日 時:2009年 7月 22日(水)15:00~16:00
場 所:南7号館 1階 101会議室
講 師:Prof. G. Carja (ルーマニア)
講演題目:「Toward complex nanostructures: MexOy-anionic clay matrices as self ensembles」
講演内容:
Nanoarchitectural ensembles in which different components are able to join their features and organize themselves for giving rise to materials owning complex characteristics and specific architectural features is a great interest in nowadays research. Nanoparticles of metals or metals oxides have shown a great potential for applications in nanotechnology. It was found that nanosized metals and metal oxides are not very stable in time owning an accentuate tendency to aggregate and to alter their properties from nano to microlevel. The tendency to aggregate induces nanoparticles toxicity. To reduce the nanoparticles aggregation process polymers, ligands or surfactants are used as templating or directing agents. These large compounds not only increase the cost of the obtained material but also strongly decrease and alter the accessibility of the active nanosites. The ensemble consisting of nanoparticles of metals and a biocompatible inorganic matrix can offer solutions not only to reduce the aggregation process but also to increase nanoparticles biocompatibility. The matrix is also able to bring into the cumulative structure its own characteristics thus giving rise to a tailored textural organization within micro/nanorange. Hydrotalcite – like anionic clays or more generally speaking, layered double hydroxides (LDHs), represented by the empirical formula [M(II)1-x M(III)x ∙(OH)2]x+ (An-)∙mH2O, are layered inorganic matrices able to bring into the ensembled formulation the advantage of a good biocompatibility and low cytotoxicity.
We present a facile and cheap synthesis route for obtaining new materials, as self ensembles of nanoparticles of metal or metal oxides – hydrotalcite-like clay matrices (Ag/LDH, TiO2/ZnLDH, Fe2O3/ZnLDH).
The “memory effect” of the LDH anionic clay has been “manipulated” such a way that - the reconstruction process of the clay, the formation of metal or metal oxides based nanoparticles and their deposition on the surface of the larger interconnected nanoparticles of the clay layered matrix - take place in one single step at room temperature.
Some properties of metal oxides - anionic clay matrix ensembled nanoarchitectures are also presented.
問合せ先:中島 章 内線: 2525,e-mail: [email protected]