photo
of a glycerol droplet shortly
after
leaving the injector nozzle
photo
of a trapped glycerol droplet
in
an electrodynamic balance
Levitation
of Single Microdroplets in an
Electrodynamic
Balance
With
the help of an electrodynamic balance it is possible to trap single charged
particles for infinite time. Since there is no wall contact these droplets
can be supercooled or supersaturated very easily. This tool is very effective
for analysing processes in the atmospheric chemisty of clouds and also
for studying basic properties of supercooled liquids. A special emphasis
is given on the freezing process of these levitated droplets.
|
photo
of a glycerol droplet shortly
|
photo
of a trapped glycerol droplet
|
Therefore two traps have been built in this group which can both be cooled down to 180 K. The droplets are injected from an piezo driven injector and observed from a Helium-Neon laser (l=632 nm). The droplet diameter is about a hundred times larger than the incident laser light. In this region the elastically scattered light exhibit a very characteristic pattern. The analysis of this pattern makes it possible to determine the size and the state of aggregate of the droplet.
 |
|
of 50 mm calculated after the theory of Gustav Mie. |
Homogeneous
nucleation
of H2O and D2O
contact:
Peter
Stöckel
Freezing
behaviour of the n-alkanes
contact:
Inez
Weidinger