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

Abstract

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.

Bioinspired Multiscale Micro-/Nanofiber Network Design Enabling Extremely Compressible, Fatigue-Resistant, and Rapidly Shape-Recoverable Cryogels

“…In a word, the 3D structure with multiscale fibers exhibits extraordinary mechanical properties in comparison to that assembled with single-scale fibers, and similar conclusions have also been reported in 2D film materials and 3D sponge materials with combined multiscale micro-/nanostructures. − The excellent mechanical performance of the CMNF cryogel such as high compressibility, superior elasticity, and outstanding fatigue resistance could be attributed to the synergistic effect of hybrid micro-/nanofibers with a high aspect ratio through the freeze-induced physicochemical cross-linking approach, in which the microfibers contribute to the strength of the cryogel through long-range interaction, while intertwined nanofibers play a pivotal role in the enhancement of the flexibility and stability of the 3D porous network structure via the combination with the microfibers.…”

Ultralight and Superelastic Curly Micro/Nanofibrous Aerogels by Direct Electrospinning Enable High‐Performance Warmth Retention

“…Unfortunately, some key restrictions still exist, involving large diameter (usually >20 μm), simple stacking structure, and limited porosity, resulting in heavy weight and unsatisfactory heat preservation property. [17,18] Compared with the conventional fibers, micro/nanofibers exhibit the application potentials in the field of effective warmth retention due to their decreased diameters (generally 500 nm − 5 μm), [19,20] which endow them with reduced pore size and improved porosity, and thus effectively trap much still air to restrict heat transportation. In the existing cuttingedge micro/nanofibers, electrospun fibers combine the characteristics of micro/nanoscale size, low density, and tunable pore structure, which could be served as promising warmth retention materials.…”

“…Unfortunately, some key restrictions still exist, involving large diameter (usually >20 µm), simple stacking structure, and limited porosity, resulting in heavy weight and unsatisfactory heat preservation property. [ 17,18 ]…”

Direct Synthesis of Polyimide Curly Nanofibrous Aerogels for High‐Performance Thermal Insulation Under Extreme Temperature

“…To obtain the nanofibrous aerogels, electrospun nanofibers were reconstructed into the highly porous assemblies by freeze-drying method, thus improving the capacity to reduce the heat exchange. [21][22][23] However, the resulted aerogels always undergo unpredictable pore structures and weak mechanical property in the applications, since the porous structures are built by removing randomly growing ice crystals between discontinuous staple fibers. Moreover, the disadvantages of complex process and long manufacturing time caused by the complicated and immature equipment limit the direct and facile synthesis of nanofibrous aerogels.…”