Superelastic and Fire-Retardant Nano-/Microfibrous Sponges for High-Efficiency Warmth Retention
Ruihong Zhang, Xiaobao Gong, Sai Wang, Yucheng Tian, Yitao Liu, Shichao Zhang, Jianyong Yu, Bin Ding
Abstract
Warmth retention equipment for personal cold protection is highly demanded in freezing weather; however, most present warmth retention materials suffer from high thermal conductivity, weak mechanical properties, and strong flammability, resulting in serious security risks. Herein, we report a facile strategy to fabricate nano-/microfibrous sponges with superelasticity, robust flame retardation, and effective warmth retention performance via direct electrospinning. The three-dimensional fluffy sponges with low volume density and high porosity are constructed by accurately regulating the relative humidity; meanwhile, the mechanically robust polyamide-imide nanofibers with high limit oxygen index (LOI) are innovatively introduced to improve the structural stability and flammability of the nano-/microfibrous sponges. Strikingly, the developed nano-/microfibrous sponges exhibit ultralight characteristics (6.9 mg cm–3), superelasticity (∼0% plastic deformation after 100 compression tests), effective flame retardant with LOI of 26.2%, and good heat preservation ability (thermal conductivity of 24.6 mW m–1 K–1). This work may shed light on designing superelastic and flame-retardant warmth retention materials for various applications.