Synthesis Of Microporous Compounds With Special Congregated Morphology

Microporous zeolite materials with uniform and molecular-size pores have been used in many fields such as ion exchange, adsorption and separation, and industrial catalysts. However, One of the reasons that zeolites have not yet found a wider range of industrial applications is the sole presence of micropores, which imposes diffusion limitations on the reaction rate. Mass transport to and from the active sites located within the micropores is slow and limits the performance of industrial catalysts. To over the limitation, there has been a long-standing drive to either minimize the size of the zeolite crystals or to increase the pore size of zeolites. Several synthesis schemes have been reported which allow the preparation of very small zeolite crystals. However, none of these attempts has produced an easy means of controlling the crystal size. Moreover, the small sized zeolite particles tend to agglomerate, limiting the utility of the external surface and the internal micropores of zeolites. Zeolites with hierarchical pore architecture have been found to present a solution to the problem. The effect of the presence of mesopores is already used in a number of industrial processes that make use of zeolite catalysts. The preparation and development of functional materials is captivated interest, such as optoelectronic devices, nonlinear optics, membrane reactors, selective sensors, ceramic membranes, zeolite-polymer composites and reactive membranes. However, the application of such functional materials, especially micro-devices, are based on better morphology, higher quality, and larger size of zeolites crystals, which are very difficult to achieve. Therefore our research work focused on the syntheses of zeolite with special congregated morphology. We obtained new structure carbolic materials through the carbonization the leaves of Carex meyeriana, which specially grows in the east-north area of China. The leaves of Carex meyeriana possess special character of structure, which can be used to synthesis the congregated zeolite with hierarchical pore architecture. By assembling nano-zeolite particles to the leaves, seed growth, calcined, we got zeolite replicated the morphology of the leaves with special architecture, which was demonstrated by XRD and SEM. The various vivid morphologies exhibited by zeolitic tissue reveal the complexity of the leaves of Carex meyeriana, which would provide a novel and important perspective to study bio-organisms. Utilizing the positive electricity of the polyelectrolytes, we obtained ordered chains of silicalite crystals. The silicalite chains, which consist of up to 20 coaligned crystals, are prepared by a novel process involving hydrothermal synthesis in the presence of the cationic polymer, PDDA, poly (diallydimethylammonium chloride). The chains were formed in situ within the reaction medium and consisted of pris-matic particles that were coaligned with their crystallographic b axes parallel to the chain axis, as shown by TEM/electron diffraction analysis and XRD. Moreover, the mass quantity of TPAOH is a crucial factor. We find that the large single MOR zeolite crystal can be synthesised by using "seed solution"as precursors. By adjusting the quantity of "seed solution", the number of the zeolite nucleus can be controlled. Accordingly, the size of the single mordenite zeolite crystal is under control. The polymorph C of beta zeolite can growth to 40μm by adjusting the quantity of water in a fluoride system. In the presence of aliphatic alcohol, the synthesis of BEC single crystal was demonstrated. It has been indicated that a slow release of silicon and aluminium species into the reaction medium is essential for the synthesis...