Nano silica-carbon-silver ternary hybrid induced antimicrobial composite films for food packaging application

In this work, Ag assisted biobased silica-carbon nanoparticles (SCAg-NPs) were incorporated into a viscous biopolymer solution to fabricate antimicrobial thin films using 3D printing technique. The Ag NPs were prepared in situ from AgNO3 through one-step ball milling in the presence of silica-carbon hybrid obtained from pyrolysis of rice husk. The nanostructure of the SCAg-NPs was determined by XRD and TEM. These as-synthesized particles were also characterized by XPS analysis. The printed films were characterized by XRD, FE-SEM, Raman microanalysis, TGA, DSC and tensile testing to investigate the influence of nanoparticles on the thermal and mechanical properties on the films. Antimicrobial testing was carried out on the films to assess the inhibitory effect of SCAg NPs on Salmonella Enteritidis inoculum. XRD, XPS and Raman microanalysis confirmed the incorporation of Ag particles into SCNPs, while FE-SEM size measurement of the SCAg NPs ranged between 10-100 nm in diameter. Thermal analysis revealed that the inclusion of SCAg NPs led to improvement in the thermal stability of the fabricated nanocomposites films. Tensile test was carried out to determine the influence of SCAg NPs on mechanical properties of the films and found moderate increase in the strength of the polymer film.