Tuning the Thermoresponsivity of Amphiphilic Copolymers via Stereocomplex Crystallization of Hydrophobic Blocks.

Thermoresponsive polymers that exhibit a cloud point temperature (Tcp) are an important class of stimuli-responsive polymers that have great potential for biomedical applications. Precise tuning of the Tcp is of fundamental importance for designing thermoresponsive polymers. However, tuning the Tcp generally requires sophisticated control over the chemical and assembled structures of thermoresponsive polymers. Here, we report a simple yet effective method to tune the Tcp of thermoresponsive polymers only by mixing and varying the mixing ratios of amphiphilic copolymer pair that contains l- and d-configured hydrophobic blocks in a dilute solution. Stereocomplex (SC) crystallization of the l- and d-configured blocks led to form core-shell micelles with a larger size, a bigger core, and a higher aggregation number, which facilitated the intermicellar aggregation upon heating due to improved intermicellar attractions. SC crystallization of the hydrophobic blocks improved the separation efficacy of the thermoresponsive copolymers for removal of hydrophobic pollutants from water.