ELECTROPHORETIC FINGERPRINTING OF A SINGLE ACID SITE POLYMER COLLOID LATEX

The electrophoretic fingerprint of a system of colloidal particles is the contour diagram of the measured mobility as a function of the measured pH and the measured p-lambda (logarithm of the specific conductance in S/m). In earlier work the electrophoretic fingerprint was shown to be a characteristic property of a system of charged colloidal particles. In the present work, the electrophoretic fingerprint of a carboxylic polystyrene latex is compared with theoretical calculations in order to explore the nature of the surface electrochemical properties and the structure of the double layer. Theoretical calculations include fingerprints (pH-p-lambda contour plots) of the surface potential, the zeta potential, and the electrophoretic mobility. An explanation of the anomalous maximum in the zeta potential is offered and the sensitivity of electrokinetic properties to electrophoretic relaxation, shear plane expansion, and conductance within the shear plane is quantitatively investigated for the model carboxylic acid polystyrene latex.