New surfaces repel most known liquids

January 18, 2013

SEM image of superomniphobic surface (credit: Shuaijun Pan et al./JACS)

Scientists have developed new “superomniphobic” surfaces that will lead to stain-proof, spill-proof clothing, protective garments, and other products that shrug off virtually every liquid — from blood and ketchup to concentrated acids.

Anish Tuteja and colleagues point out that scientists have previously reported “omniphobic” surfaces, the term meaning that such surfaces can cause a range of different liquids to bead up and not spread on them. But typically very low surface tension liquids such as some oils and alcohols can adhere to those surfaces.

Scientists have also mostly focused on making surfaces that repel only one of the two families of liquids — Newtonian liquids (most liquids) named for the English scientist who described how they flow.

Tuteja’s team set out to do the same for non-Newtonian liquids, which include blood, yogurt, gravy, non-drip paint, various polymer solutions, concentrated acids and bases, and a range of other liquids. They say that virtually all liquids easily roll off and bounce on the new surfaces, which makes them ideal for protecting  materials from the effects of chemicals.

Their hierarchically structured superomniphobic surfaces possess more than one scale of texture (a finer length scale texture on an underlying coarser length scale texture).

Applications include stain-free clothing; spill-resistant, breathable protective wear; surfaces that shrug off microbes like bacteria; and corrosion-resistant coatings.

Funding was provided by the Air Force Office of Scientific Research, donors of the American Chemical Society Petroleum Research Fund, and the China Scholarship Council.