Acrylamide-Based Cationic Polyelectrolytes and Their Potential Applications: A Survey

Abstract

Polyelectrolytes are water soluble polymers bearing ionic groups along the polymeric chains. In terms of their charges, they can be divided into anionic, cationic, nonionic and amphoteric types. These polymers open a lot of applications in different fields such as paper-making processes, water and waste water treatment, oil and drilling industries, mineral separation, paint and food industries, cosmetics and pharmacy. The cationic polyelectrolytes are one of important classes of these which bearing positive charges. These polymers are widely used as flocculants and rheology control agents. These polymers are especially employed in oil field operations as viscosity control agents for enhanced oil recovery and also as modifying flow and stability properties of aqueous solutions. Mining and water treatment processes also benefit from the use of acrylamide-based polymers to flocculate solids in aqueous dispersions. These polymers are made by free radical polymerization of acrylamide and their derivatives by copolymerization technique which include of solution, precipitation, and emulsion methods. The Mannich reaction is another important method by which the cationic polymers can be made. The cationic polymers may interact with particles in aqueous dispersions in several ways, in which their interactions may result in stability or instability of dispersion. The particles can be destabilized through three different main mechanisms namely polymer bridging, charge neutralization and polymer adsorption.