Zeta Potential Analyzer

Zeta potential analyzers usually require information on the particle size for properly calculating zeta potential from the measured raw data. The particle size measurement can be performed with various techniques that are not essentially based on the same principles and zeta potential analyzer. However, consistence of the methods might be highly desirable. It would enforce consistency of results. Our zeta potential analyzer employs electroacoustic method that is based on ultrasound. Acoustic particle size measurement is complimentary because ultrasound is the driving force for it as well. These two methods are combined in our DT-1200 model, making this instrument universal and internally consistent for broad spectrum of application in concentrated dispersions and emulsions.

There are several other parameters that are required for proper zeta potential calculation. Non-aqueous conductivity is one of them. This parameter is critical for adequate calculation of zeta potential in low conducting non-polar liquids. Our non-aqueous conductivity probe is suitable for an extremely wide range of conductivities from pure toluene to distilled water. At the same time, non-aqueous conductivity is not required for calculating surface charge density in non-polar liquids. This parameter can be used instead of zeta potential.

Particle Size Measurement

Acoustic particle size measurement can be used in rheological mode. In particular, measured attenuation spectra can be converted into bulk viscosity for Newtonian liquids and longitudinal viscosity for non-Newtonian liquids. Bulk viscosity is similar to the dynamic viscosity but for longitudinal stress instead of shear stress. Our studies have proven that bulk viscosity is a completely independent parameter, which reflects the unique properties of various Newtonian liquids. In the case of non-Newtonian liquids, longitudinal viscosity is similar to the shear viscosity. Longitudinal frequency spectra can be used as fingerprints of the heterogeneous system. The advantage of this longitudinal rheology over traditional shear rheology is its ability to characterize complex liquids at very high frequencies of MHz range.

Additional article to read: Streaming Current