Elucidation of Reverse-micelle Formation by Small Angle Scattering Method and Development for Controlling Third Phase Formations in Biphasic Extraction System

用小角中子散射研究了反胶束的形成机理，它是萃取过程中第三相的来源。由Baxter模型分析可知，萃取体系中的反胶束物种为一种低聚物，低聚物数量的增加会导致可见的第三相形成。胶束的形成与萃取剂的烷基链长密切相关，因此，烷基链长是抑制第三相形成的重要因素。此外，U(IV)萃取体系的第三相形成曲线表明，萃取体系的临界胶束浓度显著降低。

The formation mechanism for the reverse micelle which is as an origin of the third phase in the extraction was elucidated by small angle neutron scattering. From analysis based on Baxter model, species of reverse micelle in the extraction system is one oligomer and increase in number of oligomer would result in a visible third phase formation. The micelle formation is strongly correlated with alkyl chain length of an extractant and thus, this length is considered to be an important factor to suppress the third phase formation. Furthermore, the curves of the third phase formation in the U(IV) extraction systems suggested that the critical micelle concentration of an extraction system decreased drastically.