Flocculation mechanism induced by cationic polymers investigated by light scattering

Abstract

Three cationic polymers with molecular weights and charge densities of 3.0 × 105 g/mol and 10%, 1.1 × 105 g/mol and 40%, and 1.2 × 105 g/mol and 100% were chosen as flocculants to aggregate silica particles (90 nm), under various conditions, including change in polymer dosage, particle concentration, background electrolyte concentration, and shear rate. The size and structure of flocs produced were determined using the static light scattering technique. On the basis of measurements of polymer adsorption and its effect on the zeta potential and floe properties, it has been found that the polymer charge density plays an important role in determining the flocculation mechanism. Polymers with a ..