Everyone knows oil and water don’t mix.
Yet separating oil from water is a notoriously difficult task – as various major oil spills have proven.
The trick comes down to removing the oil without taking gallons of water with it, too. You can imagine how difficult this was during the Deepwater Horizon oil spill, when 210 million gallons of oil gushed into the Gulf of Mexico.
Oil spill cleanup crews often use absorbents – like clays, straw, and wool – to sop up oil. But these materials aren’t very efficient because they also absorb a lot of water.
Plus, this method requires extra steps and more equipment to remove the oil from the absorbent!
But a brilliant new filtration technology is tackling the problem in a new extraordinary way…
Bring on the Nano-Filter!
At Ohio State University, Bharat Bhushan, Eminent Scholar and Professor of Mechanical Engineering, and Philip Brown, a postdoctoral researcher, have created a unique oil filtration technique.
Using state-of-the-art nanotechnology and existing structures found in nature, they’ve invented a new way to filter oil from water.
Specifically, the oleophobic-hydrophilic coating repels oil, but allows water to pass through it.
The coating consists of two parts…
- A fine dusting of silica nanoparticles, which create a bumpy surface.
- A polymer, which is embedded with molecules of surfactant – the same chemical that gives soap and detergent its cleaning ability.
When the coating is applied to a piece of mesh fabric, the water filters through, but the oil is caught.
Take a look at it in action…
Two other bonuses: First, the coating is only a few hundred nanometers thick, making it mostly undetectable.
And the silica, polymer, and surfactant are all non-toxic – and relatively inexpensive.
Indeed, Brown estimates that a large mesh net could be created for less than $1 per square foot.
Needless to say, a net made from this coating could prove invaluable when it comes to cleaning up large oil spills.
Bhushan and Brown say it should be relatively simple to scale up the technology, so it can be used in real-world applications.
It could also have revolutionary applications in fracking, which uses water to release oil and gas from shale.
Taking a Page From Mother Nature
The scientists’ work is partially inspired by the structure of the lotus leaf, which does the opposite of the coating – it absorbs oil and repels water.
They then created the coating by using the same materials and processes that they believe nature uses to create those surfaces. But they improved on them by using more advanced materials that could stand up to commercial applications.
“We’ve studied so many natural surfaces – from leaves to butterfly wings and shark skin – to understand how nature solves certain problems,” Bhushan says. “Now we want to go beyond what nature does, in order to solve new problems.”