著者
秋山 哲夫 五十嵐 栄 長岡 正博 大橋 明石 植田 正彦 アキヤマ テツオ イガラシ サカエ ナガオカ マサヒロ オオハシ アカシ ウエダ マサヒコ Tetuo AKIYAMA Sakae IGARASHI Masahiro NAGAOKA Akashi OHASHI Masahiko UEDA
雑誌
奥羽大学歯学誌
巻号頁・発行日
vol.31, no.3, pp.207-212, 2004-09-30

In recent years titanium dioxide (TiO_2) has been widely identified as a photocatalyst. Compound materials with their surface covered with apatite microcrystals have been used in various fields. On the other hand, titanium was substituted for the calcium ion in the apatite crystal. The titanium-ion-substitution apatite exhibited photocatalytic properties and was termed photocatalytic apatite. It is thought that the titanium ion was substituted for column calcium in photocatalytic apatite. However, X-ray diffraction analysis of photocatalytic apatite revealed a feeble peak that was attributed to TiO_2. Therefore, the question arised as to if the titanium signal from the apatite crystals indicated that the titanium existed as titanium dioxide microparticles. To answer this question, photocatalytic apatites with various titanium concentrations were synthesized. Additionally apatites with concentration of 0% titanium and measured amounts of titanium dioxide were also synthesized. Then the photocatalytic apatites with variable concentration of titanium and the apatites with variable concentration of titanium dioxide were compared with them, using X-ray diffraction analysis and chemical analysis. The following results were obtained : (1) The author could not completely deny the possibility that the titanium which existed as titanium dioxide particles had been mixed with apatite particles in the photocatalytic apatite. (2) In the photocatalytic apatite, where the substitution of titanium (IV) for Calcium (II) occurred, the substitution ratio was likely 1 : 1.