Facial Amphiphilicity-Induced Self-Assembly (FAISA) of Amphiphilic Copolymers

Amphiphilic molecules, including macromolecules and small surfactants, inherently self-assemble into a wide variety of nanostructures in selective solvents. However, the sequential structure for synthetic polymers is largely restricted to block copolymers. In this work, we report facial amphiphilicity-induced self-assembly (FAISA) of gradient amphiphilic copolymers. This new approach is demonstrated using facial amphiphilic multicyclic compounds. The facial amphiphilicity of bile acids allows cationic copolymers to form aggregates with different morphologies in aqueous solution. By tuning the compositions of hydrophilic and hydrophobic segments, these copolymers can self-assemble in water to produce spherical, vesicle, and rodlike nanostructures via supramolecular and electrostatic interactions. The hydrophobic interaction from multicyclic hydrocarbon moieties largely dictates the self-assembly process, which can be further modulated by integrating neutral hydrophilic poly(ethylene glycol) in copolymer compositions with additional stimuli such as temperature, charge density, and ionic screening.