不锈钢表面渗铜扩散复合处理合金层的抗菌性能研究

Improvement of Antibacterial Properties of Stainless Steel by Combining Plasma Cu and Thermal Diffusion

采用等离子表面合金化及辉光轰击热扩散复合处理技术在不锈钢表面进行了铜合金化处理.利用薄膜密贴法对改性层的抗菌性能进行了测试.通过扫描电子显微镜(SEM)、辉光放电光谱分析仪(GDOES)和X射线光电子能谱(XPS)等手段,研究了铜合金层的微观组织、化学成分分布及抗菌前后表面铜的价态变化.结果表明,铜合金层对大肠杆菌(E.coli)和金黄色葡萄球菌(S.aureus)都展现了优良抗菌性能;合金层表面铜约为5.7wt%,合金层厚度约2.7μm;表面铜合金化不锈钢与菌液接触后,不锈钢表面的铜元素以铜离子析出,并且与试验菌种发生作用,杀灭试验细菌.

The duplex treatment consisting of plasma surface alloyed with copper followed by thermal diffusion under the bombardment of glow was carried out on AISI 304 stainless steel in order to improve its antibacterial properties. The antibacterial properties against Gram-negative E.coli ATCC10536 and Gram-positive S.aureus ATCC25923 of the untreated and duplex-treated stainless steel were investigated by using a spread plate method. The microstructure, chemical composition and the change of the chemical state of copper on the surface of the du- plex treated stainless steel were characterized using scanning electron microscope （SEM）, glow discharge optical emission spectroscope （GDOES） and X-ray photoelectron spectroscope （XPS）. The results show that the antibacte- rial rates gradually rise with increase of the contact time between the bacteria and the copper-alloyed stainless steel, and the alloyed surface exhibits excellent antibacterial properties against both E.coli and S.aureus within 12 h. The copper concentration on the alloyed surface reaches to 5.7wt% and the thickness of the alloyed layer is about 2.7μm. XPS analysis indicated that Cu ions was released when the copper-alloyed surface contacted with bacterial solution, which led to death of the bacteria