Keywords

carbon nanotubes, CNT, superhydrophobic coating, tunable geometry, superhydrophobic behavior

Abstract

Use of carbon nanotubes to create superhydrophobic coatings has been considered due to their ability to offer a relatively uniform nanostructure. However, carbon nanotubes (CNTs) may be considered delicate with a typical diameter of tens of nanometers for a multi‐walled CNT; as‐grown carbon nanotubes often require the addition of a thin‐film hydrophobic coating to render them superhydrophobic. Furthermore, fine control over the diameter of the as‐grown CNTs, or overall nanostructure is difficult. This work demonstrates the utility of using carbon infiltration to layer amorphous carbon on multi‐walled nanotubes to improve structural integrity and achieve superhydrophobic behavior with tunable geometry. These carbon‐infiltrated carbon nanotube (CICNT) surfaces exhibit an increased number of contact points between neighboring tubes, resulting in a composite structure with improved mechanical stability. Additionally, the native surface can be rendered superhydrophobic with a vacuum pyrolysis treatment, with contact angles as high as 160° and contact angle hysteresis on the order of 1°. CICNT diameter, static contact angle, sliding angle, and contact angle hysteresis were examined for varying levels of carbon‐infiltration to determine the effect of infiltration on superhydrophobicity. The same superhydrophobic behavior and tunable geometry was also observed with CICNTs grown directly on stainless steel without an additional catalyst layer. The ability to tune the geometry while maintaining superhydrophobic behavior offers significant potential in condensation heat transfer, anti‐icing, microfluidics, anti‐microbial surfaces and other bio‐applications where control over the nanostructure is beneficial.

Original Publication Citation

Kimberly A. Stevens, Christian D. Esplin, Taylor M. Davis, D. Jacob Butterfield, Philip S. Ng, Anton E. Bowden, Brian D. Jensen, Brian D. Iverson. (2018). Superhydrophobic, Carbon-Infiltrated Carbon Nanotubes on Si and 316L Stainless Steel with Tunable Geometry. Applied Physics Letters, 112(21). https://doi.org/10.1063/1.5034471

Document Type

Peer-Reviewed Article

Publication Date

2018-5

Publisher

AIP Publishing

Language

English

College

Ira A. Fulton College of Engineering and Technology

Department

Mechanical Engineering

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