A Ti electrode with a noble metal coating was used for sterilization of water. The main product from electrolysis for sterilization is hypochlorite acid. It was found that the hypochlorite acid production rate was consistently higher on Pt-Ir and Pt-Ir-Ta coated Ti electrodes, compared to Pt coated Ti electrodes. The production rate of hypochlorite was independent of temperature. Therefore, it was thought that this hypochlorite would be effective in sterilization of hot bath water and pool water. At the same time, ozone was generated in the electrolyte water. Generation of ozone was conspicuously observed under electrolysis of Pt electrodes. The production rate of ozone depended on the temperature and the concentration of chloride ions in the electrolyte. A high concentration of ozone was observed when the temperature of the solution was below about 15ºC, concentration of chloride ions was 1mM, and a membrane was used to separate the cell. The ozone generated by electrolysis of Pt coated Ti electrodes had a significant effect on sterilization for Bacillus subtilis spores.
We prepared a self-assembled monolayer (SAM) from p-aminophenyltrimethoxysilane (APhS : NH2C6H10Si(OCH3)3) on Si substrate through chemical vapor deposition. The microstructured APhS-SAM/SiOx template onto Si substrate was fabricated by conventional vacuum ultraviolet lithography. Pd was selectively immobilized on regions of APhS-SAM as a catalyst for electroless Cu plating. The pH of the Pd solution was optimized by measuring the amount of deposited Pd obtained by X-ray photoelectron spectroscopy. At the pH values of 5 and 6, the amount of deposited Pd on the APhS-SAM increased. A Pd micropattern was prepared on the microstructured APhS-SAM from the solution. Cu was site-selectively deposited onto the microstructured Pd regions. The obtained Cu micropattern was transferred onto a Nafion® sheet by nanoimprint lithography. The shape of Cu micropattern on the sheets was observed to be the same as it is on the silicon substrate.
As a coating method for the improvement of the corrosion resistance of stainless steel plates, we examined the preparation of inorganic-organic composite coating using chemically modified metatitanic acid particles. Metatitanic acid particles were allowed to react with 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane in xylene to give the derivative of metatitanic acid including epoxy group. This derivative was treated with 3-aminopropyltriethoxysilane in ethanol containing water and acetic acid to prepare the precursor suspension solutions. The stainless steel (SUS304) plates were dip-coated using these suspension solutions, and then these plates were heat-treated at 200ºC. SEM observation of the surfaces on these samples found that the surfaces were effectively coated with the metatitanic acid particle-organic composite coating. The peeling test of these samples with tape indicated that these coatings were not removed. A corrosion resistance test of the coated samples was also carried out using FeCl3 according to JIS G 0578. As a result, corrosion of the coated SUS304 was significantly inhibited compared with the non-coated sample.