Preparation of lanthanide aluminate‐encapsulated silica nanoparticles toward long‐persistent photoluminescent polymer paint with superhydrophobic and anticorrosion properties

Abstract Smart afterglow paints can function as energy‐saving products that are able to persist lighting in the dark. Additionally, polyurethane paints (PURPs) have shown some limitations, including weak adhesion, poor mechanical performance, poor corrosion, and low water resistance as compared with solvent‐based paints. Herein, nanoparticles of lanthanide aluminate (NLA; 16–24 nm) were mixed with polyurethane and silica to develop novel photoluminescent nanocomposite paints. A precursor of NLA‐encapsulated silica nanoparticles (NLA@Silica; 200–225 nm) can be described as a SiO 2 ‐coated NLA pigment prepared by the heterogeneous precipitation method. Steel was coated with nanocomposite paints made of PURP, silica, and NLA. Using emission spectra and Commission Internationale de l'Eclairage (CIE) Lab coordinates, the coloring and transparency of painted films were investigated. Upon excitation at 365 nm, the UV‐irradiation of transparent painted films showed green emission at 518 nm. The hydrophobic activity and hardness properties were examined. Using electrochemical impedance spectroscopy (EIS), the anticorrosion of coatings applied to mild steel was studied. Improved anticorrosion characteristics were observed due to the fluorescence of NLA@Silica in the applied coatings. The optimal long‐lasting luminous characteristics were observed for nanocomposite films containing 12.5% of NLA@Silica.