Nano-coated mesh could help clean up oil spills, cheaply

COLUMBUS, Ohio, April 15 (UPI) -- Environmental cleanups could become a lot easier, cheaper and more effective if researchers at Ohio State University can find a way to scale their newly developed stainless steel mesh technology.

Designing steel mesh doesn't sound all that impressive, but this isn't an ordinary sheet of metal with holes in it. This mesh can separate water and oil.

Pour a solution of oil and water through the mesh and the magic can be witnessed firsthand. The oil collects on top, while the water filters through and collects in a beaker below.

"If you scale this up, you could potentially catch an oil spill with a net," Bharat Bhushan, a professor of mechanical engineering at Ohio State, said in a press release.

By layering a series of materials atop the mesh -- including silica, surfactant and polymer -- researchers created a nanostructure that binds to oil but not water. Tiny pieces of glass, or silica, were sprayed atop the mesh to mimic the texture of lotus leaves, which have been proven to repel oil and attract water. Surfactant, a compound that lowers surface tension, was then embedded in a polymer layer and laid atop the mesh.

Together, the layers create a half-smooth, half-rough surface that performs the opposite function of the lotus leaf, attracting oil and repelling water. Bhushan says his latest work is the product of ten years of testing differing combinations of materials.

"We've studied so many natural surfaces, from leaves to butterfly wings and shark skin, to understand how nature solves certain problems," Bhushan said. "Now we want to go beyond what nature does, in order to solve new problems."

"Nature reaches a limit of what it can do," added research partner Philip Brown. "To repel synthetic materials like oils, we need to bring in another level of chemistry that nature doesn't have access to."

Bhushan is working on variations of the new technology for use on automotive glass like car mirrors, and also as an additive for liquid lubricants.

The research is detailed in two new papers published in Nature Scientific Reports.