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We prepared self-assembled monolayers(SAM) of alkanethiols having CH₃, COOH, OH and NH₂ terminal groups on sputter-coated Au films on mirror polished SUS316L. We fabricated such special set-up(spatial design) as these SAM specimens, where a SAM surface was faced to another one with intervals of 0.1-1.0 mm. Then, they were soaked in a simulated body fluid(Kokubo solution,SBF,pH7.4,36.5C)in order to evaluate their apatite formation(in vitro bioactivity). It is concluded that apatite deposition on SAMs in the spatial design depended on the surface charge of the SAMs.

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Nano-structured titanium oxide layer was prepared on mirror polished titanium substrates by thermal oxidation at 600C for various periods ranging from 1 hour up to 24 hours in order to examine the effect of nanometer-scale surface roughness of titanium oxide layer on adhesion and proliferation of osteoblast-like cell;MC3T3-E1. TF-XRD analysis showed that rutile was formed on the titanium substrates and its crystallite size increased with the heat-treatment time. AFM analysis showed that surface roughness depended on the heat treatment time and the roughness average (Ra) was controlled in the range from 15 to 64 nm. The cell proliferation was remarkably increased on the substrate after being heated for 6 hours. It is concluded that cell proliferation is highly affected by nanometer-scale surface roughness.

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Size-controllable flower-like TiO₂. superstructure was successfully prepared by simple hydrothermal method from amorphous TiO₂ sphere precursor without any template. The as-prepared samples possess titanate nanosheet structure with high surface area in the range of 290.1 to 350.7 m²g^-1. Upon thermal treatment at 500 ^oC, the titanate nanosheets were converted into anatase TiO₂ with deformation of their structures. The as-prepared flower-like titanate showed high photocatalytic activity for H₂ evolution from water splitting reaction. Moreover, the sample heat treated at 500 ^oC exhibit higher photocatalytic activity than that of commercial TiO₂ anatase powder (ST-01).

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The photocatalytic deNO_x activities of titania, nitrogen-doped titania, Fe loaded nitrogen-doped titania and Pt loaded nitrogen-doped titania under irradiation from monochrome LED lamps using various light wavelengths were investigated in details. The improvement of visible light induced photocatalytic activity was successfully realized using Fe and Pt loading. Both iron loaded nitrogen-doped titania and platinum loaded nitrogen-doped titania showed excellent visible light response ability. The photocatalytic activity exhibited by platinum loaded nitrogen-doped titania was several times higher than that of nitrogen-doped titania under the visible-light irradiation of wavelength = 627 nm and 530 nm. The relationship between photocatalytic activity and irradiation light wavelength was investigated in detail.

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Photocatalytic water splitting is attracting much attention as an ideal clean hydrogen production method.In this study, dye sensitized effects on water splitting activity of KTaO₃ was studied. It was found that hydrogen formation rate is much improved by dye sensitization, mixing organic dye, and optimized organic dye. In particualr, mixing two organic dyes shows significant positive effects on hydrogen formation rate. On the other hand, it is also found that the organic dye with redox potential of -0.8 V seems to be suitable as dye sensitization.

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Nanometer sized gold fine particles are well know to show a particular optical absorption in visible range due to their surface plasmon resonance (SPR). The change of SPR is very sensitive to refractive index of a near-field region of gold particles surface. Thus, the application of gold fine particles have received a lot of attention as a chemical-biosensor. In order to make a SPR sensor tip which consists of simple equipments and can detect target substances with ease, silica gel thin films loading gold fine particles were prepared on a glass substrate by a sol-gel method and subsequent thermal-reduction process. The prepared thin films exhibited the particular optical absorption due to the localized surface plasmon resonance (LSPR) of a nanometer sized gold particle. Additionally, the absorption maxima showed liner red shift depending on refractive indices of respective solvents.

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Monodisperse silica particles grafted with well-defined, concentrated poly(methyl methacrylate) brushes were synthesized by surface-initiated living radical polymerization. A suspension of the hybrids in a certain concentration range formed a colloidal crystal with an iridescent color. The colloidal crystal showed a sharp phase inversion into a fluid phase depending on the particle volume fraction. The critical particle volume fraction for the crystallization of the present system was intermediate between those of the conventional (soft and hard) colloidal crystals. The crystal structure was strongly dependent on the graft chain length.

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Because of the damaging effects of UV-rays many kinds of UV-shielding materials have been developed. For example, fine powders of titania (TiO2), zinc oxide (ZnO) and Calcia-doped ceria (Ce1-xCaxO2-x) (donated as: CDC) etc. Generally, the using feeling and the covering on skin of inorganic nanoparticles are not so satisfying, so the plate-like particles are often used to improve the comfort and covering ability. Here, in order to improve the using feeling and at the same time ensure the UV-shielding ability different methods are developed to coat the plate-like potassium lithium titanate (donated as: PLT) substrate with CDC nanoparticles.

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