Enhanced dielectric and thermal properties of Zn/PVDF composites by tailoring core@double-shell structured Zn particles. (June 2022) - Li, Ting
Graphical abstract: Highlights: A unique core@double-shell structured Zn/PVDF composites have been designed. High ε in percolative polymer composites is contributed by inter- and intra-particle polarizations. The formation of charge traps along the double interface suppressed tan δ . Achieving high ε, low loss, improved TC in the developed composites. Abstract: In this study, poly(vinylidene fluoride) (PVDF) composites containing a core@double-shell structured zinc (Zn) filler (i.e., Zn@ZnCH@ZnO) were synthesized. The primary focus is to investigate the effect of double shell on the polarization mechanism of composites by analyzing the dielectric properties and fitting the experimental data with a Havriliak–Negami (HN) expression. The results verify that the Zn@ZnCH@ZnO/PVDF composites exhibit prominently enhanced dielectric constant, suppressed loss and conductivity over pure PVDF and the pristine Zn/PVDF thanks to induced multiple polarizations generated in the core@double-shell configuration. The fitting curves reveal that the multiple polarizations are derived from the combined contributions of the α relaxation of PVDF, fast intra-particle polarization and slow inter-particle polarization. Furthermore, the thermal conductivity of Zn@ZnCH@ZnO/PVDF composites is enhanced by changing the amorphous ZnCH to crystalline ZnO shell promoting phonon transport. This work opens a new avenue to obtain comprehensively good performances of dielectric composites for potential application in microelectronics.