New Reusable Sponge can Absorb and Remove Oil Spills

We’ve seen tons of materials designed to remove oil spills from water in the past. Unfortunately, many of them are single-use, and they usually end up in landfills.

Now, a team of scientists from Northwestern University has created a new reusable oil-absorbing sponge. In other words, the invention can remove oil from water over and over again.

The sponge itself is not exceptional. In fact, it’s like any other sponge you’ve ever seen. The magic comes from a thin coating called OHM (oleophilic hydrophobic magnetic) nanocomposite slurry.

The coating consists of magnetic nanostructures on a carbon-based substrate. Meanwhile, the substrate is both hydrophobic and oleophilic — repels water and attracts oil, respectively.

As a result, the sponge can soak up as much as 30 times its weight in oil without attracting a drop of water. After that, we can squeeze the oil out for safe disposal or reuse while the sponge remains intact and ready to take more oil.

There’s more!

Using Ship-Mounted Electromagnet to Steer the Reusable Sponge

Thanks to the coating’s magnetic aspect, the sponge’s movement can be controlled on a water surface using an external magnetic field. For example, a sizeable ship-mounted electromagnet can do the trick.

Also, applying an external radio to the sponge makes the magnetic nanostructures absorb it.

As such, the sponge heats up to about 60 ºC, which forces the sponge to release its oil payload. The ability is particularly useful when squeezing isn’t enough.

Speaking about the project, lead scientist and professor at Northwestern University, Vinayak Dravid said:

“Our sponge works effectively in diverse and extreme aquatic conditions that have different pH and salinity levels. We believe we can address a giga-ton problem with a nanoscale solution.”

At the moment, the researchers have designed the sponge to soak up spilled oil only.

However, over time, they can adapt the technology to soak up other waterborne pollutants selectively. These include dissolved nutrients from agricultural runoff, as well as sewage.

The researchers published their paper in the journal Industrial Engineering and Chemical Research.