Self-assembly of comb-like amphiphilic copolymers in aqueous solution

Comb-like amphiphilic copolymers (polysoaps) have been studied by small-angle neutron scattering and light scattering techniques. The copolymer was synthesized by randomly grafting pendant quaternized alkylamine moieties (surfactant-like unit) to a polystyrene (hydrophobic) chain. In aqueous solution, the polymers self-assembled into platelet aggregates at low concentrations. When the electrostatic repulsions are screened by increasing the polymer concentration or by the addition of salt, hydrophobic interactions lead to a faster aggregation of platelets and leads to a phase separation. As the polymer concentration increases, the platelets extend by the edges to yield a final smectic organization of large sized lamellae. As a consequence visco-elastic solutions or hydrogels were formed at higher concentrations.