Effect of Polyaniline Content on the Photoelectric Properties and Corrosion Resistance of Titanium Dioxide/Polyaniline/Epoxy Composite Coatings

Introduction: Industrial activities have contributed to ecological acidification and pollution, creating conditions that accelerate material corrosion. Anticorrosion coatings (which are easy to apply) can be used to form a protective barrier on metallic surfaces. They physically or chemically impede corrosive reactions and reduce corrosion rates, making them commonly used in the field of metal corrosion prevention. Methods: Binary TiO2/PANI composite materials were synthesized via in-situ oxidative polymerization. Then, the titanium dioxide /Pani composite was stirred by adding organic matter and a curing agent. The Q235 carbon steel was pretreated. The photocurrent density time (I-T) and open circuit potential time (OCP-T) curves of different composite coatings were measured by an electrochemical workstation and electrochemical analyzer. Results and Discussion: Based on analysis of the photocurrent-time and photovoltage- time curves, the TiO2/PANI-3 composite coating exhibited the best photoelectrochemical cathodic protection performance for Q235 carbon steel in this experiment. Additionally, TiO2/PANI nanocomposites, when added as functional fillers to the EP resin, enhanced the protective performance of the EP coating on the Q235 carbon steel substrate, regardless of the light exposure. Conclusion: These findings highlight the beneficial effects of the TiO2/PANI composite nanoparticles in enhancing both the photoelectrochemical properties and corrosion resistance of EP coatings on Q235 carbon steel surfaces.