Surface modification of dielectric materials by Ar/toluene DBD plasma for flotation and drag reduction

In this study, a new approach based on dielectric barrier discharge (DBD) plasma was used to fabricate super-buoyant dielectric materials for drag-reduction. We used a glass slide as a high-density substrate for buoyancy tests and a model boat made from Polymethyl methacrylate (PMMA) for drag-reduction experiments. In the first step, an atmospheric pressure DBD plasma was used for the deposition of the hydrogenated amorphous carbon (a-C:H) film using argon working gas and toluene precursors. The layer characterizations were performed versus the plasma deposition time by FE-SEM, AFM, FTIR, and Raman analysis. The morphological characterizations showed the formation of some micro and nanostructures on the surface followed by an increase in surface roughness. Moreover, the chemical characterizations suggested the successful formation of a-C:H film. In the next step, the effect of the deposited layer was assessed on the buoyance and drag reduction. Based on the results, the plasma coating produced a super-buoyant glass slide with remarkable load-bearing capacity, high durability, and robustness. In addition, the drag force was reduced noticeably after the plasma treatment. The results of this study promise the use of atmospheric pressure plasma for the fabrication of super-buoyant surfaces for buoyancy applications. Graphical abstract