| NO SUDS, ONLY SPRAY
London, Feb. 7: It is good news for householders, but bad news for soap manufacturers. A British scientist has found a way of cleaning clothes using nothing but water.
Richard Pashley, a professor of physical chemistry at the Australian National University in Canberra, has discovered that when tiny air 'particles' are removed from water ' a process known as 'degassing' ' the water lifts oily stains from the surface of clothes, allowing soap-free cleaning.
Pashley said the technique was so effective that even the greasiest stains could be removed. 'You can use de-gassed water to clean whatever you have dirtied. We even experimented with Vaseline. We cleaned it off completely. This is a new area of science ' the mixing of oil and water. It could be a cleaning revolution.'
The technique could also satisfy environmentalists, who claim that detergent residues in rinsing water promote algae growth and threaten ecosystems.
The consumer goods companies Unilever and Proctor & Gamble are likely to be less enthusiastic.
Pashley said he had already been approached by a European detergent company, with an offer to fund further research.
Air particles in water 'glue' dirt together by creating a surface tension between them. When these air particles are removed, the glueing effect ceases and the oil disperses in the water as fine droplets. In his experiment, Pashley, whose findings are published in The Journal of Physical Chemistry, de-gassed water by freezing it with liquid nitrogen.
To simplify the process in the future, he intends to develop semipermeable membranes to de-gas water as it passes through.
Such membranes are already used on oil rigs to remove oxygen, which causes rusting, from the water used to cool pipes, but could ultimately be manufactured for household use, he said.
Soap-free cleaning also has potential industrial applications, such as the cleaning of surgical instruments. These are normally cleaned with detergent, but removing the soapy residue can prove difficult. The relatively new field of building nano-scale devices is also vexed by the problems of soapy residue. 'Nanomachines' are so small that the layer of residue often impedes their function.
Bernie Binks, a professor of physical chemistry at the University of Hull, whose work is part-funded by Unilever, said, however, that the cleaning powers of soap powders were more sophisticated than those of water.
'Detergents allow oil and water to mix, as de-gassed water does, but they perform many other roles too. Soap powders contain at least 15 components, all of which do different jobs. Scientists don't know how all of these work, but they know that if they took these components away, they would have a less effective product.'
A spokesman for the UK Cleaning Products Industry Association said the industry was not concerned. 'What customers value is performance ' and we don't think that using water could clean clothes to an acceptable standard,' he added.