A template-based superhydrophobic tube structure with nanofiber forests and its mass flow characteristic

A variety of two-dimensional (2D) superhydrophobic surfaces have been fabricated for biological and industrial applications. Here, we report a simple and inexpensive non-planar (i.e. three-dimensional, 3D) superhydrophobic structure with nanofiber entanglements. The 3D structure with the contact angle of about 170 degrees is fabricated by the dip coating of polytetrafluoroethylene and the etching process of an anodic aluminum oxide (AAO)/aluminum (Al) wire template which is prepared by anodization of an industrial Al wire (99.5% purity, 1000 times cheaper than Al of 99.999%). The 3D superhydrophobic surface was fabricated on the inside of a tube using a template AAO replica. Flow characteristics were then determined by measuring the mass flow of water through the tube. The superhydrophobic surface gives better flow and an increasing mass flow rate.