Abstract Improving the piezoelectric performance of poly(vinylidene fluoride) (PVDF) is important for many applications, including energy harvesting. The addition of barium titanate (BaTiO3) nanoparticles in the polymer matrix is a popular method to facilitate β phase formation in PVDF films. For pure PVDF, mechanical drawing (i.e. stretching) has also been shown to increase piezoelectric performance. This work examines, for the first time, the combined effect of stretching and BaTiO3 addition on phase transformations in BaTiO3-PVDF composite films. The results indicate that an alternative phase transformation mechanism occurs during the stretching of PVDF composite films. While stretching of pure PVDF films results in the conversion of non-polar α phase into the electroactive β phase, stretching of BaTiO3-PVDF composite films results primarily in the conversion of weakly electroactive γ phase into the more electroactive β phase. Overall, stretching of BaTiO3-PVDF films is shown to be beneficial for increasing β phase content of PVDF.

中文翻译：

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钛酸钡-聚偏二氟乙烯柔性复合压电薄膜的拉伸诱导相变

摘要 提高聚偏二氟乙烯 (PVDF) 的压电性能对于包括能量收集在内的许多应用都很重要。在聚合物基体中添加钛酸钡 (BaTiO3) 纳米颗粒是促进 PVDF 薄膜中 β 相形成的常用方法。对于纯 PVDF，机械拉伸（即拉伸）也已被证明可以提高压电性能。这项工作首次检验了拉伸和 BaTiO3 添加对 BaTiO3-PVDF 复合薄膜相变的综合影响。结果表明，在 PVDF 复合薄膜的拉伸过程中发生了另一种相变机制。虽然纯 PVDF 薄膜的拉伸导致非极性 α 相转化为电活性 β 相，BaTiO3-PVDF 复合薄膜的拉伸主要导致弱电活性的 γ 相转化为更具电活性的 β 相。总体而言，BaTiO3-PVDF 薄膜的拉伸被证明有利于增加 PVDF 的 β 相含量。