Titania–silver and alumina–silver composite nanoparticles: Novel, versatile synthesis, reaction mechanism and potential antimicrobial application

A facile, reproducible synthesis of titania–silver and alumina–silver composite nanoparticles is reported. Both composite nanoparticles formed via different modes of assembly. Epoxy nanocomposites formulated using these nanoparticles exhibited antimicrobial activity against E. coli and S. epidermidis. [Display omitted] ► Facile, synthesis of titania–silver and alumina–silver composite nanoparticles. ► Oxide surfaces modified using oleic acid as intermediate. ► Titania–silver and alumina–silver nanoparticles form via different modes of assembly. ► Epoxy composites exhibit antimicrobial activity against E. coli and S. epidermidis. Titania–silver (TiO 2–Ag) and alumina–silver (Al 2O 3–Ag) composite nanoparticles were synthesised by a simple, reproducible, wet chemical method under ambient conditions. The surface of the oxides was modified with oleic acid, which acted as an intermediate between the oxide surface and the silver nanoparticles. The resulting composite nanoparticles were thoroughly characterised by XRD, TEM, XPS, FTIR and TGA to elucidate the mode of assembly of Ag nanoparticles on the oxide surfaces. Epoxy nanocomposites were formulated with TiO 2–Ag and Al 2O 3–Ag to examine potential applications for the composite nanoparticles. Preliminary results from disc diffusion assays against Escherichia coli DH5α and Staphylococcus epidermidis NCIMB 12721 suggest that these TiO 2–Ag and Al 2O 3–Ag composite nanoparticles have potential as antimicrobial materials.