Quantifying the Contribution of the Dispersion Interaction and Hydrogen Bonding to the Anisotropic Elastic Properties of Chitin and Chitosan

Abstract

The elastic tensors of chitin and chitosan allomorphs were calculated using density functional theory (DFT) with and without dispersion correction, and compared with experimental values. The longitudinal Young's moduli were 114.9 GPa or 126.9 GPa for α-chitin depending on hydrogen bond pattern, 129.0 GPa for β-chitin, and 191.5 GPa for chitosan. Furthermore, the moduli were found to vary between 17.0 to 52.8 GPa in the 1 transverse directions, and between 2.2 to 15.2 GPa in shear. Switching off the dispersion correction lead to a decrease in modulus by up to 63%, depending on the direction. The transverse Young's moduli of α-chitin strongly depended on the hydroxylmethyl group conformation coupled with the dispersion correction, suggesting a synergy between hydrogen bonding and dispersion interactions. The calculated longitudinal Young's moduli were in general higher than experimental values obtained in static conditions and Poisson's ratios were lower than experimental values obtained in static conditions.

The major role of London dispersion interaction in the assembly of cellulose, chitin, and chitosan

“…The total-energy computation was subsequently performed by freezing both the box size and coordinates, and the obtained energy is noted as E 1D_disp . This is slightly different from our previous work (Chen et al 2022), in which the enlarged box and atoms were both relaxed, and makes the E intra_E truly constant, In the previous studies the E intra_E was "assumed" to be unchanged which turned out to be not the case as can be seen in the comparison between Table 1 and Table S1. By switching off the dispersion correction and freezing the atoms in the 3D system when dispersion correction switched off and in 1D system when dispersion correction was turned on and off, two other energy terms can be generated, noted as E 3D_nodisp and E 1D_nodisp , corresponding to the bottom left and right states in Figure 2, respectively.…”

Chitin Nanofibers Enable the Colloidal Dispersion of Carbon Nanomaterials in Aqueous Phase and Hybrid Material Coassembly

“…Suspension stability is closely tied to ChNF surface charge. 28 Table S8 includes our results compared to those from the literature about SWNT dispersion, processing, and stability. Two options are apparent as far as the available approaches, focusing on processing in aqueous phase by chemical modification and physical surfactant-assisted dispersion.…”

Transitional chelal digit patterns in saprophagous astigmatan mites

“…Arthropod cuticle has a tensile strength in excess of aluminium and of a scale similar to that of bone (see Bowman 2024). Chitinous materials can show different Young's moduli that vary in directions (Chen et al 2022), but not majorly differ by arthropod origin (Caldwell and Mendez 2016). A strong stiffened base-plate (as in saws, Bowman (2024), effectively from an elevated Young's modulus to resist dorsal elongation and buckling) should be needed for efficient dentition under time varying vertical loads during food mastication.…”