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Plasma polymerized (pp) layers are promising owing to their ease of deposition. Moreover, incorporation of suitable nanoparticles into a polymer matrix can provide improved properties, for instance an increased corrosion resistance, to the final nanocomposite layer. The efficiency of such an incorporation is highly dependent of the layer structure in general, and more particularly of nanoparticles dispersion in the coating. The synthesis of a hybrid coating for anticorrosion purpose is described. Deposition of a plasma polymerized hexamethyldisiloxane (ppHMDSO) coating matrix with aluminum–cerium oxide nanoparticles incorporation is performed by means of an atmospheric pressure plasma reactor in a dielectric barrier discharge (DBD) configuration. Admixture of ethanol within hexamethyldisiloxane (HMDSO) is carried out in order to improve homogeneity and properties of the coating.

In this study, we explored thin films of nanofibrous functionalised conducting plasma polyaniline (pPANI) with platinum deposited by an atmospheric plasma deposition process for the potential design of anodes for hydrogen fuel cell applications. We observed that the incorporation of such a polymer, characterised by both electronic and ionic conductivity, associated with a catalyst in a 3D porous network, could lead to an increased probability of the three‐phase contact to occur. In this context, aniline was mixed with functionalised platinum nanoparticles and used as the precursor. The role of these functionalised nanoparticles was not only to act as the catalyst for fuel cell purposes, but also as nucleation sites promoting the formation of the nanofibrous pPANI thin film during the plasma polymerisation. The morphology of the thin film was analysed by scanning electron microscopy and the efficiency, in terms of energy conversion, was assessed in a single fuel cell test bench.

Finding alternative treatments to reproduce anticorrosion properties of chromated coatings is challenging since both physical barrier and self-healing effects are needed. Siloxane based treatments are known to be a promising way to achieve physical barrier coatings, mainly plasma polymerized hexamethyldisiloxane (ppHMDSO). In addition, it is known that cerium-based coatings can also provide corrosion protection of metals by means of self-healing effect. In this frame, innovative nanoAlCeO3/ppHMDSO layers have thus been deposited and studied. These combinations allow to afford a good physical barrier effect and active properties. Liquid siloxane and cerium-based particles mixture is atomized and introduced as precursors into a carrier gas. Gas mixture is then injected into an atmospheric pressure dielectric barrier discharge (DBD) where plasma polymerization of the siloxane precursor occurs. The influence of cerium concentration on the coating properties is investigated: coating structure and topography have been studied by scanning electron microscopy (SEM) and interferometry, and corrosion resistance of these different coatings is compared by electrochemistry techniques: polarization curves and electrochemical impedance spectroscopy (EIS). Potential self-healing property afforded by cerium in the layer was studied by associating EIS measurements and nanoscratch controlled damaging. Among the different combinations investigated, mixing of plasma polymerized HMDSO and AICeO3 nanoparticles seems to give promising results with a good physical barrier and interesting electroactive properties. Indeed, corrosion currents measured on such coatings are almost as low as those measured with the chromated film. Combination of nanoscratch damaging of layers with EIS experiments to investigate self-healing also allow to measure the active protection property of such layers.

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