Slip length and contact angle over hydrophobic surfaces

The relation between contact angle and slip length is explored using molecular dynamics for Couette flow of a Lennard-Jones fluid between graphite-like walls. Obtained results vary from the common notion that higher contact angles lead to greater slip and to more effective friction reduction. Effects of varying LJ parameters on contact angle and slip length are investigated parametrically. Results are shown in a 3D map, where the third dimension is the square root of the solid-fluid atom size ratio. The present data can be applied to developing artificial supersolvophobic surfaces that are fundamental to friction drag reduction on interfaces. (c) 2007 Elsevier B.V. All rights reserved.