Zeta potential measurements of fibres. D‐C. Streaming current method

Streaming current techniques have been extensively used in measurements of zeta‐potential, ζ, at the solid/liquid interface of capillary systems. In the case of porous, swelling and deformable materials, the application becomes less certain because of the complex geometry of the flow paths and interactions of neighboring electric double layers. The applicability of the equations developed by Goring, Biefer and Mason to papermaking fibres in various electrolytes is examined and found inadequate. An exponential form of the concentration function in the streaming current equation is proposed, IηL/pD = (Aζ/4π) exp(–Bc), and its reliability in evaluating ζ, is demonstrated. Factors affecting the parameter B are discussed.