A new measurement method of complex electrophoretic mobility μ* of colloidal particles in suspension was developed using a heterodyne technique of quasi-elastic light scattering under a sinusoidal electric field. The influence of diffusion was removed by squaring the time-domain signal of scattered light and we succeeded in accurate and highly sensitive measurement of μ* in a wide frequency range for the first time. The frequency dependence of μ* of latex particles was measured up to 50 kHz by this method. The relaxation of mobility due to anomalous double-layer polarization was observed above 1 kHz in the obtained spectrum.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)