Molecular Dynamics on Interfacial Interaction Between Modified Nano-SiO2 and H3O+ in Ester Insulating Oil

As an emerging environmentally friendly liquid insulation material, natural ester requires thorough performance research for its widespread adoption in electrical equipment. The utilization of nanotechnology to improve the performance of various liquids has been underway for several decades. For insulating liquid materials, the systematic incorporation of nanoparticles into the base liquid has illustrating its effectiveness in enhancing the thermal-electrical properties. Herein, this work investigates the interfacial interaction between surfactant modified nanoparticles and natural ester insulation oil (triglycerides and typical aging products) via molecular dynamic simulation and density functional theory. The simulation results showed that the interfacial interaction between KH550-SiO2 and H3O+ is negative, demonstrating the adsorption effect on H3O+. Furthermore, the ESP (electrostatic potential) and frontier molecular orbitals analysis suggested that the attraction of KH550-SiO2 on positive charged particles in natural ester, resulting in a limitation on H3O+ ions diffusion behavior.