Enhancement of electroactive phases in miniaturized 0.3BaTiO3–0.7BiFeO3 based PVDF–HFP composites: effect on the dielectric and capacitive sensing response†

Multifunctional piezoelectric composites are gaining momentum in the industry as a sustainable source of energy. 0.3BaTiO₃–0.7BiFeO₃ (BT–BF) was prepared using a hydrothermal process and utilized to prepare a BT–BF/PVDF–HFP flexible composite with enhanced sensing and dielectric properties as compared to pristine PVDF–HFP. The synergistic combination of a multiferroic ceramic filler and a ferroelectric polymer matrix demonstrated the improved properties of the composites. X-ray diffraction and scanning electron microscopic characterization of the prepared BT–BF sample revealed the perovskite crystal structure and nano-size spherical morphology, respectively. Dielectric characterization of the BT–BF/PVDF–HFP composites showed enhanced dielectric permittivity with a substantial decline in the loss tangent in a higher frequency regime. Also, the stability of the ceramic fillers was confirmed with the help of NMR-based solvent relaxation experiments. It is observed that the stable interfacial interactions between the matrix and the filler played a dominant role in enhancing the dielectric properties. Again, the temperature-dependent dielectric properties were investigated for the 10BP (10 mg BT–BF/PVDF–HFP) composite to explore the temperature-dependent dielectric response of the fabricated system. Finally, a capacitive pressure sensor with enhanced performance was demonstrated with for the 10BP composite, as compared to pristine PVDF–HFP .