Cellulose Nanoparticles Prepared by Ionic Liquid-Assisted Method Improve the Properties of Bionanocomposite Films

Bionanocomposites have garnered wide interest from the packaging industry as a biocompatible alternative to non-biode-gradable petroleum-based synthetic materials. This study presents a simple and eco-friendly alternative to produce cellulose nanoparticles using a protic ionic liquid, and the effects of their incorporation in cassava starch and chitosan films are evaluated. Bionanocomposite films are prepared using the solvent casting method and are characterized using X-ray diffraction, Fourier transform infrared spectroscopy, zeta potential, thermogravimetric analysis, and transmission electron microscopy. The achieved yield of cellulose nanoparticles is 27.82%, and the crystalline index is 67.66%. The nanoparticles' incorporation (concentration from 0.1 to 0.3% wt) results in a progressive reduction of water vapor permeability up to 49.50% and 26.97% for starch and chitosan bionanocomposite films, respectively. The starch films with 0.1% cellulose nanoparticles exhibit significantly increased flexibility compared to those without any addition. The nanoparticles' incorporation in chitosan films increases the thermal stability without affecting the mechanical properties. The cellulose nanoparticles obtained using protic ionic liquid, as an alternative pathway avoiding the classic acid hydrolysis can be a simple, sustainable, and viable method to produce bionanocomposites with tailored properties, useful for applications in the packaging industry. [GRAPHICS] .

Automated summary

This study presents an eco-friendly method for producing cellulose nanoparticles using an ionic liquid, and evaluates their effects in starch and chitosan films. The incorporation of the nanoparticles results in a reduction of water vapor permeability and increased flexibility in starch films, while improving the thermal stability of chitosan films.