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!
Graphene microphone outperforms traditional nickel and offers ultrasonic reach
27.11.2015 | Institute of Physics
Tracking down the 'missing' carbon from the Martian atmosphere
25.11.2015 | California Institute of Technology
Planet Earth experienced a global climate shift in the late 1980s on an unprecedented scale, fuelled by anthropogenic warming and a volcanic eruption, according to new research published this week.
Scientists say that a major step change, or ‘regime shift’, in the Earth’s biophysical systems, from the upper atmosphere to the depths of the ocean and from...
The Fraunhofer Institute for Solar Energy Systems ISE has installed 70 photovoltaic modules on the outer façade of one of its lab buildings. The modules were...
Nerve cells cover their high energy demand with glucose and lactate. Scientists of the University of Zurich now provide new support for this. They show for the first time in the intact mouse brain evidence for an exchange of lactate between different brain cells. With this study they were able to confirm a 20-year old hypothesis.
In comparison to other organs, the human brain has the highest energy requirements. The supply of energy for nerve cells and the particular role of lactic acid...
In laser material processing, the simulation of processes has made great strides over the past few years. Today, the software can predict relatively well what will happen on the workpiece. Unfortunately, it is also highly complex and requires a lot of computing time. Thanks to clever simplification, experts from Fraunhofer ILT are now able to offer the first-ever simulation software that calculates processes in real time and also runs on tablet computers and smartphones. The fast software enables users to do without expensive experiments and to find optimum process parameters even more effectively.
Before now, the reliable simulation of laser processes was a job for experts. Armed with sophisticated software packages and after many hours on computer...
Researchers at Heidelberg University have devised a new way to study the phenomenon of magnetism. Using ultracold atoms at near absolute zero, they prepared a...
25.11.2015 | Event News
17.11.2015 | Event News
21.10.2015 | Event News
27.11.2015 | Press release
27.11.2015 | Life Sciences
27.11.2015 | Materials Sciences