| 含铜抗菌不锈钢的抗菌特性和抗菌机理研究 | |
| Alternative Title | Studies on Antibacterial Characteristics and Mechanism of Copper-bearing Antibacterial Stainless Steels |
| 南黎 | |
| Subtype | 博士 |
| Thesis Advisor | 杨柯 |
| 2008-12-03 | |
| Degree Grantor | 中国科学院金属研究所 |
| Place of Conferral | 金属研究所 |
| Degree Discipline | 材料加工工程 |
| Keyword | 抗菌不锈钢 抗菌特性 抗菌机理 Ε-cu相 |
| Abstract | 随着人们对生活环境、卫生和保健的要求日益提高，人们将更加关注居住空间环境及用品的清洁、净化、人身安全等环境健康问题，因此抗菌功能材料及制品的应用将会成为21世纪生态环境材料的主角之一。抗菌不锈钢是一类兼具良好机械性能、加工性能和抗菌性能的新型功能材料，具有广泛的应用前景。开发和推广应用抗菌不锈钢，具有重要的经济价值和社会意义。本文以中科院金属研究所研制的铁素体和奥氏体两种类型含铜抗菌不锈钢作为研究对象，对其抗菌特性及抗菌机理进行了深入研究和探讨，以期为抗菌不锈钢的研发和推广应用提供理论依据。本文开展的研究工作内容及主要结论如下： （1）抗菌不锈钢的抗菌特性研究 本文采用覆膜法研究了抗菌不锈钢的抗菌广谱性及作用时间、作用菌浓、作用温度、打磨次数等对含铜铁素体和奥氏体抗菌不锈钢抗菌性能的影响，结果表明抗菌不锈钢具有优异的抗菌特性。 （2）从微生物学角度对抗菌不锈钢抗菌机理的研究探讨 巯基氧化实验显示出抗菌不锈钢对还原性酶的氧化作用，同时抗菌过程中还存在着O2-的氧化杀菌作用。ICP实验结果以及EDTA络合实验结果证实抗菌不锈钢表面溶出的铜离子在抗菌过程中的作用。生物透射电镜观察表明，与抗菌不锈钢作用后的大肠杆菌细胞的外形发生变化，细胞壁和细胞膜破裂，细胞内容物漏出，有的菌体完全溶解为碎片。随着作用时间延长，细胞通透性增加，菌液中K+浓度显著升高。 （3）从材料学角度对抗菌不锈钢抗菌机理的研究探讨 通过测量抗菌不锈钢及对照不锈钢的极化曲线，分析了ε-Cu相对抗菌不锈钢在0.1mol/L氯化钠溶液中电化学行为的影响。结果显示，抗菌不锈钢与大肠杆菌作用后，会由于其表面抗菌相中铜离子溶出的加快，表现为耐点蚀电位的下降，杀菌率随着抗菌不锈钢与细菌接触时间的延长逐渐增加到最大值，这与铜离子从抗菌不锈钢表面溶出量的增加刚好吻合。利用原子力显微镜观测了大肠杆菌与抗菌不锈钢作用不同时间后的形貌变化。结果显示，大肠杆菌与抗菌不锈钢接触后，细胞壁会由完整逐渐变为模糊不清，细胞内物质大量漏出，使细胞重度扭曲变形，最终导致细菌死亡。 （4）抗菌不锈钢中抗菌相的微观结构研究 光学金相观察表明，奥氏体抗菌不锈钢中的富Cu棒状析出相的径向与各正方体蚀坑（100）面相平行，顺加工方向生长。利用高分辨透射电镜对奥氏体抗菌不锈钢中抗菌相的微观结构观察表明含铜抗菌不锈钢基体中存在大量具有fcc结构的ε-Cu相，平均直径约30nm，平均长度达到70nm，并与基体保持一定的取向关系。时效过程中在基体中大量析出的ε-Cu相赋予了奥氏体抗菌不锈钢优异的抗菌性能，ε-Cu相具有有序的原子排列，这与其周围的奥氏体基体上的相对扭曲的原子排列形成鲜明的对比，这种相对扭曲的原子排列可能表明ε-Cu相周围的奥氏体区域处于亚稳状态，ε-Cu相的析出可能会对其周围产生一定的内应力作用。 |
| Other Abstract | Health problems should be considered from the aspects of cloth, food, housing and travel with increasing needs in life environments, sanitations and health cares. People will pay more attention to all kinds of healthy environmental problems, such as environment of living space, cleaning of goods, personal safety, etc. Therefore, application of antibacterial functional materials and products will become one of leading actors in the 21 century ecological environment. Antibacterial stainless steels are classes of new functional materials which have both mechanical and antibacterial functions, and its application fields will be broad. Research and development of new antibacterial stainless steel is of both economical and social importance. In order to provide more information for the development of new antibacterial stainless steels, in this thesis, antibacterial characteristics and mechanism of both austenitic and ferritic Cu-bearing antibacterial stainless steels, which were developed by Institute of Metal Research, Chinese Academy of Sciences, were deeply investigated, and the main conclusions have been made as follows: (1) Study on antibacterial characteristics of antibacterial stainless steel The film attachment method was adopted to study the broad antibacterial spectrum of the antibacterial stainless steels and effects of action time, bacterial concentration, action temperature and milling times on the antibacterial properties, indicating that the steels possess excellent antibacterial characteristics. (2) Study on antibacterial mechanism of antibacterial stainless steels in aspect of microbe The result of radicel-SH oxidation indicated that the antibacterial stainless steel possibly has the ability of oxidation of the reducible enzyme, and the O2- also plays an important role during the sterilization. Experimental results of ICP and EDTA complexing proved the antibacterial effect of copper ions dissolved from surface of antibacterial stainless steels. It was observed on bio-TEM that the morphology of E. coli was changed a lot after contacting with antibacterial stainless steels, cell walls being broken into pieces and lots of contents in the cells being leaked. The permeation through cells grew and the concentration of K+ in the solution greatly increased after contact of E. coli with antibacterial stainless steels for a long time. (3) Study on antibacterial mechanism of antibacterial stainless steels pointing aspect of material Through measurement of potentiodynamic polarization on antibacterial stainless steel and the contrast stainless steel, effect of ε-Cu precipitation on the electrochemical behavior of antibacterial stainless steels in a 0.1mol/L NaCl solution was analyzed. The results showed that after interaction between the bacteria and antibacterial stainless steels, pitting potentials of the steels decreased because of the dissolution of copper ions from the antibacterial phase. The antibacterial rate reached the maximum with the contact time between antibacterial stainless steels and bacteria, which well corresponded to the dissolution amount of copper ions from the surface of antibacterial stainless steels. Morphology changes of E.coli after contact with antibacterial stainless steels for different time were observed on AFM. The results showed that after contact with antibacterial stainless steel, the cell membrane or cell wall of bacteria was destroyed, permeability of the cell was increased and the inner contents were largely leaked, thus leading to death of bacteria. (4) Study on microstructure of antibacterial phase in austenitic antibacterial stainless steel Microstructural observation on austenitic antibacterial stainless steel under optical microscopy showed that the radical of Cu-rich precipitation was paralleled to (100) face of each eched square pit, growing along with the mechanical processing direction. Microstructrual observation on the antibacterial phase in austenitic antibacterial stainless steel was investigated on High Resolution TEM. The results indicated that large amounts of ε-Cu phase existed in the matrix of austenitic antibacterial stainless steel, with average diameter of 30nm, average length of 70nm and FCC structure, and orientation relationship of ε-Cu phases well matched with the matrix. Large amounts of ε-Cu precipitates dissolving from the matrix during ageing gives excellent antibacterial properties to the austenitic antibacterial stainless steel. ε-Cu phases showed much ordered atoms arrangement, compared with the distorted atoms arrangement of austenitic matrix, indicating that the austenitic matrix around ε-Cu precipitates were in the metastable state and the internal stress might be produced by ε-Cu phase. |
| Pages | 135 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.imr.ac.cn/handle/321006/17143 |
| Collection | 中国科学院金属研究所 |
| Recommended Citation GB/T 7714 | 南黎. 含铜抗菌不锈钢的抗菌特性和抗菌机理研究[D]. 金属研究所. 中国科学院金属研究所,2008. |
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