Evaluation of the anticorrosive performance of epoxy coatings containing new core/shell pigments

Purpose - Core-shell is structured particles having several chemical compositions. The advantage of these particles arise from their specific design, to be used in decreasing costs by using inexpensive material (natural ore or waste material) as carrier for thin shell of active material. This study aims to prepare ferrites/silica core-shell pigments and compare their inhibition efficiency to original ferrites. These pigments have shells of different ferrites that comprise 10-15 per cent of the prepared pigments on silica fume. Silica fume which is the core is a byproduct in the ferro-silicon industry; this core comprises 85-90 per cent of the prepared pigments. Design/methodology/approach - The prepared core-shell pigments were characterized using transmission electron microscopy analysis, energydispersive X-ray analysis and sequential wavelength dispersive X-ray fluorescence. These pigments were integrated in epoxy-based paint formulations, and the physical, mechanical and corrosion properties of dry films were examined. The corrosion properties were studied by using immersion test in 3.5 per cent NaCl for 28 days. Findings - This study showed that these new eco-friendly and inexpensive pigments are similar to ferrites in their inhibition performance, i.e. they exhibited high corrosion prevention. Research limitations/implications - Domestic waste materials were reused in paints and only simple modification was used, and then, their effectiveness showed similar performance to that of the original pigments. Originality/value - Ferrite and ferrite/silica pigments are environmentally friendly pigments that can replace other hazardous pigments (e.g. chromates) with almost the same quality in their performance; also, they can be used in industries other than paints (e.g. paper, rubber and plastics composites).