Three-Dimensional random network of metacomposites by synergizing Multi-Walled carbon Nanotube-Carbon black for tunable Epsilon-Negative and Epsilon-Near-Zero responses

Abstract

Epsilon-near-zero (ENZ) and epsilon-negative (EN) responses are remarkable properties of electromagnetic (EM) metamaterials that have sparked considerable interest. This paper introduces an innovative strategy using ternary metacomposites that achieve excellently tunable ENZ (|ε’| < 1) and EN (ε’ < 0) parameters within the radio-frequency band. The approach leverages a synergistic effect of multi-walled carbon nanotube-carbon black (MWCNT-CB) composites integrated into a polyaniline (PANI) matrix to construct three-dimensional (3D) carbon networks. As the loading content of MWCNT-CB increases, these networks evolve from clusters, enabling a finely tunable range of EN parameters from 100 to 103. The ENZ response occurs at approximately 265 MHz and 830 MHz, triggered by dielectric resonance due to electric dipoles at MWCNT-CB/PANI interfaces and a low-frequency plasmonic state in the 3D MWCNT-CB networks, respectively. This research establishes a foundation for tunable ENZ and EN responses by introducing a new class of ternary metacomposites.