Research on super-hydrophobic surfaces could result in cleaner, more efficient power
In a basement lab on BYU’s campus, mechanical engineering professor Julie Crockett analyzes water as it bounces like a ball and rolls down a ramp.
A droplet of water beads up on top of a hydrophobic surface. Water beads up even more on super-hydrophobic surfaces
This phenomenon occurs because Crockett and her colleague Dan Maynes have created a sloped channel that is super-hydrophobic, or a surface that is extremely difficult to wet. In layman’s terms, it’s the most extreme form of water proof.
Engineers like Crockett and Maynes have spent decades studying super-hydrophobic surfaces because of the plethora of real-life applications. And while some of this research has resulted in commercial products that keep shoes dry or prevent oil from building up on bolts, the duo of BYU professors are uncovering characteristics aimed at large-scale solutions for society.
Their recent study on the subject, published in academic journal Physics of Fluids, finds surfaces with a pattern of microscopic ridges or posts, combined with a hydrophobic coating, produces an even higher level of water resistance--depending on how the water hits the surface.
“Our research is geared toward helping to create the ideal super-hydrophobic surface,” Crockett said. “By characterizing the specific properties of these different surfaces, we can better pinpoint which types of surfaces are most advantageous for each application.”
Their work is critical because the growing list of applications for super-hydrophobic surfaces is extremely diverse:
But where Crockett and Maynes’ research is really headed is toward cleaner and more efficient energy generation. Nearly every power plant across the country creates energy by burning coal or natural gas to create steam that expands and rotates a turbine. Once that has happened, the steam needs to be condensed back into a liquid state to be cycled back through.
If power plant condensers can be built with optimal super-hydrophobic surfaces, that process can be sped up in significant ways, saving time and lowering costs to generate power.
“If you have these surfaces, the fluid isn’t attracted to the condenser wall, and as soon as the steam starts condensing to a liquid, it just rolls right off,” Crockett said. “And so you can very, very quickly and efficiently condense a lot of gas.”
The super-hydrophobic surfaces the researchers are testing in the lab fall into one of two categories: surfaces with micro posts or surfaces with ribs and cavities one tenth the size of a human hair. (See images of each to the right.)
To create these micro-structured surfaces, the professors use a process similar to photo film development that etches patterns onto CD-sized wafers. The researchers then add a thin water-resistant film to the surfaces, such as Teflon, and use ultra-high-speed cameras to document the way water interacts when dropped, jetted or boiled on them.
They’re finding slight alterations in the width of the ribs and cavities, or the angles of the rib walls are significantly changing the water responses. All of this examination is providing a clearer picture of why super-hydrophobic surfaces do what they do.
“People know about these surfaces, but why they cause droplets or jets to behave the way they do is not particularly well known,” Crockett said. “If you don’t know why the phenomena are occurring, it may or may not actually be beneficial to you.”
Todd Hollingshead | Eurek Alert!
Interstellar seeds could create oases of life
28.08.2015 | Harvard-Smithsonian Center for Astrophysics
Draw out of the predicted interatomic force
28.08.2015 | Hiroshima University
Longer, more severe, and hotter droughts and a myriad of other threats, including diseases and more extensive and severe wildfires, are threatening to transform some of the world's temperate forests, a new study published in Science has found. Without informed management, some forests could convert to shrublands or grasslands within the coming decades.
"While we have been trying to manage for resilience of 20th century conditions, we realize now that we must prepare for transformations and attempt to ease...
A University of Oklahoma astrophysicist and his Chinese collaborator have found two supermassive black holes in Markarian 231, the nearest quasar to Earth, using observations from NASA's Hubble Space Telescope.
The discovery of two supermassive black holes--one larger one and a second, smaller one--are evidence of a binary black hole and suggests that supermassive...
A team of European researchers have developed a model to simulate the impact of tsunamis generated by earthquakes and applied it to the Eastern Mediterranean. The results show how tsunami waves could hit and inundate coastal areas in southern Italy and Greece. The study is published today (27 August) in Ocean Science, an open access journal of the European Geosciences Union (EGU).
Though not as frequent as in the Pacific and Indian oceans, tsunamis also occur in the Mediterranean, mainly due to earthquakes generated when the African...
In mountainous regions earthquakes often cause strong landslides, which can be exacerbated by heavy rain. However, after an initial increase, the frequency of these mass wasting events, often enormous and dangerous, declines, in fact independently of meteorological events and aftershocks.
These new findings are presented by a German-Franco-Japanese team of geoscientists in the current issue of the journal Geology, under the lead of the GFZ...
Bacteria do not cease to amaze us with their survival strategies. A research team from the University of Basel's Biozentrum has now discovered how bacteria enter a sleep mode using a so-called FIC toxin. In the current issue of “Cell Reports”, the scientists describe the mechanism of action and also explain why their discovery provides new insights into the evolution of pathogens.
For many poisons there are antidotes which neutralize their toxic effect. Toxin-antitoxin systems in bacteria work in a similar manner: As long as a cell...
20.08.2015 | Event News
20.08.2015 | Event News
19.08.2015 | Event News
31.08.2015 | Awards Funding
31.08.2015 | Materials Sciences
31.08.2015 | Materials Sciences