Achieving thermally conductive low loss PVDF-based dielectric composites via surface functionalization and orientation of SiC nanowires
B. Wang, X. H. Yin, D. Peng, R. H. Lv, B. Na, H. S. Liu, X. B. Gu, W. Wu, J. L. Zhou, Y. Zhang
Vol. 14., No.1., Pages 2-11, 2020
DOI: 10.3144/expresspolymlett.2020.2
DOI: 10.3144/expresspolymlett.2020.2
Corresponding author: B. Na 
GRAPHICAL ABSTRACT
ABSTRACT
Semi-conductive silicon carbide (SiC) nanowires were amino-functionalized to achieve better dispersion in poly(vinylidene fluoride) (PVDF) matrix. It was found that PVDF based composites with amino-functionalized SiC (f-SiC) nanowires exhibited lower loss tangent than their counterparts with bare SiC nanowires, especially at a filler loading of 13.8 vol%. The loss tangent at 1 kHz of PVDF/f-SiC nanowires (86.2/13.8, v/v) composite is only 0.048, which is nearly one quarter of that of its counterpart with bare SiC nanowires. The nearly one order of magnitude lower AC conductivity at 1 kHz is responsible for the remarkable decrease of the loss tangent, since the interlacing of f-SiC nanowires was avoided via their parallel orientation, facilitated by the enhanced interfacial interaction. In addition to the low loss, the PVDF/f-SiC nanowires (86.2/13.8, v/v) composite exhibited about twofold increase of the dielectric permittivity at 1 kHz, compared to neat PVDF. Moreover, the thermal conductivity of PVDF/f-SiC nanowires (86.2/13.8, v/v) composite was increased to twice that of neat PVDF. The thermally conductive, high dielectric permittivity, and low loss PVDF/f-SiC nanowires composites may find potential applications in capacitors for microelectronics.
