Play with emulgators
The individual droplets can coalesce depending on the degree of coverage. This results in peanut-like shapes. The coalescence changes the ratio of volume to surface area, which means that there is less space available for the particles on the interface. The particles covering two droplets are forced to move together on a smaller area, and the coverage of the double droplet increases in density. The coated droplets are stabilised in this way – and so is the emulsion, whose properties also derive from the shape and length of the droplets.
“We can also determine the shape of the droplets using our method, allowing us to create emulsions with previously inconceivable properties”, enthuses Vermant. The newly discovered principle is very robust. “We’ve been working on this for ten years, and now the problem is solved.”
The method described here is only suitable for research because it only works on a very small scale. However, the ETH researchers are working on scaling it up to process larger quantities. They are developing an apparatus that would already be suitable for industrial testing methods based on the sale and the throughput.
On an even larger scale, applications in the food, pharmaceutical, cosmetics and even the oil industry, for example separating oil and water during oil extraction, would be possible.
