Electric and Dielectric Properties in Low-Frequency Fields of Composites Consisting of Silicone Rubber and Al Particles for Flexible Electronic Devices

Abstract

Understanding the electrical conduction and dielectric polarization properties of elastomer-based composites is important for the design of flexible and elastic electronic devices and circuits. Five samples were manufactured by mixing silicone rubber (RTV-530) with Al particles in different volume fractions, x equal to 0%, 0.5%, 1%, 2.5% and 5.1%. Using the complex impedance measurements, the electric modulus, M, the electrical conductivity, σ, and the dielectric permittivity, ε, over the frequency range 100 Hz–200 kHz were analyzed. The electrical conductivity spectrum, σ(f), follows the Jonscher universal law and the DC conductivity of the samples, σDC, increases from 2.637·10−8 S/m to 5.725·10−8 S/m, with increasing x from, 0 to 5.1%. The conduction process was analyzed in terms of Mott’s variable-range-hopping (VRH) model. The hopping distance of the charge carriers, Rh decreases with increasing x, from 7.30 nm (for x = 0) to 5.92 nm (for x = 5.1%). The frequency dependence of permittivity, ε(f) = ε′(f) − iε″(f), reveals a relaxation process with the maximum of ε″(f) shifting from 301 Hz to 385 Hz and values of ε′(f) increasing with the increase of x.

Effect of Inorganic Fillers on Electrical and Mechanical Properties of Ceramizable Silicone Rubber

“…The results show that the composites with BN and muscovite exhibited excellent insulating performances with a breakdown strength of 29.2 kV/mm and a failure rate of 5%, while the addition of YMT gave rise to a degraded insulating performance of SIR. Alexandrina et al [ 25 ] studied the effect of different volume fractions of Al particles on the conductivity and dielectric polarization characteristics of silicone rubber composites. Nowadays, CSR as a potential flame retardant material was seldom studied for power cables, and the effect of dopants on its ceramization process is still unclear.…”