Mechanically Strong Chitin Fibers with Nanofibril Structure, Biocompatibility, and Biodegradability

The environment-friendly fibers fabricated from natural polysaccharides have attracted much attention in the development of sustainable materials, owing to the global pollution caused by fibers and textiles fabricated from petroleum-based polymers. Chitin derived from seafood wastes possesses excellent biocompatibility and biodegradability, but it is still far from being fully explored. Here, we designed and prepared, for the first time, chitin fibers with nanofibril structures from the chitin solution in the NaOH/urea aqueous system by cooling on a lab-scale wet-spinning machine. Because of the slow diffusion of phytic acid into the chitin dope, the stiff chitin chains could self-aggregate sufficiently in a parallel manner to form the nanofibers via a “bottom-up” approach and then be bundled into the gel-state fibers. The dried chitin fibers were demonstrated to be composed of nanofibers with a mean diameter of 27 nm and exhibited a tensile strength of 2.33 cN/dtex, which is higher than those reported in...