The use of nanomaterials, including metallic as active fillers in polymeric nanocomposites for food packaging
has been extensively investigated. Silver nanoparticles (AgNPs), in particular, have been exploited
for technological applications as bactericidal agents. In this paper, AgNPs were incorporated into a
hydroxypropyl methylcellulose (HPMC) matrix for applications as food packaging materials. The average
sizes of the silver nanoparticles were 41 nm and 100 nm, respectively. Mechanical analyses and water
vapor barrier properties of the HPMC/AgNPs nanocomposites were analysed. The best results were
observed for films containing smaller (41 nm) AgNPs. The antibacterial properties of HPMC/AgNPs thin
films were evaluated based on the diameter of inhibition zone in a disk diffusion test against Escherichia
coli (E. coli) and Staphylococcus aureus (S. aureus). The disk diffusion studies revealed a greater bactericidal
effectiveness for nanocomposites films containing 41 nm Ag nanoparticles.