Figure 2.

Schematic phase diagram of thermoresponsive polymers in water. Mostly, only a lower critical solution temperature (LCST) is observed for water-soluble polymers. The LCST is the lowest temperature in the phase diagram at which the polymer can lose solubility. At temperatures above the phase boundary (the critical solution temperature (CST)), the polymer loses solubility and can aggregate. This property can be transferred to core–shell nanoparticles grafted with thermoresponsive polymers and used to achieve a reduction in the core–shell nanoparticle size or aggregation of nanoparticles above the CST.