Flexible Carbon Nanotubes/Polystyrene Membranous Composites Toward Ultraweakly and Frequency-Stable Negative Permittivity at kHz Region
Xinxue Tang, Zheng Zhang, D. Jaya Prasanna Kumar, Yunpeng Qu, Peitao Xie, Gemeng Liang, Jiaqi Wang, Qingqing Yang, Qingqing Yang, Xiaosi Qi, Zhanhu Guo
Abstract
Negative permittivity (ε′ < 0) has been a vital and eye-catching electromagnetic parameter for designing new-generation electrical devices.However, ε′-negative materials generally suffer from the overhigh absolute value of ε′ and serious frequency dispersion, especially in the radio-frequency region.Hence, carbon nanotubes/polystyrene (CNTs/PS) membranous composites were ingeniously designed and fabricated by a spin-coating procedure.The ultraweakly and frequency-stable negative permittivity (ɛ′ ~ -200) was amazingly achieved over 10 kHz-1 MHz region, attributing to the weakly low-frequency plasmonic state within a 3-dimensional (3D) CNTs network.With increased CNTs content, hopping conduction behavior in composites evolved to metal-like conduction.The impedance analysis based on equivalent circuit models confirmed the inductive characteristic of ε′-negative materials.The obtained flexible CNTs/PS membranous composites could significantly enrich their application on novel wearable electrical devices.