Superhydrophobicity of a material made from multiwalled carbon nanotubes

Abstract

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 20min was calculated to be drastically decreased from 27.04to4.06×10−7mJ∕m2.

Superhydrophobic silica films by sol–gel co-precursor method

“…The specialized surface morphology prevents dirt from forming an intimate contact with the surface, while the high hydrophobicity makes leaf water repellent. In order to mimic these properties, artificial superhydrophobic surfaces have been prepared by several means, including the generation of rough surfaces coated with low surface energy molecules [2][3][4], roughening the surface of hydrophobic materials [5,6], and creating well-ordered structures using micromachining and etching methods [7,8]. Water on such a superhydrophobic surface forms a spherical droplet, and both the contact area and the adhesion to the surface are reduced.…”

Superhydrophobic carbon-based materials: a review of synthesis, structure, and applications

“…CNTs, especially those with a cylindrical nanostructure, are of immense research interest for their outstanding behavior in practical applications such as nanotechnology, electronics, optics and other fields of materials science and technology [43,63,90,[113][114][115][116][117][118][119]. However, in many cases, CNTs wettability and dispensability are crucial factors in their performance; example applications include reinforced polymer composites, templates, sensors, catalysts, electrode, etc.…”

“…Previous studies have mostly focused on aligned CNTs films [43,90,[117][118][119]. Zhu et al [117] fabricated two model surfaces with two-tier scale roughness in a well-controlled manner and compared the superhydrophobicity and contact angle hysteresis of these surfaces with those of microscale rough surfaces by controlled growth of CNT arrays followed by coating with fluorocarbon layers formed by plasma polymerization.…”

“…These results improve the understanding of the effects of two-tier roughness on superhydrophobicity and offer additional design approaches for stable and robust superhydrophobic surfaces with self-cleaning properties. Hong and Uhm [118] prepared superhydrophobic CNTs by low-pressure CF 4 glow plasma to provide roughness and fluorination to CNTs. The total surface free energy of CNT powder treated by CF 4 plasma for 20 min was calculated to be drastically decreased from 27.04 to 4.06 × 10 -7 mJ/m 2 .…”

Dry Oxidation and Vacuum Annealing Treatments for Tuning the Wetting Properties of Carbon Nanotube Arrays

“…Several examples of these nanostructured materials include ZnO, 12,13 SiO 2 , 12,14 ITO, 12 and carbon nanotubes (CNT). [15][16][17] We believe that the ability to reversibly tune the wetting properties of CNT has its own virtue since they are considered as one of the most promising materials for future applications.…”