Synthesis and Characterization of PVDF/FLG and PVDF/GO Nanocomposites for EMI Shielding

Abstract

The structural, thermal, mechanical and dielectric properties of polyvinylidene fluoride (PVDF) embedded with few layer graphene (FLG) and graphene oxide (GO) are investigated. The concentration of FLG and GO in PVDF is varied from 0.1 to 1.0 wt% and the nanocomposites samples are prepared using solution casting method. Both, FLG and GO are dispersed well at lower concentrations ≤ 0.5 wt%, while at higher concentrations, the formation of the filler agglomerations takes place in the PVDF matrix as shown by scanning electron microscopy. X-ray diffraction confirms the evolution of α and β-phases in the neat PVDF. Increasing the FLG concentration up to 0.5 wt% in PVDF, β-phase dominates while at 1.0 wt%, both α and β-phases are present, probably due to the agglomeration of FLG. While for all the concentrations of GO in PVDF, β-phase dominates in PVDF. Differential scanning calorimetry also confirmed the melting of both α and β-phases in PVDF/FLG and PVDF/GO nanocomposites. The mechanical properties like tensile strength and modulus of PVDF are increased by the addition of both types of nanofillers. Whereas, the microhardness of PVDF/FLG is higher than PVDF/GO nanocomposites as the values are increased from 23 to 60 and 23 to 40 by the addition of FLG and GO, respectively. The dielectric properties of PVDF in both nanofillers are increased. However, the values are higher in PVDF/FLG system than PVDF/GO system owing to the more conductivity of FLG over GO.