JAPAN NANONET BULLETIN - 9th Issue - January 8, 2004

YOUNG RESEARCHERS’ INTRODUCTION

Isamu MORIGUCHI Associate Professor, Department of Applied Chemistry, Faculty of Engineering, Nagasaki University Researcher, Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST) 1988 Master of Engineering, Graduated School of Engineering, Kyushu University 1988 -1999 Reserch Associate, Faculty of Engineering, Nagasaki University 1996 Ph. D. (Engineering), Nagasaki University 1997 -1998 Visiting Scholar of Clarkson University, USA 1999 - Associate Professor, Faculty of Engineering, Nagasaki University 2001 - Researcher, Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST) E-mail address:

Of late, the soft chemical process for the synthesis of inorganic materials has attracted considerable attention, especially with regard to its application in green material science & technology, processing of new materials, and nanotechnology. The present work is an interdisciplinary study of colloid and surface chemistry, molecular assembly chemistry and ceramic chemistry which aims at designing and fabricating organic-inorganic nanocomposites and inorganic nanostructured materials which would, in turn, lead to the development of novel functional materials.

To date, we have been studying the soft chemical synthesis of thin films and porous materials with the assistance of molecular and colloidal assembly systems. As an example, ultrathin and hetero-layered films of metal oxides were successfully synthesized using a two-dimensional sol-gel process (Figure 1), in which the sol-gel reaction was carried out at an air/water interface and the obtained floating gel film was transferred onto substrate by Langmuir-Blodgett (LB) technique. Porous materials have also been subjected to soft chemical synthesis using micelle, middle phase microemulsion, and polystylene latex (opal) crystals as templates (Figure 2).

In addition to the above syntheses, we are now investigating the correlation between nanostructures and their photo- and electro-chemical properties in order to develop novel nanodevices.

Fig. 1 Large Image Cross-sectional TEM image of the (ZrO2/ TiO2)5 heterolayered film synthesized by the two-dimensional sol-gel process. Twenty-nine layers of titanium butoxide and zirconium butoxide gel films, prepared on a water surface, were deposited in each layer, and this deposition was repeated five times. The gel film was heated at 823 K. The multilayered nanostructure made up of ultrathin laminae of TiO2 and ZrO2, with a thickness of ca. 10-15 nm, was fabricated on throughout the substrate surface.

Fig. 2 Large Image SEM images of a colloidal crystal of polystylene latex (left image) and an ordered macroporous TiO2 film, prepared using the colloidal crystal template (right image). The method involved an infusion of titanium propoxide into the void between the orderly arranged PS particles and a heat-treatment (removal of template). A three-dimensionally interconnected porous structure, with a pore size corresponding to the diameter of the PS particle, was successfully fabricated.