On synergistic effect of BaTiO3 and graphene reinforcement in polyvinyl diene fluoride matrix for four dimensional applications

This work presents the synergistic effect of BaTiO3 and graphene (Gr) reinforcement in polyvinyl diene fluoride (PVDF) matrix by chemical-assisted mechanical blending (CAMB) for possible 4D applications. The PVDF matrix was prepared (in form of filament) by solvent casting followed by twin-screw extrusion (TSE) as CAMB process. The filament was used on fused deposition modelling (FDM) setup for preparing standard flexural and pull-out specimens. The mechanical testing revealed that the parts printed with 100% in-fill density (ID), 70 mm/s infill speed (IS), and 45 degrees in-fill angle (IA) has shown better flexural strength (FS). For pull-out properties, part printed at IS 90 mm/s, 0 degrees IA, and 100% ID have shown better results. Further optimized settings of FS were used to 3D print thin cylindrical discs followed by electric poling (for possible piezoelectric properties). The results of X-ray diffraction (XRD) and Fourier transmission infrared spectroscopy (FTIR) analysis show more beta-phase formation in the electrically poled sample as compared to non-poled specimen. Moreover, XRD spectra show the homogenous dispersion of doped material in the PVDF matrix. The piezoelectric coefficient (d(33)) 30.2pC/N was observed on 3D printed specimen (prepared from filament processed with CAMB), suitable for 4D applications.