Thermal Conductivity of PNIPAm Hydrogels and Heat Management as Smart Windows

Though thermoresponsive lower critical solution temperature (LCST) hydrogels have attracted intense attention to be applied in smart windows, less efforts are paid on the LCST effect on the heat transfer process. Herein, the research mainly focuses on heat transfer process of thermoresponsive PNIPAm hydrogels. It is the first time reported that LCST behaviors can decrease thermal conductivity upon heating process. To be utilized as a smart window, thermal conduction flux is investigated yet the thermal conduction energy occupies little to manage the thermal transfer process in a model house. It is found that radiation thermal transfer predominates the heat transfer process for PNIPAm‐based smart windows. These results are meaningful to provide basic data for energy transfer in using thermoresponsive hydrogels. The research mainly focused on the heat transfer process of thermoresponsive PNIPAm hydrogels. Lower critical solution temperature behaviors decreased thermal conductivity upon the heating process.In a model house, thermal conduction flux through the PNIPAm hydrogel window occupied little in the thermal transfer process, while radiation thermal transfer predominated the heat transfer process.