Microwave absorption and dielectric behavior of lead sulfide – graphene composite nanostructure embedded polyvinylidinedilfuoride thin films

Abstract

A lightweight and flexible microwave absorbing composite of polyvinyledine difluoride (PVDF) was fabricated by loading PbS nanocubes embedded Graphene hybrid nanostructures into the PVDF matrix. The PbS embedded graphene nanosheets (PbS/GNs) are synthesized by hydrothermal technique. The PXRD pattern of the PbS, GNS and PbS/GNS suggested face-centered cubic structured PbS loaded GNS nanosheets. FE-SEM images of the graphene-bound lead sulfide octahedral nanocubes are found to have a size of 100 nm and are unvaryingly distributed on the surface of graphene nanosheets. HRTEM image of graphene surface image showing sheet-like structure is embedded with PbS nanocrystals. The PbS/GNs in PVDF matrix were found to exhibit enhanced dielectric constant, reduction in resistivity, and electrical conductivity. The high dielectric constant was exhibited by the 4% GNs dispersed PVDF with a value of 3.7x105 and 6% GNs/PbS dispersed PVDF showed 3.5 x105 at 1 MHz. The composite PbS/GNs into PVDF exhibit the maximum reflection loss dips in frequency band X for the PbS/Gra/PVDF samples. It is apparent that there are three absorption peaks in the region of 9–12 GHz in which the absorption of −6.9 dB is observed at 10 GHz.