Dielectric property determination of hybrid Al2O3-filled MWCNT buckypaper by the rectangular cavity perturbation technique

Abstract

This study investigated the complex dielectric permittivity of freestanding multiwalled carbon nanotube buckypaper (MWCNT-BP) and a synthesized hybrid alumina-filled buckypaper (Al 2 O 3 -BP) composite with different alumina loadings (5-30 wt%). The non-destructive microwave transmission technique for complex permittivity determination involving cavity perturbation was employed to characterize a set of Al 2 O 3 -BP sheets. This was done by filling a rectangular cavity resonator with a standard dielectric Teflon sample and then performing permittivity measurements for the buckypaper (BP) samples in the X-band frequency range (7-12 GHz). Field-emission scanning electron microscopy (FESEM) was used to analyze the morphology of the MWCNT-BP and the aluminaloaded BP composites. DC electrical resistivity measurements clearly demonstrated conductor-insulator transition. The effect of alumina loadings on the dielectric properties of the synthesized hybrid Al 2 O 3 -BP sheet is discussed.

Effect of MWCNT nanofiller on the dielectric performance of bio-inspired gelatin based nanocomposites

“…3(e) it was observed that the nanotubes form a cluster in the 0.05 wt% MWCNT containing the sample and this can be attributed to the agglomeration of nanotubes due to the van der Waals force. 35 A similar morphological pattern was discovered for gel-based carbon nanotube composite films where CNTs form a bundle at higher concentrations. 36 Also, MWCNTs were wrapped with gelatin by the different functional groups of its polymer chain during the sonication process which helps them to disperse evenly throughout the polymer matrix.…”