Significantly improved dielectric properties of multiwall carbon nanotube-BaTiO₃/PVDF polymer composites by tuning the particle size of the ceramic filler

Abstract

The effects of different BaTiO 3 sizes (z100 nm (nBT) and 0.5-1.0 mm (mBT)) on the dielectric and electrical properties of multiwall carbon nanotube (CNT)-BT/poly(vinylidene fluoride) (PVDF) composites are investigated. The fabricated three-phase composites using 20 vol% BT with various CNT volume fractions (f CNT ) are systematically characterized. The dielectric permittivity (3 0 ) of the CNT-nBT/PVDF and CNT-mBT/PVDF composites rapidly increases when f CNT > 0.015 and f CNT > 0.017, respectively. The former is accompanied by the dramatic increase in the loss tangent (tan d) and conductivity (s), but surprisingly, not for the latter. At 10 3 Hz, the low tan d and s values of the CNT-mBT/PVDF composite are about 0.06 and 6.82 Â 10 À9 S cm À1 , while its 3 0 value is greatly enhanced (z154.6). The variation of the dielectric permittivity with f CNT for both composite systems follows the percolation model with percolation thresholds of f c ¼ 0.018 and f c ¼ 0.02, respectively. With further increasing f CNT to 0.02, 3 0 is greatly increased to 253.8, while tan d # 0.1. Without mBT particles, the 3 0 and tan d values of the CNT/ PVDF composite with f CNT ¼ 0.02 are as high as z240 and >10 3 , respectively. Greatly enhanced dielectric properties are described in detail.

Effects of Sub-Micro Sized BaTiO3 Blocking Particles and Ag-Deposited Nano-Sized BaTiO3 Hybrid Particles on Dielectric Properties of Poly(vinylidene-fluoride) Polymer

“…These disadvantages must be resolved to achieve the maximized properties using the blocking concept. According to our previous report [33], we found that the µBT particles could disperse multiwall carbon nanotube (MWCNT) in the PVDF polymer matrix better than that of nBT particles, giving rise to enhanced dielectric properties of the µBT/MWCNT/PVDF composites.…”

Surface silanized MWCNTs doped PVDF nanocomposite with self-organized dipoles: an intrinsic study on the dielectric, piezoelectric, ferroelectric, and energy harvesting phenomenology

“…The increase in dielectric loss is due to the poor distribution of MWCNTs inside the polymer matrix. 41 With the addition of 0.25 wt% MWCNT-APTES NPs the dielectric value reduced from $1.8 to $0.47, corresponding to good polymer matrix interaction with MWCNTs. A suitable interaction of MWCNT-APTES NPs with the PVDF matrix will diminish the percolation conduction pathways inside the matrix and reduce the dielectric loss.…”

Synergistic enhancement in mechanical, thermal, and dielectric properties of PANI@BT/PVDF composites by adding 2D nanoplatelets

“…One the other hand, it is expected that the insulate ceramics can prevent the conductive fillers from the mutual connection and forming percolation paths. 17,18 For instance, Shen et al introduced reduced graphene oxide (RGO) into polyvinylidene fluoride (PVDF) along with barium titanate (BT) particles. With only additional 1 wt% RGO, the dielectric constant of RGO/BT/ PVDF composites increased to 2.2 times that of BT/PVDF composites, accompanied with the maintenance of high breakdown strength ($150 kV/mm) and relatively low dielectric loss ($0.2@100 Hz).…”

“…The incorporating of conductive fillers can greatly reduce the addition of ceramic fillers, thus alleviating the performance degradation caused by the agglomeration of ceramic fillers. One the other hand, it is expected that the insulate ceramics can prevent the conductive fillers from the mutual connection and forming percolation paths 17,18 . For instance, Shen et al introduced reduced graphene oxide (RGO) into polyvinylidene fluoride (PVDF) along with barium titanate (BT) particles.…”