Publication details
Preparation of protective hydrophobic layers on aluminum using plasma polymerization at atmospheric pressure
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| Year of publication | 2022 |
| Type | Conference abstract |
| MU Faculty or unit | |
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| Description | Preparation of hydrophobic layers, and polymerization in general, is conventionally realized by the means of chemical processing. Besides monomers, these methods also require the use of solvents and catalysts, which produce additional toxic waste. Plasma polymerization (PP) is a method by which polymer-like layers are deposited using a plasma source. Highly reactive particles produced by the plasma activate a gaseous or liquid monomer present in the working gas in order to start the PP process [1]. The prepared functional layers are mechanically and chemically resistant, insoluble, thermally stable and homogeneous due to their high degree of monomer cross-linking, and they adhere well to different types of surfaces [2]. Further advantages of PP include generally lower costs than conventional polymerization methods and the ability to control multiple working conditions (input power, exposure time, electrode system configuration, etc.) to create layers of a precisely defined thickness and chemical functionality. Therefore, plasma polymerization can be considered a promising and environmentally friendly method of hydrophobic-layer preparation. Many works on the topic of pp(plasma polymerized)-hydrophobic layers deal with polymerization of hexamethyldisiloxane (HMDSO). The presented work builds on our previous promising research in this field related to PP of HMDSO on aluminum [3] and glass substrates [4]. The main objective of this work is to carry out, study and optimize PP of HMDSO using plasma generated by a Diffuse Coplanar Surface Barrier Discharge (DCSBD) on aluminum substrate. Nitrogen was used as the carrier gas with admixtures of HMDSO in different concentrations. Water contact angle measurements were used to evaluate wettability of the sample surfaces and confirmed the hydrophobic effect of the pp-HMDSO layer. ATR-FTIR and XPS analyses were conducted to show the presence of the characteristic chemical groups corresponding to the pp-HMDSO layer as well as to determine its chemical composition. We observed the PP process at various working conditions and showed how they are related to the resulting hydrophobicity of the prepared layers. The effect of plasma post-treatment on already polymerized layers was also studied. Importance of securing the optimal distance between the sample and the DCSBD ceramic was demonstrated. |