Molecular Motion of Amorphous Silicone Polymers

In this paper, we have studied silicone polymers based on poly(dimethylsiloxane) (PDMS) molecules, which have versatile applications in many fields because of their flexible molecular properties. These polymers are of interest because when used for high-voltage insulation, surfaces exposed to weather need to be hydrophobic because a hydrophilic surface can cause leakage currents. Indeed, after damaging electrical discharges, self-recovery of the hydrophobic surface occurs, requiring molecular diffusion and surface reconstruction for repair. We use large-scale, all-atom molecular dynamics simulations that enable an atomic-level description of molecular motion in mixed, amorphous, PDMS-based materials. The local properties that contribute to enhanced molecular motion are characterized based on their local structural and electrostatic environment. With this knowledge, molecular components with desirable diffusion properties may be designed for improved material functionality.