A double-well potential model for the ionic electrokinetic polarization in low concentration cell suspensions

Abstract

In order to understand the effects of cells on the ionic electrokinetic polarization process in cell suspensions, a double-well potential electrokinetic polarization model for ions in cell suspensions under a pressure gradient field is established with reference to the ionic double-well potential model in dielectric polarization. By analyzing the ionic electrokinetic polarization process in the double-well potential, the relation between the electrokinetic polarization field of the ions in the well potential and the external pressure gradient field is derived. The “repression effect” of cell concentration on the ionic electrokinetic polarization voltage is theoretically analyzed, and the mechanisms of the effects of cells on the ionic electrokinetic polarization are obtained. The electrokinetic polarization voltages of the suspensions with different concentrations of rabbit blood cell in phosphate buffer solution are measured. The experiment results showed that the ionic electrokinetic polarization voltage decreased with increased cell concentration in the range of 105~ 107/ml, which is consistent with the theoretical models. The experiment has shown the validity of the double-well potential model for cell suspensions of low concentration. Our research deepens the understanding of the mechanism of electrokinetic polarization of cell suspensions, and provides a new model for using electrokinetic polarization to analyze the charge characteristics on cell surface.