Recent advances in textile materials for personal radiative thermal management in indoor and outdoor environments

Abstract

Thermal radiation plays an important role on managing clothing comfort, which is also the main heat dissipation pathway for human body heat transfer. There are two contradictions when traditional clothing regulates the human body comfort: clothing is demanded to block extra heat input but hinders human body heat dissipation in hot environment; Clothing prevents heat loss to keep human body warm but is impermeable and high IR emission towards outer space in cold environment. To solve these problems, the recently emerged Personal Radiative Thermal Management (PRTM) technologies have been adopted to fabricate advanced clothing materials, which promote the thermal comfort of wearers and also to alleviate the energy consumption on building heating or cooling. Different from the indoor controllable thermal environment, the outdoor thermal environment is characterized as strong intensity of solar irradiance. Based on the differences for radiation sources between outdoor thermal environment and indoor thermal environment, we comprehensively review the clothing materials composition and nano/microstructures underlying the PRTM strategies to control the heat exchange the human body and the surrounding. Two mechanisms for managing thermal radiation transports including radiative heating and radiative cooling are demonstrated in detail from the perspectives of hot and cold environments. In particular, the review also distinguishes the radiative cooling effect owning to high emittance from the radiative cooling effect due to high transparency. Embodiment of the general PRTM concept on military thermal infrared camouflage is presented. Discussions about the future research trend are also provided, which may be useful for further study and development in these fields, such as energy harvesting, building, fluidic cooling.