碳氟表面活性剂在分光光度分析中的应用——Ⅲ.全氟辛酸钠(SPFO)-溴化十六烷基三甲铵(CTAB)混合胶束微环境的性质

Application of Specific Surfactant in Micelle Spectrophotometry Ⅲ. The Microenvironmental Properties of the Mixed Micelle of Sodium Perfluorooctanoate (SPFO) and Cetyltrimethylammonium Bromide (CTAB)

本文采用荧光探针、ESR自旋标记和NMR技术研究了SPFO-CTAB混合胶束的微环境性质.发现在CTAB溶液中添加SPFO,使胶束内芯的微粘度增大,微环境的极性(反映在介电常数上)减弱.由此推测SPFO插入了CTAB胶束的栅状层并与之形成混合胶束.

Our previous reports have indicated that AI(Ⅲ)(or Sc(Ⅲ))-ECAB(Eriochrome Azurol B)-SPFO-CTAB(pH=5)system is a supersensitive reaction system for micelle spectrophotometric determination of aluminium (or scandium). In this study, the properties of the SPFO-CTAB mixed micelle microenvironment were studied using fluorescence probe, electron spin resonance (ESR)-spin labeled tcchuique,and nuclear magnetic resonance (NMR) spectroscopy.The DPH (1,6-diphenyl-1,3,5-hexatriene)fluorescence probe reveals a low dielectrlc const ant in the SPFO-CTAB micellar core.The degree of polarization(P value) of DPH is increased in SPFO-CTAB mixed micelle,indicating a change of the micellar core microviscosity.ESR using 5NS (5-DOXYLstearic acid) label technique also reveals the increase of microviscosity of the mixed micelle.As shown by ~1H NMR and ^(19)F NMR experiments,SPFO and CTAB have formed a mixed micelle and the fluorocarbon chain of SPFO has a strong interaction with the hydrocarbon chain of CTAB,indicating that a number of SPFO fluorcarbon chain penetrates into the interior of CTAB micelle.