Ultralight, Washable, and Antibacterial Ultrafine Fiber Sponges by Direct Electrospinning for High‐Performance Warmth Retention

Abstract Extreme low temperature imposes huge burden on both societal security and the global economy, thus requiring advanced warmth retention materials to protect human from the cold environment. However, the common fibrous heat preservation materials always suffer from heavy weight, poor mechanical properties, inadequate thermal insulation performance, and a lack of antibacterial properties. In this study, a facile approach for fabricating washable and antibacterial polystyrene (PS)/polyurethane (PU) fibrous sponges by direct electrospinning is demonstrated. The ultrafine fibers with rough structures are created due to the different phase separation rate of two polymers in the jet, which endows the sponge with hydrophobic property. Meanwhile, stiff PS and soft PU can synergistically improve the mechanical properties of the sponge (nearly without deformation after 1000 stretching and compression), which further endows washable property to the sponge. Moreover, the antibacterial performance is obtained through the incorporation of antibacterial agents, demonstrating a high antibacterial rate of 98.9% even after 10 washing cycles. In addition, the fibrous sponge also shows ultralight property (3.89 mg cm −3 ) and desired warmth retention performance with thermal conductivity of 23.77 mW m −1 K −1 . The fabrication of ultrafine fiber sponge represents a significant advancement for the development of high‐performance materials in various fields.