Atmospheric plasma polymer films as templates for inorganic synthesis to yield functional hybrid coatings

Abstract

Plasma polymer films produced via dielectric barrier discharge under atmospheric conditions can simultaneously host charged segments and poly(dimethysiloxane)/silica like polymers. The former segments afford some anion exchange properties and the latter ones allow stabilization of the whole coating in the presence of water. The anion exchange capacity of the film can then be used to nucleate and to grow inorganic particles in the plasma polymer coating. In particular, we exploit the presence of allylamine oligomers in a plasma coating made from a mixture of allylamine and hexamethyldisiloxane to hydrolyse titanium(IV) (bisammonium lactato dihydroxyde) and to condense it in TiO₂. As a second example, Prussian Blue is produced by the successive incubation of the coating in a solution of potassium hexacyanoferrate and iron(III) chloride. The distribution of TiO₂ and of Prussian Blue across the film thickness is investigated, in a semi quantitative manner, by means of Rutherford backscattering. The functional properties of the hybrid coatings are then investigated and it is found that the TiO₂ containing films display photoinduced hydrophilicity whereas the films with Prussian Blue display magnetic properties.