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联用紫外可见反射光谱电化学与电化学石英晶体微天平(EQCM)方法,结合傅里叶变换红外(FTIR)反射光谱表征,研究了酸性和碱性水溶液中金电极上恒电位(0.8V vs SCE)聚合所得聚邻苯二胺(PoPD)中线型类聚苯胺链结构和梯形吩嗪环链结构间的相互转化.聚合介质分别为含0.20mol·L?1H2SO4(PoPD1膜)或0.40mol·L?1NaOH(PoPD2膜)的0.20mol·L?1Na2SO4+0.10mol·L?1邻苯二胺水溶液.实验结果表明,线型结构可向梯形结构转化,但逆转较难.通过PoPD2新鲜膜在0.10mol·L?1H2SO4中0.6V vs SCE电位附近的氨基氧化峰电量和EQCM测得的PoPD2膜质量求得PoPD2新鲜膜中线型类聚苯胺链结构占19%摩尔分数(相对于邻苯二胺单元总摩尔数),与该膜的甲醛结合(羰氨反应)实验结果一致.PoPD2膜通过40圈电位环扫(0.2~0.8V vs SCE)处理可经由分子内环化反应全部转变成梯形吩嗪环链结构.而PoPD1由梯形吩嗪环链结构组成,共轭程度更高而更稳定,经?0.4~0.1V vs SCE区间40圈电位环扫处理后也仅有约2.5%摩尔分数的梯形吩嗪环链结构能转变为线型类聚苯胺链结构.
Combined with UV-Vis and electrochemical quartz crystal microbalance (EQCM) methods and Fourier Transform Infrared (FTIR) reflectance spectroscopy, the potentials of gold electrodes in acidic and basic aqueous solutions (0.8V vs (PoPD) and the trapezoid phenazine ring-chain structure of poly-ortho-o-phenylenediamine (PoPD) polymerized by SCE, respectively.The polymerization media consisted of 0.20 mol·L -1 H 2 SO 4 (PoPD 1 film) or 0.40 mol · 0.20 mol·L · 1Na2SO4 + 0.10 mol·L-1 o-phenylenediamine aqueous solution of L · 1NaOH (PoPD2 film) .The experimental results show that the linear structure can be transformed into the trapezoidal structure, but the reversal is difficult.According to the PoPD2 fresh film In 0.10mol · L · 1H2SO4 0.6V vs SCE potential near the peak of amino oxidation and EQCM measured PoPD2 film quality obtained PoPD2 fresh film linear polyaniline chain structure accounted for 19% molar fraction (relative to o-benzene The total number of moles of diamine units), which was in good agreement with the experimental results of formaldehyde binding (carbonyl-ammonia reaction) .PoPD2 membrane was completely converted into (3) by 40 ring potentials (0.2 ~ 0.8V vs SCE) Trapezoid phenazine ring chain structure. PoPD1 by the trapezoidal phenazine ring chain structure, a higher degree of conjugation Stability, the? 0.4 ~ 0.1V vs SCE potential after ring section 40 is also circular scanning process only about 2.5% mole fraction of a trapezoidal phenazine chain structure type polyaniline can be converted into a linear chain structure.