聚邻甲氧基苯胺薄膜对pH的光学响应

Optical sensing of pH using the thin film of poly(o-methoxyaniline)

在盐酸介质中,应用循环伏安法通过电聚合在氧化铟锡（ITO）透明导电玻璃上形成聚邻甲氧基苯胺薄膜。用紫外可见光谱方法测定了聚合物薄膜在不同pH下的特征吸收光谱,聚邻甲氧基苯胺薄膜的λmax在557～746nm之间,作出了相应的滴定曲线。结果表明,在pH为1～12范围内聚合物薄膜对pH的变化表现了极高的光学敏感性,其表观pKa约为6.4。应用聚邻甲氧基苯胺薄膜测定了不同pH的溶液,其测定结果与精密酸度计相比误差〈±4%。

In acidic solutions,film of poly（o-methoxyaniline） was deposited onto the indium tin oxide transparent conductive glass,through applying the cycle voltammetry electropolymerization.The spectral absorption of the film was characterized in different pH ranges by UV-vis spectroscopy.The absorption maximum of the film was in the range of 557-746nm.The titration curves was also presented and the results showed that the film had high sensitivity in the pH range of 1-12,with apparent pKa values of 6.4.Furthermore,the thin film of poly（o-meThoxyaniline） was applied to determine the solutions pH values.The satisfactory results were obtained with a measurement error less than ±4% compared to that of the precise pH meter.