Determination of Zeta Potential of Wood Pulp by Stream Current Method

Abstract

Stream current apparatus with flow circuits capable of continuous operation by circulation of permeant liquid has been developed. Zeta potential data were obtained with the systems containing wood pulp and electrolyte solution, and then surface charge density of wood pulp in electrolyte solution were calculated.Change in surface properties of wood pulp, such as liberation of carboxyl groups by treatment with hydrochlolic acid and decrystallization by treatment with ethylenediamine, had a marked influence on the value of zeta potential.Measurements of liberated hydrogen ion concentration in external liquid phase after immersion of wood pulp were also carried out and data were compared with the results of zeta potential.These experiments demonstrate that zete potential is dependent on the type of ion adsorption and that hydrogen ion as well as cation plays an important role as potential determining ion at interface between wood pulp and electrolyte solution.