High-Efficiency Dry-Jet Wet Spinning of Ultratoughness Regenerated Wool Keratin Fibers

Regenerated wool keratin fibers (RWKFs) featuring their ecofriendliness, ample resources, and intrinsic biocompatibility have attracted significant interest, while their high-value-added applications are still severely limited by inadequate mechanical properties and complex fabrication processes. Herein, a straightforward dry-jet wet spinning technique without post-treatment processes is proposed to prepare ultratoughness RWKFs. The as-spun fibers achieve a macroscale hierarchical structure due to the preorientation of nanoscale α-keratin protofibrils in air-gap drawing of dry-jet wet spinning, while α-keratins are preserved in large quantities because of no additional post-treatment stretching. As a result, the fabricated RWKFs achieve a tensile strength of ∼142.7 MPa, an outstanding elongation of ∼171.7%, and a record high toughness of ∼176.3 MJ m^-3, outperforming natural wool and previously reported regenerated keratin fibers. Moreover, the reported RWKFs' dyeability, moisture-induced shape-memory capacity, and electric generation performance remarkably expand their applications in textiles or even smart apparel.