In-situ preparation of hierarchical flower-like TiO2/carbon nanostructures as fillers for polymer composites with enhanced dielectric properties

Abstract

Novel three-dimensional hierarchical flower-like TiO2/carbon (TiO2/C) nanostructures were in-situ synthesized via a solvothermal method involving calcination of organic precursor under inert atmosphere. The composite films comprised of P (VDF-HFP) and as-prepared hierarchical flower-like TiO2/C were fabricated by a solution casting and hot-pressing approach. The results reveal that loading the fillers with a small amount of carbon is an effective way to improve the dielectric constant and suppress the dielectric loss. In addition, TiO2/C particles with higher carbon contents exhibit superiority in promoting the dielectric constants of composites when compared with their noncarbon counterparts. For instance, the highest dielectric constant (330.6) of the TiO2/C composites is 10 times over that of noncarbon-TiO2-filled ones at the same filler volume fraction, and 32 times over that of pristine P (VDF-HFP). The enhancement in the dielectric constant can be attributed to the formation of a large network, which is composed of local micro-capacitors with carbon particles as electrodes and TiO2 as the dielectric in between.

High dielectric constant epoxy nanocomposites containing ZnO quantum dots decorated carbon nanotube

“…31 However, surface modification of CNTs with low molecular weight surfactants or polymers usually leads to an adverse effect on glass transition temperature (T g ) and coefficient of thermal expansion of the hosting polymer, making it undesirable for microelectronic applications. 19,32 To overcome the disadvantages of organic coatings on MWCNT, inorganic materials, such as SiO 2 , 33 CuO, 34 and TiO 2 , 35 were used to modify the MWCNT surfaces to maintain the physical and mechanical properties of the hosting matrix. However, the poor dispersion of the inorganic particle-coated CNTs in their polymer matrices limited their effectiveness for property improvement.…”

Effect of oxygen and structural properties on the electrical conductivity of powders of nanostructured carbon materials

“…In the last decade, the study of filler materials that impart electrical conductivity in polymer composites has been implemented in order to be used for antistatic electricity, electromagnetic shielding, electronic components or electrodes in energy conversion electrochemical devices [1][2][3][4][5][6][7][8][9][10][11][12]. Among these fillers, nanostructured carbon materials exhibit clear advantages over the use of metal powders or fibers as filler, according to their high electrical and thermal conductivities, potentially low production cost, oxidation stability or low density [5].…”

Enhanced energy density of PVDF-based nanocomposites via a core–shell strategy

“…The crystallinity is enhanced from 40.1% for the pure PVDF to 46.5% for the 1 wt% TiO 2 @SrTiO 3 @PDA NWs/PVDF NC. However, the crystallinity declines with further increasing the weight fractions of TiO 2 @SrTiO 3 @PDA NWs since nanofillers have a two-side influence on the crystallization behavior of the polymer matrix 39 . On one hand, the addition of TiO 2 @SrTiO 3 @PDA NWs provides more heterogeneous nucleation sites, thus reducing the nucleation energy and promoting the crystallization of the PVDF matrix.…”