Certech has a ZetaSizer SZ 100 from Horiba in the framework of the Duratex project (Interreg V France-Wallonie-Vlaanderen program). The project objective is to develop a superhydrophobic and oleophobic coating from dispersions of silica nanoparticles. This equipment allows to measure the zeta potential of particles in suspension as well as their size by dynamic light scattering (DLS). Zeta potential represents the charge of a particle at the shear plane. This surface charge measurement allows to understand and to predict the interactions between particles in suspension. Zeta potential modification allows to stabilize suspensions which is crucial for the development of new products for the pharmaceutical, cosmetic and personal care industry. By modifying this potential it is also possible to accelerate particles flocculation for water treatment.
The development of new products for the pharmaceutical, cosmetic and personal care industry requires also a precise control of the particles size in liquid formulations. DLS is the most appropriated non-destructive method to determine the size distribution of submicronic particles. This method is based on the Brownian motion measurement of particles which is linked to their size by the Stokes-Einstein equation. The latest developments in this technology allow to measure particles size below the nanometer scale. The application examples include the size measurements of gold nanoparticles, proteins, latex particles and colloids.