有机清漆在5％氢氧化钠溶液中的半导体导电行为

Semiconducting Behavior of Organic Polymer Coatings in 5% Sodium Hydroxide Solution

采用电位-电容法及Mott-Schottky分析技术研究了有机清漆在5%氢氧化钠溶液中的半导体导电行为。研究表明,有机清漆空间电荷层电容(Capacitance of space charge layer,C_(sc))远小于裸露碳钢电极,随着浸泡时间的延长,其C_(sc)逐渐增大,其空间电荷层逐渐减小。有机清漆在5%氢氧化钠溶液中呈现不同类型的半导体导电特征,环氧清漆膜呈绝缘体,而酚醛和醇酸清漆膜则表现为双极膜特征,在电位(—0.3～0 V)范围呈p型半导体,在电位(0～0.4 V)范围呈n型半导体,且随着浸泡时间的延长,漆膜中载流子浓度逐渐增加。

The semiconducting behavior of organic polymer coatings in 5% sodium hydroxide solution was studied by potential-capacitance and Mott-Schottky analysis. It was pointed out that the capacitance of space charge layer （Csc） of organic polymer coatings was much lower than that of carbon steel. With the increase of immersion time in the solution, the Csc of organic polymer coatings increased gradually, and the thickness of space charge layer decreased gradually. In the solution, the polymer coatings showed different semiconducting behaviours, i. e. , the polymer of epoxy resin was an insulator, while phenol aldehyde resin and alkyd resin were bipolar films; At potential range of -0. 3-0 V, the coatings showed a p-type semiconductor; At potential range of 0-0. 4 V, the coatings showed a n-type semiconductor. The concentration of charge carriers in the polymer coatings increased along with increasing immersion time.