Synergic behavior of graphene-based filler and thermochromic pigments in cataphoretic coatings

This study aims to assess the synergic effect of graphene-based filler and thermochromic pigments on the protectiveand aesthetical performances of cataphoretic acrylic coatings. The nature of the thermochromic pigmentswas investigated by electron microscopy observations and infrared spectroscopy analysis. The aesthetical featuresof the coatings were evaluated by colorimetric measurements, estimating the colour change with temperature due to the filler addition. The corrosion protection properties were assessed by means of salt spray chamber exposure and electrochemical impedance spectroscopy measurements, which evidenced a negative contribution of the combined presence of functionalized graphene oxide flakes and thermochromic pigments. Otherwise, the incorporation of both the two fillers improved the abrasion resistance of the cataphoretic coating, as observed thanks to scrub test, as well as its aesthetical performances after chemical degradation due to UV-B exposure. Thus, this work highlighted both the positive and the negative effects caused by the synergy of reinforcing graphene-based fillers and functional pigments on the properties of cataphoretic coatings.