Effect of dc-bias on the dielectric behavior of CNT/ABS nanocomposites

Several aspects of the dielectric behavior of multi-walled carbon nanotube (MWCNT)/acrylonitrile–butadiene–styrene (ABS) nanocomposites were studied. MWCNT/ABS nanocomposites with filler content between 2 wt% and 15 wt% were prepared by melt mixing and characterized by the impedance technique. The results showed that the dc and ac conductivities increase with increasing dc bias and MWCNT content. The effect of dc bias was more pronounced for nanocomposites with low MWCNT content. The bode diagram of the real impedance for nanocomposites containing 2 wt% MWCNT or higher exhibited a frequency independent plateau in the low frequency region revealing that dc conduction is the dominant conduction mechanism. The critical frequency at which ac conductivity becomes frequency dependent increased with increasing dc bias and MWCNT content.