Controlled release active antimicrobial corrosion coatings with Ag/SiO2 core–shell nanoparticles

Ag/SiO2 core–shell nanoparticles within the size of 60 nm were applied in marine antimicrobial corrosion coatings. TEM and XRD results indicated silver was completely covered by silica and its crystal form was not affected after coated by silica. Effects of Ag/SiO2 nanoparticles in the microbial corrosion of acrylic-coated steel were studied by means of electrochemical noise analysis (ENA). ENA results reveal that 1 wt% Ag/SiO2 nanoparticles exhibit better antimicrobial corrosion activity than that of conventional 40 wt% Cu2O biocides. Inductively coupled plasmaoptical emission spectrometry (ICP) showed very lower amount of Ag ions leaching from the matrix resin, whereas a higher amount of copper ion leaching from the resin in the same period. It was concluded Ag/SiO2 core–shell nanoparticles could enhance long-term corrosion protection in comparison with the copper biocides. This composite has a strong potential use in environmentally friendly antimicrobial coatings.