Electrokinetics of polystyrene latices: The role of the hydrophobic surface

Abstract

Experimental data from electrophoretic mobility, conductivity and dielectric response measurements on polystyrene latices and colloidal alkane particles are presented. Interpretation of the data using the exact numerical solution of O'Brien and White (J. Chem. Soc., Faraday Trans. 2, 1978, 74, 1607) and De Lacey and White (J. Chem. Soc., Faraday Trans. 2, 1981, 77, 2001) does not yield single ζ potentials for the different measurements on the same suspensions. A model is proposed to explain the data in terms of the classical electrokinetic model combined with a spatially varying entropic perturbation in the ion distributions in the interfacial region owing to the presence of destructured wat..