Multi-Scale Simulation of Dielectric Breakdown in Polymer Nanocomposites: The Role of Interface

Breakdown simulation has become a crucial tool in designing polymer nanocomposites with high breakdown strength. However, simulating the breakdown behavior of nanocomposites is difficult due to the complex interplay of various factors across different scales, such as mesoscopic structures and microscopic interfaces. Integrating multi-scale factors into a breakdown simulation framework to accurately predict the breakdown behavior presents a significant challenge. In this work, a multi-scale breakdown simulation model is established to investigate the mechanism of dielectric breakdown in nanocomposites, especially the role of interfaces in the breakdown process. The finite element method and molecular dynamics method are used to study the impact of mesoscopic structures and microscopic interfaces on breakdown, and the breakdown strength and path can be obtained by Monte Carlo-based simulation. It is found that considering only the mesostructure effect is insufficient to effectively predict the breakdown behavior. By introducing the interface effect, the simulated breakdown strengths agree well with experimental results. This work provides a new theoretical and methodological approach for a comprehensive understanding of the breakdown mechanism in nanocomposites, and is expected to be used for guiding the design of high-performance nanocomposites.