Electrosynthesis of Silica Reservoir Incorporated Dual Stimuli Responsive Conducting Polymer-Based Self-Healing Coatings

The current work describes a unique corrosion-protective self-healing coating approach. Porous silica reservoirs were synthesized by the Stober process. The silica reservoirs were preloaded with a corrosion inhibitor (oxalic acid) (dopant) and simultaneously covered with polyelectrolytes layers. Using the cyclic-voltammetry approach, a silica reservoir was dispersed into the aniline oxalate solution to successfully produce the poly(aniline-silica reservoir) (PASR) coatings on a steel electrode. The number of cycles had a major influence on the development and thickness of the PASR coating. The presence of a reservoir during the repeating cyclic voltammetry scans limits the polymer oxidation process. The composite coatings adhered well to the steel electrode and had excellent electroactive properties. The corrosion performance of PASR-coated steel was evaluated using electrochemical impedance spectroscopy and Tafel studies in 1% NaCl solutions. The enhanced corrosion prevention and self-healing function of this newly developed PASR coating was confirmed by a simulated corrosion process using the scanning vibrating electrode technique (SVET). The results imply that a dopant release caused by the corrosion process results in an anticorrosion/inhibition effect.