1. 毕业设计（论文）的内容和要求

具有压电性的晶体对称性较低，当受到外力作用发生形变时，晶胞中正负离子的相对位移使正负电荷中心不再重合，导致晶体发生宏观极化，而晶体表面电荷面密度等于极化强度在表面法向上的投影，所以压电材料受压力作用形变时两端面会出现异号电荷，这种现象称为”压电效应”。

反之，压电材料在电场中发生极化时，会因电荷中心的位移导致材料变形称为”逆压电效应”。

利用材料的压电特性可以使压电材料捕获外界的机械能并将其转化为电能，不但清洁，而且无污染。

2. 参考文献

[1] B. Dai, H. Huang, W. Wang, Y. Chen, C. Lu, J. Kou, L. Wang, F. Wang, and Z. Xu, Greatly enhanced photocatalytic activity by organic flexible piezoelectric PVDF induced spatial electric field. Catal. Sci. Technol. 7 (2017) 5594-5601. [2] L. Xing, Y. Nie, X. Xue, and Y. Zhang, PVDF mesoporous nanostructures as the piezo-separator for a self-charging power cell. Nano Energy 10 (2014) 44-52. [3] R. Tian, Q. Xu, C. Lu, X. Duan, and R. Xiong, Spontaneous polarization switching and piezoelectric enhancement of PVDF through strong hydrogen bonds induced by layered double hydroxides. Chem. Commun. 53 (2017) 7933-7936. [4] V. Cauda, S. Stassi, K. Bejtka, and G. Canavese, Nanoconfinement: an Effective Way to Enhance PVDF Piezoelectric Properties. ACS Appl. Mater. Inter. 5 (2013) 6430-6437. [5] V. Vivekananthan, N.R. Alluri, Y. Purusothaman, A. Chandrasekhar, and S. Kim, A flexible, planar energy harvesting device for scavenging road side waste mechanical energy via the synergistic piezoelectric response of K0.5Na0.5NbO3-BaTiO3/PVDF composite films. Nanoscale 9 (2017) 15122-15130. [6] Y. Kim, Y. Xie, X. Wen, S. Wang, S.J. Kim, H. Song, and Z.L. Wang, Highly porous piezoelectric PVDF membrane as effective lithium ion transfer channels for enhanced self-charging power cell. Nano Energy 14 (2015) 77-86. [7] Y. Zhao, Q. Liao, G. Zhang, Z. Zhang, Q. Liang, X. Liao, and Y. Zhang, High output piezoelectric nanocomposite generators composed of oriented BaTiO3 NPs@PVDF. Nano Energy 11 (2015) 719-727

3. 毕业设计（论文）进程安排

起讫日期 设计（论文）各阶段工作内容 备 注 2018.01.05～2018.01.20 查阅文献，做好实验计划 2周 2018.02.20～2018.04.11 样品制备 3 周 2018.04.12～2018.04.19 产物表征、测试 1周 2018.04.20～2018.04.27 工艺完善、实验数据的整理 1周 2018.04.28～2018.05.04 中期总结，论文初稿 1周 2018.05.05～2018.05.28 补充试验数据，完善论文 3 周 2018.05.29～2018.06.5 PPT制作，准备答辨 1 周