环氧树脂/碳钢电极在硫酸溶液中的半导体导电行为  

Semiconducting Behavior of Epoxy Resin/Carbon Steel in Sulfuric Acid Solution

作　　者：王超[1] 钟庆东[1] 周国治[1] 鲁雄刚[1] 

机构地区：[1]上海大学材料科学与工程学院,上海200072

出　　处：《物理化学学报》2008年第7期1277-1282,共6页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(50571059、50615024);2007教育部新世纪优秀人才支持计划项目(NCET-07-0536);教育部创新团队计划(IRT0739)资助

摘　　要：采用电位-电容测试和Mott-Schottky分析技术研究了环氧树脂/碳钢电极在0.5mol·L-1硫酸中腐蚀失效过程中的半导体导电行为.环氧树脂在刚刚浸入溶液时(10min)为绝缘体,随着浸泡时间延长,由于离子的腐蚀,环氧树脂外层逐渐转变为n型半导体.半导体层中的载流子密度随着浸泡时间的延长而增大,载流子由浸泡7h约1010cm-3增大到48h的约1012cm-3数量级,浸泡48h以内涂层没有完全转变为半导体,碳钢表面包括环氧树脂层在浸泡7-48h期间为MIS(metal-insulator-semiconductor)结构.此MIS结构空间电荷层在-0.5-0.5V内处于反型状态,反型层内的载流子为空穴.在较低频率下测得空间电荷层电容为反型层电容和耗尽层电容的串联电容,随电位升高而减小;较高频率下测得空间电荷层电容仅为耗尽层电容,不随极化电位变化.该MIS结构的电位-电容特性曲线与理想MIS结构相比发生了阳极漂移.Semiconductor behavior of epoxy resin coated on carbon steel immersed in 0.5 mol·L^-1 sulfuric acid aqueous solution during its degradation was investigated. Potential （U）-capacitance （C） measurement and Mott-Schottky analysis technology were utilized to understand the coat＇s conduction mechanism during its degradation in the electrolyte. The epoxy resin film was still an insulator in the initial immersion stage （10 min）, but its outer layer （the side that contacts with solution） gradually changed into n type semiconductor due to the corrosion with growing immersion time. Charge carrier density of this semiconductor film increased by degrees with extension of immersion time from 10^10 cm^-3 at 7 h to 10^10 cm^-3 at 48 h approximately. Between 7 h and 48 h, the organic film had not entirely transformed into semiconductor but only the outer side, and the inner was still insulator. Therefore, an MIS structure （metal-insulator-semiconductor） was generated. The result indicated that this MIS structure was in inversion state between -0.5 V and 0.5 V, and carder charges were electron holes in inversion layer. The measured space-charge capacitance was series capacitance of inversion layer capacitance and depletion layer capacitance at relatively low frequency. The capacitance value decreased with growing polarization potential. The measured capacitance at relatively high frequency was only the depletion layer capacitance and remained constant in the total scanning potential region. An anodic drift occurred about the C-U characteristic curve of the MIS structure.

关 键 词：环氧树脂 Mott-Schottky分析 腐蚀 半导体行为 MIS结构 反型态 

分 类 号：O649[理学—物理化学]