Division of Applied Chemistry,
Graduate School of Engineering,
The University of Osaka

We are developing new materials by manipulating surfaces and interfaces with electrochemical methods. Among them, we focus on ionic liquid that consists of salts and has nonvolatile nature. New analytical techniques for surfaces are developed in combination with electron microscopes, and they are utilized in the development of new types of batteries. Another material of interest is semiconductor nanoparticles that are recently known as fluorophores. Efforts to recognize the nature of nanomaterials are made by looking closely at electrons and photons.

Nature has created exotic biological systems with effective and selective functionality by adapting reversible intermolecular interaction such as hydrogen bond. Such systems inspire us to construct artificial functional materials beyond nature by using well-designed intermolecular interactions. Our research includes the following four phases: (1) Design and synthesis of functional organic compounds capable of self-assembling in desired crystalline state. (2) Structural characterization of the crystals and precise identification of intermolecular interactions. (3) Control of molecular arrangements. (4) Development of new functional materials with significant optical and electrical properties provided by self-assembled architectures. (5) Elucidation of protein structure and function.

RESEARCH OBJECTIVES
We deal with various types of the topics on nanoscience through the physical organic chemistry approach based on the synthetic chemistry.

1) Chemistry of Curved π-Aromatic Molecules
Bowl-shaped π-conjugated compounds including partial structures of the fullerenes, which are called ""buckybowls"", are of importance not only as model compounds of fullerenes but also as their own chemical and physical properties.Very few buckybowls has been achieved for preparation mainly due to their strained structure. We develop the rational route to the various buckybowls with perfect chirality control using the organic synthesis approach, and investigate their physical properties.

2) Chemistry of Metal Nanocluster Catalyst
We also investigate to develop novel catalytic properties of metal nanoclusters. We focus on the following projects: Preparation of size-selective gold and gold-based alloy nanoclusters supported by hydrophilic polymers and its catalytic activity: Development of designer metal nanocluster catalyst using the highly-functionalized protective polymers.

We focus on unique relationships between structures and reactivities in various kinds of molecules, including organic molecules, metal complexes and biomolecules. Our research subjects are (1) modification of hemoproteins to enhance their catalytic activities; (2) molecular design and construction of new biohybrid catalysts prepared by incorporation of organometallic species into a protein matrices; (3) construction of hemoprotein assemblies to generate new bionanomaterials; (4) attachment of a redox active protein onto metal or carbon material surfaces; and (5) preparation and characterization of new artificial porphyrinoids with a tetrapyrrole framework.

Research in our group seeks to bring the experience and tactics of strategies of organic methodology development based on synthesis of potential molecules. Especially, our interests are focused on efficient, selective, and environmentally benign methodologies for synthesis of valuable molecules. The new methods have been developed for the synthesis of useful molecules as building blocks for organic synthesis, fullerene derivatives directing toward functional materials, and natural products.

When atoms condense, solids form and exhibit physical properties that we cannot imagine. We focus on inorganic solids, such as transition metal oxides, and promote solid-state chemistry research by synthesizing epitaxial films and bulk samples with atomically controlled structures and exploring their physical properties. We are developing various functional materials such as two-dimensional ferroelectrics, hydrogen storage oxides, ion-conducting solids, and environmental catalysts.

Polymer materials chemistry area deals with new functional polymeric materials on the basis of our original designs and syntheses. We have developed a new fabrication method of nanoporous polymer monoliths and their applications in medical, environmental, and energy fields, a new class of biomass plastics from renewable resources including cellulose and plant oils, and self-assembled prodrug nanoparticles for delivery of bioactive agents, especially bioactive gases.

Our research targets are mainly (1) formation of hierarchical nanostructure of soft materials such as polymer, molecule, and organic-inorganic hybrid materials, (2) development of novel measurement technique, and (3) design and synthesis of conjugated materials having optical, electrical, and magnetic response towards application such as organic photovoltaics and transistors. These materials are utilized in nano-structuring and functionalization, which are characterized at single molecular level.

We have been studying organic electronic materials and their application to electronic devices such as organic light-emitting diodes, organic thin-film transistors and organic solar cells. We intend to develop new concept devices by understanding fundamental properties of organic materials. This interdisciplinary field includes a wide range of academic area from organic chemistry for designing one molecule to physical chemistry for understanding solid state properties, and device physics based on semiconductor engineering for improving performances.

We design and synthesize a wide variety of new inorganic solid materials, mainly alloys and ceramics, to develop innovative catalysts. The reactions include effective utilization of shale gas and CO2, hydrogen production, and nitrogen conversion, aiming to create catalysts that can contribute greatly to the development of the chemical industry and the improvement of the global environment. We also aim to elucidate the principle of catalysis in detail in an atomic level from a physicochemical viewpoint, and to pursue and advance fundamental science.

Cellulose is the most common and abundant bioresources, mainly originating from higher plants. We have successfully extracted cellulose nanofibers with widths of 4-15 nm from wood pulps, and have developed cellulose nanofiber-based materials, such as transparent paper, especially for electronic applications.

The industrial application of quantum beam will rapidly expand in the field such as high-volume production of semiconductor devices. Cancer therapy using ionizing radiation has also attracted much attention. In Department of Beam Materials Science, the radiation-induced chemical reaction and reaction field have been investigated using state-of-the-art quantum beam (electron, extreme ultraviolet radiation, laser, synchrotron radiation, X-ray, gamma-ray, ion beam). We have studied the chemical reaction system from the energy deposition on materials to the expression of material function. On the basis of these studies, we have designed a noble chemical reaction system.