Understanding the Self-Healing Hydrophobic Recovery of High-Voltage Insulators
journal contributionposted on 21.06.2012, 00:00 by Philip T. Shemella, Teodoro Laino, Oliver Fritz, Alessandro Curioni
Amorphous siloxane polymers are designed to have high dielectric strength for use as high-voltage insulation materials. Surface hydrophobicity is essential and can be impaired by environmental, electrical, or mechanical factors, leading to leakage currents due to dielectric breakdown. Self-recovery is possible and is generally observed over a period of several hours. Using large-scale, all-atom molecular dynamics simulations, the surface wetting of water droplets on the polymer surface is simulated for various surface conditions, including oxidation and coating with small molecules, to understand the driving forces of the recovery process at the atomistic level, which is of primary importance for the developments of novel materials. In this work, we shed light onto the self-recovery mechanism and propose the use of low-molecular-weight (LMW) siloxane to accelerate the recovery of hydrophobicity.