Materials

Nanotech coating puts an end to wasted shampoo

Nanotech coating puts an end t...
A microscopic coating lets shampoo, soap, and other heavy liquids slide right out of the bottle – so you're no longer left battling to get the dregs out at the end
A microscopic coating lets shampoo, soap, and other heavy liquids slide right out of the bottle – so you're no longer left battling to get the dregs out at the end
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Unlike regular uncoated polypropylene plastic (left), which develops a strong surface tension with soap and leaves the soap molecules sticking to the walls of the bottle, soap and shampoo slides right off the coated material
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Unlike regular uncoated polypropylene plastic (left), which develops a strong surface tension with soap and leaves the soap molecules sticking to the walls of the bottle, soap and shampoo slides right off the coated material
A microscopic coating lets shampoo, soap, and other heavy liquids slide right out of the bottle – so you're no longer left battling to get the dregs out at the end
2/2
A microscopic coating lets shampoo, soap, and other heavy liquids slide right out of the bottle – so you're no longer left battling to get the dregs out at the end

Shampoo, ketchup, liquid soap, dishwashing liquid – they all come in bottles made from the same kind of plastic, polypropylene, and they're all infamous for being extremely difficult to empty. The last dregs just don't want to come out. Some of us try to squeeze the last drops out by adding a bit of water and turning the bottle upside down, but now Ohio State researchers have devised a better solution: a microscopic lining that lets the products slide right off.

The patent-pending technology promises to not only reduce that niggling frustration but also to make the plastic more durable and reusable.

It works by creating a repellant buffer between the plastic – which soapy molecules tend to stick to – and the liquid. The coating consists of microscopic y-shaped structures, which themselves are made up of silica nanoparticles. The branches of the "y" overhangs reduce surface tension by providing a cushion of air together with stiff angles too steep for droplets to stick to the plastic, and consequently soap and other kinds of droplets slide smoothly off the surface.

Unlike regular uncoated polypropylene plastic (left), which develops a strong surface tension with soap and leaves the soap molecules sticking to the walls of the bottle, soap and shampoo slides right off the coated material
Unlike regular uncoated polypropylene plastic (left), which develops a strong surface tension with soap and leaves the soap molecules sticking to the walls of the bottle, soap and shampoo slides right off the coated material

This is similar to a hydrophobic coating announced in 2013 for industrial and waste management use by Florida-based containment provider Ultra-tech. But Ultra-tech's coating uses a cocktail of chemicals that make it unsuitable for food containers, whereas the Ohio State researchers' technique is environmentally friendly – it only adds silica, which is often used in small quantities in tap water and naturally occurs in many foods.

The new coating could also aid in recycling, as it makes the bottles easier to clean, and in biomedical devices, catheters, and other plastic products that need to stay clean. The researchers have successfully applied the technique to a different kind of plastic, too – polycarbonate, which is used in corrective lenses, optical media, roofing, smartphone cases, and many other products.

A paper describing the technology was published in the journal Philosophical Transactions of the Royal Society.

Source: Ohio State University

9 comments
gizmowiz
Apply to glass and water beads right off? Might be something we could use on car windshields?
CharlieSeattle
I did not know that was a problem ...........with Chemists. Product Engineers made the cap tops flat and wide, decades ago, so the user can stand the near empty bottle upside down for day or two.
habakak
This can cut down hugely on waste. Tens of thousands of tons, if not millions, of unused product is discarded every year due to this stickiness issue. Hopefully this tech can be economically deployed globally to cut down on such waste.
wle
do i want to be eating and drinking this nano stuff?
VirtualGathis
This products usefulness is entirely dependent upon the cost of applying it. It's kind of stupid to apply a coating to a bottle that costs $0.15/unit to save $0.03 worth of product...
Lawnmowerman
Not really a problem with soap. Just fill bottle with water when you get near the end. Would be great for paints and resins. Also, salad dressings and vegetable pastes.
forsythem
I'd be interested to see a net environmental impact assessment, based on typical products it would be used for. Unfortunately, the first thing I think of these days when hearing about advances like this is how much additional waste could be created, and how much extra waste is created and energy is consumed in the production process.
ljaques
I'm with Lawnmowerman. When the shampoo or whatever gets low, I add a bit of water to make it more liquid and get the last of it. I started doing this in 1970, after celebrating the first Earth Day. Waste not, want not.
Aross
Refill reuse. Instead of buying new containers each time why not just refill the old ones. Never waste a drop that way and no need for more questionably safe technology in the environment.