[nanoPost] Low-cost, 'green' antimicrobial paint

Research Centre USA

Researchers have developed a low-cost, environmentally friendly technique for embedding antimicrobial silver nanoparticles into vegetable oil-based paints.

The research could provide homes and workplaces a new defense against germs via the application of a fresh coat of paint.

Silver's antibacterial properties have been known for thousands of years, and silver nanoparticles offer superior antibacterial activity while being non-toxic. However, coatings containing antimicrobial agents have failed commercially in the past due to their complex, multi-step preparation methods and high cost of production.

The research team developed a "green chemistry" approach to synthesize metal nanoparticles in common household paints in situ without using hazardous reagents and solvents.

The extensively worked on poly-unsaturated hydrocarbon chain-containing polymers to devise a novel approach to nanoparticle formation.

Polyunsaturated hydrocarbons undergo auto-oxidation-induced cross-linking, which is similar to lipid peroxidation, the process by which fatty acids are oxidized in biological systems. During this process a variety of chemically active species called 'free radicals' are generated. These were used by the group as a tool to prepare metal nanoparticles in situ in the oil medium.

The nanoparticle embedded coating can be applied like traditional paints to such surfaces as metal, wood, polymers, glass, and ceramics. The metal nanoparticles show characteristic color but avoid the use of short shelf-life organic pigment paints.

In addition, these coatings exhibited efficient antibacterial activity toward Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The antibacterial property is important for hospitals and other public buildings that are prone to bacterial growth, a main cause of infection and disease.