When we reach the end of a ketchup bottle, there’s always a little left, stuck to the sides. A Colorado State University lab offers a fix: a nontoxic, nonstick coating that lets loose every last drop. Materials scientists led by Arun Kota, assistant professor in the Department of Mechanical Engineering and the School of Biomedical Engineering, have created a “superhydrophobic” coating that easily slicks away viscous liquids like syrup, honey and ketchup. They detail the engineering feat in Applied Materials and Interfaces, published by the American Chemical Society.
Superhydrophobic coatings are not new, but they’re typically fabricated with fluorocarbons. These materials, while generally safe in low doses, are labeled as “emerging contaminants” because of their potential decomposition into perfluorooctanoic acid, a known human toxin, according to the paper. The FDA recently banned three perfluorinated compounds (PFCs). “Companies are very specific about toxicity levels in these products, which is why they don’t get into the market very easily,” Kota said of hydrophobic coatings.
One of Kota’s students came up with the idea of trying to make a simple, nontoxic, extremely liquid-repellant coating out of beeswax. Although their coating allows a wide range of aqueous liquids to bounce and roll away, there is room for improvement in the mechanical durability of their coatings, which currently can’t withstand abrasive environments, according to the paper. Read full story here: http://source.colostate.edu/waste-not-edible-wax-coating-slicks-liquids-with-ease/.