02547naa a2200229 a 450000100080000000500110000800800410001902200140006002400560007410000200013024501820015026000090033230000110034152017490035265300400210170000160214170000250215770000220218270000220220470000130222677300780223921710352024-12-30       2024    bl uuuu     u00u1 u    #d  a0141-81307 ahttps://doi.org/10.1016/j.ijbiomac.2024.1357262DOI1 aLEITE, L. S. F.  aInsights into the effect of carboxylated cellulose nanocrystals on mechanical and barrier properties of gelatin films for flexible packaging applications.h[electronic resource]  c2024  a1 - 10  aIn this study, gelatin/carboxylated cellulose nanocrystal (cCNC) bionanocomposite films were developed as an eco-friendly alternative to non-biodegradable flexible plastic packaging. Cellulose nanocrystals were modified by 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-mediated oxidation (cCNC) to strategically interact with amino groups present in the gelatin macromolecular backbone. Gelatin/cCNC bionanocomposite films (0.5–6.0 wt% cCNC) obtained by solution casting were transparent to visible light while displayed high UV-blocking properties. The chemical compatibility between gelatin and cCNC was deepened by electrostatic COO− /NH3 + interactions, as detected by FTIR spectroscopy and morphologically indicated by scanning electron microscopy (SEM). Accordingly, Young’s modulus and tensile strength of films were largely increased by 80 and 64 %, respectively, specifically near the cCNC percolation threshold (4 wt%), whereas the water vapor permeability (WVP) was reduced by 52 % at the optimum 6.0 wt% cCNC content in relation to the non-reinforced gelatin matrix (0.10 vs. 0.18 g H2O mm m− 2 h− 1 kPa− 1 ). The oxygen transmission rates (OTR) of the gelatin/cCNC bionanocomposites were &lt 0.01 cm3 m-2 day− 1 , making them technically competitive to most promising biopolymers like polycaprolactone (PCL) and poly(lactic acid) (PLA). This study reveals how TEMPO-oxidized cellulose nanocrystals can broaden the performance of biodegradable gelatin films for use in packaging. The gelatin/cCNC bionanocomposites also represent an effective approach for designing newly sustainability-inspired flexible materials from the surface modification of nanocelluloses targeting specific interactions with protein structures.  aCarboxylated cellulose nanocrystals1 aLe GARS, M.1 aAZEREDO, H. M. C. de1 aMOREIRA, F. K. V.1 aMATTOSO, L. H. C.1 aBRAS, J.  tInternational Journal of Biological Macromoleculesgv. 280, 135726, 2024.