The effect of packing density of cellulose plugs on streaming potential phenomena

Abstract

An experimental investigation on streaming potentials of porous plugs of cellulose in both the linear and the non-linear range is described. The variation of the electrokinetic coefficients as a function of fibre concentration in the porous pad has been studied, using solutions of different concentration of Congo Red dye as a permeant. The trend observed for changes of both linear electrokinetic coefficient ~i and non-linear coefficient /ali as packing density, CF, increases, is somewhat analogous, the similarity suggesting some proportionality between both coefficients. The electroviscous effect accounts for the decrease of L21 l with the increase of c r. The coefficient ~2i was found to be always negative and, in absolute value, to decrease with increasing c F. Second-order coefficients have been interpreted in terms of modifications of "generalized conductivities" produced by the changes of thermodynamic forces.

Physicochemical Characterization of Variously Packed Porous Plugs of Hydroxyapatite: Streaming Potential Coupled with Conductivity Measurements

“…The interaction of proteins on HAP and artificial dental materials has, moreover, been reported in the literature in studies related to bacteria adhesion on tooth material. , In situ monitoring of the adsorption/desorption of various adsorbates on adsorbents may be done by streaming potential (SP) measurements. , In addition to adsorption/desorption studies, the technique of SP measurements has become a useful tool for studying the interface between electrolyte solutions and macroscopic solid surfaces, owing to its versatility that allows handling planar surfaces, cylindrical capillaries, and packed beds of granular or fibrous materials. − The measurement of SP in packed beds of granular materials is much more elaborate than microelectrophoresis in dilute suspensions, but it has the advantage that the ζ-potentials of large particles can be determined. Furthermore, measurements can be performed at high electrolyte concentrations, well above the critical coagulation concentration.…”