The Renewable and Sustainable Conversion of Chitin into a Chiral Nitrogen‐Doped Carbon‐Sheath Nanofiber for Enantioselective Adsorption

Abstract

Well-known hard-template methodsf or nitrogen (N)-doped chiral carbon nanomaterials require complicated construction and removal of the template, high-temperature pyrolysis, harsh chemicalt reatments, and additional N-doping processes. If naturallyo ccurring chiral nematic chitin nanostructures [(C 8 H 13 NO 5 ) n ]i ne xoskeletons were whollyt ransformed into an N-doped carbon, this would be an efficient and sustainable methodt oo btain au seful chiral nanomaterial. Here, as imple, sacrificial-template-free, and environmentally mild method was developed to produce an N-doped chiral nematic carbonsheath nanofibril hydrogel with as urfacea rea > 300 m 2 g À1 and enantioselective properties from renewable chitin biomass. Calcium-saturated methanol physically exfoliated bulk chitin and produced ac hiral nematic nanofibril hydrogel. Hydrothermal treatment of the chiral chitin hydrogel at 190 8Cp roduced an N-doped chiralc arbon-sheath nanofibril hydrogel without N-doping. This materialp referentially adsorbed d-lactic acid over l-lactic acid andp roduced 16.3 %e nantiomeric excesso f l-lactic acid from ar acemic mixture.[a] H.Supporting Information and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

Environmental Impact Assessment of Chitin Nanofibril and Nanocrystal Isolation from Fungi, Shrimp Shells, and Crab Shells

“…Suggested applications for fungi-derived ChNFs. The images for chiral nematic material applications are reproduced with permission from refs − .…”

“…7 Similarly, ChNFs cannot form helically ordered hybrid materials via biomineralization, which is possible using colloidal liquid-crystalline chitin obtained through conventional hydrolysis of chitin powders. 75 Such chiral structures are interesting for the enantioselective separation of chiral molecules 76 or to develop materials with enhanced mechanical energy dissipating capacity by forming a twisted plywood structure. 77 However, the group of Vignolini recently reported films having structural coloration formed by chitin nanoparticles derived from fungi.…”

Nanochitin and Nanochitosan: Chitin Nanostructure Engineering with Multiscale Properties for Biomedical and Environmental Applications

“…These carbonized hydrogels exhibit a chiral separation ability, preferentially adsorbing d ‐lactic acid over l ‐lactic acid at an enantiomeric excess of 16.3% (Figure 14i,j). [ 203 ]…”

“…[201,202] Ndoped carbon mate rials are prepared from chitin or chitosan by thermal treatment, which involves pyrolysis at high temperatures (900 °C) in an inertgas atmosphere, or hydrothermal treatment at milder temperatures (≈200 °C). [203][204][205][206] Pyrolysis produces whole carbon materials with higher surface area and low Ndoping levels, whereas hydrothermal treatment results in carbon sheath/chitincore materials with high Ndoping levels. [203,207]…”

“…[203][204][205][206] Pyrolysis produces whole carbon materials with higher surface area and low Ndoping levels, whereas hydrothermal treatment results in carbon sheath/chitincore materials with high Ndoping levels. [203,207]…”