Physical,mechanical, and antibacterial characteristics of bio-nanocomposite films loaded with Ag-modified SiO2 and TiO2 nanoparticles |
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Authors: | Hamed Hajizadeh Seyed Jamaleddin Peighambardoust Seyed Hadi Peighambardoust Donatella Peressini |
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Affiliation: | 1. Faculty of Chemical and Petroleum Engineering, Univ. of Tabriz, Tabriz, 51666-16471 Iran;2. Dept. of Food Science, College of Agric., Univ. of Tabriz, Tabriz, 51666-16471, I.R. Iran;3. Dept. of Agriculture, Food, Environmental and Animal Sciences, Univ. of Udine, via Sondrio 2/A, 33100 Udine, Italy |
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Abstract: | In this study, starch-based films incorporating metal oxide (MO2) nanoparticles (NPs) of TiO2 and SiO2 (at a concentration of 1 to 4 wt. %) were produced by solution casting method. In order to exhibit antimicrobial properties, MO2 NPs were modified by synthesizing silver (Ag) ions over the NPs using cationic adsorption method. Ag ions were then reduced to metallic Ag by sodium borohydride solution. Scanning electron microscopy showed a smooth surface for the pure starch film. Incorporating MO2@Ag NPs in the films increased surface roughness with agglomerated NPs within starch matrix. Energy dispersive X-ray analysis exhibited a uniform dispersion of Ag-loaded MO2 NPs, which increases surface contact between these NPs and the biopolymer matrix leading to improved physical and mechanical properties of the resulting films. With increasing in the NPs concentrations, the tensile strength and elongation at break % of the films increased and decreased, respectively. Incorporating MO2@Ag NPs into starch matrix decreased solubility in water and water vapor permeability of the obtained films, and significantly inhibited the growth of Escherichia coli and Staphylococcus aureus. The most antibacterial effect was obtained for the films containing higher weight concentrations of Ag-loaded SiO2-NPs. |
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Keywords: | Ag antibacterial properties bio-nanocomposite films food packaging SiO2 starch surface modification TiO2 |
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