Janus polyoxymethylene fabric with unidirectional moisture transport and all-weather passive radiative cooling

Abstract

Passive radiative cooling has promising applications in the field of personal thermal management textiles due to its zero-energy consumption and zero pollution. Nevertheless, recently reported radiative cooling textiles are mostly made of hydrophobic fibers, which makes it difficult to expel perspiration in hot and humid environments. Here, a novel Janus polyoxymethylene (POM) fabric with unidirectional moisture transport and all-weather passive radiative cooling was prepared by an electrospinning method using a POM/polyvinylpyrrolidone (PVP)/SiO₂ hydrophilic layer and a pure POM hydrophobic layer. It was found that the introduction of PVP and nano-SiO₂ not only enhanced the solar reflectance from 94.8% to 97.4% but also increased the infrared (IR) emittance from 81.7% to 93.7%. Particularly, the Janus POM fabric exhibited efficient radiative cooling performance under all-weather conditions, realizing a cooling effect of nearly 8.2 °C below the ambient temperature in the daytime and nearly 2.5 °C in the nighttime. Furthermore, this fabric possessed an outstanding unidirectional moisture transport function, enabling the anti-gravity perspiration transfer from the hydrophobic layer to the hydrophilic layer. Moreover, its water evaporation time on simulated sweaty skin decreased by 35.3% compared to that of cotton fabrics and 68.6% compared to that of pure POM fabrics. This study proposes a strategy for the preparation of high-comfort radiative cooling textiles, which have great application potential in outdoor clothing and personal protection wearables.