Zeolite membranes and films

20-0-01 - Polyamines as strong covalent linkers for the assembly of mono and double layers of zeolite crystals on glass 

Center for Microcrystal Assembly, Department of Chemistry, Sogang University, Seoul 121-742, KOREA 

20-0-02 - The use of seeds in the synthesis of mono-and bi-layered zeolite membranes 

Supported zeolite Y, silicalite-1, A and a composite of silicalite-1 on A can be synthesised in a membrane configuration in a reproducible manner. Synthesis techniques using seeds were applied in the membrane preparation. The double layer type membrane has great potential in the bifunctional operation in one integrated unit. 

20-0-03 - Growth of oriented mordenite membranes on porous a-A Os supports 

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Nakao, S., Ed., Proceedings of the International Workshop on Zeolitic Membranes and Films, Japan Association of Zeohte, Gifu, Japan, 1998. 

In addition to porous ceramic and stainless steel plates and tubes commonly employed as supports of zeolite membranes and films, a wide variety of alternative supports have been used. Among these are steel [250], ceramic [251,252] monoliths... 

Zeolite membranes and films have been employed to modify the surface of conventional chemical electrodes, or to conform different types of zeolite-based physical sensors [49]. In quartz crystal microbalances, zeolites are used to sense ethanol, NO, SO2 and water. Cantilever-based sensors can also be fabricated with zeolites as humidity sensors. The modification of the dielectric constant of zeolites by gas adsorption is also used in zeolite-coated interdigitaled capacitors for sensing n-butane, NH3, NO and CO. Finally, zeolite films can be used as barriers (for ethanol, alkanes,...) for increasing the selectivity of both semiconductor gas sensors (e.g. to CO, NO2, H2) and optical chemical sensors. 

Various improvements have broadened the research in the field of zeolite membranes and films, such as the development of new synthesis procednres, the use of new supports with specific characteristics (monoliths, foams, etc.), or the use of modified supports by means of masking or grafting techniques, the application of new analytical techniques (isotopic-transient experiments, permporometry, pulsed field gradient nuclear magnetic resonance [NMR], interference microscopy, IR microscopy, etc.), the control of the orientation of the crystals (by means of covalent linkages, synthesis conditions, etc.) and of the thickness of the membranes, and the preparation of new zeolites as membranes or new zeolite-related materials. In addition, a variety of zeolites can now be prepared as colloidal systems with particle dimensions ranging from tens to a few hnndred nanometers. 

In addition to porous ceramic and stainless steel plates and tubes commonly employed as supports of zeolite membranes and films a wide variety of alternative supports have been reported steel [357] and ceramic monoliths [119,358,359] (see Figure 11.29) (also shaped as wheels or rotors [360]), ceramic hollow fibers [23,57,166,306], stainless steel grids [361,362], porous metal support sheet [363], wire gauze packing [364], glass fibers [365,366], nonporous ceramic [367], and metal plates [368,369], glass and steel beads [370], and zeolite discs to avoid mismatch in expansion coefficient [371]. 

Kita H. Pervaporation using zeolite membranes. Proceedings of International Workshop on Zeohtic Membranes and Films Post Conference of ICIM5, Gifu, Japan, June 28-30, 1998 43 6. 

Chiang AST and Chao K-J. Membranes and films of zeoUte and zeolite-like materials. J Phys Chem Solid 2001 62 1899-1910. 

Synthesize defect-free thin film zeolite membranes and microporous bulk phases for future membrane applications. 

S mthesize and characterize of thin films and bulk novel microporous phases including of Al/Si zeolite thin films doped and/or ion exchanged with other elements, unsupported aluminosilicate zeolite membranes, and silicotitanate phases. 

The approach for this program is the development of defect-free thin film zeolite membranes and new bulk microporous phases for the selective separation of light gases. The development of these membranes includes synthesis, modeling/ simulation, permeation studies and validation for separation and isolation of H2. The permeation of pure and mixed gases through membranes is studied at room temperature and 80°C. The modeling and... 

The sun is the primary source for most forms of energy found on Earth. Solar energy is clean, abundant, widespread, and renewable. Various technologies have been developed to utilize solar energy. Zeolite membranes or films also take part in this capture. 

When zeolites are grown as films, zeolite membranes are formed. Efforts to prepare polycrystalline zeolite membranes started in the late 1980s, but not until the early 1990s were MFI-type zeolite membranes (ZSM-5 and silicalite-1) successfully prepared with very good permeation and separation properties [3]. Since then, zeolite membranes have constantly attracted considerable attention because of their unique properties in terms of size uniformity, shape selective separation behavior, and good thermal/chemical stabilities. So far, more than 20 different types of zeolite membranes have been prepared - such as LTA, FAU, MOR, FER, MEL, CHA, DDR, and AFI - with significant separation interest [4, 5]. Table 3.1 lists a few typical zeolite membranes and their potential applications for separation of fluid mixtures. 

Nakayama, K., Suzuki, K., Yoshida, M., Yajima, K., and Tomita, T. (2006). Method for preparing DDR type zeolite film, DDR type zeolite membrane, and composite DDR t3fpe zeolite membrane, and method for preparation thereof. U.S. Patent 7,014,680B2. 

Mizumaki F 1999 Application of zeolite membranes, films and coatings Stud. Surf. Sol. Catal. 125 1-12... 

The separation factors are relatively low and consequently the MR is not able to approach full conversion. With a molecular sieve silica (MSS) or a supported palladium film membrane, an (almost) absolute separation can be obtained (Table 10.1). The MSS membranes however, suffer from a flux/selectivity trade-off meaning that a high separation factor is combined with a relative low flux. Pd membranes do not suffer from this trade-off and can combine an absolute separation factor with very high fluxes. A favorable aspect for zeoHte membranes is their thermal and chemical stability. Pd membranes can become unstable due to impurities like CO, H2S, and carbonaceous deposits, and for the MSS membrane, hydrothermal stability is a major concern [62]. But the performance of the currently used zeolite membranes is insufficient to compete with other inorganic membranes, as was also concluded by Caro et al. [63] for the use of zeolite membranes for hydrogen purification. 

Recent developments in zeolite synthesis and new materials include (i) the use of combinatorial methodologies, microwave heating, multiple templates or SDAs and concentrated fluoride media in synthesis, (ii) synthesis using the charge density mismatch (COM) concept, (iii) synthesis in ionothermal media, (iv) synthesis with complex designer templates or SDAs, (v) synthesis of nanozeohtes, (vi) zeoUte membranes and thin films (vii) and germanosilicate zeoHtes [76]. Several of these developments are discussed here. 

McLeary, E.E., Jansen, J.C., and Kapteijn, E. (2006) Zeolite based films, membranes and membrane reactors progress and prospects. Micropor. Mesopor. Mater., 90,198-220. 

C. Photochemical Rearrangement in Zeolites, Nation Membranes, and LDPE Films... 

S. Yamazaki and K. Tsutsumi, Synthesis of an A-type zeolite membrane on silicon oxide film-silicon, quartz plate and quartz fiber filter, Microporous Materials 4 205 (1995). 

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