Synthesis Of B-Oriented MFI Zeolite Films

Zeolite films, a kind of inorganic films, have excellent performance and some advantages, such as, its pore diameter and pore diameter distribution can be altered, it can realize the catalytic reaction, adsorption and separation of molercular levels, and have widely used in some fields, such as: catalysis, separation, adsorption, environment protection and photoelectricity communication. Oriented zeolite films can enhance the adhension between zeolte films and substrates, decrease the grain boundraries and increase the separation selectivity. MFI zeolites have attracted considerable interest and have been widely studied. The preparation of MFI zeolite films is in research. Due to the preferred b-oriented MFI zeolite film, the straight channels are perpendicular to the substrate surface. When infiltration moleculars pass b-oriented MFI zeolite films, the distance is the shortest. Because the beeline channel is bigger slightly than the sinusoidal channel, the transport resistance is the smallest;b-orientated MFI zeolite films are looked forward to obtaining.This paper studies several aspects as follows:1. MFI zeolite films can be synthesized on stainless steel by in situ hydrothermal method and the seed growth method using TEABr and TPABr as structure-directing agent (SDA).2. Ideally b-oriented Silicalite-1 zeolite films with high degree of crystallization can be synthesized on glass using TPAOH as SDA. Effects of the crystallization times, types of the substrates and pH values of the synthesis solution on the orientation of the zeolite films have been investigated. The synthesis conditions have been optimized. On other hand, substituting TPABr for TPAOH, under the condition of OH-/Si = 0.32, Na+/TPA+<0.31, partially (101)-oriented Sil-1 zeolite films with high degree of crystallization have been synthesized.3. Partially b-oriented Sil-1 zeolite films with high degree of crystallization can be synthesized on glass using TPABr as SDA by in situ hydrothermal method. Effect of the crystallization times, crystallization temperatures, the molar ratio of the gels, the substrates and the orders of adding materials on the degree of crystallization and orientation of the zeolite films have been studied, the most suitable material rations and synthesis condition have been determined. The mechanism of the oriented zeolite films in the system has been discussed in detail.