Synthesis and Characterization of Nano-SiO2@octadecylbisimidazoline Quaternary Ammonium Salt Using as Acidizing Corrosion Inhibitor

Aiming at the current situation that the existing acidizing corrosion inhibitors are difficult to apply to high temperature, high concentration acid, and other complex conditions. This paper uses nano-SiO2 as the core and preferably functional monomers to synthesize nano-SiO2@octadecylbisimidazoline quaternary ammonium salt. Analytical methods such as nuclear magnetic resonance, infrared, SEM were used for characterization. The corrosion inhibition performance of the N80 steel sheet by nano-SiO2@octadecylbisimidazoline quaternary ammonium salt 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-SiO2@octadecylbisimidazoline quaternary ammonium salt has good high-temperature resistance. When the temperature is 180℃ and the dosage of nano-SiO2@octadecylbisimidazoline quaternary ammonium salt is 4%, the corrosion inhibition rate is 61.42g·m− 2·h− 1. Studies have shown that the adsorption of nano-SiO2@octadecylbisimidazoline quaternary ammonium salt on the surface of the N80 steel sheet follows the Langmuir isotherm adsorption model, which is spontaneous chemical adsorption.