Eco-Friendly, Green Packaging Materials from Akaganeite and Hematite Nanoparticle-Reinforced Chitosan Nanocomposite Films

Abstract

In this study, chitosan nanocomposite thin films were successfully fabricated by incorporating hematite nanoparticles (HNPs) and akaganeite nanoparticles (ANPs) as reinforcing fillers using the solution casting method. HNPs and ANPs were synthesized via a urea-assisted synthesis route using naturally occurring ferruginous laterites. Scanning electron microscopic (SEM) images indicated the spherical to subhexagonal morphology of the HNPs and rice-like morphology of the ANPs. X-ray diffractograms indicate the crystalline structure of iron oxides as hematite and akaganeite. Tensile tests were carried out to evaluate the mechanical properties of the nanocomposite films where maximum tensile stress of the chitosan/HNP composites was improved as high as 35.7% while chitosan/ANP composites indicated 43.5%. Thermal decomposition curves obtained by thermogravimetric analysis (TGA) indicate that the thermal stability of the nanocomposites has improved remarkably compared to neat chitosan films. Furthermore, these nanocomposites exhibited excellent UV barrier properties as identified by UV-visible spectrometry. Fourier-transform infrared (FTIR) spectroscopic results are evident in the presence of Fe-O bond in the wavenumber around 480-500 cm-1, and the result also indicated that the nanofillers interact with the chitosan matrix via hydrogen bonding, which enhanced the physical properties of the nanocomposites. Incorporation of iron oxide nanoparticle varieties into chitosan has led to improvements of certain physical and chemical properties, which make chitosan a promising material for packaging applications.