Xi'an University of Technology, Faculty of Printing, Packaging, and Digital Media Technology, Xi'an 710048, Shaanxi, China.
Department of Civil and Environmental Engineering, the University of Utah, Salt Lake City, Utah 84112, USA.
Phys Chem Chem Phys. 2020 Mar 11;22(10):5711-5722. doi: 10.1039/c9cp06553a.
Concerning the study of flexible piezoelectric devices, both scholars and engineers propose that poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) shows more merits than oriented polyvinylidene fluoride (OPVDF) in terms of dielectric, piezoelectric, mechanic-electric, acoustic emission reception performances, etc. Thus, in this study, to clarify the differences between the two types of polymers on their ferroelectric and piezoelectric behaviors, we systematically investigated samples to analyze their molecular structures and phase structures, and to compare their dielectric properties and acoustic emission reception performances. It was found that the wedge effect of TrFE, P(VDF-TrFE), possesses higher regular β phase crystal grains, which are easier to order along the electric field and possess more ordered static charge distribution than that of OPVDF. Consequently, a considerable saturated electric polarization (Pm ∼ 15 μC cm-2 under 225 MV m-1), a large piezoelectric coefficient (d33 ∼ -21.5 pC N-1) and a low coercive electric field (Ec ∼ 50 MV m-1) were obtained in the P(VDF-TrFE) films. It is worth noting that P(VDF-TrFE) shows a more stable d33 piezoelectric response (up to 120 °C) than that of the OPVDF. Additionally, the P(VDF-TrFE) piezoelectric films exhibit a sensitive acoustic emission reception property at approximately 70 dB and an extensive response frequency range from 10 to 100 kHz. These combined properties demonstrate that P(VDF-TrFE) piezoelectric films are a promising material for flexible and easily shaped electronic devices, including hydroacoustic sensors, actuators, and energy transfer units.
关于柔性压电器件的研究，学者和工程师都提出聚（偏二氟乙烯-三氟乙烯）（P（VDF-TrFE））在介电、压电、力电、声发射接收性能等方面比定向聚偏二氟乙烯（OPVDF）更具优势。因此，在这项研究中，为了阐明这两种聚合物在铁电和压电行为上的差异，我们系统地研究了样品，以分析它们的分子结构和相结构，并比较它们的介电性能和声发射接收性能。结果发现，三氟乙烯（TrFE）的楔形效应使 P（VDF-TrFE）具有更高的规则β相晶粒，更容易沿电场排列，具有更有序的静态电荷分布，这比 OPVDF 更优越。因此，在 P（VDF-TrFE）薄膜中获得了相当大的饱和极化（在 225 MV m-1 下约为 15 μC cm-2）、大的压电系数（d33 ∼ -21.5 pC N-1）和低的矫顽电场（Ec ∼ 50 MV m-1）。值得注意的是，P（VDF-TrFE）的 d33 压电响应（高达 120°C）比 OPVDF 更稳定。此外，P（VDF-TrFE）压电薄膜在大约 70 dB 时表现出敏感的声发射接收特性，并且在 10 至 100 kHz 的广泛响应频率范围内具有广泛的响应。这些综合性能表明，P（VDF-TrFE）压电薄膜是一种很有前途的柔性和易成型电子器件材料，包括水声传感器、执行器和能量转换单元。
