title: Tough and catalytically active hybrid biofibers wet-spun from nanochitin hydrogels.
abstract: Sustainable alternatives for high-performance and functional materials based on renewable resources are intensely needed as future alternatives for present-day, fossil-based materials. Nanochitin represents an emerging class of highly crystalline bionanoparticles with high intrinsic mechanical properties and the ability for conjugation into functional materials owing to reactive amine and hydroxyl groups. Herein we demonstrate that hydrogels containing surface-deacetylated chitin nanofibrils of micrometer length and average diameters of 9 nm, as imaged by cryogenic transmission electron microscopy, can be wet-spun into macrofibers via extrusion in a coagulation bath, a simple low energy and large-scale processing route. The resulting biofibers display attractive mechanical properties with a large plastic region of about 12% in strain, in which frictional sliding of nanofibrils allows dissipation of fracture energy and enables a high work-of-fracture of near 10 MJ/m3. We further show how to add functionality to these macrofibers by exploiting the amine functions of the surface chitosan groups to host catalytically active noble metal nanoparticles, furnishing biobased, renewable catalytic hybrids. These inorganic/organic macrofibers can be used repeatedly for fast catalytic reductions of model compounds without loss of activity, rendering the concept of hybridized chitin materials interesting as novel bioderived supports for nanoparticle catalysts.
authors.affiliation: Interactive Materials Research, DWI at RWTH Aachen University, D-52056 Aachen, Germany.
authors.forename: Paramita
authors.initials: P
authors.lastname: Das
authors.forename: Thomas
authors.initials: T
authors.lastname: Heuser
authors.forename: Andrea
authors.initials: A
authors.lastname: Wolf
authors.forename: Baolei
authors.initials: B
authors.lastname: Zhu
authors.forename: Dan Eugen
authors.initials: DE
authors.lastname: Demco
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Ifuku
authors.forename: Andreas
authors.initials: A
authors.lastname: Walther
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D002384:Catalysis; D002686:Chitin / Q000737:chemistry*; D048271:Chitosan / Q000737:chemistry; D020100:Hydrogels / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D053768:Metal Nanoparticles / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D010984:Platinum / Q000737:chemistry*; D013499:Surface Properties; D014961:X-Ray Diffraction
chemical_list: D001672:Biocompatible Materials; D020100:Hydrogels; D002686:Chitin; D010984:Platinum; D048271:Chitosan