Stretching-induced phase transitions in barium titanate-poly(vinylidene fluoride) flexible composite piezoelectric films
Stretching-induced phase transitions in barium titanate-poly(vinylidene fluoride) flexible composite piezoelectric films
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DOI：
10.1016/j.scriptamat.2020.10.036
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发表时间：
2021-03-01
影响因子：
6
通讯作者：
Warren, Roseanne
中科院分区：
文献类型：
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作者：
Khan, Fariha;Kowalchik, Tim;Warren, Roseanne
改善聚偏氟乙烯(PVDF)的压电性能对包括能量收集在内的许多应用具有重要意义。在聚合物基质中添加钛酸钡纳米颗粒是促进PVDF薄膜中β相形成的一种流行方法。对于纯PVDF，机械拉伸(即拉伸)也被证明可以提高压电性能。本工作首次研究了拉伸和添加BaTiO_3对BaTiO_3-PVDF复合薄膜相变的联合影响。结果表明，PVDF复合膜在拉伸过程中发生了另一种相变机制。纯PVDF薄膜的拉伸导致非极性α相向电活性β相的转变，而BaTiO_3-PVDF复合薄膜的拉伸主要导致弱电活性的伽马相向更电活性的β相转变。总体而言，拉伸BaTiO_3-PVDF薄膜有利于提高PVDF的β相含量。(C)2020 Acta Materialia Inc.由爱思唯尔有限公司出版。版权所有。
Improving the piezoelectric performance of poly(vinylidene fluoride) (PVDF) is important for many appli-cations, including energy harvesting. The addition of barium titanate (BaTiO3) nanoparticles in the polymer matrix is a popular method to facilitate beta 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 alpha phase into the electroactive beta phase, stretching of BaTiO3-PVDF composite films results primarily in the conversion of weakly electroactive gamma phase into the more electroactive beta phase. Overall, stretching of BaTiO3-PVDF films is shown to be beneficial for increasing beta phase content of PVDF. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.