Phase-Changing Copolymers for Thermoresponsive Transmittance Modulation

Thermoresponsive materials exhibiting switchable transmittance via temperature change are useful for smart window applications. We have introduced solid-state thermoresponsive phase-changing copolymer films with large transmittance modulation between room and elevated temperatures. The copolymer films comprise two phase-separated co-monomers. By controlling the domain size and the crystallinity of the phase-changing domain, two distinct transmittance modulation modes are made possible. The first mode undergoes opaque-to-transparent transition from room to elevated temperatures, while the second has the opposite transition. The copolymer films are investigated for either electrically controlled opacity change or autonomous and climate-adaptable solar modulation.