Advanced Janus coatings for thermal management and synergistic flame retardancy in polyester fabric

In the context of low-carbon and energy conservation initiatives, smart thermal management textiles for the human body, which operate without energy consumption and pollution, are gaining increased attention. However, ensuring the fire safety of these textiles for human protection remains a key challenge for their practical application. Meanwhile, complicated and changed environments demand a high self-adaptation for designed textiles. This study introduces a dual-mode textile designed for freely switching radiative cooling (RC) and solar heating (SH). The textile is created by applying a high-white flame retardant and black phosphorus to both sides using a convenient scrape coating method. The combination of the cooling layer (90.0% solar reflectance and 95.9% infrared emissivity) and the heating layer (r̥80% solar absorptivity) provides a comfortable thermal environment for the human body. Furthermore, a Janus coating, consisting of advanced flame retardants, synergistically enhances the textile's fire safety, confirmed by a limiting oxygen index of 28.0%, a reduction of 40.1% in the peak value of heat release, and self-extinguishing properties. This research presents a simple and convenient approach for creating dual-mode smart textiles for maintaining a comfortable micro-environment towards changing seasons and weather, significantly contributing to the development of fire-safe personal thermal management technology.