Measurement of the Size and Zeta Potential of Polymer Microspheres Using Dynamic Light Scattering and Electrophoretic Light Scattering Methods: Effect of Viscosity of Dispersion Media

In this paper, the hydrodynamic size and zeta potential of various polymer spherical particles (70-350 nm) were measured. The measurements were carried out using the methods of dynamic light scattering (DLS) and electrophoretic light scattering (ELS). It was shown that the values of zeta-potential of 70-180 nm particles undergo changes of 10-20 % of the initial values during two years. However, the aggregation of some sample was observed during storage or ultrasonic treatment which could be explained by surface charge density undergoing transformation upon storage. Water, ethanol, propanol, glycerin were used for the preparation of the dispersion media, and the effect of medium with different viscosities on size distribution analysis was evaluated. Not quite accurate reference data of the dispersion media introduces the size measurement errors of about 18 %, which, however, acceptable for rough and quick estimation of particle sizes at different stages of preparation and transformation.