Whimsical: Perfume smells better the more you sweat

Compound binds sweat odor while releasing fragrances

When we sweat, bacteria quickly produce stinking decomposers © thinkstock
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Odor instead of sweat Mief: Chemists have developed a novel perfume that automatically adjusts to our sweating. If sweat is present, the substance binds the stinking bacteria products and releases the fragrances at the same time. This makes it all the more effective the more we sweat.

Sweating is an important help to our body for thermoregulation. Unfortunately, the sweat exudes an unpleasant odor after a short time. This is due to bacteria that, for example, live under our armpits and eat away the substances that are contained in sweat. They produce sulfur-containing thioalcohols - and these produce the typical smell of sweat.

Nimal Gunaratne from Queen's University Belfast and his colleagues have now developed a substance that reacts in a novel way with our sweat. The perfume consists of a so-called ionic liquid - a salt that is liquid at room temperature without having to be dissolved in water or another solvent. To this salt, the researchers coupled a proto-fragrance, a chemical precursor of perfume fragrance, which smells completely neutral in this form.

The proto-Dufstoff is bound to an ionic liquid udn is only released when it reacts with the water in the sweat. © Gunaratne et al., / Chemical Communications

The highlight behind it is a liquid salt

If this perfume is applied to the skin, then it does not happen at all: as long as we do not sweat, it remains odorless. But if the substance in contact with sweat, then the ionic liquid reacts with the water. The fragrance precursor dissolves from the salt, "snaps" an OH group, making it a pleasantly scented and slightly evaporating perfume. At the same time, the ionic liquid now binds the thioalcohols out of the perspiration, thus ensuring that the typical smell of perspiration does not come through under the fragrance.

Thus, this perfume adapts flexibly to our sweating and is only active when it is needed. "This is an exciting breakthrough, " says Gunaratne. "This has great commercial potential and could be used in perfumes and creams." The researchers are already working with a company to develop specific products. At the same time, however, this form of controlled release of volatile substances could also be useful in other areas of science. (Chemical Communications, 2015; doi: 10.1039 / C5CC00099H) Display

(Queen's University Belfast, 02.04.2015 - NPO)