Stability of monodisperse polystyrene latex dispersions of various sizes

Abstract

A series of monodisperse polystyrene latex dispersions has been prepared covering a range of particle sizes from 600 to 4230 Å. The kinetics of flocculation of the latex dispersions by barium nitrate solutions were examined and the results used to construct curves of the logarithm of the stability ratio against the logarithm of electrolyte concentration. The slopes of the curves were calculated theoretically and compared with those obtained experimentally. The theory predicted an increase of slope with particle size which was not observed experimentally. Experimental estimates of the Hamaker constant give values ranging from 1.03 × 10^–14 to 1.10 × 10^–13 erg.