Super‐Strong and Super‐Stiff Chitosan Filaments with Highly Ordered Hierarchical Structure

Abstract

Currently, the world is facing the problems of the gradual depletion of nonrenewable fossil resources and the severe harm of non-degradable plastic waste to the land and marine ecological environment. Because of the rapid increase in the demand for fiber materials, the development of high-performance biomass-based fibers has emerged as an important research topic to reduce the reliance on petroleum-based synthetic fibers. In this study, a novel green wet-spinning strategy is used for the fabrication of super-strong and super-stiff chitosan filaments from an aqueous KOH/urea solution using a two-step drawing process. The highly ordered hierarchical structure of the resulting filaments contributes to their excellent mechanical properties. The tensile strength and Young's modulus of the chitosan filaments are 878 ± 123 MPa and 44.7 ± 12.3 GPa, respectively, and these values are comparable to those of spider silk and bacterial cellulose. The chitosan filaments prepared in this study are superior to low-density steel in terms of the specific strength and modulus. The green and scalable strategy proposed in this study will broaden the application range of chitosan filaments in flexible bioelectronics, biomaterials, and textiles.

Dynamically Cross‐Linking Soybean Oil and Low‐Molecular‐Weight Polylactic Acid toward Mechanically Robust, Degradable, and Recyclable Supramolecular Plastics

“…[7,11] Bio-based plastics have attracted attention of scientists because they can reduce the degree of dependency on fossil resources and greenhouse gas emissions. [12,[16][17][18] As a typical bio-based plastic, polylactic acid (PLA) has been widely used as an alternative to commodity plastics. [19,20] Generally, high-molecular-weight PLA plastic is synthesized through the ring opening polymerization of lactides.…”

Electrical signals regulate the release of insulin from electrodeposited chitosan composite hydrogel: An in vitro and in vivo study

“…The diffraction pattern of chitosan showed two crystallization peaks at 10.2° and 20.6°, corresponding to the (020) and superimposed (200)/(220) reflections 20 . While LDHs showed diffraction peaks at lower 2 θ (sharp and symmetric peaks at 11.6° and 23.1°) and higher 2 θ (wide and asymmetric peaks at 34.7°, 38.8°, 45.7°, 60.8°, and 62.1°), which corresponded to the (0 0 3), (0 0 6), (0 1 2), (0 1 5), (0 1 8), (1 1 0), and (1 1 3) crystal planes of a layered hydrotalcite‐like material, respectively 21 . After LDHs loaded with INS, the position of diffraction peak did not shift but the crystallinity decreased due to the adsorption of INS on the surface.…”

Knittable Composite Fiber Allows Constant and Tremendous Self‐Powering Based on the Transpiration‐Driven Electrokinetic Effect

“…Because the intensity of characteristic peaks (G‐band at 1600 cm −1 and D‐band at 1310 cm −1 ) with the laser beam polarized in the direction 50° to the fiber axis is the highest and then decreases when the laser beam is polarized parallel and perpendicular to the fiber axis. [ 30 ] This anisotropic trait is expected to facilitate axial hopping of charged carriers during transpiration and contributes to the wearable requirements and self‐powering based on the electrokinetic effect.…”