研究論文
アナターゼ型酸化チタンを添加したCu粉体の抗菌特性
キーワード:
copper powder,
antibacterial activity,
heat treatment,
anatase TiO2,
reactive oxygen species (ROS)
2023 年 70 巻 3 号 p. 121-131
詳細
2023 年 70 巻 3 号 p. 121-131
To understand the mechanism of antibacterial activity of bulk Cu, N2-atomized Cu powder has been used instead. It was heated from 425 to 673 K in air for 4.2 • 102 s and measured by XRD and Chemi-luminescence (CL) to determine the contents of Cu2O and CuO, and reactive oxygen species (ROS), respectively; ROS being much affected by Cu2O and CuO can play a role to kill bacteria. Cu2O increased from 3.3 mass% (R.T.) to around 20% (673 K), however, CuO was almost constant (1.2~3.5%). High CL intensity was observed for Cu powders heated at 598~673 K. Then, a small amount of anatase TiO2 (a-TiO2) was added and heated at 673 K for 4.2 • 102 s in air, 1% O2-99% N2, and N2. The powder heated under 1% O2 showed the high CL intensity summation (∑CL), especially, 8.0 mol% a-TiO2 added and heated sample (“8.0Ti powder”) gave the about 4.7 times higher ∑CL than the starting material. ESR results using the spin-trap method showed that they contained hydroxyl radical •OH and its intensity increased from starting material to “8.0Ti powder”. However, bio-test proved that these samples revealed the same antibiotic activity. Formation mechanism of ROS (•OH and super oxide radical •O2-) on the surfaces of Cu/Cu2O/CuO has been proposed.
