Self-Assembly of Amphiphilic Random Copolymers: Precision Nanoaggregates Controlled by Primary Structure

This comprehensive article summarizes our recent efforts to investigate self-folding and self-assembly of amphiphilic random copolymers bearing hydrophilic poly(ethylene glycol) (PEG) and hydrophobic or functional pendants in aqueous, organic, and fluorinated media. For this, well-controlled amphiphilic/functional random copolymers were synthesized by ruthenium-catalyzed living radical copolymerization of hydrophilic PEG methyl ether methacrylate (PEGMA) and hydrophobic alkyl or functional (hydrogen-bonding urea, fluorous perfluoroalkyl) methacrylates. Selective self-folding of copolymers was achieved by controlling the primary structure (composition, chain length); the folding media were dependent on the design of the functional pendants. Importantly, PEGMA/dodecyl methacrylate (DMA) random copolymers afforded precision intermolecular self-assembly into uniform nanoaggregates in water; the size was precisely controlled by the composition (DMA content). Because of composition-dependent size control, the mixtures of the copolymers with different composition further induced self-recognition, i.e., self-sorting, to provide discrete nanocompartments with different composition (hydrophobicity) in water. A series of self-folding and self-assembly polymers served as thermoresponsive aggregates in water, unique nanoreactors in water, and novel biomaterials for protein conjugation and storage.