Dynamic dewetting through micropancake growth.
We experimentally investigate the dynamics of nanometer-high, micrometer-wide gassy layers at the interface between a hydrophobic solid and bulk water. These micropancakes grow laterally in time, on the timescale of an hour, leading to partial dewetting of the solid. The growth is directional, mediated by chemical roughness on the substrate, and transient, occurring within the first hour after liquid deposition. We use circularity to measure the roundness of a micropancake (circularity C = 2(piA)(1/2)/L, where A is the surface area and L is the perimeter). The growth is anisotropic, as demonstrated by a decrease in circularity with time. However, once a micropancake reaches size saturation, its bulk rearranges its shape in order to minimize the length of its three-phase line. We interpret this combination of growth followed by bulk rearrangement as dynamic dewetting.
Seddon
James R T
JR
Physics of Fluids, MESA+ Institute for Nanotechnology, and IMPACT, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands. j.r.t.seddon@utwente.nl
Bliznyuk
Olesya
O
Kooij
E Stefan
ES
Poelsema
Bene
B
Zandvliet
Harold J W
HJ
Lohse
Detlef
D
D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D013499:Surface Properties; D014867:Water / Q000737:chemistry; D017155:Wettability
D014867:Water