Flexible fluorinated multi-walled carbon nanotube/polyarylene ether nitrile metacomposites with negative permittivity

Abstract

Flexible metacomposites demonstrating negative permittivity have shown promising applications in flexible electronics. In this work, flexible fluorinated multi-walled carbon nanotube/polyarylene ether nitrile porous metacomposite films (FMWCNT/PEN) with negative permittivity have been fabricated via a delayed phase inversion method. FMWCNT, which demonstrates excellent dispersion in PEN, was prepared via the fluorination of MWCNT by treating it with NaOH and HF sequentially, and then characterized by XPS, XRD, FT-IR, Raman spectroscopy, SEM and TEM. SEM observations indicate the honeycomb porous structure of FMWCNT/PEN, and FMWCNT disperses homogeneously on the surface of the walls of the porous PEN matrix. The results show that a continuous conductive network is formed in the FMWCNT/PEN porous metacomposite at an FMWCNT content as low as 2 wt%, resulting in a plasma-type negative permittivity spectrum of FMWCNT/PEN via the plasma oscillation of the delocalized charge carriers in the system. In addition, the FMWCNT/PEN metacomposite reveals outstanding flexibility with an elongation at break of 80.3% and stable dielectric properties even after 50 folding and unfolding cycles. This work shows an innovative technique to realize metacomposites demonstrating regulable negative permittivity and outstanding mechanical properties.