During the past few years, there has been extensive research and development in the plasma-induced modification of surfaces. Plasma-assisted processes can nowadays be found in many applications, ranging from surface activation and cleaning to thin film deposition and etching. In this study, the treatment of aluminum 6061 substrates using an atmospheric pressure plasma jet (AAPJ-PlasmaTreat) operated in air and further thin film deposition by PE-CVD in organosilicon containing gas mixtures is reported. After a single pass treatment of aluminum samples by AAPJ in air, scanning electron microscopy (SEM) images reveal the formation of localized craters and porous micro-domains, similar to those observed in laser ablation. SEM analysis combined with Energy Dispersive Spectroscopy (EDS) measurements further indicate significant oxidation, leading to alumina-like surfaces. Based on optical emission spectroscopy of the second positive system of N2, the jet exhibits very high vibrational and rotational temperatures. Combined with the presence of randomly distributed sparks in the air APPJ, this indicates its capability of delivering relatively high amount of thermal energy in very localized region of the sample and over very short periods of time. This can in turn leads to the formation of thermal craters on the surface along with aluminum phase explosion sites, as seen in the experiments. By increasing the number of passes, highly uniform micro-porous surfaces with superhydrophilic properties can be achieved. The porous aluminum surfaces were then used as a substrate for the deposition of micro/nano-structured coatings by plasma polymerization using hexamethyldisiloxane (FMDSO) as the monomer. This coating exhibits multiple levels of roughness ranging from tens of micrometers to a few nanometers. Static and dynamic water contact angle measurements show that the surface is superhydrophobic with perfect roll-off behavior. Ice adhesion strength was also measured on the coating. It is shown that compared to a bare Al-6061 sample, such coating can reduce the ice adhesion strength by at least a factor of 3.
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