Topography driven spreading.
Roughening a hydrophobic surface enhances its nonwetting properties into superhydrophobicity. For liquids other than water, roughness can induce a complete rollup of a droplet. However, topographic effects can also enhance partial wetting by a given liquid into complete wetting to create superwetting. In this work, a model system of spreading droplets of a nonvolatile liquid on surfaces having lithographically produced pillars is used to show that superwetting also modifies the dynamics of spreading. The edge speed-dynamic contact angle relation is shown to obey a simple power law, and such power laws are shown to apply to naturally occurring surfaces.
School of Biomedical and Natural Sciences, The Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, United Kingdom. glen.mchale@ntu.ac.uk
G
G
McHale
N J
NJ
Shirtcliffe
S
S
Aqil
C C
CC
Perry
M I
MI
Newton
D057927:Hydrophobic and Hydrophilic Interactions; D008956:Models, Chemical; D013499:Surface Properties; D017155:Wettability