Enhanced Antibacterial effect of chitosan film using Montmorillonite/CuO nanocomposite

Abstract

Montmorillonite −copper oxide (MMT-CuO) nanocomposites were prepared by a facile and eco-friendly method and introduced into chitosan (Cs) matrix to enhance its optical, mechanical and antibacterial properties. The synthesized composites were characterized using diffuse reflectance spectroscopy (DRS), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and energy dispersive X-ray (EDX) spectroscopy. The antimicrobial activity of MMT-CuO nanocomposites showed more than 99% mortality against two Gram-negative bacterium (E.coli (PTCC 1270), P.aeruginosa (PTCC 1430)) and two Gram-positive bacterium (S.aureus (PTCC1112) B.cereus (PTCC- 1015)). The effect of weight fraction of MMT-CuO nanocomposites (1, 3 and 5% w/w) as antibacterial nanofiller on physical, optical, mechanical, microstructural, and antibacterial properties of chitosan films were evaluated. The obtained data showed that introducing small amount MMT-CuO to chitosan films could enhance the mechanical, antibacterial properties, and decreased both water solubility and UV transition with the lowest effect on the transparency of the films. The incorporation of 3% w/w MMT-CuO-90 nanocomposite into the films increased the tensile strong (TS), and elongation at break (E%) values 58.5% and 52.4%, respectively while reduced the water vapor permeability and oxygen permeability about 55% and 32%, respectively. CSG3MMT-CuO-90 films showed intense antibacterial activity against food borne pathogenic and more effective against S. aureus and B.cereus. than E.coli and P.aeruginosa.