OSU makes soap (bottles) slippery

One of the nation's largest universities, a high-profile school that excels in academics and athletics, cares about your hygiene.

And your pocketbook.

News out of Central Ohio has researchers from The Ohio State University developing a coating that allows soaps and shampoos and detergents to flow easily out of polypropylene bottles. No more shaking. No more hitting. No more turning upside-down.

Just a free flow of all that lathery goodness.

The patent-pending coating “involves lining a plastic bottle with microscopic y-shaped structures that cradle the droplets of soap aloft above tiny air pockets,” according to OSU.

The lining is made from nanoparticles of silica, and the soap never actually touches the plastic bottle and flows freely, OSU said.

Surface tension is the key here. Food products, such as ketchup and sauces, are mostly made of water. And water likes to stick to itself more than plastic, the university said.

But surfactants contained in soap have what the university calls “a very low surface tension” and easily stick to plastic.

The newly created coating would change that surfactant-to-plastic dynamic.

“We all struggle with shampoo bottles at home," Bharat Bhushan, a professor of mechanical engineering at OSU, who worked on the project, in a statement. "I have a few in my shower right now. Trying to get the last drop out, I put it upside down, and my wife adds water to the bottle and fights with it for a while, and then we give up and just throw it away."

Bhushan worked with fellow OSU engineer Philip Brown on the project. Their findings are laid out in a paper published this week in a journal called Philosophical Transactions of the Royal Society.

The duo developed a way to line the inside of bottles with a solvent and the silica nanoparticles. The solvent softens the inside of polypropylene bottles to allow the silica to embed in the plastic, the university reported.

OSU want to license its new approach to manufacturers, and sees a market beyond just soaps. Other applications could include medical products.

The same coating approach also works on polycarbonates, the university said.