MOSCOW, November 14. /TASS/ Researchers from Tyumen State University (TyumSU) have succeeded in controlling drop cluster hovering over water surfaces, the press service of TyumSU said. According to the scientists, forming and studying levitating microdroplets will shed a light on the nature of chemical processes which occur in very small volumes of liquids.
A drop cluster is an accumulation of very small drops with a diameter about 1/20 mm which appears when water evaporates and hovers over the water surface at a height approximately equal to the diameter of drops. Herewith, the microdroplets are aligned in a single-layer hexagon structure forming a "flat-like fog". The first time a drop cluster was created in Russia had been in 2004.
In the new study at TyumSU, a laser was applied to heat the water, and an infrared irradiation was utilized to control the drops. The water on the base of the glass ceramics support (smoother than an ordinary glass) was heated from below with a laser. Upon evaporating, a layer of drops formed over the surface of the water, with the drops’ mean diameter being about 35 micrometers.
The researchers directed the infrared rays onto the drops and found out that it was possible to change the drop size. Without irradiation, the drops continued to grow, yet while under IR-irradiation they shrank in size. As a result, the scientists announced the possibility of creating and controlling levitating microdroplets structures. Drop clusters are essential for studying the processes which occur in various aerosols. This is a highly significant, since chemical processes in small drop volumes differ significantly from those in large liquid volumes.
"One can take a drop, place a chemical substance of interest in there and find out what is going on in these particular microdroplets. This gives us principally new chances to explore processes in, for example, aerosols which are formed during spraying pesticides," Alexander Fedorets, the author of the study said. He believes the drop clusters are helpful also in studying biochemical processes occurring normally in cells.