Physical, mechanical and antimicrobial properties of gelatin based active nanocomposite films containing AgNPs and nanoclay

Antimicrobial bionanocomposite films were prepared with gelatin and silver nanoparticles (AgNPs) and organoclay (Cloisite 30B) and their film properties were characterized. Transparency of nanocomposite films decreased, but UV barrier was greatly improved, which was more pronounced with AgNPs-included films. Hydrophobicity and water vapor barrier properties were also improved after formation of nanocomposite. The incorporation of AgNPs or clay into the gelatin film could affect the mechanical properties of films. Tensile strength (TS) increased significantly in the gelatin/clay and gelatin/AgNPs/clay films while decreased in the elongation at break (EB). EDX and XRD analysis were performed to examine the presence of elemental silver and crystallinity of AgNPs in the films. Microscopic surface structure analysis showed homogenous compact surface structure of the composite films. Interaction between the polymer and nanoparticles was tested by FT-IR analysis. The nanocomposite films, especially for gelatin/AgNPs/clay, exhibited strong antibacterial activity against food borne pathogens. These results suggested that the use of gelatin based nanocomposite films will help to compete and eliminate the bacterial invaders and to improve the shelf life and quality of food.