Electrospinning of aligned PVDF nanofibers with piezoelectricity and its application in pressure sensors

针对传统静电纺丝法制备聚偏二氟乙烯(PVDF)压电纤维工艺复杂和效率低等问题,提出了采用滚筒收集方式制备PVDF有序纳米纤维的方法。通过改变滚筒转速收集纤维,得到了有序程度不同的PVDF纤维膜。用傅立叶变换红外光谱(FTIR)分析了有序纤维膜β晶相的含量,并利用NI数据采集卡在相同条件下测试了纤维膜的压电特性。结果表明:随着滚筒转速提高,纤维有序度增强,β相的含量提高,压电电压输出也明显增大,由此得知滚筒转速变化对β晶相的含量及压电输出电压的影响规律基本一致。基于得到的结果,设计制作了利用该有序PVDF纤维膜的压力传感器,并在不同气压下进行了动态响应测试。结果显示:所制备的PVDF有序纤维压力传感器在0.145~0.165 MPa下的电压输出随气压的增加呈线性增大,表现出了良好的线性度,其灵敏度达179mV/kPa。采用该种方法制备PVDF纤维对研制动态压力传感器极有意义。It has complex process and lower efficiency when traditional electrospinning preparation method is used to prepare the poly(vinylidene fluoride)(PVDF)piezoelectric fibers,so this paper proposes a new method for the PVDFs by using a rotation drum to collect aligned PVDF nanofibers.Aligned fiber membranes with different alignment degrees were collected by changing the rotating speed.Then,the Fourier Transform Infrared(FTIR)spectroscopy was used to analyze the content ofβphase of the fiber membranes and a data acquisition card of National Instrument(NI)was used to research the piezoelectric property of piezoelectric fiber membrane under the same pressing force.The results show that the order of fiber alignment and the content ofβphase are both improved as the rotating speed increasing,and the output voltage of piezoelectric also increases,which indicates that the change of rotating speed has the same influence on the content ofβphase and the output voltage.Based on the aligned PVDF fiber membrane,apressure sensor was designed and its dynamic responses under different air pressures were obtained with a lab-made testing system.In the pressure range of0.145-0.165 MPa,the piezoelectric output of the sensor increases linearly with the increment of air pressure,showing excellent linearity and high sensitivity up to 179mV/kPa.The preparing method for PVDF nanofibers has wide application prospects,especially in the field of high accuracy dynamic pressure tests.国家自然科学基金青年基金资助项目(No.51105320