Transition in the evaporation kinetics of water microdrops on hydrophilic surfaces.
We describe a technique that allows measurement of the mass and shape of sessile liquid microdrops during evaporation. Therefore, the microdrops are deposited by an inkjet onto a silicon microcantilever, and the bending and the shift in resonance frequency are monitored. From hydrophobized surfaces, microscopic water drops evaporate with the same kinetics as macroscopic drops; we verify the validity of known evaporation laws to drops with diameters from 100 microm to below 10 microm. From hydrophilic surfaces, the evaporation is slowed down during the last approximately 100 ms; we believe that this occurs due to flattening of the drops, which are then stabilized by interfacial forces and disjoining pressure.
Golovko
Dmytro S
DS
Max-Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany.
Butt
Hans-Jürgen
HJ
Bonaccurso
Elmar
E