New smart coating could make oil-spill cleanup faster and more efficient

May 14, 2014
New smart coating could make oil-spill cleanup faster and more efficient

In the wake of recent off-shore oil spills, and with the growing popularity of "fracking"—in which water is used to release oil and gas from shale—there's a need for easy, quick ways to separate oil and water. Now, scientists have developed coatings that can do just that. Their report on the materials, which also could stop surfaces from getting foggy and dirty, appears in ACS Applied Materials & Interfaces.

J.P.S. Badyal and colleagues point out that 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 sop up a lot of . Extra steps and equipment also are needed to remove the oil from the absorbent, which is difficult to do on a ship. Recently, researchers have turned their attention to new smart materials called "oleophobic-hydrophilic" coatings that instead let the water through and repel the oil. However, the films that have been reported so far take several minutes to do the separation, are complicated to make or aren't very good at repelling oil. So, Badyal's team set out to improve these materials.

They developed oleophobic-hydrophilic coatings that they applied to pieces of metal mesh, just like what's used in screen doors. When they poured an oil-water mixture onto it, the water dripped through into the container below, while the oil remained perched atop the mesh . Then, they simply tilted the mesh so the oil went into another container. The separation was instantaneous and more efficient than existing films, and it only took one step to make the . The team also demonstrated that it could serve as an anti-fogging and self-cleaning film.

Explore further: Purdue membrane technology could help cleanup oil spills

More information: "Ultrafast Oleophobic-Hydrophilic Switching Surfaces for Antifogging, Self-Cleaning, and Oil-Water Separation" ACS Appl. Mater. Interfaces, Article ASAP. DOI: 10.1021/am500882y

Smooth copolymer–fluorosurfactant complex film surfaces are found to exhibit fast oleophobic–hydrophilic switching behavior. Equilibration of the high oil contact angle (hexadecane = 80°) and low water contact angle (<10°) values occurs within 10 s of droplet impact. These optically transparent surfaces display excellent antifogging and self-cleaning properties. The magnitude of oleophobic–hydrophilic switching can be further enhanced by the incorporation of surface roughness to an extent that it reaches a sufficiently high level (water contact angle <10° and hexadecane contact angle >110°), which, when combined with the inherent ultrafast switching speed, yields oil–water mixture separation efficiencies exceeding 98%.

Related Stories

Oil spill cleanup: Smart filter can strain oil out of water

August 29, 2012

(—A smart filter with a shape-shifting surface can separate oil and water using gravity alone, an advancement that could be useful in cleaning up environmental oil spills, among other applications, say its University ...

A complete solution for oil-spill cleanup

October 3, 2012

Scientists are describing what may be a "complete solution" to cleaning up oil spills—a superabsorbent material that sops up 40 times its own weight in oil and then can be shipped to an oil refinery and processed to recover ...

Nanocellulose sponges to combat oil pollution

May 6, 2014

A new, absorbable material from Empa wood research could be of assistance in future oil spill accidents: a chemically modified nanocellulose sponge. The light material absorbs the oil spill, remains floating on the surface ...

Recommended for you

The universe's most miraculous molecule

October 9, 2015

It's the second most abundant substance in the universe. It dissolves more materials than any other solvent. It stores incredible amounts of energy. Life as we know it would not be possible without it. And although it covers ...

New method facilitates research on fuel cell catalysts

October 8, 2015

While the cleaning of car exhausts is among the best known applications of catalytic processes, it is only the tip of the iceberg. Practically the entire chemical industry relies on catalytic reactions. Therefore, catalyst ...

Trio wins Nobel Prize for mapping how cells fix DNA damage

October 7, 2015

Tomas Lindahl was eating his breakfast in England on Wednesday when the call came—ostensibly, from the Royal Swedish Academy of Sciences. It occurred to him that this might be a hoax, but then the caller started speaking ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.