Abstract
Flexible dielectric materials with high dielectric constant and low loss have attracted significant attention. In this work, we fabricated novel polymer-based nanocomposites with both homogeneously dispersed conductive nanofillers and ion-conductive nanodomains within a polymer matrix. An unsaturated ionic liquid (IL), 1-vinyl-3-ethylimidazolium tetrafluoroborate ([VEIM][BF4]), was first coated on the surface of multi-walled carbon nanotubes (CNTs) by the mechanical grinding. The ILs coated CNTs were then well dispersed in poly(vinylidene fluoride) (PVDF) matrix by melt-blending. The ILs on the surface of CNTs were subsequently grafted onto the PVDF chains by electron beam irradiation (EBI). The formed ILs grafted PVDF (PVDF-g-IL) finally aggregated into ionic nanodomains with the size of 20–30 nm in the melt state. Therefore, novel PVDF nanocomposites with both homogenously dispersed CNTs and ionic nanodomains were achieved. Both carbon nanotubes and ionic nanodomains contributed to the enhancement of the dielectric constant of PVDF significantly. At the same time, such homogeneously dispersed CNTs along with the confined ions in the nandomains decreased current leakage effectively and thus led to the low dielectric loss. The final PVDF nanocomposites exhibited high dielectric constant, low dielectric loss and good flexibility, which may be promising for applications in soft/flexible devices.
Highlights
Dielectric materials have attracted significant attention in terms of their energy storage applications [1,2,3,4]
carbon nanotubes (CNTs) can enhance the dielectric constant of poly(vinylidene fluoride) (PVDF) at a low levels, their agglomeration nature due to the Polymers 2017, 9, 562; doi:10.3390/polym9110562
It is very interesting to find in the present work that the nano-PVDF/ionic liquid (IL)-CNTs samples loss
Summary
Dielectric materials have attracted significant attention in terms of their energy storage applications [1,2,3,4]. Extensive investigations have been carried out to make the composites by combining the high-permittivity inorganic [5,6,7,8,9,10,11] or conductive nanofillers [12,13,14,15,16,17,18] with flexible polymers. Among the numerous dielectric polymer composites, poly(vinylidene fluoride)/carbon nanotubes (PVDF/CNTs) nanocomposites have been extensively investigated [19,20,21,22,23]. CNTs can enhance the dielectric constant of PVDF at a low levels (below the percolation threshold [19]), their agglomeration nature due to the Polymers 2017, 9, 562; doi:10.3390/polym9110562 www.mdpi.com/journal/polymers
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have