Dielectric polymer matrix composite films of CNT coated with anatase TiO2

An innovative method to reduce the energy loss of conductive filler/polymer composites for charge storage applications

“…The material requirements for embedded capacitors include high real permittivity, low leakage current (imaginary permittivity) and process compatibility with PCBs. Recently, conductive filler/ polymer composites (CPCs) have been proposed as candidates for embedded capacitors, due to their high real permittivity, low cost, light weight and process compatibility with PCBs [3][4][5]. According to the percolation theory, a high real permittivity with a low leakage current in CPCs can only be achieved at filler loadings very close to the percolation threshold [6].…”

“…This poses a challenge to use CPCs as charge storage materials, because of the typically narrow insulator-conductor transition window around the percolation threshold. Two strategies are usually used to avoid the direct contact between conductive fillers and thereby obstruct the insulator-conductor transition: (1) covering the surface of conductive fillers with an insulative layer [3,7]; and, (2) introducing secondary particles as insulating barriers between conductive fillers [8,9]. Both of these methods require additional processing steps to obtain the final composite and may also adversely affect the real permittivity.…”

Amorphous TiO2-coated reduced graphene oxide hybrid nanostructures for polymer composites with low dielectric loss

“…For the low loss, TiO 2 particles anchored on rGO in rGO-TiO 2 /PVDF-HFP can coat rGO completely by in situ assembling TiO 2 nanoparticles on the surface of rGO nanosheets with strong binding between them [19]. Sufficient insulation can prevent direct contact among the conductive rGO nanosheets and the jump of fee electrons enough between the rGO dispersed in PVDF-HFP matrix [16]. These results suggest that the TiO 2 deposition reduces the dielectric loss of the composites by suppressing the leakage current [4].…”

“…Carbon-TiO 2 hybrid nanostructures can been prepared using the hydrothermal [13,14], solvent-thermal [5], sol-gel [15,16], in situ assembly [4,17], and self-assembly methods [18]. In the work reported in this paper, uniform and layered graphene oxide-TiO 2 (GO-TiO 2 ) nanoparticles with graphene sheets as the inner core and TiO 2 as the outer wall were fabricated based on Jiang's work [19].…”

“…The XRD pattern of GO only shows a peak at 2θ = 10.3°, corresponding to the inter-planar spacing of 8.6 Å. The GO-TiO 2 hybrid composite particles showed a around 20-30° due to the dominant effect of amorphous TiO 2 on GO surface[14,16]. In addition, there was no peak at the 10.3°indicating that the GO sheets were separate and that the deposition of TiO 2 on the surface had not caused agglomeration.…”