Material that repels hot water developed by scientists from University of Minnesota
In a breakthrough study, scientists from University of Minnesota in St Paul have developed a new material that can repel hot water.
The new discovery could help protect vulnerable members of the population such as elderly, children, physically impaired people from hot-water burns.
Scientists have long been working on producing water-repelling materials inspired by natural surfaces, such as lotus leaves.
These leaves have waxy hydrophobic – water hating – coating and a spiky surface texture that helps to trap small pockets of air beneath water droplets.
During the study, Yuyang Liu along with colleagues from Hong Kong Polytechnic University, reviewed studies suggesting carbon nanotubes are powerfully hydrophobic in their search for a material that can repel hot water as well as cold, and found that they seem indifferent to temperature.
To further improve resistance to hot water, the team added carbon nanotubes to Teflon – a substance commonly used as a non-stick coating on cookware.
The researchers later dipped a cotton fabric into the mix.
They found that the material is able to repel hot water, milk, coffee and tea at 75 degree Celsius – a sufficient temperature to cause scalding – without problems.
Moreover, the hot droplets retain a near spherical shape and roll off the material.
However, Liu insists that Teflon coating alone is not so effective. He said that carbon nanotubes create a dimpled surface texture on a nanoscopic scale – small enough to trap air even under drops of hot liquid and prevent droplet impalement on the surface.
Philippe Brunet at the Mechanics Laboratory of Lille, France, thinks the work is promising.
“It has been claimed that a dense carpet of nanowires, coated with ad-hoc chemistry, should have a very high robustness to impalement but he doesn’t think anyone has tested such materials against hot water before,” New Scientist quoted him as saying.
The study appears in Journal of Materials Chemistry.