Chemistry matters. Join us to get the news you need.

If you have an ACS member number, please enter it here so we can link this account to your membership. (optional)

ACS values your privacy. By submitting your information, you are gaining access to C&EN and subscribing to our weekly newsletter. We use the information you provide to make your reading experience better, and we will never sell your data to third party members.



Low-cost polyurethane sponge cleans oil spills

With graphite-nanoparticle coating, sponges are chemically selective, magnetic, and reusable

by Mitch Jacoby
June 3, 2020 | APPEARED IN VOLUME 98, ISSUE 22


Credit: Vikas Nandwana/Northwestern
Coated with an inexpensive graphite composite, this sponge selectively absorbs oil and repels water.

The words “sponges” and “cleanup” might evoke dirty dishes and kitchen duty. But to a team of materials scientists, they are the inspiration for a way to remediate aquatic oil spills. Researchers at Northwestern University have developed an inexpensive way to convert ordinary sponges to ones that selectively soak up oil from water. The oil can be recovered simply by squeezing the sponges.

Oil leaking from tankers and pipelines harms marine life and the environment. Existing methods for treating the spills have significant shortcomings. On-site burning, for example, emits pollution and greenhouse gases. Chemical dispersants, which break up the oil into tiny droplets and scatter them throughout the water, can harm wildlife. Other methods don’t discriminate well between oil and water, or they leave the water covered with an oily sheen.

Several research groups have proposed alternatives to these commercial cleanup methods, such as soaking up the oil with sponges coated with silanes, fluorocarbons, or graphene. But these lab-scale studies rely on reagents and procedures that are expensive, toxic, or unscalable.

Credit: Vikas Nandwana and Vinayak P. Dravid/Ind. Eng. Chem. Res./C&EN

Vikas Nandwana, a research associate working with Northwestern’s Vinayak P. Dravid, and coworkers developed a simple dip-coating method to apply a composite film of graphite and iron oxide nanoparticles to polyurethane and other sponges. The coating, which can also be prepared with iron manganese oxide, is made from inexpensive, abundant, and environmentally benign starting materials and is formulated as an aqueous slurry. Applying it to standard polyurethane furniture cushions that are typically landfilled creates a sponge that selectively absorbs a wide variety of oils from oil-water mixtures while excluding water (Ind. Eng. Chem. Res. 2020, 10.1021/acs.iecr.0c01493).

Tests with reference oils and crude-oil samples showed that the coated sponges can absorb up to 30 times their weight in oil and work well across wide-ranging pH values and water salinity. After squeezing to recover the oil, the sponges can be reused dozens of times with little change in uptake capacity. The nanoparticles make the sponges magnetic, so they can be steered to oil spills and later drained of their oily cargo via radio-frequency heating without physical contact.

Debra Shore, commissioner of Chicago’s Metropolitan Water Reclamation District (MWRD), notes that not only do the sponges “have potentially interesting applications in pollution reduction,” they also might be used to recover phosphorus and other nutrients, which she notes, “is a broad concern for wastewater treatment plants.”


Justin Hart, a water-science and policy specialist with MWRD, is encouraged by the study, but says he’d like to see the sponges tested with diluted bitumen from Canadian tar sands, a dangerous and tough-to-remediate form of oil that flows through the Chicago region.

Nandwana says the team is studying other cleanup applications and working to commercialize the sponges.



This article has been sent to the following recipient:

Udeani Franklin (June 10, 2020 6:55 AM)
Exciting development, this innovations lessens the work for emergency workers in spill response at land or sea.Can it be applied in medical devices to extract venomous bites from tissues
Vikas Nandwana (August 15, 2020 3:10 PM)
Thanks for your appreciation and interest. I am the first author of the paper. We do have a startup placed for commercializing this invention. I am curious about the second application you mentioned. Could you please elaborate? In case of venomous bites, is the venom present in tissue is oleophilic and/or hydrophobic? You can directly reach out to me, email is on Northwestern Website.
Jim Parsons (June 13, 2020 6:41 PM)
Liked this article. Sounds like a real money maker for things like oil spills. I suspect that this application is only scratching the surface.
Vikas Nandwana (August 15, 2020 3:11 PM)
Thanks Jim for your appreciation. Yes, we have a startup placed and already got a lot of inquiries from all over the world. We have a series of smart sponges in line.
Diane (August 19, 2020 2:50 PM)
Is there any chance this would be able to be used for the oil spill that happened in Mauritius on 08/6/2020, the consequences of which the tiny island is still reeling from?
Vikas Nandwana (September 6, 2020 4:04 PM)
Yes, we have been approached by several parties regarding this issue and we have been already in conversation with several NGOs to deploy the sponge at the spill site.

Leave A Comment

*Required to comment