Researchers at Melbourne University have found that a specially engineered steel surface allows liquids to boil without bubbling — a development that could lead to safer industrial processes.
‘This would be advantageous for use in industrial situations such as nuclear power plants, where vapour explosions are best avoided, or where gentle heating is desirable,’ said Prof Derek Chan from the university’s Department of Mathematics and Statistics.
The study suggests that the new surface could also be applied to other situations that involve the transfer of heat, such as reducing fogging and preventing ice or frost formation on windows.
‘Our results show the potential of using this textured surface to control heating and cooling events that affect the formation of frost on windows and ice on the control surfaces of aircraft or even refrigeration units,’ Chan said in a statement.
The international study, published in Nature, was carried out in collaboration with Dr Neelesh Patankar from Northwestern University in the US and Dr Ivan Vakarelski and his team at the King Abdullah University of Science and Technology in Saudi Arabia where the experimental studies were carried out.
The research found that a textured, highly water-repellent steel surface controls the boiling process of a liquid and stops it from bubbling up the sides of a container and boiling over.
This is achieved by using a textured surface structure to control the stability of the vapour layer, namely the layer of steam that forms on a surface when water is boiled.
‘In most smooth surfaces, heat transfer from the surface to the liquid is prevented by the low thermal conductivity of the vapour layer,’ said Chan.
‘This vapour layer collapses when the surface cools, which could result in an explosion.’
He added that in textured surfaces the vapour layer is maintained until the surface is completely cooled, preventing the liquid from bubbling and boiling over.
‘The discovery shows how the texture of surfaces can combine to control the boiling of liquid in a way that was not thought to be possible’, Chan said.