Influence of various surface treated silica nanoparticles on the electrochemical properties of SiO2/polyurethane nanocoatings

Various organosilane-treated SiO2 nanoparticles were dispersed in a 2-pack polyurethane coating. The influence of surface modification and silica content on the electrochemical behaviour of the resultant nanocoatings was investigated. Electrochemical impedance spectroscopy (EIS) and open circuit potential (OCP) variations were examined. The surface chemistry of nanoparticles and its effect on the resultant nanocoating morphology were also studied utilising FTIR, and TEM analyses. The results reveal that the presence of more hydrophobic groups and longer-lengthed hydrophobic chains on the surface of nanoparticles, greatly improves the interfacial interactions at the polymer/filler interfaces resulting in a better corrosion performance.

► Organosilane-treated SiO2 nanoparticles considerably improve corrosion performance. ► Type of surface treatment and silica content affect the electrochemical behaviour. ► Octylsilane-modified SiO2 nanoparticles exhibit the best corrosion resistance. ► Morphology of nanocoatings is impressed by type of surface modification.