原位聚合沉积聚苯胺薄膜及其电致变色性能

Preparation and Electrochromism of Polyaniline Films by in-situ Polymerization

采用原位聚合的方法,以水溶性高分子聚乙烯吡咯烷酮(PVP)为空间稳定剂,直接在玻璃基体表面聚合沉积导电聚苯胺(PANI)薄膜。用扫描电镜(SEM)、紫外可见光谱(UV-Vis)、四探针电导率测试仪和热重分析仪(TG)对聚苯胺膜结构及性能进行了表征。采用循环伏安法测试了薄膜的电致变色性。结果表明:盐酸掺杂聚苯胺薄膜呈翠绿色,薄膜厚115 nm,表面电导率为4.6×10-3S/cm。电致变色实验中聚苯胺电极电位在-6^+6 V循环变化时,薄膜颜色在黄绿和蓝绿间可逆变化。电致变色前后聚苯胺薄膜的紫外可见吸收光谱表明,随着电极电位的降低,极化子峰发生红移,说明聚苯胺分子链中醌式结构单元被还原,聚苯胺薄膜质子化程度提高。

The polyaniline（PANI） films were prepared on glass surface directly during dispersion polymerization by using of a water-soluble polymer of polyvinyl-pyrrolidone （PVP） as a steric stabilizer. The morphology, thickness and conductivity of PANI films were characterized by SEM, UVVis, Four-probe testing meter and TGA. Electrochromism of the film was tested by cyclic voltammetry. HCl doped films were light green. The thickness and conductivity of the doped PANI films were 115 nm and 4. 6 × 10^-3 S/cm respectively. The PANI film color changed reversibly from yellow to blue when voltages of the PANI electrode changed from -6 V to ＋6 V. The film absorption spectrum show that the quinoid ring is deoxidized when PANI electrode voltage decreases. The red shift of polaron band is observed when the protonation state increases.