论文总字数：31835字

摘 要

碱金属铌酸盐系压电陶瓷是一种新型无铅压电材料，作为其中应用最广泛的一类，铌酸钾钠(K_0.5Na_0.5)NbO₃（KNN）极有可能取代传统的高压电性PZT陶瓷。KNN基材料具有压电性高、介电常数小等特点，而其纳米压电纤维因柔性、质轻、灵敏等特性，被普遍地应用于实际生活中。目前对KNN体系的研究主要集中在材料本身的压电铁电性能方面，对其纤维的制备和传感特性研究较少，因而对KNN基压电纤维的制备和传感性能进行系统深入的研究是很有意义的。

本文采用溶胶-凝胶法制备铌锑酸钾钠-锆酸铋钠钾(1-x)(K_1-yNa_y)(Nb_1-zSb_z)O₃-xBi_0.5(Na_1-uK_u)_0.5ZrO₃（0≤x≤0.05，0.40≤y≤0.68，0.02≤z≤0.06，0≤u≤1，KNNS-BNKZ）前驱体溶胶，利用静电纺丝工艺制备出KNNS-BNKZ纳米纤维，通过查阅文献和实际操作确定了纤维的热处理工艺。应用XRD、SEM和TEM这些分析方法对KNNS-BNKZ压电纤维的形貌和物相进行了表征，从而获得了其组分、微观形貌、直径大小等信息。

利用热处理后的纤维制备了压电传感器，主要讨论了不同加载频率和变形幅度对传感器性能的影响。利用电化学综合测试系统检测了传感器的输出特性并表征了所做器件的线性度和灵敏度，证明了KNNS-BNKZ压电纤维的响应大小随加载频率或形变幅度增大而增大，且在低频变形条件下，传感器的线性度和灵敏度较高。

关键词：铌酸钾钠；静电纺丝；KNNS-BNKZ压电纤维；压电传感器；传感特性

Research on the preparation of KNNS-BNKZ piezoelectric fiber and its sensing characteristics

Abstract

Alkali niobate-based piezoelectric ceramic is a new kind of lead-free piezoelectric materials, as one of the most widely used, potassium sodium niobate (K_0.5Na_0.5) NbO₃ (KNN) is very likely to replace the traditional PZT ceramics of high piezoelectric properties. KNN-based materials have some excellent characteristics like high piezoelectricity and small dielectric constant. Due to characteristics of flexible, lightweight, sensitive, etc, their piezoelectric nanofibers are widely applied in real life. The current research on KNN system is mainly focused on its piezoelectric and ferroelectric performance, but the studies on the preparation of its fibers and sensing characteristics are few. So it is quite meaningful to carry out a systematic and thorough study of the preparation of KNN-based piezoelectric fiber and its sensing properties.

In this experiment, we successfully prepared (1-x)(K_1-yNa_y)(Nb_1-zSb_z)O₃-xBi_0.5(Na_1-uK_u)_0.5ZrO₃ (KNNS-BNKZ) precursor sol through the sol-gel method, and then we synthesized KNNS-BNKZ nanofibers by an electrostatic spinning process. Furthermore, through the literature and actual operations, the heat treatment process of fibers was determined. By means of XRD, SEM, TEM, the morphology and phase of KNNS-BNKZ piezoelectric fibers were characterized, thus the fibers’ components, micro topography, diameter and other information was obtained.

We prepared the piezoelectric sensor by the use of heat-treated fibers and discussed the effects of different loading frequency and deformation amplitude in the performance of sensors. Through the electrochemical testing system, we detected the sensors’ output characteristics and identified the linearity and sensitivity of our devices. We confirmed that by increasing loading frequency or deformation amplitude, the response size of KNNS-BNKZ piezoelectric fibers was increased. What’s more, in the condition of low frequency deformation, the linearity and sensitivity of the transducer were higher.

KEY WORDS: potassium sodium niobate, electrostatic spinning, KNNS-BNKZ piezoelectric fibers, piezoelectric transducer, sensing properties

目 录

摘 要 I

Abstract II

第一章 绪论 1

1.1引言 1

1.2压电材料 1

1.3铌酸钾钠压电材料 3

1.3.1 KNN基压电陶瓷的研究进展 3

1.3.2 KNN基压电纤维 6

1.3.3压电纤维的制备方法 7

1.4压电传感器 9

1.4.1压电传感器的发展现状 9

1.4.2传感器性能表征方法 10

1.5主要研究内容 10

第二章 KNNS-BNKZ压电纤维的制备及性能表征 12

2.1实验原料和仪器 12

2.1.1实验原料 12

2.1.2实验设备 13

2.2 KNNS-BNKZ压电纤维的制备 13

2.2.1工艺路线 13

2.2.2 KNNS-BNKZ溶胶的配制 14

2.2.3静电纺丝制备KNNS-BNKZ压电纤维 15

2.2.4 KNNS-BNKZ压电纤维的热处理工艺 17

2.3 KNNS-BNKZ压电纤维的性能表征 18

2.3.1 XRD分析 18

2.3.2 SEM分析 19

2.3.3 TEM分析 20

2.4小结 21

第三章 KNNS-BNKZ传感器的制备及其性能表征 22

3.1传感器的制备 22

3.1.1传感器的基本结构 22

3.1.2传感器的制备工艺 23

3.2传感器的性能分析 24

3.2.1变形频率对响应信号的影响 26

3.2.2传感器的线性度测量 27

3.2.3传感器的灵敏度测量 29

3.3小结 30

第四章 结论与展望 31

4.1结论 31

4.2展望 31

致谢 32

参考文献 33

第一章 绪论

1.1引言

随着材料科学的革新与进步，压电材料因其独特的压电性能和机电能量转换特性，被广泛应用于换能器、驱动器和传感器等领域，同时在监测土木结构关键部位的应力与应变、检测建筑物的缺陷损伤等方面也有着突出贡献。由于现代人类的需求，器件正在朝微型化与集成化的方向发展，而微纳电子元件恰好符合这一主流趋势，故如何让它们适合大规模生产与应用成为了首要任务。一维压电纳米材料具有优良的性能，适用于多种器件与环境中，同时根据其机电转换特性，可实现对环境中微小机械振动能量的收集及其向电能的有效转换，从而推动自供电微型元件的开发与应用。

在压电材料领域中，自上世纪50年代发现锆钛酸铅（以下简称PZT）压电陶瓷以来，因其高压电常数与机电耦合系数的特点，使PZT成为了研究热点和重点。现今，PZT已具备成熟和科学的生产体系，并且制备出的压电陶瓷具有尺寸小、重量轻、工作电压低等诸多优良性能，故PZT被广泛应用于各类器件当中。由于PZT压电陶瓷为铅基材料，其中PbO或Pb₃O₄的含量占60%左右，当被遗弃时，会造成严重的铅污染，从而危害环境与人体。随着可持续发展与绿色环保观念的提出，PZT已不适合普遍化的使用，因而研发新型的、性能优异的无铅压电材料成为了迫在眉睫的问题。

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