Breathable, Thermally Insulating Phase-Change Fibrous Mat and Yarn Inspired by Penguin Feather Microstructure for Personal Thermal Management

In response to the growing challenges of global warming and the energy crisis, the development of advanced personal thermal management fabrics is essential for conserving thermal energy, reducing carbon emissions, and ensuring thermal comfort. In this article, we present an effort to develop a polystyrene (PS)-polyethylene glycol (PEG)-based fibrous mat and yarn with unique morphology, inspired by natural systems like penguin feathers. This material not only undergoes phase changes within a specific temperature range but also demonstrates excellent thermal insulation properties, effectively minimizing heat flux. Incorporating PEG improves the mechanical properties of both the fibrous mat and yarn structures, with the material retaining its structural integrity and effectively containing PEG during repeated thermal cycling. The phase-changeable fibrous mat and yarn achieved fusion enthalpies of 33.13 ± 0.36 and 31.63 ± 0.89 J g^-1, respectively, with excellent thermal stability and durability, as confirmed through multiple heating-cooling cycles of up to 30 cycles. The thermal conductivity coefficient (λ) of the PS-PEG fibrous mat reaches 0.033 W m^-1 K^-1, signifying excellent thermal insulation properties of the fabricated electrospun mat. Infrared imaging reveals the effective thermal buffering effect of phase-change fiber mats and yarns when weaved onto cotton fabric under drastic temperature changes. Moreover, the fibrous mats show a water vapor transmission rate (WVTR) of 3735 ± 234 g m^-2 day^-1, indicating high breathability, alongside thermal performance. These results position the proposed biomimetic fibrous material as a promising candidate for next-generation wearable textiles in the future that enhance personal thermal comfort, offering both performance and sustainability.