Space Charge Characters in PDMS/SiO 2 Nanocomposites at Different Temperatures Under DC Electric Field

Dielectric elastomers (DE) have attracted great attention from researchers due to their great potential for application in energy conversion devices. Among them, silicone elastomer stands out for its excellent characteristics such as softness and flexibility, heat resistance, chemical resistance and insulation properties. When used in energy transducers at high temperatures, silicone elastomers are always subjected to multiple stresses including the mechanical, thermal and electrical stresses. In this case, the insulation performance influenced by the space charge accumulation and the distorted electric field distribution should be considered. In this paper, the space charge profiles in the undoped PDMS and its composites added with two kinds of nano-sized SiO2 (2 phr) were studied using the pulsed electro-acoustic (PEA) method. The influence of temperature on the space charge accumulation and electric field distortion in the film is discussed. The results show that the higher the temperature, the larger the charge formation and the maximum electric field distortion. Compared with the undoped PDMS, the accumulation of space charge near electrodes and inside the film is strongly reduced by the introduction of nano-sized particles.