Synthesis and characterization of nano-SiO2@octadecylbisimidazoline quaternary ammonium salt used as acidizing corrosion inhibitor

Abstract Aiming at the current situation that the existing acidizing corrosion inhibitors are difficult to apply in high temperature, high concentration acid, and other complex conditions, this article uses nano-SiO 2 as the core and preferably functional monomers to synthesize nano-SiO 2 @octadecylbisimidazoline quaternary ammonium salt (nano-SiO 2 @OBQA). Analytical methods such as nuclear magnetic resonance, infrared, and scanning electron microscopy were used for characterization. The corrosion inhibition performance of the N80 steel sheet by nano-SiO 2 @OBQA in 20% concentrated hydrochloric acid was studied using the high-temperature corrosion testing machine and adsorption isotherm model combined with quantum chemistry calculations to explore its mechanism of action. The results show that nano-SiO 2 @OBQA has good high-temperature resistance. When the temperature is 180℃ and the dosage of nano-SiO 2 @OBQA is 4%, the corrosion inhibition rate is 61.42 g·m −2 ·h −1 . Studies have shown that the adsorption of nano-SiO 2 @OBQA on the surface of the N80 steel sheet follows the Langmuir isotherm adsorption model, which is spontaneous chemical adsorption.