What is surface zeta potential and how to measure it?
The Zetasizer Nano has an optional Surface Zeta Potential cuvette. This kit can help gain an understanding of the charge at interfaces . Thus, the surface zetapotential cell measures the zeta potential at the surface of a planar flat material in an aqueous environment.
The Zetasizer has been around for a few years. Subsequently, the Zetasizer series now includes several models (90 degrees, backscattering, size and zeta, flowmode for chromatography detection, automated plate sampler). One unique accessory for the zeta potential capable models is the surface zeta potential cell. You will therefore find it listed on our cell and cuvette options.
What is the surface zeta and how can we measure it?
In aqueous systems, almost all wall surfaces will acquire some kind of charge. This charge can influence the mobility of tracer particles diffusing close to the wall. The electrophoretic mobility or Zeta potential is highly dependent on both the sample surface and the medium in which it is immersed.
We can measure the zeta potential of tracer beads as a function of distance from the surfaceplane of investigation. This then extrapolates to the surface zetapotential. The cuvette itself has part number ZEN1020 . Likewise, the consumable PEEK sample holders can be reordered under part number ZEN4060. As a glue many household fasteners, like cyanoacrylate, should work well.
For tracer particles, often the negatively charged polystyrene beads in the Malvern transfer standard DTS1235 may be suitable. For positive charge, however, the dilute fabric softener Downy® can provide quite reasonable cationic particles. There is also the choice of carboxylated melamine particles such as MEL0665 and MEL1180 as an option.
Further zeta potential resources
- Manual: Surface ZetaPotential Cell Accessory
- Brainshark: What type of surfaces are suitable? [or also a longer recorded presentation 57min]
- User story: How to use the surface zeta cell kit (by Cornell University)
- Application Notes: Measuring surface zetapotential of PTFE , The influence of ionic strength on surface zeta potential, Measuring the surface zetapotential of silica vs pH
- Publication reference: Corbett, JCW et al. Colloids and Surfaces A: Physicochemical and Engineering Aspects 395, pp 169-176 (2012) “Measuring surface zetapotential using phase analysis light scattering in a simple dip cell arrangement“
- Request a Quote for a surface zetapotential cuvette or replacement mounting brackets
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