Drying Transition of Water Confined between Hydrophobic Pillars

Abstract

The phase behavior of the water confined between hydrophobic pillars was studied by using a simple thermodynamic theory and the lattice gas Monte Carlo simulation. The drying transition of water with decreasing spacing between pillars is related to the Wenzel (WZ) to Cassie–Baxter (CB) transition of droplet. Our theory agrees with simulation for pillars with heights ranging from 11 to 100 nm. The present theory further predicts that sufficiently large circular pillars cannot sustain a CB state even if the pillars are in contact with each other.