Random Copolymer Polyelectrolyte Complexes and the Role of Local Heterogeneity in Removing Organic Contaminants from Water

A polyelectrolyte complex consisting of an anionic polysoap with hydrophobic, hydrophilic and charged groups and a cationic copolymer with hydrophilic and charged groups is investigated for its ability to encapsulate organic molecules in aqueous solution. Cationic, anionic, and hydrophobic dyes were found to be effectively sequestered into the complex, and the macroscopic nature of the polyelectrolyte complex facilitates its easy removal from water. This highlights a potential application in removing a wide variety of organic contaminants from water with a single technique. Coarse-grained molecular dynamics simulations of the system reveal that hydrophobic interactions play a major role in complex formation and local heterogeneity in charge distribution arising from the random nature of the polyelectrolyte copolymers play a key role in the encapsulation of charged organic molecules.