RHEOLOGY OF AGGREGATED POLYSTYRENE LATEX-GELATIN DISPERSIONS

The diameter of aggregates of a polystyrene latex-gelatin dispersion was calculated from theological data. An anomalous increase in the diameter of aggregates with an increase in temperature was attributed to the prevailing role of variation in the viscosity of the dispersion medium with temperature, as compared to other effects. By substituting the experimental data into Batchelor's equation, it was found that, even at a high shear rate (epsilon approximate to 1300 s(-1)), the disintegration of aggregates to single particles is incomplete, and the disperse system contains both particles and aggregates. The combined effective concentration of the particles and aggregates was estimated to be approximately tenfold higher than the actual concentration of the individual particles used in this study (4.8%). Hence, ultimate breakdown of the structure does not occur under high-rate shear deformation.