Flocculation and adsorption properties of cationic polyelectrolytes toward Na-montmorillonite dilute suspensions

Abstract

Adsorption and flocculation properties were examined for the system Na-morillonite copolymers of acrylamide with a cationic monomer. Adsorption isotherms underlined the high affinity of the highly charged polymers for the clay surface and showed the crucial role of the interfacial conformation of the polyelectrolyte according to its cationicity. Performances of these copolymers when used as flocculants were followed as a function of their ionicity and molecular weight. The results are consistent with a balance between two flocculation mechanisms: charge neutralization which prevails for highly charged polymers and interparticular bridging which occurs at low cationicity when the optimal flocculation concentration (ofc) is strongly molecular weight dependent. © 1987.