Tea, Wine, and a Cleaner Environment
EPA scientists have developed innovative ways to produce nanoparticles using green chemistry rather than toxic chemicals.
Research has shown powerful health benefits of antioxidant chemicals found in tea, wine, and red grape pomace (a major byproduct of wine making). EPA scientists are now learning how to tap antioxidants benefits not for health, but for a cleaner environment.
EPA scientist Dr. Rajender S. Varma and his team have developed innovative ways to produce nanoparticles using green chemistry rather than toxic chemicals. Nanoparticles are so small that they must be measured in nanometers, which are 100,000 times thinner than a human hair. Nanoparticles are the miniscule building blocks for new commercial products and materials in the emerging field of nanotechnology.
One promising application of this environmentally friendly research is a technology for cleaning up pollution that uses nano-scale zero valent iron (NZVI) to promote the breakdown of contaminants in ground water.
Dr. Varma and his team began by making NZVI from tea. They steeped tea in hot water, and then mixed it with ferric nitrate, an iron compound. This process did not use any hazardous chemicals, such as sodium borohydride, which is commonly used to make nanoparticles. Not only did the process eliminate the use of hazardous chemicals, the nanoparticles made with tea showed no significant signs of toxicity when applied to human skin cells in a petri dish.
The researchers next used wine to make nanoparticles. They tested white wine and red wine, finding superior results with red wine. They reported that high-quality nanocrystals of gold, silver, palladium, and platinum were easily produced. They went even further, testing red grape pomace, and found it very effective.
Dr. Varma and his team are being recognized throughout the scientific community for their innovative work. For example, their paper, “In vitro biocompatibility of nanoscale zerovalent iron particles (NZVI) synthesized using tea polyphenols,” in Green Chemistry is one of the journal’s “hot articles” because it is so highly viewed and cited. (Green Chem., 2010, (12) 114–122, http://www.rsc.org/greenchem .) This is exactly the kind of innovative research that is needed if we are to move toward a more sustainable society.
Mallikarjuna N. Nadagouda and Rajender S. Varma “Green synthesis of silver and palladium nanoparticles at room temperature using coffee and tea extract.” Green Chem. 2008 (10) 859–862.
Babita Baruwati and Rajender S Varma. “High Value Products from Waste: Grape Pomace Extract—A Three-in-One Package for the Synthesis of Metal Nanoparticles.” ChemSusChem. 2009 (2) 1041–1044.More information on EPA’s nanotechnology research: http://www.epa.gov/nanoscience.