Booms made of porous materials called sorbents can be used to soak up spills from oil tankers, but they also absorb water – which drastically limits the amount of oil they can mop up. Now the Lawrence Livermore National Laboratory in California has increased oil absorption a hundredfold by making a porous fibreglass-based sorbent that repels water (US 2004/0173536).
The secret is to trap fluorine in the fibres’ weave: the fluorine repels the water, but allows oil in. In a test, sheets of fibreglass dipped into a slurry of silica and a fluorine-containing chemical were dried and cut into discs.…
