3-氨基苯硼酸-苯胺共聚物薄膜对pH的光学响应

Optical Response of Copolymer of 3-Aminophenylboric Acid with Aniline Film a Gainst pH

在硫酸介质中,以氧化铟锡(ITO)透明导电玻璃为基质材料,应用循环伏安法制备3-氨基苯硼酸-苯胺共聚物薄膜。用紫外可见光谱方法测定了共聚物薄膜在不同pH下的特征吸收光谱,结果表明,在pH2—12范围内共聚物薄膜对pH的变化表现了极高的光学敏感性,当pH从2增加到12时,其λmax从773nm(pH=2)变化到614nm(pH=12);由相应的滴定曲线计算共聚物薄膜的表观pKα为6.2;薄膜对pH响应速度快,光谱变化在20s内基本完成;共聚物薄膜对pH响应的重现性较好,重复使用在最大吸收773nm处吸光度的变化为1.0%,在614nm处吸光度的变化为0.7%。

In sulfuric acid medium, on indium-tin oxide transparent conductive glass,a copolymer of 3-aminophenylboric acid and aniline film was formed by cyclic voltammetry.The characteristic absorption spectrum of this film under different pHs was determined by UV-Visible spectrometry.The film showed very high optical sensitivity against pH variation.The characteristic spectrum changed remarkably from 773nm at pH 2 to 614nm at pH 12.The corresponding titration curve was done,and the apparent pKa of this film was calculated as 6.2.The response time of copolymer film against pH is quick, and the relaxing time of the response being within 20 seconds.The reproducibility of the response was good.The characteristics and pH response showed the same when experiments were repeated,and absorption spectrum changed marginally,1.0% deviation at 773nm,and 0.7% at 614nm.