Effect of graphene oxide doping on the room temperature shear and dynamic rheological behaviour of PVDF

Poly (vinylidene fluoride) (GO/PVDF) nanocomposites (NCs) are prepared via dispersing 1 mg and 5 mg of graphene oxide (GO) sheets in PVDF/Tetrahydrofuran (THF) and 2-dimethylformamide (DMF) solution. X-Ray Diffraction (XRD) and FTIR analysis confirm that NCs exhibits β-phase and their crystallinity increased with GO doping. This paper presents a solution method for GO/PVDF NCs preparation and explored their shear and dynamic rheology at room temperature than that of melt state/rheology. GO/PVDF NCs show shear-thinning to discontinuous shear thickening (DST) behavior, increase of the flow viscosity (20045.16 mPa.s and 50311.81 mPa.s for 1 mg and 5 mg) and altered critical shear rate as a function of increasing GO doping concentration. The observed rheological behaviors could be a result of hydrodynamic forces. Dynamic rheology and relaxation frequency and time measurements confirm that the doping GO leads to the viscoelastic behavior in NCs than that of glassy behavior of neat PVDF. Viscoelastic and gelation properties of GO/PVDF NCs make them potential candidates for lubrication applications.