Temperature adaptive regulating window boosted by incorporating modified PNIPAM hydrogels with PVDF for building energy efficiency

This study proposed a temperature adaptive regulation window that can be fabricated on a large scale for building energy savings. We first synthesized the modified PNIPAM hydrogel, and then the temperature adaptive regulation window was fabricated by incorporating the modified PNIPAM hydrogel with a PVDF membrane (TAR PP window) in a square acrylic glass mold. Then, the micromorphology, thermal response characteristics, and infrared spectroscopy of the modified PNIPAM hydrogel as well as the optical properties of the TAR PP window were characterized. Finally, the experiments were conducted to determine the thermal response characteristics of the TAR PP window, and preliminary calculations were also performed to derive the energy-saving potential and heat gain of the TAR PP window. By incorporating PVDF with the modified PNIPAM hydrogel, the TAR PP window not only achieves 80 % visible light modulation and 73 % solar modulation but also exhibits an emissivity of > 90 % within the atmospheric transparency window. In addition, the preliminary evaluation indicates that the energy consumption of the experimental chamber with the TAR PP window can be decreased by 31.6 % compared with that with the conventional double-glazed (CDG) window.