Effect of Silica Content and Surface Chemistry on the Dielectric Performance of Silicone Rubber

Commercial silicone rubbers are typically pre-filled with fumed silica (SiO
2
). Interestingly, such products might still be considered “unfilled” matrices for further nanodielectric improvements rendering interpretation and repeatability challenging. This study reports on the dielectric performance of entirely unfilled silicone rubbers and their (SiO
2
-) filled counterparts and compares these systems with the commercial Sylgard 184. It is shown that the critical (SiO
2
) contents vary significantly with surface chemistry. The DC conductivity and dielectric losses of the bespoke systems display “bathtub” characteristics with optimum fill-grades showcasing performance similar or superior to the commercial product.