Samenvatting

In this research there was looked at the connection between the Zeta potential and the pressure sensitivity of a chloroprene dispersion in order to gain insight in dispersion stability. This was done by varying the pH and ionic strength of the chloroprene dispersion. There was also looked at whether pressure sensitivity could be measured based on the Zeta potential using a PU-dispersion. In addition, there was looked at the detection of roller instability of an acrylate dispersion by means of the Zeta potential and particle size. The Zeta potential and particle size were measured using ELS and DLS. Dispersions were diluted by dropping 1 droplet of dispersion into 10 ml of 1 mM KCl solution. The KCl solution was made with ion free water. Temperature has an effect on the Zeta potential and particle size, therefore measurements were performed at 22 °C. For a chloroprene dispersion, a Zeta potential of -57 mV and a particle size of 108 nm were measured. It was not possible to separate the dispersion medium from the dispersion by using the stirred cell method. It was found that a difference in Zeta potential could be measured between a pressure sensitive and a non-pressure sensitive PU dispersion. While changing the pH of a chloroprene dispersion from 12 to 9.5, the Zeta potential as well as the particle size remained the same. When the pH dropped below 9.5, the Zeta potential changed from -57 mV to -75 mV at a pH of 9.0. In this same pH range, the particle size increased from
115 nm to 237 nm, while the pressure sensitivity decreased. The ionic strength does have an effect on the stability of the chloroprene dispersion, but more research on this parameter is needed. Finally, it was not possible to detect roller instability of an acrylate dispersion in formulation or on its own by means of the Zeta potential or particle size.