Wetting behavior and drag reduction of superhydrophobic layered double hydroxides films on aluminum

We present a novel method to fabricate Zn-Al LDH (layered double hydroxides) film with 3D flowerlike micro-and nanostructure on the aluminum foil. The wettability of the Zn-Al LDH film can be easily changed from superhydrophilic to superhydrophobic with a simple chemical modification. The as-prepared superhydrophobic surfaces have water CAs (contact angles) of 165 +/- 2 degrees. In order to estimate the drag reduction property of the surface with different adhesion properties, the experimental setup of the liquid/solid friction drag is proposed. The drag reduction ratio for the as-prepared superhydrophobic sample is 20-30% at low velocity. Bearing this in mind, we construct superhydrophobic surfaces that have numerous technical applications in drag reduction field. (C) 2016 Elsevier B.V. All rights reserved.