Understanding the surface condition of silicone rubber nanocomposite due to corona ageing using afm imaging and libs spectroscopy

Silicone rubber insulators undergo degradation when they are exposed to corona discharges. The present study explores the surface degradation behavior of silicone rubber alumina nanocomposites due to corona ageing using high-frequency AC voltage. The electric field distribution on the sample surface during corona ageing is simulated using COMSOL. The change in silicone rubber functional group is studied using Fourier transform infrared spectroscopy (FTIR) analysis. The influence of corona ageing time on the surface roughness recovery of silicone rubber nano alumina composites is studied using an atomic force microscope (AFM). The elemental distribution behavior and change in the emission spectra persistence time are analyzed during recovery period of corona-aged silicone rubber nanocomposites using Laser-Induced Breakdown Spectroscopy (LIBS) technique. The addition of alumina nanofiller to the silicone rubber improves the resistance to ageing due to corona discharge. Loss and recovery of hydrophobic property of silicone rubber due to corona aging were determined using static contact angle measurement. The results show a direct correlation between the contact angle and the surface roughness recovery characteristics. They indicate that the nanocomposite having a 5 wt% alumina content exhibits the highest resistance to corona discharge with least surface damage. Furthermore, fast recovery was observed in the first few hours after corona ageing, and most samples eventually regained their properties after about 8 hours of recovery time