Surfaces coated with this liquid are called “superomniphobic surfaces”. The coating is good at repelling water, oil, concentrated acid and alkali solutions, and even polymer solutions. So, maybe soon, we will see a simple yet formidable protective coating for surface applications enter the commercial market.
Almost any liquid that you throw at a surface coated with this new chemical is thrown off, so claims the team. According to one report in Chemistry World quoting Professor Anish Tuteja from the University of Michigan, it’s always been a challenge before chemists to create a coating that can repel “non-Newtonian” fluids (your ketchup, gravy, and so on). While a lot of effort had gone into creating ‘self-cleaning’ superomniphobic surfaces that repel both oily and water-based liquids, less attention was paid so far to non-Newtonian fluids. But the new film will tackle even the latter.
Researchers at the Michigan University tested over 100 liquids and found that only two of them were able to penetrate the coating. The new film can repel common substances like coffee, soy sauce, vegetable oils as well as toxic substances like sulphuric acid. The coating is a mixture of rubbery plastic particles, polydimethylsiloxane (PDMS), fluorodecyl polyhedral oligomeric silsesquioxane (POSS), and liquid resisting nanoscale cubes which was developed by the US Air Force. It hugs the porous structure of the surface it is applied to, creating a web within those pores.
The surfaces are also highly resistant to chemical attack. Tuteja and his group covered one side of aluminium plates with their material and dunked them into baths of concentrated hydrochloric acid and sodium hydroxide. The uncoated sides of the aluminium were quickly attacked, but the coated surfaces remained protected.
But there still remains one problem to be licked. By Tuteja’s own admission, if you scratch this coating too strongly, it peels off. That’s the last challenge before him prior to introducing it as a commercial product.
[Image courtesy: AnishTuteja Blog]