Programmed Self-Assembly Systems of Amphiphilic Random Copolymers into Size-Controlled and Thermoresponsive Micelles in Water

Abstract

We report programmed self-assembly systems of amphiphilic random copolymers bearing hydrophilic poly(ethylene glycol) (PEG) and hydrophobic alkyl pendants into size-controlled and thermoresponsive micelles in water. This system affords simultaneous and precise control of the size, aggregation numbers, and cloud point (Cp) of micelles in water by primary structure (pendant alkyl groups, composition, and chain length) that is programmed in the copolymers. Typically, random copolymers bearing PEG and alkyl pendants (butyl, octyl, dodecyl, and octadecyl groups) universally induce intermolecular self-assembly in water to produce uniform size micelles (<10 nm). The size is just determined by the content and alkyl pendant length of the hydrophobic monomers, independent of main chain length (below critical length for self-folding): The size increased with increasing the content and the pendant length. Design of hydrophobic alkyl groups with tuning composition allow us to widely control the size (molecular weight:...