Investigation of synergistic effect of nano sized Ag/TiO2 particles on antibacterial, physical and mechanical properties of UV-curable clear coatings by experimental design

• Synergistic effect of nano TiO2 and nano silver on UV curable clear coating by experimental design.
• Evaluation of antibacterial properties on gram-negative bacteria (Escherichia coli).
• Evaluation of physical–mechanical properties.
• Surface morphology of UV curable clear coating containing nano particles were confirmed using SEM and AFM.

The synergistic effect of nano titanium dioxide (10 and 30 nm) and nano silver (10 nm) as antibacterial agents were investigated on UV curable clear coating. Antibacterial and physical–mechanical properties of coating were optimized using experimental design in response surface method. Twenty different samples of nano Ag and nano TiO2 were prepared in this method. Antibacterial properties on Gram-negative bacteria (Escherichia coli) were investigated. The results revealed that using equal amounts of two sizes of nano TiO2 promote the antibacterial activity of nano Ag. So, the coating shows strong activity against E. coli. Physical–mechanical properties such as surface hardness, abrasion resistance, scratch resistance and gloss of the coating were evaluated. The results depicted appropriate physical–mechanical properties. Also, scanning electron microscope (SEM), atomic force microscope (AFM) and Fourier transform infrared (FT-IR) spectroscopy were used to study the effect of nano particles on coating properties.