Effect of cold spray conditions and coating post treatment on antiviral performance of copper-based coatings against coronaviruses

Application of high performance antimicrobial coatings on high touch components (e.g. door handles, stair railings, grab bars) in public spaces, such as healthcare facilities, mass transit, commercial and residential buildings or schools, has the potential to drastically reduce the burden of performing frequent disinfection protocols, especially those put in place during the COVID-19 pandemic, thus lowering transmission probability while reducing operating costs.

We have previously demonstrated that an inactivation of 99.9% of VSV-G pseudoviruses, hCoV 229E and SARS-CoV-2 (Delta variant) is obtained in less than 20 minutes on polished cold spray copper coatings, among the highest inactivation kinetics of these viruses reported so far.

In this presentation we report on the effect of cold spray conditions and surface post-treatment on coating characteristics and its correlation to virus inactivation performance. Coatings with different levels of particle deformation and microstructural characteristics were produced. Post-cold spray treatments yielding different surface states were performed. Coatings were characterized by Scanning Electron Microscopy, Electron Back-Scattered Diffraction, X-Ray Diffraction, X-Ray Photoelectron Spectroscopy and Vickers micro-hardness. Copper ion release during exposition to the cell culture medium was measured with inductively coupled plasma. Correlations between coating characteristics and inactivation rates of coronaviruses were established and will be discussed.