Assessing the zeta potential at high salinity

For the analysis of a membrane's surface charge we make use of the zeta potential at the membrane-water interface.

The corresponding measuring parameters of streaming potential, Ustr, and streaming current, Istr, limit the analysis of the zeta potential to low and medium ionic strength. On the other hand, we want to understand the behaviour of a membrane and its surface charge at high salinity conditions, especially for membranes used in seawater desalination and related processes, such as reverse osmosis and forward osmosis membranes. We are therefore facing a discrepancy in the ionic strength between measuring conditions and membrane operating conditions.

Download the full report which examines the correlation between the zeta potential and the ionic strength, and to find a reliable procedure for an extrapolation of experimental data - obtained at low and medium ionic strength - to high salinity conditions.