Plasma oxidation of plasma deposited polystyrene (pPS) films was performed in an inductively coupled plasma reactor. Reconstruction of the oxygen concentration depth profiles based on angle‐resolved XPS data showed that two competitive mechanisms (functionalization and etching) happened during the oxygen plasma treatment. Static water contact angle measurements confirmed this result. Oxidized pPS films were also not stable with time; a loss of hydrophilicity was observed and reorganization of the topmost functionalized surface occurred involving diffusion of oxygen groups from the surface towards the bulk and re‐contamination by reaction of trapped radicals with hydrocarbon molecules present in ambient air.

In this work, WO 3 films loaded with different amounts of Ag atoms, prepared by screen-printing onto Si substrates and annealed in air at 300 and 600 • C, were investigated. Atomic force microscopy micrographs showed that the films are nano-particulate with increasing final grain size on increasing the annealing temperature and/or Ag loading level. The observation of a Raman band near 930 cm −1 , whose intensity increased on increasing the level of Ag loading for the samples annealed at 600 • C, suggests the intercalation of Ag into WO 3 tunnels; this is supported by the presence of a peak at 32 eV binding energy in the high-resolution x-ray photoelectron (XP) spectra. From the analysis of the W 4f core level XP spectra it was also observed that when the level of Ag loading increases, the component in the spectra associated to surface defects decreased; as the measured concentration of Ag in the films is 1.8 higher then the nominal one when the samples are annealed at 600 • C, the XPS observations strongly suggest that the Ag atoms migrate to the surface of the WO 3 grains, localizing at defect sites.

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Summary A new plasma reactor, set up with a large planar inductively coupled source, is used for the first time to deposit a polymer coating (pPS) from a styrene monomer. This work is devoted to the relationship between external plasma parameters and substrate topography, and pPS coating morphology, which is investigated by scanning electron microscopy and atomic force microscopy. Stainless steel, gold and glass surfaces are used as substrates. It is clearly demonstrated that the film morphology can be controlled by adjustment of RF input power, pressure. The analysis performed further reveals that the pPS film's characteristics strongly depend on the substrate topography and its electrical potential during the discharge. Finally, the plasma duration also strongly influences the morphology of the films. The morphologies obtained include smooth films without any specific feature, worm‐like structures, particles (nanometer‐ and micrometer‐sized) associated along preferential directions and randomly distributed particles (micrometer‐sized). The intrinsic topography of the substrate influences the film structure in the case of thin films (thickness lower than about 100 nm). Polymerization is suggested to take place at the surface in contact with the discharge rather than in the gas phase. Nucleation and growth start preferentially on substrate defects such as polishing scratches.

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