Modulating the isotopic hydrogen-deuterium exchange in functionalized nanocellulose to optimize SANS contrast
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Date
2024-12
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
Contrast matching by isotopic exchange in cellulose allows visualizing functional groups, biomolecules, polymers and nanoparticles embedded in cellulosic composites. This isotopic exchange varies the scattering length density of cellulose to match its contrast with the background network.
Here, contrast matching of microcrystalline-cellulose (MCC) and the functionalized nanocellulose-fiber (CNF) and cellulose nanocrystals (CNC) are elucidated by small angle neutron scattering (SANS). Results show no isotopic exchange occurs for the CNF surface functionalized with carboxyl nor for the CNC-High with a high sulfate groups concentration.
Both CNC-Low, with low sulfate groups, and MCC exchange 1H with 1D in D2O. This is due to the high exchange probability of the labile C6 position primary -OH group.
The structure of thermo-responsive poly-N-isopropylacrylamide (PNIPAM) chains grafted onto CNF (PNIPAM-grafted-CNF) was extracted by CNF contrast matching near the lower critical solution temperature. Contrast matching eradicates the CNF scattering to retain only the scattering from the grafted-PNIPAM chains. The coil to globule thermo-transition of PNIPAM was revealed by the power law variation from q−1.3 to q−4 in SANS.
Isotopic exchange in functionalized cellulosic materials reveals the nano- and micro-scale structure of its individual components. This improved visualization by contrast matching can be extended to carbohydrate polymers to engineer biopharmaceutical and food applications. © 2024 The Authors. Published by Elsevier Ltd. - Open Access CC BY 4.0
Description
Keywords
Contrast Media, Small angle scattering, Deuterium, Isotopes, Cellulose, Nanocrystals, Carboxylase
Citation
Raghuwanshi, V. S., Mendoza, D. J., Mata, J., & Garnier, G. (2024). Modulating the isotopic hydrogen-deuterium exchange in functionalized nanocellulose to optimize SANS contrast. Carbohydrate Polymers, 345, 122591. doi:10.1016/j.carbpol.2024.122591