“Why not soak up an oil spill with a giant sponge?” Sure, maybe that’s something a third-grader would ask. But it’s something Northwestern engineers decided to make.
The key problem, when you think about it, is that something that soaks up oil will quickly get filled with seawater. So they made a sponge that repels water and only soaks up oil.
The OHM [oleophilic hydrophobic magnetic — since you asked] sponge consistently absorbed up to 30 times its weight* in oil, leaving the water behind. To mimic natural waves, researchers put the OHM sponge on a shaker submerged in water. Even after vigorous shaking, the sponge release less than 1% of its absorbed oil back into the water.
Now it’s just a matter of scaling up the process to a sponge the size of a city block. Which, you have to admit, would be pretty cool to see.