Hydrophobic coatings that can take the heat
A new approach for coating the surfaces of condensers used in power plants and for water purification has been developed. The method means the hydrophobic coating can be far thinner, is more durable and able to withstand significantly higher temperatures.
When exposed to 100 degrees Celsius steam, the hydrophobic materials currently in use begin to degrade after just one minute. Although the steam in power-plant condensers is typically about 40 degrees Celsius, this is testament to their limited durability.
This week, a team from the Massachusetts Institute of Technology (MIT) published the findings of their breakthrough research. They have developed a covalent-bonding process that is significantly more stable than previous approaches.
Metals coated using the newly developed process remain efficiently hydrophobic even when exposed to steam at 100 degrees Celsius. Impressively, the hydrophobic coating can be just one-thousandth the thickness of conventional coatings, meaning there is minimal impact on the properties of the underlying material. And with little fuss the coating can also be applied to condensers in existing facilities via the process of initiated chemical vapour deposition (iCVD).
It is hoped the durability of the material may surpass the positive results suggested by initial tests, perhaps by ‘tens of years’, according to Karen Gleason, the Alexander and I. Michael Kasser Professor of Chemical Engineering at MIT.