Modeling receding contact lines on superhydrophobic surfaces.
We use mesoscale simulations to study the depinning of a receding contact line on a superhydrophobic surface patterned by a regular array of posts. For the simulations to be feasible, we introduce a novel geometry where a column of liquid dewets a capillary bounded by a superhydrophobic plane that faces a smooth hydrophilic wall of variable contact angle. We present results for the dependence of the depinning angle on the shape and spacing of the posts and discuss the form of the meniscus at depinning. We find, in agreement with ref 17 , that the local post concentration is a primary factor in controlling the depinning angle and show that the numerical results agree well with recent experiments. We also present two examples of metastable pinned configurations where the posts are partially wet.
The Rudolf Peierls Centre for Theoretical Physics, 1 Keble Road, Oxford, Ox1 3np, United Kingdom. b.mognetti1@physics.ox.ac.uk
B M
BM
Mognetti
J M
JM
Yeomans
D004553:Electric Conductivity; D004563:Electrochemistry / Q000379:methods; D020100:Hydrogels / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D015233:Models, Statistical; D011108:Polymers / Q000737:chemistry; D011312:Pressure; D012492:Salts / Q000737:chemistry; D055672:Static Electricity; D013499:Surface Properties; D013696:Temperature
D020100:Hydrogels; D011108:Polymers; D012492:Salts