Unexpected selective alkaline periodate oxidation of chitin for the isolation of chitin nanocrystals

Abstract

No periodate oxidation on chitin? For the first time, direct selective alkaline periodate oxidation of chitin led to the isolation of ordered domains as uniform anisotropic and zwitterionic ChNCs after simultaneous removal of non-ordered domains.

Light Amplification Materials Based on Biopolymers Doped with Dye Molecules—Structural Insights from 15N and 13C Solid-State Dynamic Nuclear Polarization

“…Solid-state nuclear magnetic resonance (NMR) is a powerful technique that provides such information . However, there are some limitations in terms of low intrinsic sensitivity for biopolymers that have only small surface areas, contain small amounts of surface molecules, or when nuclei such as 15 N have to be detected by solid-state NMR. − To overcome this disadvantage, it is necessary to boost the sensitivity which can be done by a combination of solid-state NMR with dynamic nuclear polarization (solid-state DNP). − This technique uses the polarization of unpaired electrons, which is 3 orders of magnitude higher and transfers it into nuclear polarization. Thus, the sensitivity of solid-state NMR is significantly enhanced as shown recently for a variety of cellulose-based materials. ,− …”

Ionic liquid-assisted synthesis of chitin–ethylene glycol hydrogels as electrolyte membranes for sustainable electrochemical capacitors

“…Technological development has equipped scientists with new tools and methods for processing this polymer into desired forms 25 – 31 . For instance, acidic hydrolysis 32 , TEMPO-mediated 33 and peroxide-mediated oxidation methods 34 or a freeze-thawing process 35 are often applied for the preparation of chitin-based membranes. Nevertheless, these methods require the use of harsh chemicals, and hydrolyzed chitin nanocrystals or nanowhiskers often have an unfavourably low length/diameter ratio.…”

Surface sulfation of crab chitin for anisotropic swelling and nanodispersion

“…The glucosamine residues on the surface can be also selectively cleaved by periodate for further modifications. 8 Other methods applied to cellulose can also be applied to chitin, namely sulfuric acid hydrolysis, 9 tetramethylpiperidine-1-oxyl (TEMPO) catalyzed oxidation of primary alcohol on the surface. 10 While N-deacetylation leads to cationic particles, other methods common to nanocellulose preparation leads to introduction of negative charge on the surface.…”