Good ‘till the last drop is actually possible now thanks to researchers at Ohio State University. Bharat Bhushan and his team in Columbus have designed a coating to put on the inside of soap bottles that allow the contents to flow out more freely. Admit it, we have all put a bit of water in our shampoo bottles in an attempt to salvage the last bit of shampoo that we know is there.
The solution to this “first world problem” can be credited to a little thing called, “polypropylene.” This coating is already applied to food packaging surfaces, but needed to be modified in order to accommodate a “soapy surface.” This is because soap and detergents are made of “surfactants,—the organic molecules that make soap ‘soapy.’” According to our sudsy experts in Ohio, “They (surfactants) have a very low surface tension and stick to plastic easily.”
This modification called for use of spray on “smaller nanoparticles made of silica, or quartz—an ingredient in glass—which, when treated further, won’t stick to soap.” With these structures present on the inside of the bottle, your shampoo will no longer stick to the sides of the bottles, but will now form droplets and run right out.