The tuning of crystallization behavior of ferroelectric poly(vinylidene fluoride-co-trifluoroethylene)

Poly (vinylidene fluoride-co-trifluoroethylene) [P(VDF-TrFE)] has three crystal forms, including paraelectric alpha, ferroelectric beta, and gamma phases. In previous studies, the properties and performances of P(VDF-TrFE) have been the focus of research. However, the formation mechanism and regulation mode of various crystal forms remain unclear. Therefore, it is an important topic for further research to elucidate, summarize, and prospect the polymorphism of P(VDF-TrFE) and regulate the crystal forms. This review systematically summarizes the crystalline structure and phase transition between ferroelectric and paraelectric phase of P(VDF-TrFE) crystals; discusses the influence of annealing, blending and electric field on the crystallinity, selection of polymorphic crystals, and phase transition behavior between them; reviews the effects of annealing, melt-recrystallization, substrate and nanoconfinement on the crystal orientation. Finally, the effects of the crystal structure of P(VDF-TrFE) on its properties are briefly summarized.