Research Team Develops Low-cost Antimicrobial Paint
Researchers
at The City College of New York and Rice University have developed a
low-cost, environmentally friendly technique for embedding
antimicrobial silver nanoparticles into vegetable oil-based paints. The
method, to be reported in the March issue (online January 20) of Nature Materials, could give homes and workplaces a new defense against germs by applying a fresh coat of paint.
Silver nanoparticles offer superior antibacterial activity while
being non-toxic. Coatings containing antimicrobial agents have failed
commercially in the past, however, due to their complex, multi-step
preparation methods and high cost of production.
The research team synthesized metal nanoparticles in common household paints in situ
without using hazardous reagents and solvents. “We extensively worked
on poly-unsaturated hydrocarbon chain containing polymers/oils to
devise a novel approach to nanoparticle formation,” said George John,
PhD., professor of chemistry at City College and lead author of the
article.
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
nano-particles in situ in the oil medium.
“The simplicity of the process and economics should allow us to
commercialize these paints as a versatile coating material for health
and environmental applications” said Pulickel M. Ajayan, PhD.,
professor of mechanical engineering and materials science at
Houston-based Rice University and co-author.
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.
The 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.