Clean ceramics

the smooth, white surface of your bathroom sink hides the fact that the process of making it is a notoriously dirty and polluting one. Aluminium oxide ceramics which find applications in a range of products (from sinks to lasers) are made by dissolving aluminium oxide powder in organic solvents and using many other chemicals in the process.

Given the widespread use of these ceramics, millions of litres of these hazardous chemicals need to be disposed off safely every year. This is expensive and also potentially dangerous. Now a team of chemists from Rice University in Houston, us, have demonstrated a much cleaner way of making aluminium oxide ceramics, which does away with hazardous solvents. Andrew Barron and his colleagues are reportedly using water to make ceramics ( Science , Vol 272, No 5259).

The conventional method starts by using aluminium oxide powder. Since this does not dissolve in water, organic solvents are used to make a solution to which other organic binders are added for cohesion. This slurry is then poured into a mould and after the material has set, is fired to high temperatures (upto 1000