Please wait.'

Page is loading'


Home  > Raw materials & technologies  > Technologies  > Functional coatings  > Superhydrophobic coating could suppress ex...

Saturday, 21 September 2019
pdf
Raw materials & technologies, Technologies, Functional coatings

Superhydrophobic coating could suppress explosive boiling

Tuesday, 2 October 2012

New superhydrophobic coating may help suppress explosive boiling reactions like those that can occur in nuclear reactors and other equipment exposed to water at high heat.

Scientists have developed a new superhydrophobic coating that may help suppress explosive boiling reactions

Source: BASF

Scientists have developed a new superhydrophobic coating that may help suppress explosive boiling reactions

Source: BASF

Known as the Leidenfrost effect, the reaction "can be big trouble for equipment exposed to water at high temperatures, such as nuclear reactors, because sometimes the transition away from it leads to explosive boiling,” the researchers explain.

Their research focuses on controlling the reaction that causes water droplets to skitter across a hot frying pan. Led by Ivan U. Vakarelski, of Saudi Arabia’s King Abdullah University of Science & Technology, and Neelesh A. Patankar, of Northwestern University, the scientists started with steel spheres, then applied a patented coating that is normally used to keep rain from accumulating on car side mirrors. The textured coating renders the spheres super-water-repellent (superhydrophobic) and leads to smooth, nearly bubble-less boiling.

Use of high-speed photopraphy

The researchers used high-speed photography to monitor the processes of the steel balls treated with a variety of coatings. In one case, they found that immersing 20 mm hydrophilic balls heated to more than 400 °C in water caused the water to boil at the steel surface gently in a nearly bubble-free manner known as film boiling. As the surface temperature cooled to 275 °C, the protective vapor layer collapsed, leading to an explosive transition to the "nucleate boiling” regime. The textured superhydrophobic coating completely suppressed the violent transition, they report.

top of page
Comments (0)
Add Comment

Post comment

You are not logged in

register