Fabrication Of Oriented Molecular Sieve Layers

Molecular sieve arrays and thin films have wide application prospects as advanced functional materials in separation and catalytic membranes, micro-reactor components, chemical sensor devices, modified electrodes, optoelectronic and low-k materials, anti-corrosion coatings, and hydrophobic antimicrobial materials, so they have received considerable interests in recent years. The micro-structures of zeolite films have great effect to their properties, therefore, it is very important to synthesize polycrystalline zeolite membranes of preferred orientation. In situ hydrothermal synthesis and crystal self-assembly on substrate surface are two main methods to produce molecular sieve arrays and thin films. For in situ method, the oriented polycrystal molecular sieve arrays and thin films could be produced by modification of the substrate surface or controlling the synthetic condition; for crystal self-assembly method, molecular sieve crystals can be assembled onto the substrate surface via various bonding forces or by different strategies to produce ordered molecular sieve arrays and thin films.In this thesis, the manual assembly and sonication with stacking are adopted to produce b-oriented silicalite-1 layers on porousα-Al₂O₃ supported PVA surface. For sonication with stacking method, 3CP-TMS is used as the covalent linker to produce b-oriented silicalite-1 monolayers with strong zeolite-polymer bonding and high surface coverage. For manual assembly method, b-oriented silicalite-1 mutilayers were obtained. It has no need of covalent linkers, the process is easier and more quickly compared to sonication with stacking method. For sonication with stacking method, the SAPO-5 crystals are too big to get satisfied results. We turned to manual assembly method,instead. The aspect ratio of SAPO-5 crystals are reduced to be manually assembled onα-Al₂O₃ supported polymers. The SAPO-5 crystals are more easier to be assembled on theα-Al₂O₃ supported PEI surface than the PVA surface. We adopt manual assembly method to produce a c-oriented SAPO-5 monolayer onα-Al₂O₃ supported PEI surface. At the same time, several conclusions for suface assembly are gained.