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.

Keywords:

• Polyvinylidenedifluoride
• lead sulfide nanoparticles
• graphene
• hybrid nanostructures
• polymer nanocomposites
• thermal properties
• dielectric studies
• electromagnetic interference shielding studies
• microwave absorption

Acknowledgments

Prof. K. Dinakaran acknowledges the financial support of the DST, New Delhi through grant No.CRG/2019/002512 during 2020–2023 and DRDO, New Delhi, India, through Grant No. ERIP/ER/DG-NS&M/991115704/M/01/1707 during 2018–2021.

Disclosure statement

No potential conflict of interest was reported by the author(s).