【作者】 王洪芬；

【导师】 尹衍升；

【作者基本信息】 中国海洋大学 ， 海洋化学工程与技术， 2010， 博士

【摘要】 随着经济的发展和科技的进步,世界逐渐步入了海洋开发的时代。海洋资源开发、海上运输、海港和海防建设等涉海领域都需要大量的材料作为基础。然而对于涉海材料而言,海洋是一个十分严酷的腐蚀环境,材料腐蚀尤其是海洋微生物附着导致的材料腐蚀失效问题往往会导致巨大的经济损失,甚至引发严重事故。因此,研究制备防止微生物附着并具良好抗腐蚀性能的涉海功能材料对于海洋开发战略的实施具有重要意义。论文针对海洋环境中金属材料受微生物附着腐蚀非常严重的问题,设计研究制备一种集抗菌、耐腐蚀性能于一体的涉海功能材料,通过对海洋微生物附着与金属电化学性质之间相互作用的分析来探索材料的抗菌耐腐蚀性能。课题首先用分离纯化方法获得了导致海洋结构材料尤其是钢结构腐蚀破坏的主要菌种----硫酸盐还原菌,并通过测定细菌生长曲线的方法确认了该菌在一定培养条件下的生长规律,利用该菌来研究海水环境中材料的抗菌耐腐蚀性能。通过优化制备工艺条件,在常用海洋结构材料----304不锈钢表面制备了TiO2及(银)铈掺杂TiO2薄膜。通过测试透光度曲线的方法研究了薄膜的光谱响应范围,发现经(银)铈掺杂后,TiO2薄膜的响应光波长明显红移,且在可见光区出现强度较大的吸收峰,大大增强了TiO2薄膜的可见光利用率。通过测试涂层/金属电极的光生开路电位-时间曲线,确定TiO2及(银)铈掺杂TiO2薄膜具备较强的光电转化能力,在海水环境中能够对304不锈钢产生一定的光生阴极保护作用。利用静态杀菌方式考察了304不锈钢基体上TiO2及(银)铈掺杂TiO2薄膜的光催化杀菌率,发现薄膜均具杀菌性,对海洋环境中提取的硫酸盐还原菌具有一定杀灭作用；并且,经(银)铈掺杂后,TiO2薄膜的杀菌性能得到进一步提高。将制备得到的涂膜不锈钢和空白304不锈钢浸泡在硫酸盐还原菌的培养液中,浸泡不同时间后,通过扫描电镜进行形貌观察及电化学手段对两种测试样的抗菌耐腐蚀性进行了评测。扫描电镜观察结果显示TiO2及(银)铈掺杂TiO2薄膜可以减少硫酸盐还原菌在304不锈钢基体上的附着繁殖,并减小不锈钢在硫酸盐还原菌菌液中的腐蚀程度。电化学极化曲线分析认为,不锈钢表面TiO2及(银)铈掺杂TiO2薄膜的存在,使不锈钢的腐蚀电流密度Icorr减小,腐蚀速率下降,即TiO2及(银)铈掺杂TiO2薄膜成功地减缓了金属基体的阳极溶解过程。阻抗谱解析与等效电路拟合数据显示,在不锈钢表面涂覆TiO2及(银)铈掺杂TiO2薄膜后,电极反应中的电荷转移电阻Rct增大,试样的抗腐蚀能力增强,进而说明薄膜的存在能有效地阻止海水及硫酸盐还原菌对于金属材料表面的侵蚀。更多还原

【Abstract】 With the development of science and technology, the exploitation of marine is becoming urgent for the forecast of energy crisis in the world. The marine materials are needed in almost all the area of exploitation of marine, such as transport in ocean and marine engineering. However, marine is a very hard corrosive environment to the materials. Corrosion of marine materials, especially the corrosion caused by marine microbe could result in huge economic losses. Therefore, research on the fabrication of marine functional materials with antibacterial and anti-corrosion properties is of great importance for the exploitation of marine.In this paper, marine functional materials with antibacterial and anti-corrosion properties were fabricated to relieve the serious corrosion condition caused by attachment of marine microbe on stainless steel. The antibacterial and anti-corrosion properties of the as-obtained materials were tested by investigating the relationship between the attachment of marine microbe and the electrochemical properties.In present work, sulphate-reducing bacterium(SRB) from Qingdao offshore was obtained by isolation and purification method, for SRB was a main bacterium which caused the corrosion of metals. The growth pattern of SRB was confirmed by analyzing its growth curve, and the properties of as-obtained materials were studied in environment in which SRB existed.TiO2 film and TiO2 composite films were prepared on 304 stainless steel, in which silver ion and cerium ion were doped for their antibacterial activity. The process parameters of fabrication were discussed, on the basis of which, the optimum fabrication technology was obtained. The spectral response of TiO2 films was researched by analyzing the UV-VIS transmittance spectra. A noticeable shift of absorption edge to the visible light region was observed for TiO2 composite films, and an enhanced absorption peak appeared in the visible region, which was propitious to the photocatalytic effect of TiO2 under visible light.TiO2 film and TiO2 composite films exhibited an additional cathodic protective function to 304 stainless steel exposed to SRB in seawater by investigating their photoelectrochemical properties. Bactericidal ratio confirmed that the TiO2 films appeared strong bactericidal activity and most of SRB could be killed in seawater. Moreover, the TiO2 films could exhibit stronger bactericidal activity for the silver ion and cerium ion dopant.The antibacterial and anti-corrosion properties were investigated by means of scanning electron microscopy(SEM) and electrochemical method, comparing bare 304 stainless steel with the ones coated with TiO2 films immersed in SRB medium for different time. The results of SEM suggested that TiO2 films could prevent the attachment of SRB on substrates and decrease the extent of corrosion for 304 stainless steel immersed in SRB medium. The measurements of potentiodynamic polarization suggested that TiO2 films decreased the corrosion currents densities(Icorr), corrosion rates, which implied the inhibition of corrosion for 304 stainless steel. Furthermore, the results of electrochemical impedance spectra(EIS) showed that the impedance value decreased with immersion time, but the impedance value of TiO2 films were higher than that of bare 304 stainless steel. Utilizing the equivalent circuit models to interpret the EIS data, it could be obtained that the existence of TiO2 films increased the charge transfer resistance, and inhibited the corrosion rate of 304 stainless steel exposed to SRB in seawater.更多还原