Engineers have produced sustainable nanobubbles for the first time

Engineers from the School of Engineering and Applied Sciences at Harvard University produced, for the first time, long-lasting nanobubbles - bubbles that were stable for more than a whole year * among the possible applications - for the introduction of nanoparticles into the cosmetics industry

With the help of household mixers, engineers from the School of Engineering and Applied Sciences at Harvard University produced, for the first time, sustainable nanobubbles - bubbles that were stable for more than a full year - from a collection of foams of a mixture of glucose syrup, sucrose stearate and water. Their research was published in the 30 Director of the respected journal Science.

The research, led by Howard Stone (Stone), sprouted from a conference lecture on foams given by Dr. Rodney Bee, a retired physical chemist from Unilever in 2005. Bee, who tested ice cream recipes at the commercial company, was interested in finding Ways to extend the shelf life of foams and other gas-containing mixtures such as ice creams. He managed to create a unique type of bubbles during his research, and included their image in his lecture.

Stone, a professor of engineering and applied mathematics, was in the audience when Bee presented the image of a micrometric bubble with a highly regular polygonal geometry. On the surface of the bubble were visible irregular areas of pentagons, hexagons and heptagons which together formed a football-like structure. None of the wigs exceeded fifty nanometers in size. "Bubbles of such small sizes never extended life due to the surface tension of their surface - they collapsed and disappeared almost immediately.

The image that appeared on the screen at this conference was extraordinary," says Stone. "It was impossible; We all agreed that it was not possible at all." Small bubbles have more surface tension and a higher internal gas pressure than larger bubbles. As a result, larger bubbles are often obtained at the expense of small ones, which have an extremely short life span. "I asked him how he managed to create his own foam, and he replied that he used a regular household blender. The next day I went and bought a mixer like this for our labs," explains Stone.

In the study, which was conducted in collaboration with the scientists of the commercial company, it was discovered that when the bubbles were coated with a very specific mixture of surfactants, these formed over the bubble and formed an almost impenetrable shell shell. The resulting shells have sufficient flexibility that allows them to curve and arrange themselves in structures The stability of these microbubbles exceeded one year and their structural integrity was maintained throughout this period, the researchers note Future applications of such microbubbles could significantly improve the shelf life of common foamed products that undergo rapid degradation, such as those used in cosmetics and medical imaging contrast agents.

to the notice of the researchers