Every Last Drop of Shampoo Pours out of This New Bottle

Researchers hope that their technology will cut down on waste.
(Photo: Getty Images)
Jul 3, 2016· 1 MIN READ
Samantha Cowan is an associate editor for culture.

The squeeze, shake, repeat cycle of trying to get the last stubborn drops of shampoo out of a nearly empty bottle is a shower ritual. But the days of throwing away a plastic container that still has a few ounces of your favorite product could soon be over, thanks to two engineers from Ohio State University.

Bharat Bhushan and Philip Brown declared this week that they had created a plastic surface coating that can repel soapy liquids. The result? A shampoo bottle that can empty entirely, resulting in an extra wash or two. Along with saving consumers precious moments by cutting out the need to violently shake the bottle, the researchers are also hopeful their technology will cut down on waste.

“We throw a lot of shampoo away,” Bhushan, a mechanical engineering professor at OSU, told TakePart. He estimates that about 5 percent of the liquid in each bottle of shampoo gets tossed.

Back in 2012, engineers from the Massachusetts Institute of Technology designed a coating to help burger lovers squeeze out the last drops of ketchup. Creating a soap-repellent coating proved more challenging than designing one that could be used with condiments, Bhushan explained.

Oils and soaps are difficult to extract from their containers because they have low surface tension, meaning the individual molecules spread apart rather than bead together.

To make a soap-repellent bottle, the researchers embedded chemical-coated silica nanoparticles into polypropylene, a type of plastic commonly used to make shampoo bottles. The chemicals repel the soap, and the silica particles create a roughness, which allows the soap to come out without leaving behind a trail of residue. The demo video shows how easily shampoo slides off the treated plastic.

Residue in bottles can complicate the recycling process. About 177 million pounds of polypropylene were sold in 2014, and roughly 44 percent of it was recycled, according to the American Chemistry Council.

Emptying out won’t be a problem for bottles treated with Bhushan and Brown’s technology. To create the soap-resistant material, however, they used fluorosilane. Environmentalists warn that fluoride compounds degrade slowly and can be toxic if ingested by wildlife.

Bhushan acknowledged that the use of fluorosilane could be problematic but said the technology is still environmentally friendly because it would reduce product waste. He and Brown recently applied for a patent and hope to license the soap-repellant coating to larger companies.

“We absolutely expect that shampoo companies will have an interest,” Bhushan said. “The question really is how much time and effort they’re willing to invest in order to make it a manufacturable product.”