Improved hydrophobicity of carbon nanotube arrays with micropatterning

The hydrophobicity of vertically aligned multiwalled carbon nanotubes (MWCNTs) was improved through the creation of a parallel array of microwalls via a laser pruning technique. Changes to the hydrophobic nature of the patterned MWCNTs due to artificially induced roughness through variations in both the widths of the walls and the distance between adjacent walls, channel width, were investigated. The sample became more hydrophobic whenever water droplets landed on one microwall 7 or 13 microm in width. However, when a droplet bridged two microwalls, the surface became less hydrophobic. The optimal superhydrophobic MWCNT surface corresponded to a parallel array of microwalls with a width of 13 microm and a channel width of approximately 50 microm. Such findings could possibly serve as value-add for further developments in the creation of water-repelling CNT surfaces via micropatterning.