物理化学学报 >> 2008, Vol. 24 >> Issue (07): 1277-1282.doi: 10.3866/PKU.WHXB20080726

研究论文 上一篇    下一篇

环氧树脂/碳钢电极在硫酸溶液中的半导体导电行为

王超; 钟庆东; 周国治; 鲁雄刚   

  1. 上海大学材料科学与工程学院, 上海 200072; 北京科技大学冶金与生态工程学院, 北京 100083
  • 收稿日期:2008-01-07 修回日期:2008-03-26 发布日期:2008-07-04
  • 通讯作者: 钟庆东 E-mail:qdzhong@shu.edu.cn

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

WANG Chao; ZHONG Qing-Dong; CHOU Kuo-Chih; LU Xiong-Gang   

  1. School of Material Science and Engineering, Shanghai University, Shanghai 200072, P. R. China; School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, P. R. China
  • Received:2008-01-07 Revised:2008-03-26 Published:2008-07-04
  • Contact: ZHONG Qing-Dong E-mail:qdzhong@shu.edu.cn

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0.5 mol·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(10 min)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7 h约1010 cm-3增大到48 h的约1012 cm-3数量级, 浸泡48 h 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7-48 h 期间为MIS(metal-insulator-semiconductor)结构. 此MIS 结构空间电荷层在-0.5 - 0.5 V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.

关键词: 环氧树脂, Mott-Schottky分析, 腐蚀, 半导体行为, MIS结构, 反型态

Abstract: 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 1010 cm-3 at 7 h to 1012 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 carrier 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.

Key words: Epoxy resin, Mott-Schottky analysis, Corrosion, Semiconductor behavior, MIS structure, Inversion state

MSC2000: 

  • O649