Recent advances in multi-temperature-responsive polymeric materials

Temperature-responsive (or thermoresponsive) polymers belong to the most studied class of smart polymers and are mainly classified into two types based on their temperature-responsive behavior: lower critical solution temperature (LCST) and upper critical solution temperature (UCST). Based on polymeric design, when two temperature-responsive segments are connected through a covalent bond at each chain end, the block copolymers are expected to show a dual-temperature-responsive property upon conformational changes. Moreover, in recent years, multi-temperature-responsive properties that can represent complex states/structures have been reported. These multi-temperature-responsive block copolymers can set the stage for development in various research fields, such as drug-delivery carriers, sensors in solvents, model proteins, and memory storage. This review focuses on current multi-temperature-responsive polymeric materials and their applications and is divided into three parts: (1) dual-temperature-responsive block copolymers, (2) dual-temperature-responsive hydrogels, and (3) multi-temperature-responsive block copolymers.