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

以傅克反应与氨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,色谱纯度为97%;通过铂金板法测定了30℃下FTMA在还原态与氧化态(FTMA+)下的临界胶束浓度(CMC)分别为0.6 mmol/L与1.0mmol/L,两种状态表面活性发生了大幅度变化;采用循环伏安法考察了FTMA在0.2 mol/L L i2SO4溶液中的电化学性能,FTMA氧化峰和还原峰电位分别为0.457 0 V和0.416 8 V(vsSCE),峰电位之差ΔEp=40.2 mV,峰电流之比Ipa/Ipc=1.26,显示出良好的电化学可逆变化特性,并用电化学方法完成了FTMA在还原态与氧化态之间的转换。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的表面活性剂。

A novel redox-active cationic surfactant（11-ferrocenylundecyl） trimethylammonium bromide（hereinafter referred to as FTMA） was synthesized by the main method of Friedel-Crafts reaction and amination reaction.The synthesized target compounds were characterized by means of 1HNMR and 13CNMR,showing that the molecular structure of FTMA was identical to its theoretical structure,and that the purity of FTMA was 97%.Surface tensions of FTMA and FTMA＋ were measured at 30 ℃ by adopting the platinum plate method.The critical micella concentration（CMC） values were changed from 0.6 mmol/L to 1 mmol/L when FTMA was oxidized into FTMA＋,resulting in significant changes at the concentration of the CMC.The electrochemical behavior of FTMA in 0.2 mol/L Li2SO4 solution was investigated by cyclic voltammetry methods.The results indicate that the oxidation potential and reduction potential were 0.457 0 V and 0.416 8 V（vs SCE） respectively,the ΔEp is 40.2 mV,and the ratio of Ipa/Ipc was 1.26.Thus,FTMA possesses good reversible characteristics,leading to the realization of free reversibility between reduction and oxidation,and the changes between FTMA and FTMA＋ by electrochemical method were carried out.All these studies indicate that the surface activity of FTMA can be reversibly controlled through electrochemical switchable method,and that it may be a new kind of surfactant which can be applied to the reversible surfactant-enhanced remediation.