CaAlO 水泥结构中自由氧自由基阴离子和自由电子对其光学、电学及抗菌性能的影响。
Effect of free oxygen radical anions and free electrons in a CaAlO cement structure on its optical, electronic and antibacterial properties.
作者信息
Phrompet Chaiwat, Sriwong Chaval, Srepusharawoot Pornjuk, Maensiri Santi, Chindaprasirt Prinya, Ruttanapun Chesta
机构信息
Smart Materials Research and Innovation Unit (SMRIU), Faculty of Science, King Mongkut's Institute of Technology Ladkrabang, Chalongkrung Road, Ladkrabang, Bangkok 10520, Thailand.
Department of Physics, Faculty of Science, King Mongkut's Institute of Technology Ladkrabang, Chalongkrung Road, Ladkrabang, Bangkok 10520, Thailand.
出版信息
Heliyon. 2019 May 30;5(5):e01808. doi: 10.1016/j.heliyon.2019.e01808. eCollection 2019 May.
The aim of this work was to investigate the effect of free oxygen radicals and free electrons in a CaAlO (C12A7) cement structure on the optical, electronic and antibacterial activity of this material. CaAlO was successfully fabricated via rapid heating to high temperatures by high frequency electromagnetic induction. CaAlO cement samples were characterized using XRD and UV-Vis-DRS spectroscopy. The morphology and chemical composition of the samples were also investigated using SEM and EDS techniques. The presence of free oxygen radicals (O ions) in the insulating structure of CaAlO was confirmed using Raman spectroscopy showing a spectrum peak at 1067 cm. The excitation of free electrons in the CaAlO cement was indicated by UV-Vis absorption spectra at 2.8 eV and an optical energy gap of 3.5 eV, which is consistent with the first-principles calculations for the band energy level. The effects of free oxygen radicals and free electrons in the CaAlO structure as antibacterial agents against . and . were investigated using an agar disk-diffusion method. The presence of O anions as a reactive oxygen species (ROS) at the surface of CaAlO caused inhibition of . and . cells. The free electrons in the conducting C12A7 reacted with O gas to produce ROS, specifically super oxides (O ), superoxide radicals (O ), hydroxyl radicals (OH) and hydrogen peroxide (HO), which exhibited antibacterial properties. Both mechanisms were active against bacteria without effects from nano-particle sized materials and photocatalytic activity. The experimental results showed that the production of ROS from free electrons was greater than that of the free O anions in the structure of CaAlO. The antibacterial actions for insulating and conducting CaAlO were different for . and . . Thus, CaAlO cement has antibacterial properties that do not require the presence of nano-particle sizes materials or photocatalysis.
这项工作的目的是研究CaAlO（C12A7）水泥结构中的游离氧自由基和自由电子对该材料的光学、电子和抗菌活性的影响。通过高频电磁感应快速加热至高温成功制备了CaAlO。使用XRD和紫外可见漫反射光谱对CaAlO水泥样品进行了表征。还使用SEM和EDS技术研究了样品的形态和化学成分。利用拉曼光谱在1067 cm处出现的光谱峰证实了CaAlO绝缘结构中存在游离氧自由基（O离子）。紫外可见吸收光谱在2.8 eV处以及3.5 eV的光学能隙表明CaAlO水泥中自由电子的激发，这与能带能级的第一性原理计算结果一致。使用琼脂扩散法研究了CaAlO结构中的游离氧自由基和自由电子作为抗菌剂对. 和. 的作用。CaAlO表面作为活性氧（ROS）的O阴离子的存在导致. 和. 细胞受到抑制。导电的C12A7中的自由电子与O气体反应生成ROS，特别是超氧化物（O）、超氧自由基（O）、羟基自由基（OH）和过氧化氢（HO），它们具有抗菌性能。这两种机制对细菌均有活性，不受纳米颗粒尺寸材料和光催化活性的影响。实验结果表明，CaAlO结构中自由电子产生的ROS比游离O阴离子产生的ROS更多。绝缘和导电CaAlO对. 和. 的抗菌作用不同。因此，CaAlO水泥具有抗菌性能，不需要纳米颗粒尺寸材料的存在或光催化作用。
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