Turning the sticky to slippery

From massive airplanes to tiny camera lenses, many of the technologies that support daily life rely on products that keep them functional in different and sometimes extreme weather conditions. Ice and frost, for example, can be hazardous to people and can reduce the operational functionality of many essential technologies.

Unfortunately, most techniques to repel harmful materials—such as frost and ice formation on surfaces in cold conditions—rely heavily on heating or liquid chemicals that need to be repeatedly reapplied because they easily wear away.

But research presented by scientists from the University of Illinois Chicago (UIC) at the 74th Annual Meeting of the APS Division of Fluid Dynamics shows that with new techniques, it is possible to create materials that not only keep harmful materials like disease causing bacteria and frost off industrial surfaces, but also make accumulation of these materials (if it all) easier to shed.

Further, the experiments described by the UIC researchers provide evidence that the developed coatings are at least 10 times more effective than current materials.

The group will announce the results and take questions from journalists at a live virtual press briefing on Monday, November 22, 2021, from 4:00 p.m. to 5:00 p.m. U.S. Mountain Standard Time (MST).

The coatings leverage certain thermoresponsive properties, which the UIC researchers first described in 2019, of “phase switching” liquids (PSL). PSLs are a subset of phase change materials that have melting points higher than the freezing point of water. The bio-friendly coatings work by creating a hygroscopic slippery layer that functions like a barrier and prevents harmful substances from coming in direct contact with the underlying surface—thus making it harder for any accumulation to maintain a grip of the surface when it’s being removed.

The researchers envision that the developed physical concept opens a rational route to potentially minimize adhesion of various solid species (i.e., ice, dust, and even bacterial biofilms) on a wide variety of surfaces, with immediate applications in transportation systems (planes, cars, and marine ships), energy systems, and consumer electronics.

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