An extended Maxwell-Wagner theory for the electric birefringence of charged colloids

Recent frequency resolved electric birefringence experiments on dilute suspensions of charged, ellipsoidal particles reveal new relaxation features in the MHz frequency range. Such behavior can be explained in terms of surface transport processes. Here we develop a model for the electric polarizability of spheroidal particles by combining features of electrokinetic and Maxwell–Wagner theories. The model accurately depicts the high frequency features and relates them to the colloidal properties of the polyelectrolyte. Using the model, particle charge can be extracted from electric birefringence measurements.