Ultralight, Superelastic, and Washable Nanofibrous Sponges with Rigid-Flexible Coupling Architecture Enable Reusable...

Nanofibrous sponges enable promising potentials in warmth retention but are impeded by short service life and nonwashability, owing to their inadequate mechanical properties. Herein, a scalable strategy is reported to develop ultralight, superelastic, and washable micro/nanofibrous sponges (MNFSs) with a rigid-flexible coupling architecture created by bridging high-modulus polyethylene terephthalate microfibers with flexible polyacrylonitrile nanofibers via robust bonding structures. Meanwhile, the in situ doping of fluoropolymer endows micro/nanofibers with desirable amphiphobicity. The resultant MNFSs present high resilience, superior compressive fatigue resistance (5.7% residual strain at 1000th), low-temperature-resistant superelasticity (up to -196 °C), and unique washing-invariant superelasticity. Moreover, the fascinating structures of high porosity, high tortuosity, and small pores enable MNFSs both ultralight property (7.5 mg cm^-3) and effective warmth retention (28.51 mW m^-1 K^-1). Additionally, the MNFSs possess remarkable antifouling, robust stability, and long service life. The work might provide an avenue to develop mechanically robust nanofibrous sponges for various applications.