Carbon Nanotube Arrays with Tunable Wettability and Their Applications

A combination of UV/ozone and vacuum pyrolysis treatments is introduced to tune the wetting properties of vertically aligned multiwalled carbon nanotube arrays. The UV/ozone treatment renders these arrays superhydrophilic by functionalizing them with oxygenated functional groups. These superhydrophilic arrays have a high affinity to water such that they have a very high specific capacitance in aqueous electrolytes. The vacuum pyrolysis treatment renders these arrays superhydrophobic by deoxidizing them. The presence of a thin film of air at the surface of superhydrophobic arrays when they are submerged in water creates a slip condition that is useful for drag reduction.