Thermal spray copper-based coatings against contamination of thermoplastic surfaces: A systematic review

Abstract

Currently, an extensive effort is ongoing in academia and industry to design cost-effective coatings that can protect the surfaces against microorganisms, by limiting their transmission and growth. Thermal spray can be used to improve the functionality of thermoplastic surfaces by combining an innovative design with the antimicrobial properties of metallic materials. This systematic review deals with copper coatings deposited on thermoplastics by thermal spray techniques. Its aim is to understand the role that surface roughness, material microstructure and surface chemistry plays on the inactivation rate of microorganisms, especially viruses. In addition, a general view of the interaction mechanisms between metallic surface and microorganisms is emphasized. The antimicrobial coatings should be engineered to control the release of metal ions which is directly linked with the lifespan of the microorganism. They must also comply with the ISO 21702:2019 that stipulates suitable methods for antiviral activity measurement on plastics and other non-porous surfaces of antiviral-treated products. The designed coatings should provide long-lasting virus protection and prevent the degradation of the surface. Finally, an outline of the effect of the copper deposition method onto thermoplastic surfaces, coating microstructure, and surface specific oxygen species is presented in correlation with antimicrobial properties.

Keywords

• Thermoplastics
• Thermal spray methods
• Copper
• Antimicrobial coatings
• Surface engineering