Dynamic Light Scattering Applied to Electrorotation: Measurement of

Dynamic Light Scattering Applied to Electrorotation: Measurement of Internal Particle Properties and Layer
Capacitance.
Prüger, B., Eppmann, P., Gimsa, J., Donath, E., 1996. In W. Waidelich, H. Hügel, H. Opower, H. Tiziani, R. Wallenstein, W.
Zinth (Eds.): Laser in Forschung und Technik, in Research and Engineering. Vorträge des 12. Internationalen
Kongresses Laser 95, 160–163, Springer-Verlag GmbH, Berlin. ISBN 3-540-61316-1.
Abstract: Dynamic light scattering (DLS) is widely used to characterize the properties of colloidal particles. We combine
DLS with electrorotation spectroscopy [see GIMSA et. al. in this issue]. In electrorotation individual particle rotation is
induced by a rotating radio-frequency field. Electrorotation is sensitive to the particle’s internal dielectric structures. Our
measurements on human red blood cells give the same results as electrorotational spectra measured microscopically.
From characteristic points of the spectrum, values for the cell’s membrane capacitance and internal conductivity can be
obtained. We found the need of high field strength and low particle concentration to get a clear separation of the
rotation from other field-induced particle motions