Ultralight, Superelastic, and Washable Nanofibrous\nSponges with Rigid-Flexible Coupling Architecture Enable Reusable\nWarmth Retention

Abstract

Nanofibrous\nsponges enable promising potentials in warmth retention\nbut are impeded by short service life and nonwashability, owing to\ntheir inadequate mechanical properties. Herein, a scalable strategy\nis reported to develop ultralight, superelastic, and washable micro/nanofibrous\nsponges (MNFSs) with a rigid-flexible coupling architecture created\nby bridging high-modulus polyethylene terephthalate microfibers with\nflexible polyacrylonitrile nanofibers via robust bonding structures.\nMeanwhile, the <i>in situ</i> doping of fluoropolymer endows\nmicro/nanofibers with desirable amphiphobicity. The resultant MNFSs\npresent high resilience, superior compressive fatigue resistance (5.7%\nresidual strain at 1000th), low-temperature-resistant superelasticity\n(up to −196 °C), and unique washing-invariant superelasticity.\nMoreover, the fascinating structures of high porosity, high tortuosity,\nand small pores enable MNFSs both ultralight property\n(7.5 mg cm^–3) and effective warmth retention (28.51\nmW m^–1 K^–1). Additionally, the\nMNFSs possess remarkable antifouling, robust stability, and long service\nlife. The work might provide an avenue to develop mechanically robust\nnanofibrous sponges for various applications.