The Study of Gel Formation and Flocculation in Aqueous Clay Dispersions by Optical and Rheological Methods

Optical and Theological methods have been used to study the gelling and flocculation of aqueous dispersions of a synthetic hectorite‐like clay, Laponite CP, on the addition of electrolytes or water miscible organic solvents. There is a positive correlation between the yield value and turbidity when the dispersions are flocculated with electrolyte. Addition of polar solvent, however, shows no such correlation, only a sudden change from very clear to very cloudy dispersion, while the yield value increases gradually until gross flocculation takes place. It is suggested that two different flocculation mechanisms are being observed.