二茂铁表面活性剂的合成及其电化学行为研究

摘要

The reversible surfactant ( ferrocenylmethyl) octanedimethylammonium bromide ( Fc8) was synthesized. Effect of micellar on electrochemical behavior of Fc8 was studied in 0. 1 mol/L NaCl solution with cyclic voltammetry using glassy carbon electrode as working electrode. The influences of pH , scan rate and concentration on the electrochemical behavior were investigated. It was showed that Fc8 possessed well reversible characteristic with the pH value less than 8 ,which realized reversibility between reduction (I+ ) and oxidation ( I2+ ) freely. Otherwise,based on the linear relation between the peak current (Ipc) and scan rate with more than 0. 998 correlation coefficient,the electrochemical behavior of Fc8 was a diffusioncontrolled reversible process. The Ipc and diffusion coefficient (D) changed around the critical micellar concentration ( CMC) of the ferrocenyl surfactant and altered tardily with increasing concentration above the CMC. The results indicated that the trendency was coincided with the change of surface tension, which Ipc and D altered sharply with increasing monomer concentrations.%合成了具有可逆特性的二茂铁表面活性剂N,N-二基二茂铁甲基正辛烷基溴化铵(Fc8),并以玻碳电极为工作电极,采用循环伏安法研究了Fc8在0.1 mol/L NaC1溶液中的电化学行为,讨论了pH、扫描速度及底物浓度对Fc8电化学行为的影响.结果表明,Fc8在pH<8的条件下具有良好的可逆性,可在氧化态(I<'2+>)与还原态(I<'+>)之间实现变换;Fc8在玻碳电极上的氧化峰电流(I<,pc)与扫描速度呈现线性关系(P<'2>0.998),说明Fc8鸪的电化学行为是受扩散控制的可逆过程;I<,pc>和扩散系数(D)在Fc8的临界胶束浓度(CMC)附近出现突变,在CMC以上.I<,pc>与D随表面活性剂浓度缓慢变化,该规律与Fc8表面张力变化趋势吻合,表明峰电流和扩散系数随Fc8浓度变化较快.