Solution in sight for dregs of soap bottle struggle

A nanoparticle coating has been developed to enable the last dregs of washing up liquid to be poured out of the bottle. Picture: Getty/iStockphoto

Scientists have developed a nanoparticle coating for plastic bottles that allows soap products to flow freely.

What this means is that every drop of liquid soap, shampoo or laundry detergent can be removed and none is wasted.

Technology already existed to help food products pour out of containers, but soap is a much stickier problem.

Lead scientist Professor Bharat Bhushan, from Ohio State University in the US, said: “Compared to soaps, getting ketchup out of a bottle is trivial.”

His team has developed a way of lining plastic bottles with microscopic Y-shaped structures that cradle droplets of soap above tiny air pockets.

As a result, the soap never actually touches the sides of the bottle. Instead of spreading out, the soap droplets form beads and roll off the surface.

The Y structures are built up using much smaller nanoparticles made from silica or quartz, an ingredient in glass.

Prof Bhushan said: “It’s what you’d call a first-world problem, right? ‘I can’t get all of the shampoo to come out of the bottle. But manufacturers are really interested in this, because they make billions of bottles that end up in the garbage with product still in them.”

“We all struggle with shampoo bottles at home. I have a few in my shower right now.”

The invention could also aid recycling, said the researchers.