High Solar Energy Absorption and Human Body Radiation Reflection Janus Textile for Personal Thermal Management

Abstract

A large of energy consumption is required for indoor and outdoor personal heating to ameliorate the comfortable and healthy conditions. Main personal thermal management strategy is to reflect mid-infrared human body radiation for human surface temperature (T_HS) regulation. We demonstrate a visible Janus light absorbent/reflective air-layer fabric (Janus A/R fabric) that can passively reflect radiative heating meanwhile can actively capture the solar energy. A series of azobenzene derivatives functionalized with alkyl tails are reported to co-harvest the solar and phase-change energy. The T_HS covered by Janus A/R fabric can be heated up to ~ 3.7 °C higher than that covered by air-layer fabric in cold environment (5 °C). Besides, integrating the thermo- and photo-chromic properties is capable of monitoring comfort T_HS and residue energy storage enthalpy, respectively. According to the colour monitors, intermittent irradiation approach is proposed to prolong comfortable-T_HS holding time for managing energy efficiently.

Graphical Abstract

For the personal thermal management, we fabricate a visible Janus light absorbent/reflective fabric, which can actively capture solar energy and passively reflect the human radiation reflection (MIR). The solar energy can be released as heat to actively warm human surface temperature up, and the reflective MIR can passively heat the human body. The surface temperature and residue energy storage can be monitored by distinct colour change.

Funding

National Natural Science Foundation of China(21975107); Natural Science Foundation of Jiangsu Province(SBK2019020945); National First-Class Discipline Program of Light Industry Technology and Engineering(LITE2018-21); Postgraduate Research & Practice Innovation Program of Jiangsu Province(KYCX20_1783); China Scholarship Council(202006790096)