientation, whereas the dilute reactant crystallizes the preferred zeolite film with (101) and (200) planes parallel to the support surface. The seed layer has no direct influence on the orientation of the zeolite film. The continuing growth of the seed layer forms a mono-layer zeolite film.

Key words: MEL, zeolite film, preferred growth, seed layer