Ferroelectric and piezoelectric properties of poly(vinylidene fluoride–trifluoroethylene) gels

Abstract

The structural, ferroelectric, and piezoelectric properties of poly(vinylidene fluoride–trifluoroethylene) [P(VDF–TrFE)] gels fabricated using poly(pyridinium-1,4-diyliminocarbonyl-1,4-phenylenemethylene thiocyanate) (PICPM-SCN) as a gelator are investigated in this study. The P(VDF–TrFE)/PICPM-SCN composites formed thermally reversible physical gels and their analysis by Fourier transform infrared spectroscopy revealed that the P(VDF–TrFE) molecules in these gels exhibit predominantly the ferroelectric phase I (Form β). Furthermore, the polarization switching peaks of the P(VDF–TrFE)/PICPM-SCN gel films were clearly observed. The coercive electric field for these gel films was estimated to be 2 MV/m, which is dramatically lower than the values typically observed for P(VDF–TrFE) solid films (50 MV/m). Finally, the P(VDF–TrFE)/PICPM-SCN gel films exhibited a piezoelectric response, and the highest piezoelectric coefficient was determined to be ∼53 pm/V at an applied voltage frequency of 4 kHz.