Applied Surface Science, Vol.472, 127-134, 2019
Obtaining of superhydrophobic surface in RF capacitively coupled discharge in AR/CH4 medium
The aim of this work was to obtain superhydrophobic surfaces in a plasma medium. The experiment was carried out using the Plasma-Enhanced Chemical Vapor Deposition (PECVD) method in two different modes: constant and pulsing. The surface roughness was obtained by applying nanoparticles synthesized in a plasma in a mixture of argon and methane. The resulting particles were deposited on the surface of silicon and glass materials. The dependence of the contact angle on the nanoparticle application cycle on the surface was obtained. The contact angle increased linearly depending on the number of cycles, until it reached 160 degrees at 150-160th cycles, after that the increase in cycles does not affect the contact angle, since the saturation process is in progress. Also the effect of the working gas composition on the hydrophobicity of the surface was studied. At low concentrations of methane (1%) only particles are synthesized in the working gas, and hydrophobicity is unstable, with an increase in methane concentration (7%) nanofilms are synthesized from nanoclusters, and surface hydrophobicity is relatively stable. In addition, a pulsing plasma mode was used to obtain superhydrophobic surfaces. A nanofilm consisting of nanoclusters with a diameter of 4-10 nm was synthesized. The hydrophobicity of the sample showed that the strength of the nanofilm was stable in comparison with the sample obtained in the first mode, but the contact angle was lower. The obtained samples were examined using SEM, SPM, optical analysis, and their contact angles were determined. The experiment was carried out at various plasma parameters. It was found that when a superhydrophobic surface is treated with a buffer plasma (argon), it becomes superhydrophilic. (C) 2018 Elsevier B.V. All rights reserved.