Abstract:
ABSTRACT
The present article reports the dynamic complex dielectric responses of non-polar nanocolloids of graphene (G) and carbon
nanotubes (CNTs). The frequency dependent complex relaxation behaviors of G and CNT colloids were determined in the range
of 100 Hz to 3 × 105 Hz employing dielectric spectroscopy at a constant temperature. The governing roles of nanostructure
concentration, conductivity, frequency, and amplitude variation of the forcing electric field on the dielectric response have been
examined. The experimental observations reveal that the presence of G or CNT, as well as their concentrations, significantly
governs the overall dielectric responses of the nanocolloids. The dilute and concentrated colloids display grossly distinguishable
capacitive and dissipative behaviors, hinting at the major role of concentration regimes on the dielectric behavior of such colloids.
In addition, the variation of electric field intensity results in altering the dielectric responses of the colloids, which points at the
role of polarization of the nanomaterials on the overall dielectric relaxation. To model the complex dipolar interactions, the
classical Havriliak-Negami model is employed and good agreement has been achieved against the experimental observations. It has
been observed that increasing nanomaterial concentration and field amplitude has a dominant influence upon the relaxation
parameters. Further, the effects of colloidal concentration on the AC and DC conductivity modes have also been analyzed. The
conductivity response of the colloids has been explained by appealing to percolation theories. The present article may find strong
implications toward the design and development of liquid dielectric based electrical and electronics systems.
