Background and Objectives: The aim of this study was to produce and investigate the physical, mechanical and antibacterial properties of low density polyethylene (LDPE) nanocomposite films incorporating Cu⁺² modified via ion exchange reactions clay nanoparticles.

Materials & Methods: Microstructure, physical, mechanical and antibacterial properties of LDPE-Cu modified clay nanoparticles were studied using X-ray florescence (XRF), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM).

Results: Presence and incorporation of Cu⁺² in the interlayer space of clays and its distribution in polymeric matrix were confirmed by the FTIR and XRD tests. Investigating the Cu²⁺ ions incorporation into interlayer space of nanocomposites using the XRD showed a rather uniform distribution of the nanoparticles in polymeric matrix. A coarse and nonhomogenous distribution of nanoparticles in the nanocomposite microstructure compared to that of pure LDPE was shown by scanning electron microscopy (SEM). The results of mechanical tests showed an improved 'tensile strength' and 'elongation at break' properties of Cu²⁺-Cloisite 30B incorporated nanocomposites compared to those of pure LDPE. Incorporating metallic nanoparticles into LDPE matrix promotes polymeric chain-nanoparticles reaction, leading to improved mechanical strength in the resulting films. Microbial results showed antibacterial activity for all the nanocomposite films; however, this effect was pronounced for Cu⁺²-modified Cloisite 30B type films.

Conclusion: Nanocomposites were effective against Escherichia coli and Staphylococcus aureus, and the antibacterial properties were more enhanced against gram-negative bacteria than those for gram-positive ones.

Keywords: Clay, Cu, Film, LDPE, Physical, Mechanical antimicrobial properties