二苯胺和邻-氨基苯磺酸电化学共聚的原位紫外-可见光谱研究

In Situ UV-Vis Spectroelectrochemical Investigation of the Copolymerization of Diphenylamine and o-Aminobenzenesulfonic Acid

运用原位光谱电化学和循环伏安法(CV),研究了二苯胺(DPA)和邻氨基苯磺酸(ABSA)在4.0mol/L H2SO4中单独聚合,及二者共聚的原位紫外-可见光谱电化学过程。CV结果表明,DPA和ABSA单独聚合与二者共聚过程具有不同的电化学行为,且共聚过程与二者浓度比有关。原位紫外-可见光谱研究采用氧化铟锡(ITO)导电玻璃为工作电极,电位保持为0.8V。结果表明,在DPA与ABSA的共聚过程中有中间体生成,此中间体是由DPA阳离子自由基和ABSA的阳离子自由基发生交互反应产生的,在紫外-可见吸收光谱中对应于570nm处的吸收峰。另外,随着混合溶液中DPA浓度的增加,DPA的聚合逐渐占主导地位,说明DPA与ABSA的共聚过程与单体浓度比有关。

In situ ultraviolet-visible（UV-Vis）spectroelectrochemical and cyclic voltammetry（CV） techniques have been used to investigate the homo-polymerization and co-polymerization of diphenylamine（DPA） and o-aminobenzenesulfonic acid（ABSA）in 4.0 mol/L H2SO4.The cyclic voltammograms（CVs）exhibit different electrochemical characteristics between the homopolymerizations of DPA and ABSA and the copolymerization of DPA with ABSA.The voltammetric characteristics show the dependence of the copolymerization on the concentration ratios of DPA and ABSA.The in situ UV-Vis study on the homo-/ co-polymerization of DPA and ABSA has been performed at 0.8Vby using indium tin oxide（ITO）coated glass electrode as working electrode.The results reveal the formation of an intermediate in the initial stage of copolymerization through the cross-reaction of the cation radicals of DPA and ABSA with a absorption peak at 570nm.Moreover,the polymerization of DPA becomes dominant with increase of the amount of DPA,which demonstrates that the copolymerization is related to the concentration ratio of DPA and ABSA.