Epoxy‐based coatings containing bentonite and ZnO obtained by modified solution blow spinning

Abstract Active coatings have been extensively studied due to their ability to contain active substances that can promote ab/adsorption and/or catalysis of compounds of interest. In this work, solution blow spraying (SBSp), which is a modification of the solution blow spinning (SBS), was used to produce active coatings via a multistep process: The first stage consisted in applying a cross‐linkable polymer layer (epoxy) to a metallic substrate, followed by heating at 50°C to promote partial cross‐linking; in the second step, particle suspensions containing zinc oxide (ZnO) and/or bentonite/ZnO were sprayed over the resin layer so that particles adhered to the surface rather than embedded in, what would reduce surface activity. Primarily, rheology of the suspensions and resin cure were characterized by rheometry and differential scanning calorimetry (DSC), respectively. Infrared spectroscopy and scanning electron microscopy of the ZnO synthesized by the Pechini method was performed. Coatings were analyzed by optical microscopy (OM), scanning electron microscopy (SEM), and x‐ray diffraction (XRD). Based on the suspension studies, the optimized particle concentration was found to be 10 wt% in water. Thermal analysis of resin showed the ideal time and temperature of 16 min or 33 min at 50°C. Using these variables, active coatings with ZnO and bentonite/ZnO particles exposed to the surface were successful produced by SBSp.