Role of a 3D Nanoskeleton in Hindering Electrical Tree Growth in Nanocomposites: Insights from in Situ Self-Fluorescence Imaging

Despitethe proposal of nanodielectrics in 1994, the impact ofnano- and microstructures on composite performance is still not completelyunderstood. A key reason for this knowledge gap is the lack of insitu characterization of micro- and nanoscale structures within materials.In this study, we observed the self-excited fluorescence of a microscale-damagedmicrochannel inside a composite under the influence of an electricfield. Furthermore, we conducted in situ imaging of the internal microstructuresand discharge channels in the composite utilizing external laser excitation.The imaging results reveal that the electrical treelike damage inthe composites grows with a single channel under the guidance of thenanoskeleton embedded in the matrix, which demonstrates that the three-dimensional(3D) nano-order skeleton hinders the development of electrical trees.Furthermore, we analyzed the nanoskeleton intervention's enhancementmechanism on the insulation properties of the composites. This workaids in the precision imaging-guided structural design of nanodielectrics.