NANO-SPONGES TO THE RESCUE!
Oh no! I’ve spilled my wine! Be a dear and pass me that carbon nanotube. I’ll admit, it’s not the first thing you think of when it comes to mopping up spills, but tiny tubes made of a sheet one carbon atom thick may soon be the answer to a whole host of cleaning jobs. As the name suggests, carbon nanotubes (CNTs) are small… really small. They’re ‘nanoscopic’ to be precise! Since their discovery in the 1960s, CNTs have adopted a variety of roles – from flat screen TVs and solar panels to carbon fibre bike frames, and even nerve regeneration therapies. CNTs have taken the world of science and industry by storm, and now they promise to help the environment by cleaning up pollution. Is there nothing these little guys won’t do? Clever Italian chaps at the University of Roma have led the way in making this new type of CNT supersponge by changing the way CNTs are normally made. To the complicated manufacturing process, they have added a key new ingredient – sulphur – which has let them synthesise longer tubes than before, fashioning
them into a porous sponge-like structure. In tests, these 2×2cm mini-sponges were able to selectively absorb up to 3.5 times more toxic substances from water than all previous efforts. They were also able to hold an amount of vegetable oil up to 150 times their initial weight – meaning a small 7 gram sponge could easily soak up your one litre bottle of olive oil. Now that’s got to come in handy during any kitchen-based fiasco! But the real applications are to environmental clean-up initiatives. After, let’s say, an oil spill, these new CNT sponges could be released into the water, selectively grabbing all the nasty toxins. “OK,” I hear you sneer, “but then what, smart guy? You’ve just replaced free-floating toxins with toxinfilled sponges. Idiot!” That’s true (and a little harsh). However, the important thing is that these CNT sponges contain iron… iron is magnetic… magnets can be used to pull stuff towards you… see where I’m going with this? After sending out the CNT troops, they can be retrieved far more easily than other water-cleaning options available by using good old-fashioned magnets. Then, like any sponge, they can simply be squeezed out and used again. Perfect. The next step is to figure out a way to produce these CNT sponges on a commercial scale. (If a 550,000-ton oil tanker bites the dust, you’re going to need a lot of sponges.) The other thing to be absolutely sure of is that the sponges themselves aren’t toxic to any wildlife. All things being well, we should soon have a new tool in the fight against dirty water, and, more importantly to you and me, an effective way to get red wine out of the carpet.
A three-dimensional carbon nanotube network for water treatment
BELOW: A scanning electron micrograph of carbon