scholarly journals Greatly enhanced dielectric permittivity in La1.7Sr0.3NiO4/poly(vinylidene fluoride) nanocomposites that retained a low loss tangent

RSC Advances ◽  
2017 ◽  
Vol 7 (28) ◽  
pp. 17128-17136 ◽  
Author(s):  
Keerati Meeporn ◽  
Prasit Thongbai ◽  
Teerapon Yamwong ◽  
Santi Maensiri

The effect of La1.7Sr0.3NiO4 nanoparticles (LSNO-NPs) on the dielectric properties of LSNO-NPs/polyvinylidene fluoride (LSNO-NPs/PVDF) composites is presented.

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3641
Author(s):  
Kanyapak Silakaew ◽  
Prasit Thongbai

This work provided an alternative route to balance the significantly increased dielectric permittivity (ε′) and effectively retained tanδ using an effective two-step concept. Ag-deposited nano-sized BaTiO3 (Ag-nBT) hybrid particle was used as the first filler to increase the ε′ of the poly(vinylidene-fluoride) (PVDF) polymer via the strong interfacial polarization and a high permittivity of nBT and suppress the increased loss tangent (tanδ) owing to the discrete growth of Ag nanoparticles on the surface of nBT, preventing a continuous percolating path. The ε′ and tanδ values at 103 Hz of the Ag-nBT/PVDF composite with fAg-nBT~0.29 were 61.7 and 0.036. The sub-micron-sized BaTiO3 (μBT) particle was selected as the blocking particles to doubly reduce the tanδ with simultaneously enhanced ε′ due to the presence of the tetragonal BT phase. The μBT blocking particles can effectively further inhibit the formation of conducting network and hence further reducing tanδ. By incorporation of μBT clocking particles with fμBT = 0.2, the ε′ value of the Ag-nBT/PVDF-μBT composite (fAg-nBT = 0.30) can significantly increase to 161.4, while the tanδ was reduced to 0.026. Furthermore, the tanδ was lower than 0.09 in the temperature range of −60–150 °C due to the blocking effect of μBT particles.


RSC Advances ◽  
2020 ◽  
Vol 10 (66) ◽  
pp. 40442-40449
Author(s):  
Pornsawan Kum-onsa ◽  
Nutthakritta Phromviyo ◽  
Prasit Thongbai

Three-phase gold nanoparticle–Na1/2Y1/2Cu3Ti4O12 (Au–NYCTO)/poly(vinylidene fluoride) (PVDF) composites with 0.095–0.487 hybrid particle volume fractions (f) were fabricated.


2018 ◽  
Vol 33 (1) ◽  
pp. 138-149 ◽  
Author(s):  
MA Ramazanov ◽  
AM Maharramov ◽  
HA Shirinova ◽  
Luca Di Palma

In the present study, the effect of magnetite (Fe3O4) nanoparticles on the structural and dielectric properties of poly(vinylidene fluoride) (PVDF) matrix was investigated. Distribution of Fe3O4 nanoparticles in the polymer matrix has been studied by scanning electron microscopy (JEOL JSM-7600 F). The structure of the nanocomposite samples was investigated by the X-ray diffraction and Fourier-transform infrared spectroscopy. It was shown that the dielectric permittivity of PVDF + Fe3O4 nanocomposite samples was gradually increased up to 7 wt% of Fe3O4 content. Further increase in the concentration of the filler leads to decrease in the dielectric permittivity. The subsequent decrease in dielectric permittivity at higher Fe3O4 content can be explained by the increase in defects in the structure of the nanocomposite. The comparison of experimental data and the results of theoretical calculations show that the reduction in the empirical value of dielectric permittivity of the nanocomposite is obviously linked with the threshold value of filler. While calculating the theoretical value of the dielectric permittivity for the higher content of the filler, defects in the nanocomposite structure should be considered.


2021 ◽  
pp. 095400832110311
Author(s):  
Dandan Yuan ◽  
Rundi Yang ◽  
Yuanting Xu ◽  
Xufu Cai

Poly(vinylidene fluoride) (PVDF)-based composites attract tremendous attention as dielectric materials. However, their development has been limited due to the raised problem in the in-homogeneous polymer composites. In this work, a novel PVDF-based film incorporated with polyamide-1, containing the highest density of dipole among all polyamides, was prepared to improve the crystallization behaviors and dielectric properties. The results showed that the optimal concentration of polyamide-1 in PVDF was 6 wt.%. The crystallization rate of PVDF was improved in the presence of polyamide-1. Interestingly, the polyamide-1 was conductive to the formation of β form crystal of PVDF, which exhibited great electric performance. The dielectric constant of PVDF increased sharply and loss tangent still kept at a low level of 0.03@100 Hz when the concentration of polyamide-1 was 6 wt.%. This work may provide a new direction to design dielectric materials for PVDF blends.


Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6952
Author(s):  
Nateeporn Thongyong ◽  
Narong Chanlek ◽  
Pornjuk Srepusharawoot ◽  
Prasit Thongbai

The Mg2+/Ta5+ codoped rutile TiO2 ceramic with a nominal composition (Mg1/3Ta2/3)0.01Ti0.99O2 was synthesized using a conventional solid-state reaction method and sintered at 1400 °C for 2 h. The pure phase of the rutile TiO2 structure with a highly dense microstructure was obtained. A high dielectric permittivity (2.9 × 104 at 103 Hz) with a low loss tangent (<0.025) was achieved in the as-sintered ceramic. After removing the outer surface, the dielectric permittivity of the polished ceramic increased from 2.9 × 104 to 6.0 × 104, while the loss tangent also increased (~0.11). The dielectric permittivity and loss tangent could be recovered to the initial value of the as-sintered ceramic by annealing the polished ceramic in air. Notably, in the temperature range of −60–200 °C, the dielectric permittivity (103 Hz) of the annealed ceramic was slightly dependent (<±4.4%), while the loss tangent was very low (0.015–0.036). The giant dielectric properties were likely contributed by the insulating grain boundaries and insulative surface layer effects.


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