二茂铁表面活性剂的电化学行为

以循环伏安法为主要手段,研究了具有可逆特性的二茂铁表面活性剂(N,N-二甲基二茂铁甲基十四烷基溴化铵,Fc14)在0.1 mol/L Na2SO4溶液中形成胶束对电化学行为的影响,并讨论了pH、扫描速度及浓度对Fc14电化学行为的影响.结果表明,Fc14在pH=2左右具有良好的可逆变化特性,在氧化态(I2+)与还原态(I+)之间可实现自由转换;Fc14在玻碳电极上的logIpc~logv呈现良好的线性关系(R20.991).当Fc14的浓度大于2 mmol/L时,电化学氧化过程以扩散控制为基本特征;当浓度小于0.2 mmol/L时,电极吸附现象的特征趋于明显.与此同时,Ipc和扩散系数(D)在Fc14的临界胶束浓度(CMC)附近出现突变,这与Fc14表面张力变化趋势相吻合.

Electrochemical Behavior of Ferrocenyl Surfactant

The effect of micelle-forming on the electrochemical behavior of ferrocenyl surfactant （N, N-dimethyl-ferrocenylmethyl tetradecyl ammonium bromide, abridged as Fc14） in 0.1 mol/L Na2SO4 solution was studied using cyclic voltammetry. And the influences of pH, scan rate and concentration on the electrochemical behavior of Fc14 were highlighted. It was found that Fcl4 possessed good reversible characteristics around pH ： 2, at which it could be easily reversed between the reduced state （I^＋） and oxidized state （I^2＋）. Moreover, the plot of its logarithm of peak current （Ipc） versus its logarithm of scan rate showed good linear correlation （correlation coefficient R^2〉0. 991）. When the concentration of Fc14 was above 2 mmol/L, the electrochemical oxidation process was dominated by diffusion. When the concentration of Fe14 was below 0.2 mmol/L, the adsorption on the electrodes was enhanced. At the same time, the Ipc and diffusion coefficient （D） changed abruptly around the critical micellar concentration （CMC） of the ferrocenyl surfaetant, well conforming to the variation tendency of the surface tension of Fc14.