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Highlights • Modifying electrical contacts by electropolymerization of MMA is studied. • Ten times increase in the corrosion resistance of electrical contacts is observed. • The electrical resistance increased, but remained well below the accepted limit. • Cathodic electrodeposition of PMMA effectively sealed the pores of Au top-layer. Abstract Cu/Ni-P/Au multi-layer systems are employed as electrical contacts. The Au top-layer is thin and porous. These pores deliver the corrosive media to the under-layer, which induces the corrosion by a galvanic coupling mechanism. Therefore, filling these pores is essential to improve the lifetime of electronic devices. The pores can be sealed by the electrodeposition of poly(methyl methacrylate) that decreased the porosity index (about 97%) and increased the corrosion resistance (about 10 times) of electrical contacts after 10 cycles of electropolymerization. A non-uniform polymeric film, however, was formed at higher number of polymerization cycles (> 50) that decreased the corrosion resistance. [ABSTRACT FROM AUTHOR]

To promote adherence, hydrophilicity and corrosion properties, TiO 2 nanotubes, compact TiO 2 films and a combination of them were formed on Ti6Al4V alloy using only electrochemical methods. Nanostructured arrays being largely studied, the work was focused on the compact layer and the effect of the additional anodization. Corrosion results in physiological conditions were supported by surface and cross-section observations to choose the best protective treatment. Contact angles were measured to have an idea of osseointegration properties. The ageing of the surface reducing the hydrophilicity, two activation treatments were proposed to recover the good initial values. Finally, interfacial adhesion was evaluated by tensile tests. Corrosion and adhesion properties of the nanotube layer (i pass : 16 μA·cm−2, pull-out surface: 100 %) can be significantly improved by the second anodization (i pass : 0,12 μA·cm−2, pull-out surface: 0 %) that seals the bottom of the tube by an underneath compact oxide layer, preserving their hydrophilicity property. [Display omitted] • Dual treatments improve adhesion and corrosion properties. • Anodizing conditions influence the topography and thickness of the oxide layer. • Hydrophilicity properties increase on simple or combined nanostructured samples. • UV or chemical activations restore the initial hydrophilicity of the surface. [ABSTRACT FROM AUTHOR]