ZetaCAD Electrokinetic Analyzer for the determination of Zeta Potential by measuring the Streaming Potential and Streaming Current of solids
Streaming Potential and Streaming Current are two methods used to measure the electro-kinetic potential, or Zeta Potential, in the double electrochemical layers based on the relative movement of an electrolyte solution over a solid surface (solid / liquid interface).
coarse particles, granular samples, fibers and fabrics : the sample is inserted
into a cylindrical measuring cell (porous plug technique)
flat surfaces : two identical rectangular pieces of solid sample are used to form a slit channel of a defined gap (tangential streaming potential technique)
An electrolyte solution is forced to pass through the porous plug, or through the slit channel, at different pressures, using nitrogen or compressed air. Excess charges are carried along the by the liquid, their accumulation causes the build-up of an electric field.
The Streaming Potentials (or alternatively the Streaming Currents), are measured at different pressures, and used to calculate the Zeta Potential.