摘要
目的通过添加铜、银元素赋予2205双相不锈钢协同抗菌效果,以提高材料的抗菌性能和耐微生物腐蚀能力。方法采用金相显微镜(OM)和扫描电镜(SEM)研究铜、银添加对材料显微组织变化和两相比例的影响,使用能谱(EDS)分析元素分布。采用电化学测试,包括动电位极化曲线(PD)、开路电位(OCP)、线性极化电阻(LPR)和交流阻抗谱(EIS),表征添加铜、银后材料耐蚀性能的改变和在硫酸盐还原菌(SRB)体系中耐微生物腐蚀的能力。采用莫特肖特基测试(MS)表征表面钝化膜缺陷密度的变化。使用扫描电镜观察浸泡试样表面生物被膜和腐蚀产物,并采用EDS分析腐蚀产物主要成分。通过共聚焦显微镜(CLSM)观察活死染色后表面生物被膜内细菌的生长情况,分析含铜、银材料的协同抗菌性能。结果添加铜元素会使2205双相不锈钢中奥氏体含量增多,银元素主要以银富集相分布于基体材料中。电化学测试显示,2205试样的腐蚀电流密度和维钝电流密度分别为10.30mA/cm^2和1.19μA/cm^2,而2205-Cu和2205-Cu-Ag的自腐蚀电流密度分别为13.73mA/cm^2和28.85mA/cm^2,维钝电流密度分别为1.54μA/cm^2和2.31μA/cm^2,添加铜和银元素都会导致自腐蚀电流密度和维钝电流密度上升。此外,铜银元素会使钝化膜掺杂浓度上升,2205试样的钝化膜掺杂浓度为2.81×10^20cm^-3,而2205-Cu和2205-Cu-Ag钝化膜掺杂浓度分别为4.46×10^20cm^-3和4.97×10^20cm^-3。由于协同抗菌效应,在硫酸盐还原菌参与腐蚀的体系中,2205-Cu-Ag试样的耐蚀性能远好于2205-Cu和2205试样,在第14天时,2205、2205-Cu和2205-Cu-Ag的极化电阻值分别为37.27、41.51、72.90kΩ·cm^2。通过活死染色和扫描电镜图片可看出,2205-Cu-Ag表面的腐蚀产物较少,生物被膜稀疏且死亡细菌多于2205和2205-Cu试样。结论铜、银的添加会改变2205双相不锈钢的两相比例,降低耐蚀性,并使钝化膜致密性降低。但同时含铜、银的材料具有明显的协同抗菌效果,能够有效抑制金属表面生物被膜的附着,显著提升了材料耐硫酸盐还原菌导致的微生物腐蚀性能。
The work aims to provide 2205 duplex stainless steel (DSS) with synergistic antibacterial effect by adding Cu and Ag elements to enhance the antibacterial property and resistance to microbiologically influenced corrosion of materials.The influence of Cu and Ag on the microstructure variations and proportion of two phases of materials was investigated by optical microscopy (OM) and scanning electron microscopy (SEM).Furthermore,energy-dispersive X-ray spectrometer (EDS) was used to analyze the elements distribution.Electrochemical tests including potentiodynamic polarization,open circuit potential (OCP), liner polarization (LPR) and electrochemical impedance spectroscopy (EIS) were adopted to characterize the change in corrosion resistance of materials and the resistance to microbiologically influenced corrosion of materials after added with Cu and Ag in sulfate reducing bacteria (SRB).Mott-Schottky tests were used to study the corrosion resistance and passive films stability of specimens.The biofilm and corrosion products were observed by SEM and the main components of corrosion products were analyzed by EDS.Confocal laser scanning microscopy (CLSM) was applied to observe the growth of bacteria in the biofilm on the surface after lipid detection so as to investigate the synergistic antibacterial effect of Cu and Ag-containing materials.Addition of Cu increased the amount of α phase in the 2205 DSS.Ag element was mainly distributed in the matrix material in Ag enriched phase.Electrochemical results showed that the passive current density (Jp) and self-corrosion current density (Jcorr) of 2205 DSS were 1.19 μA/cm^2 and 10.30 mA/cm^2,respectively.For 2205-Cu and 2205-Cu-Ag DSS,the self-corrosion current density (Jcorr) was 13.73 mA/cm^2 and 28.85 mA/cm^2,respectively and the passive current density (Jp) was 1.54 μA/cm^2 and 2.31 μA/cm2 respectively.The addition of Cu and Ag could increase the self-corrosion current density and passive current density. Correspondingly,addition of Cu and Ag obviously increased the doping density of passive film and the values of doping density were 2.81×10^20 cm^-3 for 2205 DSS,4.46×10^20 cm^-3 for 2205-Cu DSS and 4.97×10^20 cm^-3 for 2205-Cu-Ag DSS,respectively. However,in culture medium containing SRB,the Rp value of 2205-Cu-Ag DSS was much higher than that of 2205-Cu and 2205 DSS because of the synergistic antibacterial effect of Cu and Ag.After 14 days of incubation,the Rp values of 2205,2205-Cu and 2205-Cu-Ag were 37.27 kΩ·cm2,41.51 kΩ·cm^2 and 72.90 kΩ·cm2,respectively.The surface of 2205-Cu-Ag showed less corrosion products,sparse biofilm and more dead bacteria than 2205 and 2205-Cu samples by through lipid detection and scanning electron microscope images.Addition of Cu and Ag elements into 2205 DSS can change the phase ratio and reduce the corrosion resistance to some degree and the density of passive film.However,at the same time,the Ag-containing material has obvious synergistic antibacterial effect,can effectively inhibit the adhesion of biofilm on the metal surface,and obviously improves the resistance of the material to microbiologically induced corrosion caused by sulfate reducing bacteria.
作者
尹路
徐大可
杨春光
席通
李中
赵颖
杨柯
YIN Lu;XU Da-ke;YANG Chun-guang;XI Tong;LI Zhong;ZHAO Ying;YANG Ke(Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110000,China;School of Materials Science and Engineering,University of Science and Technology of China,Hefei 230000,China;Northeastern University,Shenyang 110000,China;Shenzhen Institutes of Advanced Technology,Chinese Academy of Sciences,Shenzhen 518055,China)
出处
《表面技术》
EI
CAS
CSCD
北大核心
2019年第7期316-323,共8页
Surface Technology
基金
深圳科技研究基金(JCYJ20160608153641020)~~
关键词
微生物腐蚀
抗菌不锈钢
硫酸盐还原菌
协同抗菌
生物被膜
钝化膜
microbiologically induced corrosion (MIC)
antibacterial stainless steel
sulfate-reducing bacteria (SRB)
synergistic antibacterial effect
biofilm
passive film
作者简介
尹路(1992—),男,博士研究生,主要研究方向为微生物腐蚀;通讯作者:徐大可(1982-),男,博士,教授,主要研究方向为微生物腐蚀。邮箱:xudake@mail.neu.edu.cn.
