Superhydrophobicity of a material made from multiwalled carbon nanotubes

Superhydrophobic carbon nanotubes (CNTs) were prepared by low-pressure CF4 glow plasma to provide roughness and fluorination in CNTs. The water droplet falling freely on the superhydrophobic CNT powders bounced dynamically. The superhydrophobicity resulted from the combined effects of the chemical modification and surface roughness. Using the contact angles obtained from the capillary rise method based on the Washburn equation, the total surface free energy of CNT powder treated by CF4 plasma for 20 min was calculated to be drastically decreased from 27.04 to 4.06x10(-7)mJ/m(2).