Nanocomposite films containing organoclay nanoparticles as an antimicrobial (active) packaging for potential food application

Abstract

Polyethylene nanocomposite films containing combinations of organoclay (OC) nanoparticles were prepared using extrusion molding method. The physical (X-ray diffraction [XRD] and scanning electron microscopy [SEM]), mechanical (tensile strength [TS] and elongation at break [E]) and antibacterial properties of the films against gram positive and gram negative bacteria were evaluated. XRD results showed an increase in basal reflection and intercalated-exfoliated structure prepared. SEM images revealed that Cloisite 20A had better compatibility with the polyethylene matrix in such way that it distributed homogenously in the matrix. Incorporating nanoparticles into polyethylene matrix significantly improved mechanical properties of the films in terms of TS and E parameters. Among used organoclays, Cloisite 30B, and Cloisite 15A had the most and the least antibacterial effect, respectively. A combination of three studied OCs revealed a more pronounced antibacterial effect than that of single or binary mode. Furthermore, its effect on gram negative Escherichia coli, was more pronounced than gram positive Staphylococcus aureus. Practical applications Nanocomposite films studied in this research provide bacteriostatic activities with improving mechanical properties. The main feature of this study was to use a mixture of nanoparticles for an enhanced antibacterial effect and, therefore, to reduce metallic nanoparticles' concentration in the obtained active films. Thus, such packaging material is suggested for potential use as an optimal choice for antimicrobial food packaging applications.