Shimadzu

It depends on what exactly you wish. For example, we control the Z-potential and the isoelectric point of powders and films with an Electro Kinetic Analyzer (Surpass-Anton Paar) for particle sizes higher than 25 microns, which allows measuring the charge changing the pH. It is quite easy, but the device is not cheap.

We determine the zero point charge by electrophoretic mobility in a Delsa nanosizer C. We prepare the dispersions at different pHs, but it can also be coupled to a peristalti pump to make automatic measurements as a function of pH. They should be coupled to acid-base potentiometric titrations of the powder at different ionic strenghts. If the electrophoretic mobility vs pH crosses 0 vlue and potentiometric tiutration curves intersect at the same pH, you can say with certainty that this is your pzc. This conly occurs when H+ and OH- are the only charge determining anions (let's says absence of adsorption or anion exchange processes).