Nonlocal dynamics of spontaneous imbibition fronts.
We have studied spontaneous imbibition fronts generated by capillary rise between two roughened glass plates, the separation d of which varied between 10 and 50 microm. Perfect agreement with Washburn's law was obtained. We have determined the roughness exponent chi of the fronts, and found chi=0.81+/-0.01 for small length scales. Above a certain crossover length xi, it reached chi=0.58+/-0.04, as predicted by the quenched noise Kardar-Parisi-Zhang equation. The crossover length is found to scale with the plate separation as sqrt[d], as predicted by recent models which properly include nonlocal dynamics effects on the front. We believe this to be the first clear identification of crossover from nonlocal to local dynamics.
Geromichalos
Dimitrios
D
Applied Physics Lab, Ulm University, Germany. Dimitrios.Geromichalos@physik.uni-ulm.de
Mugele
Frieder
F
Herminghaus
Stephan
S