The SV-10 measures viscosity with the accuracy required for dynamic light scattering, for the conversion of diffusion speed to size, and electrophoretic mobility to zeta potential, in an extremely simple and rapid system.
Accurate viscosity measurements are vital for accurate size and zeta potential determination.
For size measurement the speed of Brownian motion is directly related to viscosity, so as this speed is used in DLS to determine the size, an error of 1% in the viscosity will lead to an error of 1% in the size reported.
For zeta potential measurement the viscosity of the dispersant is proportional to the viscosity, hence again a 1% error in the viscosity will lead to a 1% error in the reported viscosity. Since many additives such as surfactants, polymers and alcohols will significantly affect the sample viscosity, estimates of the viscosity can be inaccurate.
The SV-10 is a stand-alone accessory that is particularly useful for complex dispersants where there are no standard literature values for the viscosity available.
As measurements of size and zeta potential usually involve dilution of the sample, it is usually only necessary to measure the viscosity of the dispersant. This is particularly useful for dilute proteins as the buffers are usually available in large quantities.
The unit includes measurement cells for aqueous samples, glass cells for non-aqueous measurements and a thermostatically controlled cell holder for measurements at a defined temperature. A recirculating water bath is required for this, which is not included.