可逆表面活性剂十一烷基二茂铁三甲基溴化铵的合成、表征及其电化学行为的研究

Preparation,Characterization and Electrochemical Behavior of Reversible Surfactant:(11-Ferrocenylundecyl) Trimethylammonium Bromide

摘要:

以傅克反应与胺基化反应为主要方法，合成了阳离子型表面活性剂十一烷基二茂铁三甲基溴化铵（简称FTMA）。核磁共振氢谱与碳谱分析结果表明FTMA的分子结构与理论结构相吻合，纯度为97%；通过铂金板法测定了FTMA在还原态与氧化态（FTMA+）下的临界胶束浓度（CMC）分别为0.6mmol/L与1.0mmol/L，两种状态表面活性发生了大幅度变化；采用循环伏安法研究了FTMA在0.2 mol/L Li2SO4溶液中的电化学性能，FTMA氧化峰和还原峰电位分别为0.457V和0.4168V（Vs SCE），峰电位之差ΔEp=40.2mV，峰电流之比Ipa/Ipc=1.26，显示出良好的电化学可逆变化特性，并利用电化学方法完成了FTMA在还原态与氧化态（FTMA+）之间的转换。研究结果表明：FTMA可通过电化学“开关”控制其表面活性态和非表面活性态之间的可逆变换，是一种新型的可用于可逆增溶修复过程中的表面活性剂。

Abstract:

A novel redox-active cationic surfactant (11-Ferrocenylundecyl) trimethylammonium Bromide (hereinafter referred to FTMA) was synthesized by the main method of Friedel-Crafts reaction and Amination reaction. The synthesized target compounds were characterized by 1H NMR and 13C NMR, the purity of FTMA was 97%.Surface tensions of FTMA and FTMA+ were measured at 30℃ condition used the platinum plate method. The critical micellar concentration (CMC) values were changed from 0.6mmol/L to 1mmol/L when FTMA was oxidized to FTMA+, resulting the surface activity occurred significant changes, the surface tension value was also increased from 38.5mN•m-1 to 55.3 mN•m-1 at the concentration of the CMC. The electrochemical behavior of FTMA in 0.2 mol/L Li2SO4 solution was investigated by cyclic voltammetry methods. Results indicate that the oxidation potential and reduction potential were 0.457V and 0.4168V respectively, the ΔEp is 40.2mV, and the ratio of Ipa/Ipc is 1.26.So FTMA possessed well reversible characteristic, which realized reversibility between reduction and oxidation freely. Otherwise, we finished the changes between FTMA and FTMA+ by electrochemical method. So the surface activity of FTMA can reversible controlled through electrochemical switchable method, and it may be a new kind of surfactant which can be used to the reversible surfactant-enhanced remediation .