Although we’ve seen a lot of materials designed to remove oil spills from the water, many of them are disposable and end up in landfill,media New Atlas reported. Now, however, scientists have created a reusable oil-absorbing sponge. The sponge was developed by a team led by Northwestern University in Illinois, and the actual sponge itself resembles other sponges. The secret is to coat it with a thin coating, known as OHM (pro-oil hydrophobic magnetism) nanocomposite slurry, which is made up of magnetic nanostructures.
This matrix is oil-friendly and hydrophobic, which means it attracts oil and repels water. As a result, sponges can absorb more than 30 times the amount of oil that bubbles exceed their weight without the need for water. The oil can then be squeezed out for safe treatment or reuse, allowing the sponge to absorb more oil at any time. In addition, the magnetic ity of the coating allows the sponge to move over the water through an external magnetic field. This means that large shipborne electromagnets can be used to deploy, recycle and “guide” sponges at oil spill sites.
What’s more, when an external radio signal is applied to the sponge, it is absorbed by a magnetic nanostructure that heats it up to about 60 oC (140 oF). This, in turn, helps the sponge release its oil, when squeezing alone is not enough.
In the future, scientists say, the technology could selectively absorb and release other water pollutants, such as dissolved nutrients from agricultural runoff or sewage. “Our sponges work effectively under different extreme aquatic conditions, with different pH and salinity levels in these aquatic environments,” said lead scientist Professor Vinayak Dravid of Northwestern University. “We believe we can solve the gigabit ton problem with nanoscale solutions. “
A paper on the study was recently published in the journal Industrial Engineering and Chemical Research.