DYNAMICS OF COMPLEX FLUIDS STUDIED BY COMPLEX ELECTROPHORETIC SPECTROSCOPY

生物聚合物和胶体在水溶液中带电，并在电场下显示平移运动（电泳）。电泳广泛用于生物聚合物如DNA和蛋白质的分离和分析。胶体的电泳迁移率是胶体的一个特征量，其定义为电泳速度与外加电场的比值。如果能测量胶体的动力学复迁移率，就能获得丰富的胶体电动力学信息。但这种研究至今尚未实现。本研究利用动态光散射技术，发展了一种在宽频率范围内测量复杂动态电泳迁移率的新方法。利用这种方法，我们在世界上首次成功地测量了1Hz到100kHz之间的动态迁移率。从这项研究中可以获得有关胶体周围反离子的丰富信息。由于电泳迁移率与溶剂粘度的倒数成正比，因此复杂流体的局部结构和局部力学性质可以通过嵌入其中的粒子的动态迁移率来获得。本文研究了分散在非离子表面活性剂片层相中的纳米级胶体颗粒的动力学运动，发现了其纳米级分级结构所产生的片层相中的分级动力学。

Biopolymers and colloids are charged in aqueous solutions and show translational motion under electric field (electrophoresis). The electrophoresis is widely used for fractionation and analysis of biopolymers such as DNA and proteins. The electrophoretic mobility defined as the ratio of velocity to applied field is one of characteristic quantity of colloids and many technical methods have been developed to measure dc mobility. If the measurement of dynamics complex mobility is available, we can obtain rich information on electrokinetics of colloids. But such kind of studied have not been realized until now. In this research, we have developed new method to measure complex dynamic electrophoretic mobility hi wide frequency range by using dynamics light scattering. By this method, we have succeeded in measuring dynamics mobility between 1Hz to 100kHz for the first time in the world. Rich information on counter ions surrounding colloids can be obtained from this study. Since electrophoretic mobility is proportional to inverse of viscosity of solvent, the local structure and local mechanical properties of complex fluids can be obtained from dynamic mobility of a particles embedded in them. In this study, we have studied dynamics mobility of nano-sized colloidal particles dispersed in lamellar phase of nonionic surfactants and found hierarchical dynamics in lamellar phase produced by its nano-scaled hierarchical structure.