Thermal energy regulated and thermochromic composite film with temperature-sensitive “breathable” stomata

Intelligent breathable membranes with multiple functions attach wide attentions of people which provide protection and comfort to meet the pressing demand for future protective clothing. We proposed a novel thermal energy regulated and thermochromic composite film with temperature-sensitive “breathable” stomata consisted of thermochromic nanofibrous membrane (TC-NFM) and thermo-sensitive polyurethane (PU) film. Thermochromic nanoencapsulated phase change materials (TC-NPCMs) were introduced as functional fillers into polyvinyl alcohol/water-soluble polyurethane (PVA/WPU) solution for electrospinning process. And methylated melamine–formaldehyde (MMF) was innovatively used to modify the water resistance of TC-NFM. By adjusting the molecular weight of the soft segment, the thermo-sensitive PU film was successfully prepared. Consequently, the prepared TC-NFM exhibited high enthalpy of 44.3 J g −1 and kept superior energy storage and release property even after 100th cyclic experiments. The water vapor permeability of thermo-sensitive PU film was triggered near the comfortable temperature of the human body. The results presented here might facilitate improvements in the field of thermal regulation clothing, intelligent clothing, wearable temperature sensor and reversible thermochromic coating materials. Graphic abstract