Zhou Zhenji, You Caiyin, Li Zhong, Xia Weimin, Tian Na
School of Materials Science and Engineering, Xi'an University of Technology, Xi'an 710048, Shaanxi, People's Republic of China.
School of Science, Xi'an Jiao tong University, 710049 Shaanxi, People's Republic of China.
ACS Appl Mater Interfaces. 2022 Oct 12;14(40):45679-45687. doi: 10.1021/acsami.2c12861. Epub 2022 Sep 27.
Magnetic nanofiller is helpful for improving the piezoelectric properties of P(VDF-TrFE)-based composites, which shows promising potential as a flexible sensor or energy harvester. In this work, we use the interaction between the magnetic nanofiller and magnetic field to modify the structure of CoFeO (CFO)@polydopamine (PDA)/P(VDF-TrFE) composite, in which CFO@PDA works as the nanofiller into the P(VDF-TrFE) matrix. It was found that the magnetic field orientation during polymer curing can significantly increase the content of the β-phase and of the composite. Regarding a typical composite film with 7 wt % CFO@PDA, the composite exhibits versatile sensing originated from the ball impact, hot-water droplet, bending, and pressing. In a noncontact magnetic field-driven experiment, the magnetic field oriented film produced the highest output voltages of 17.4 mV at 4 Hz and 12 mV at a drive amplitude of 19 Vpp, in contrast to the values of 7.1 mV and 7 mV for the film without magnetic field orientation, respectively. The LED without any charging capacitor can be instantaneously lighted through vertically pressing the oriented films. Thus, this work proposes a strategy of magnetic field orientation to improve the piezoelectric performance of the CFO@PDA/P(VDF-TrFE) multifunctional composite film.
磁性纳米填料有助于改善基于聚偏氟乙烯-三氟乙烯共聚物（P(VDF-TrFE)）的复合材料的压电性能，这使其作为柔性传感器或能量收集器具有广阔的应用前景。在这项工作中，我们利用磁性纳米填料与磁场之间的相互作用来改变钴铁氧体（CFO）@聚多巴胺（PDA）/P(VDF-TrFE)复合材料的结构，其中CFO@PDA作为纳米填料分散在P(VDF-TrFE)基体中。研究发现，聚合物固化过程中的磁场取向可显著提高复合材料中β相的含量。对于含有7 wt% CFO@PDA的典型复合薄膜，该复合材料表现出对球撞击、热水滴、弯曲和按压等多种刺激的传感特性。在非接触式磁场驱动实验中，磁场取向的薄膜在4 Hz时产生的最高输出电压为17.4 mV，在驱动幅度为19 Vpp时为12 mV，相比之下，无磁场取向的薄膜分别为7.1 mV和7 mV。通过垂直按压取向薄膜，无需任何充电电容器的发光二极管（LED）即可瞬间点亮。因此，这项工作提出了一种磁场取向策略，以提高CFO@PDA/P(VDF-TrFE)多功能复合薄膜的压电性能。
