【作者】 张寒霜；

【导师】 倪红卫；

【作者基本信息】 武汉科技大学 ， 等离子物理， 2010， 硕士

【摘要】 本文首次提出以离子注入法制备含Ag/Cu双元抗菌金属的不锈钢。采用金属蒸汽真空弧离子源(MEVVA)离子注入机,向AISI 420不锈钢中注入Ag/Cu金属离子,研究了注入剂量、热处理工艺对革兰氏阴性大肠杆菌(Escherichia coli,E.coli)、革兰氏阳性金黄色葡萄球菌(Staphylococcus aureus,S.aureus)和黑曲霉菌(Aspergillus niger,A.niger)杀菌率之间的关系,采用X射线光电子能谱(XPS)分析了注入层的微观结构及抗菌金属离子的深度分布,用电化学极化曲线研究了抗菌不锈钢的耐蚀性能。平板菌落计数法表明,在Ag、Cu的总注入剂量为2×1017 ions/cm2时,所得抗菌不锈钢对E.coli和S.aureus均具有良好的抗菌能力(抗菌率>95%),而对A.niger的抗菌效果很差。抗菌不锈钢经退火处理后,对E.coli和S.aureus依然具有良好的抗菌能力(抗菌率≥95%),对A,niger的抗菌率则随着Cu注入剂量的增加而增长,当Cu的注入剂量大于1.5×1017 ions/cm2时,对A.niger的抗菌率达98%以上。XPS精细谱表明,Ag和Cu在抗菌不锈钢中以金属原子的形式存在,深度分析结果表明,注入层中Ag、Cu原子浓度最大值都出现在表层以下46.5nm处。电化学极化曲线表明,离子注入法制备的抗菌不锈钢,其耐蚀能力较未注入的不锈钢试样略有提升。通过观察细菌形态变化,监测抗菌金属的溶出浓度研究了离子注入法制备的抗菌不锈钢杀菌机理,并研究了抗菌能力的持久性。Ag注入剂量为2.0×1017 ions/cm2时,抗菌不锈钢表面溶液经过35.5℃、24h培养后,用电感耦合等离子体发射光谱仪(ICP-AES)检测到溶液中银离子浓度为130ppb。同样条件下,向抗菌不锈钢表面的菌液中加入乙二胺四乙酸(EDTA)至3×10-4 mol/L,对E.coli的抗菌率由96%降至58%。在倒置荧光显微镜下观察到E.coli的细胞壁在Ag离子作用下,3h小时后开始变薄和收缩,5h后E.coli细胞壁溶解,从而导致细菌死亡。离子注入法制备的抗菌不锈钢经过160多天的露置或浸泡以后,对E.coli的抗菌率保持在95%以上。更多还原

【Abstract】 Stainless steel implanted by silver and copper ions simultaneously was firstly reported in this work with a metal vapour vacuum arc source. The implanted layer was characterized by X-ray photoelectron spectroscopy. The antibacterial rates were estimated by standard plate count method. The results indicated that the antibacterial SS with a total dose of 2×1017ions/cm2 of Ag/Cu ions has good antibacterial activities (sterilizing rate≥95%) against Escherichia coli and Staphylococcus aureus but poor antibacterial activities against Aspergillus niger. After annealing treatment, the antibacterial SS showed excellent antibacterial activities against Escherichia coli, Staphylococcus aureus and Aspergillus niger. The sterilizing rate against Aspergillus niger was over 98% when implantation dose of copper ions was above 1.5×1017ions/cm2. X-ray core level spectra indicated that the implanted silver and copper ions exist in metallic state in the implanted layer. The depth profile showed that the maximum concentration depth of both silver and copper ions were about 46.5 nm below the surface. Electrochemical polarization curves indicated that the corrosion resistance of stainless steel was slightly enhanced after implantation of silver and copper ions.A preliminary study was made on antibacterial mechanisms of silver implanted AISI420 stainless steel. The implantation dose of silver ions was 2×1017 ions/cm2. Antibacterial rate of silver implanted stainless steel was 96% against Escherichia coli estimated by standard plate count method. Released silver ions were found in solution by inductively coupled plasma atomic emission spectroscopy. The silver ions concentration was 130 ppb after incubation. The pericellular membrane of Escherichia coli became blurred after 3 h incubation and almost disappeared after 5 h incubation. Antibacterial rate of silver implanted SS against Escherichia coli was reduced to 58% from 96% when the bacteria solution mixed with 3×10-4 mol/L EDTA, indicating that the released silver ions play an important role in the antibacterial process. The silver ions implanted SS remained good antibacterial activities (sterilizing rate≥95%) after exposed in atmosphere or immersed in tap water for 160 days.更多还原