Radiative Cooling and Solar Heating Janus Films for Personal Thermal Management

Hot and cold seasonal temperature fluctuations pose a serious public health threat. Radiative thermal management has been shown to be an effective method for personal thermal management. However, the currently available materials cannot maintain human thermal comfort against the hot and cold seasonal temperature fluctuations, such as heating in cold weather or cooling in hot weather. Here, a Janus film that integrates the two opposite requirements of heating and cooling into one functional dual-mode film is fabricated. In cooling mode, the Al backing and embedded silicon dioxide (SiO2) microparticle can achieve a high solar reflectivity (similar to 0.85) and high IR emissivity (similar to 0.95) to induce a temperature drop of similar to 2 degrees C. In contrast, the embedded carbon nanotubes (CNTs) can improve solar absorption (similar to 0.95) and induce a temperature increase of similar to 7 degrees C. Owing to its radiative cooling and solar heating capability and compatibility with large-scale production, this Janus film is promising to bring new insights into the design of the next-generation functional textiles.

Automated summary

Hot and cold temperature fluctuations pose a threat to public health, and current materials are unable to maintain thermal comfort in such conditions. However, a newly developed Janus film has the capability of both heating and cooling, offering potential applications in functional textiles.