Smart anti-bacterial coatings
Good hygiene practices are necessary to prevent transmission of bacterial infection to vulnerable populations. Personal hygiene such as hand washing or object disinfection constitutes a valid preventative measure, but has proven insufficient to address the problem. The EU-funded AMSCOPPER (Anti-microbial, self-cleaning copper composite coatings applied in metallic objects against infections transmission) project proposed to develop specialised coatings for metallic objects with self-cleaning and anti-microbial activity. The coatings combined a copper alloy matrix that functioned as an anti-bacterial agent, with chemically modified titanium oxide nanoparticles. The latter presented with enhanced photocatalytic activity under visible light irradiation and served as a self-cleaning agent utilised for sterilisation. The rationale was to apply these innovative coatings in various metallic objects such as handles, door knobs or bedrails, and reduce the risk of viral or bacterial infection by more than 80 %. Significant efforts went towards the development of methods for the production of the alloy mix and the nanoparticles as well as the composite coating. In addition, various plating approaches were pursued for the delivery of suitable formulation. Researchers incorporated the titanium oxide nanoparticles in the copper-based matrix by the pulse plating electrodeposition method. The resultant coating exceeded expectations and prevented infection by communicable diseases by a factor of 100 %. Validation tests using the pathogenic bacteria Staphylococcus aureus and Pseudomonas aeruginosa showed the complete elimination of bacterial colonies on the surface of the coated samples. Apart from medical usage, the AMSCOPPER photocatalytic materials are expected to find application in the construction of air cleaning devices, components with anti-bacterial properties and various household appliances. Photocatalytic products already possess a big share of the market and could potentially be used in hospitals, hotels, public transportation and schools. Importantly, these materials have the power to reduce hospital-acquired infections as well as the spread of epidemics.
Keywords
Coating, AMSCOPPER, copper alloy, titanium oxide nanoparticles, photocatalytic activity