doi:10.1038/nindia.2015.50 Published online 17 April 2015
Researchers have synthesized multiwalled carbon nanotubes from ghee derived from cow’s milk. These nanotubes can scavenge free radicals, which suggests they could be used as antioxidants1.
While previous studies have investigated the use of natural materials such as camphor, neem and eucalyptus oil to produce carbon nanotubes, no studies to date have explored the potential of animal-derived fats such as ghee.
The researchers employed catalyst-free chemical vapour deposition to convert ghee into a black powder of multiwalled carbon nanotubes. Using sophisticated imaging techniques, the scientists found that the nanotubes formed micrometre-long intertwined bundles containing rolled-up graphene sheets.
The scientists then probed the antioxidant activities of the nanotubes by using 2,2-diphenyl-1-picrylhydrazyl (DPPH), a free radical widely used for testing the antioxidant properties of compounds. They found that the nanotubes removed DPPH by reducing it by accepting hydrogen ions or electrons from DPPH molecules. When the researchers added 4 milligrams of nanotubes to a solution containing DPPH, the nanotubes reduced 70% of DPPH in an hour. During the reduction process, the colour of the DPPH solution changed from purple to yellow.
The researchers say that ghee is an inexpensive renewable bioresource and offers a green method for producing antioxidant carbon nanotubes.
1. Nath, A. et al. Catalyst free low temperature synthesis and antioxidant activity of multiwalled carbon nanotubes accessed from ghee, clarified butter of cow’s milk. Mater. Lett. 152, 36–39 (2015)