Ceramic nanoparticles titania

The preparation of the required microporous ceramic layers is possible by the sol-gel route from stable colloidal dispersions with individual nanoparticles of less than 10 nm. Different types of ceramic nanofilters have been prepared from such aqueous or organic sols of the following oxides y-alumina, zirconia, ° hafnia," and titania. ... 

This new single-step synthesis unites the simplicity of preparation and lower production costs, with the outstanding properties of the final catalysts. By the single-step procedure proposed here, deposition of dispersed nanoparticles of noble metals on ceramic supports with customised textural properties and shape was achieved. Noble metals including platinum, palladium, rhodium, ruthenium, iridium, etc. and metal oxides including copper, iron, nickel, chromimn, cerium oxides, etc on sepiolite or its mixtures with alumina, titania, zirconia or other refractory oxides have been also studied. 

Fairokhi-Rad M, Ghorbani M. Electrophoretic deposition of titania nanoparticles in different alcohols kinetics of deposition. J Am Ceram Soc 2011 94 2354—61. 

Vorkapic, D., and T. Matsuoukas, Effect of temperature and alcohols in the preparation of titania nanoparticles from alkoxides.. /. Am. Ceram. Soc. 81 (1998)... 

Frey M.H., Payne D.A. Synthesis and processing of barium titanate ceramics from alkoxide solutions and monolithic gels. Chem. Mater. 1995 7 123-129 Fu X., Qutubuddin S. S)mlhesis of titania-coated sMca nanoparticles using a nonionic water-in-oil microemulsion. Colloids Surf. A 2001 179 65-70 Ganguli D. Sol-emulsion-gel synthesis of ceramic particles. Bull. Mater. Sd. 1999 22 221-226 GanguU D., Chatteijee M. Ceramic Powder Preparation A Handbook. Boston Kluwer Academic Publishers, 1997... 

Most equi-axed nanoparticles are spherical, but irregular particles are also available. The common particles are metallic (e.g., gold, silver), ceramic (e.g., silica, alumina, titania), or organic (e.g., rubber particles, fullerenes). The ceramic particles are typically prepared by sol-gel or flame-spraying methods silica and alumina are commonly used with adhesives, see O Pig. 55.1. Rubber particles are typically core-shell particles, with a soft core and a hard shell of a polymer such as poly(methyl methacrylate). 

Composite nanofibers have been made by electrospinning solutions that contain nanoparticles, such as silica, titania, carbon black, silver, and iron oxides. The nanofiber matrices can be polymer, carbon, or ceramic. For carbon and ceramic matrices, post-electrospinning treatments are needed to convert their precirrsors into carbon and ceramic materials. 

A general approach to prepare hollow spheres of ceramic materials with func-tionaUzed interior surface has also been reported [121]. The onter surfaces of the templating PS beads are first coated with submonolayers of silver nanoparlicles, and they are assembled into a three-dimensional crystalline lattice. The beads are then coated with a titania layer. After the PS beads are dissolved in toluene, uniform hollow spheres are generated, with their interior surfaces being functionalized with the silver nanoparticles. Meanwhile, silver nanoparticles can be selectively removed using another wet etchant to produce an array of nanosized cavities on the interior surface of the hollow sphere. These nanoscale cavities may have functionality similar to that of the nanoscale template, as demonstrated in the area of molecular imprinting [122,123]. 

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