Plasma modification of vertically aligned carbon nanotubes: superhydrophobic surfaces with ultra- low reflectance
Christopher S. Yung, Nathan A. Tomlin, Karl Heuerman, Mark W. Keller, Malcolm G. White, Michelle S. Stephens, John H. Lehman
Vertically aligned carbon nanotubes (VACNTs) are excellent broadband (UVVISIR) absorbers of light that can be made even darker with plasma treatments. Modification of VACNTs using O2 and/or CF4 plasmas is shown to have a significant impact on the reflectance and water repellency. By combining the two plasma treatments we show that low reflectance and superhydrophobic surfaces can be made. Scanning electron microscopy indicates that both plasma treatments change the surface morphology of the VACNTs, which is associated with a corresponding measured reduction in spectral reflectance. Raman spectroscopy of as-grown and plasma treated samples suggest that plasma treatment is introducing defects and functionalizing the nanotube walls and thereby affecting the water repellancy. O2 plasma treated VACNTs have a directional-hemispherical (0°/h) reflectance of 94 ± 4 ppm (k = 2) at 660 nm and are superhydrophilic. O2 and CF4 plasma treated VACNTs have a 0°/h reflectance of 163 ± 7 ppm (k = 2) at 660 nm and are superhydrophobic with a contact angle of 159.
, Tomlin, N.
, Heuerman, K.
, Keller, M.
, White, M.
, Stephens, M.
and Lehman, J.
Plasma modification of vertically aligned carbon nanotubes: superhydrophobic surfaces with ultra- low reflectance, ACS Nano, [online], https://doi.org/10.1016/j.carbon.2017.10.093
(Accessed November 28, 2022)