Dielectric Properties of Epoxy Composites Containing Silver Nanoparticle and Carbon Nanotube over the X-Band Frequency

Abstract

Materials with high dielectric properties have become interested due to their important applications, mainly in electronics and energy storage. This study assesses the dielectric properties of epoxy composites containing silver nanoparticles (AgNPs) and carbon nanotube (CNT) composite materials. These samples' permittivity and reflective properties were measured using Vector Network Analyser (VNA) within the X-band frequency (8.2 – 12.4 GHz). Samples were prepared at various loading (0.1-5 wt.%), with various thickness of (0.5, 1.0, 1.5 and 2.0 mm). Regardless of the fillers loading and sample thickness, it was found that the values of real permittivity, er', remain constant along the frequency range. At the same sample thickness, it was found that the values of both er' and er'' increase as loading increases, indicating the function of AgNPs and CNT in enhancing the dielectric and electrical conductivity properties of epoxy composites, respectively. The highest value of er' is recorded as 5 F/m (at f = 8.2 GHz), measured at 5 wt.% loadings and 0.5 mm sample thickness. Measurement on S11 parameters at f = 8.2 GHz indicated that the SER values are between 9 dB and 15 dB, with no obvious pattern observed, regardless of the fillers loading and sample thickness. This study highlights the dielectric properties improvement of epoxy composites by incorporating dual fillers.