防止银器文物变色的唑系复合缓蚀剂——II.SERS法研究唑系缓蚀剂防银变色的作用机理  

Azoles as Composite Corrosion Inhibitor for Anti tarnishing of Silver Antiques II. Mechanism of the Azoles for Anti tarnishing of Silver

作　　者：蔡兰坤[1] 张东曙[1] 王桂华[2] 祝鸿范 周浩[3] 

机构地区：[1]华东理工大学环境工程研究所,上海200237 [2]上海师范大学化学系,上海200234 [3]上海博物馆,上海200231

出　　处：《华东理工大学学报（自然科学版）》2002年第3期269-273,共5页Journal of East China University of Science and Technology

基　　金：国家文物局 99文物科研资助项目 ( 992 0 )

摘　　要：测定了 PMTA、MBO、MBI的普通拉曼光谱 ( NRS) ,利用表面增强拉曼散射光谱( SERS)研究了几种唑系缓蚀剂防止银器文物变色的表面成膜过程 ,复合缓蚀剂组分与银的相互作用 ,并讨论了其防变色作用的机理。实验结果表明 ,PMTA、MBI和 MBO与银表面存在着较强的相互作用 ,由于杂环结构的差异 ,不同缓蚀剂在银表面上呈现不同的吸附取向 ,形成了更为致密的防变色保护膜。在成膜溶液中 ,p H值较小时有利于缓蚀剂吸附 ,处理时间应不少于 1 2 0 min。成膜溶液和含缓蚀剂的硫化钠溶液中 ,银电极阴极极化时 (外加阴极电位≤ 60 0 m V的测试范围内 ) ,复合缓蚀剂的 SERS响应均随电位负移而增强 。The normal Raman spectra (NRS) of PMTA, MBO and MBI were measured. Surface enhanced Raman scattering (SERS) was used to study the surface filming processes of these azoles corrosion inhibitors for anti tarnishing of silver, and the interactions between components of composite corrosion inhibitor and silver surface. The mechanism of anti tranishing of silver was also discussed. The experimental results show that there are strong interactions between corrosion inhibitors and silver surface. As constituents of the composite inhibitor with different cycle configuration take on different adsorption directions on the silver surface, much more compact anti tarnishing film is formed. In the pretreatment solution , weak acid pH value is beneficial to the adsorption of corrosion inhibitor and pretreatment time should not be less than 120 min. Under the condition of cathodic polarization with additional potential less than 600mV, in the pretreatment solution and the solution of sodium sulfide, the SERS response ofcomposite corrosion inhibitor becomes stronger as the potential becomes lower. It is proved that the com posite corrosion inhibitor can prevent silver tarnish effectively from corrosion medium.

关 键 词：银器文物 变色 缓蚀剂 SERS法 唑系化合物 

分 类 号：TG174.42[金属学及工艺—金属表面处理]