Electrochemical Control of Solubilization by Redox-Active Surfactants

The solubilization of organic molecules in surfactant molecular assemblies may be controlled effectively by electrochemical reactions using redox-active surfactants. In this study, several aromatic compounds were solubilized in aqueous micellar solution of ferrocene-modified nonionic surfactant (11-ferrocenylundecyl polyoxyethylene ether : FPEG) and the effects of redox reactions on solubilization were examined. The solubilization equilibrium constant (K) of the solutes in FPEG micelles, which represents the distribution of solubilizates between micelles and bulk solution, was noted to decrease with the oxidation of ferrocenyl moieties of FPEG molecules, but increase with reduction of ferrocenyl moieties. Electrochemical control of vesicle formation and applications for solubilization control were investigated using aqueous mixtures of a ferrocene-modified cationic surfactant (FTMA) and anionic sodium dodecylbenzene sulfonate (SDBS).