| As an important type of inorganic membranes or films, zeolite membranes or films possess uniform pores, high separation selectivity, good mechanical strength, chemical resistance and thermal stability. They have been widely used in the fields of separation, sensors, electrodes, low-k dielectric materials, membrane reactions and corrosion protection coating. So far, extensive studies have been conducted on the preparation, characterization and application of various types of zeolite membranes or films. Because of the anisotropy of the crystal habit and the unique intra-crystalline channel system, the accessibility of zeolite channels in a membrane or film and the resulting performances are considerably influenced by the crystals orientation of the zeolites, especially by the zeolites with one- or two-dimensional channel systems.MFI-type zeolites (ZSM-5 and Silicalite-1) consist of 10-member-ring (10-MR) straight channels (5.3×5.6 ?) parallel to the b-axis, interconnected to 10-MR sinusoidal channels (5.1×5.5 ?) in the a-axis. No channels are present in the c-axis but mass transport in this direction is believed to be possible by jumping between the straight and the sinusoidal channels. For the highly b-oriented MFI zeolite film, the straight channels are perpendicular to the substrate surface. The mass transport through the highly b-oriented MFI zeolite film will experience the shortest distance, which will give the highest separation efficiency. Therefore, the high quality b-oriented MFI zeolite film is highly desired.In situ crystallization is the most common preparation method of zeolite films. In this study, highly b-oriented Silicalite-1 thin films with smooth surface and excellent continuity were prepared on glass substrate using TPAOH as SDA. Effects of the crystallization times and pH values of the synthesis solution on the orientation of the zeolite films have been investigated. In addition, the thin film was fully characterized with SEM and XRD analyses.Highly b-oriented continuous Silicalite-1 thin films were facilely prepared on HF-etched glass substrate under microwave heating conditions. The films were characterized by the scanning electron microscope (SEM) and Power X-ray diffraction analyses. The thickness of the films and the crystal size within the films can be easily controlled by controlling the reaction time. The investigation on the growths of Silicalite-1 films on the untreated and HF-treated glass substrates suggests that the surface properties of the substrates have significant influence on the orientation of the crystals within the films. A comparative study on the preparation of Silicalite-1 zeolite films under microwave and conventional heating was performed at 170°C. The results show that with prolonging the crystallization time, the crystal size within the film synthesized under microwave heating condition is much more big than that synthesized under conventional heating.A facile method for the hydrophobization of Silicalite-1 films through silylation with 1H,1H,2H,2H-perfluorodecyltriethoxysilane in order to protect the films against corrosive wet etch chemicals and ambient moisture adsorption is developed. The surface of the Silicalite-1 films prepared by in situ crystallization and spin-on of zeolite nanoparticles is modified with this method. The substrates of the films prepared with both methods are (100) Si wafer. After the modification, the surface of both films are highly hydrophobic as confimed by the water drop contact angle measurements.
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