Mesoporous silicates thin films

I. Honma, H.S. Zhou, D. Kundu, and A. Endo, Structural Control of Surfactant-templated Hexagonal Cubic, and Lamellar Mesoporous Silicate Thin Films Prepared by Spin-casting. Adv. Mater., 2000, 12, 1529-1533. 

Honma L, Zhou H.S. Self-assemhling functional molecules in mesoporous silicate materials Optical properties and mesophase of dye-doped M41S. Adv. Mater. 1998 10 1532-1537 Honma L, Zhou H.S., Kundu D., Endo A. Structural control of surfactant-templated hexagonal, cubic and lamellar mesoporous silicate thin films prepared by spin-casting. Adv. Mater. 2000 12 1529-1533... 

Two-dimensional DQ H MAS-NMR spectra were used to investigate the local structure of a surfactant-templated silicate thin film.498 Silicalite-1 powders (20-1000 nm. crystals) were characterised by 29Si MAS-NMR spectroscopy.499 13C and 29Si solid-state NMR data were used to characterise organic-inorganic mesoporous silica-based materials.500... 

Fig. 9 Schematic representation of three approaches to generate nanoporous and meso-porous materials with block copolymers, a Block copolymer micelle templating for mesoporous inorganic materials. Block copolymer micelles form a hexagonal array. Silicate species then occupy the spaces between the cylinders. The final removal of micelle template leaves hollow cylinders, b Block copolymer matrix for nanoporous materials. Block copolymers form hexagonal cylinder phase in bulk or thin film state. Subsequent crosslinking fixes the matrix hollow channels are generated by removing the minor phase, c Rod-coil block copolymer for microporous materials. Solution-cast micellar films consisted of multilayers of hexagonally ordered arrays of spherical holes. (Adapted from [33])...

Experiments have shown that other types of gas sensors can also use mesoporous silicas as the sensing layer. For example, selective sensing of nitric oxide has been accomplished in the presence of carbon monoxide through the application of quartz crystal microbalance technology employing a cobalt phthalocyanine-modified sol-gel thin film (Palaniappan et al. 2006,2008). Electrochemical detection of nitrite has been accomplished using a metalloporphyrin-modified silicate material... 

The EL properties of PVK multilayered EL devices doped with ZnS Mn and based on nanocrystalline particles were also investigated and compared with bulk thin film materials [271], The PVK double layer was fabricated by successive spincoating of PVK and PVK NCs, and the film thickness of each layer was about 100 nm. It was found that multilayer EL devices that exhibited luminance up to thousands of cdm [272] in the case of the application of nanocrystalline parhcles only reached a luminance of the order of 0.1cdm , probably due to an aggregation of nanoparticles. In turn, the properties of ZnSiPVK nanocomposites confined in the MCM-41 silicate were studied [273], To prepare PVK ZnS nanocomposites confined in the silicate, MCM-41 was modified with ethylenediamine followed by introduction of ZnS into their mesopores. Finally, N-vinylcarbazole was mixed with the obtained ZnS/MCM-41 and polymerized at 85°C for 6.5 h. In the PL spectra, an emission peak at 468 nm was observed. Further analysis indicated that the emission could be attributed to the exciplex of excited-state PVK molecules and ground-state ZnS clusters [272],... 

Some discrimination between different alcohols is evident (Innocenzi, 2001b). Spin coated silica films with a cubic structure have also been incorporated into a surface photovoltage gas sensor (Yamada, 2002). Dip coated mesoporous thin films on a macroporous or mesoporous support have been prepared for separation membrane applications (Kim, 2002, 2003). Spin coating has also been used to deposit CieTABr templated films where the silicate walls were composed of nanosized zeolite MFI crystals co-deposited with the TEOS solution (Petkov, 2003).The continuous film contained a wormlike mesostructure and zeolite nanocrystals aligned with the a-axis perpendicular to the substrate, however the surface roughness of the film was increased. 

Petkov N., Mintova S., Jean B., MetzgerT.H., Bein T. Stable mesostructured silicate films containing nanosized zeolite. Chem. Mater. 2003 ASAP Article Pidol L., Grosso D., Soler-IlUa G.J.A.A., Crepaldi E.L., Sanchez C., Albouy P.A., Amenitsch H., Euzen P. Hexagonally organised mesoporous aluminium-oxo-hydroxide thin films prepared by the template approach. In situ study of the structural formation. J. Mater. Chem. 2002 12 557-564... 

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