Flexible Carbon Nanotubes/Polystyrene Membranous Composites Toward Ultraweakly and Frequency-Stable Negative Permittivity at kHz Region

Xinxue Tang1,9

Zheng Zhang2

D Jaya Prasanna Kumar3

Yunpeng Qu1,Email

Yunchen Long4

Peitao Xie5,6,Email

Gemeng Liang7

Jiaqi Wang5

Qingqing Yang5

Xiaosi Qi1,Email

Zhanhu Guo8

1College of Physics, Guizhou University, Guiyang 550025, China
2Department of Applied Mathematics, The Hong Kong Polytechnic University, Hong Kong, China
3Department of Chemical Engineering, Ramaiah Institute of Technology, Bengaluru-560054, India
4Department of Chemical Engineering, School of Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
5College of Materials Science and Engineering, Qingdao University, Qingdao 266071, China
6Foshan (Southern China) Institute for New Materials, Foshan, 528200, China
7School of Chemical Engineering & Advanced Materials, The University of Adelaide, Adelaide, Australia
8Integrated Composites Lab, Department of Mechanical and Construction Engineering, Northumbria University, Newcastle Upon Tyne, NE1 8ST, UK
9School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, China 

 

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. 

Flexible Carbon Nanotubes/Polystyrene Membranous Composites Toward Ultraweakly and Frequency-Stable Negative Permittivity at kHz Region