Yoshiyuki SUGAHARA

Yoshiyuki SUGAHARA

• Inorganic Chemistry
• Professor
• Office: Room 65-406
• Phone: +81-3-5286-3204
• Fax: +81-3-5286-3204
• Email : ys6546@waseda.jp

Research Interests

Our research group is concerned with the development of chemical routes to inorganic-organic hybrids and their use as precursors of ceramic materials. Our research program makes extensive use of inorganic, organometallic, and materials chemistries.

Preparation of inorganic-organic hybrids using crystalline inorganic compounds.

A variety of inorganic-organic hybrids can be prepared by accommodating organic molecules/ions and polymers in the interlayer space of layered compounds, which consist of stacked nanosheets. In particular, we are developing graft-type reactions of layered compounds, such as ion-exchangeable layered perovskites and layered transition metal oxyhalides, to form hybrids with covalent bonds at the interfaces. We thoroughly characterize resulting products investigate reaction mechanisms.
We also develop the preparation methods for incorporation of inorganic nanobuilding blocks, such as nanoparticles and nanosheets, in organic polymers. Surfaces of nanobuilding blocks are organically modified to achieve high dispersibility of the inorganic nanobuilding blocks. We also explore properties of resulting hybrids with respect to their possible applications.

Preparation of ceramics and hybrids from polymeric precursors.

We are developing preparation methods for ceramics from organometallic and metallorganic polymers. We have particular interests in precursor polymers with Al-N or Si-N networks, and we investigate their preparation, conversion processes into ceramic materials, characterization of resulting ceramic materials.
Among preparation methods from precursors with metal-oxygen bonds, the sol-gel process starting from metal alkoxides has been mainly explored. In addition to design of the precursors and reaction conditions at polymerization steps, properties of resulting hybrids are investigated for possible application of these hybrids.

FIGURES

Preparation of hybrids by graft reactions

Preparation of AlN via pyrolysis

Selected Publications

1. “Interlayer Surface Modification of the Protonated Ion-exchangeable Layered Perovskite HLaNb2O7•xH2O with Organophosphonic Acids,” Chem. Mater., 21, 4155-4162 (2009).
2. “Organic Derivatives of the Layered Perovskite HLaNb2O7•xH2O with Polyether Chains on the Interlayer Surface: Characterization, Intercalation of LiClO4, and Ionic Conductivity,” J. Mater. Chem., 18, 3581-3587 (2008).
3. “Size- and Shape-Controlled Conversion of Tungstate-Based Inorganic-Organic Hybrid Belts to WO3 Nanoplates with High Surface Areas,” Small, 4, 1813-1822 (2008).
4. “Tungstate-Based Organic/Inorganic Hybrid Nanobelts/Nanotubes with Lamellar Mesostructures: Synthesis, Characterization and Formation Mechanism,” Chem. Mater., 19, 1808-1815 (2007).
5. “Reactivity of the Ruddlesden-Popper Phase H2La2Ti3O10 with Organic Compounds: Intercalation and Grafting Reactions,” Chem. Mater., 19, 2352-2358 (2007).

Biography

B.S. Waseda University (1983); Dr. Engineering, Waseda University (1988); Post-doctoral Fellow, Massachusetts Institute of Technology (1989-1990); Assistant Professor, Waseda University (1990-1992); Associate Professor, Waseda University (1992-2000); Visiting Scientist, Université Montpellier II (1998); Professor, Waseda University (2000-); Invited Professor, Université Montpellier II (2007). Award for Young Clay Scientist, the Clay Science Society of Japan (1989); CSJ Award for Advancement in Ceramic Science and Technology, the Ceramic Society of Japan (2002).