木质纳米纤维的压电特性及原位增强研究

木质纤维素纳米纤丝（CNF）自组装性能优异，备受压电传感器、发电机及驱动器等领域青睐，但其复合膜压电性低限制了在微型集成器件等更广领域的应用，而挖掘和增强其一维尺度的潜在压电和铁电特性是解决此难题的关键。本项目通过改进栅状镀金硅基片稳固安装CNF样品，研究采用压电力显微镜实现单根CNF的压电性和铁电性测试，揭示CNF性质与压电铁电性之间关系，调控ZnO在其表面高取向和均匀原位生长制成CNF-ZnO压电复合纤维，并嵌入聚偏二氟乙烯（PVDF）增强ZnO晶体间应力传递及纤维柔韧性和压电性，构建CNF性质、ZnO晶体结构、CNF-ZnO压电复合纤维之间的关联调控机制，分析揭示CNF、ZnO及PVDF相互增效机理；通过优化拉伸-热压-高电压取向极化，制备高性能柔性CNF-ZnO-PVDF压电复合膜；研究结果将完善木材压电效应理论，促进应用于先进压电器件及木质纳米纤维特性新型检测技术发展。

Wooden cellulose nanofibrils (CNF) have potential applications in piezoelectric sensors, generators and actuators for its excellent self-assembly performance. However, the low piezoelectric properties of its composite membrane have restricted its application in the broader fields of miniaturized and integrated devices. The key to solve this problem is to explore and enhance the potential piezoelectric and ferroelectric properties in its one-dimensional scale. In this project, CNF is stably installed on the improved grating gold-plated silicon substrate, and the piezoelectric and ferroelectric properties of a single CNF is tested and analyzed by using piezoresponse force microscopy, revealing the relationship between the properties of CNF and the piezoelectric ferroelectric, optimizing ZnO in-situ growth with high orientation and uniform on its surface to fabricate CNF-ZnO composite piezoelectric fiber. Moreover, polyvinylidene fluoride (PVDF) is embedded to enhance the stress transfer between ZnO crystals, as well as the flexibility and piezoelectric property of the composite piezoelectric fiber, to construct the correlation regulation mechanism among CNF properties, ZnO crystal structure and CNF-ZnO composite piezoelectric fiber, and to analyze the synergistic mechanism of CNF, ZnO and PVDF. By optimizing stretch-hot pressing-high voltage orientation polarization, the high-performance flexible CNF-ZnO-PVDF piezoelectric composite membrane will be prepared. The research results will improve the piezoelectric effect theory of wood, promoting the development of advanced piezoelectric devices and new-type wooden nanofiber characteristic detection technology.