Imagine a sponge that will only suck up oil. Helpful for your washing up perhaps, but maybe also useful for mopping up bigger oil spills. Japanese researchers at the University of Kyoto have developed a material that looks like a marshmallow, but can suck up oil floating on water and then be squeezed out and reused.
To make the super specific sponge the team use long polymers with lots of small side chains that stick out. They make those up into a jelly and then dry it out to leave a squidgy material with air holes and pores where the water used to be, just like a sponge. The porous structure means the material is very light, so it floats on water, and means the marshmallow-like material has a large surface area for soaking up oil.
We all know oil and water don't mix, but there are other materials that don't like water but like oil. That's why, when the sponge is dropped onto oil and water, it only soaks up the oil, leaving behind clean water. Cleaning up large oil spills might be a way off yet, as the sponge can only be made in small quantities at the moment, but for garages, small spills and cleaning up chemistry labs, this little material might have a big future...