The preparation and characterization of nanocomposite film reinforced by modified cellulose nanocrystals.

In the present study, in order to improve the properties of nanostarch-based nanocomposite film for food packaging, a type of nanocomposite film based on corn nanostarch (CNS) as the matrix and modified cellulose nanocrystals (modified-CNCs) as the reinforcement was prepared using a solution casting method. The cellulose nanocrystals (CNCs) were modified by a two-step method in which they were initially crosslinked with citric acid, and subsequently amidated with chitosan. Then, a type of CNS/modified-CNCs nanocomposite film with different content levels of modified-CNC were prepared and characterized using Fourier Transform Infrared spectroscopy (FTIR); X-ray Photoelectron Spectroscopy (XPS); X-Ray Diffraction (XRD); Differential Scanning Calorimetry (DSC); and Scanning Electron Microscopy (SEM). It was observed that when compared with the pure CNS film, the 8.0 wt% modified-CNCs loaded nanostarch-based nanocomposite film had displayed a 230.0% increase in tensile strength. And the moisture absorption ability had decreased by 25.6%; water vapor permeability had decreased by 87.4%; and the water contact angle value had increased by 18.1%. Also the results of this experimental study had revealed that the CNS/modified-CNCs nanocomposite film had displayed better antimicrobial activities against E. coli and S. aureus bacteria when compared with the pure CNS film.