柔性铁电驻极体薄膜几个基础问题的研究

项目名称： 柔性铁电驻极体薄膜几个基础问题的研究

项目编号： No.50873078

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 张晓青

作者单位： 同济大学

项目金额： 35万元

中文摘要： 聚合物基铁电驻极体膜是以空间电荷驻极体为基体材料的具有压电效应的新一代功能材料。它具有强压电活性（比传统的铁电聚合物PVDF高出约2个量级）、柔性、低成本、低声阻抗等突出的性能。为了排除微结构的无序性给铁电驻极体理论研究带来的巨大障碍，本课题重点对规则微结构铁电驻极体的构建、物理模型、压电效应，以及微结构与材料宏观性能的关系进行了系统的研究。此外，本课题还对基于铁电驻极体膜的柔性传感器进行了探索。结果表明，研发的模板制备铁电驻极体薄膜的新工艺可以精细人工调控铁电驻极体薄膜的微观结构，进而提高薄膜的力学、热学和压电性能。与原有的理论模型相比，改进的物理模型不仅反映薄膜的电学特点，而且反映薄膜的力学性能。通过模板结构和工艺参数的调控（即调控薄膜的微结构参数），可以大幅提高铁电驻极体薄膜的性能。例如，与现有的聚丙烯铁电驻极体薄膜相比，采用模板法制备的以聚四氟乙烯和氟化乙丙烯聚合物为基体的规则结构铁电驻极体薄膜的耐热性从60 oC大幅提高到150 oC。研发出的基于铁电驻极体膜的薄膜传感器具有柔韧、薄膜和高灵敏度等特点。

中文关键词： 铁电驻极体;有序微结构;物理模型;压电性;薄膜传感器

英文摘要： Ferroelectret is new type piezoelectric material based on space charge electret foam.Such material has features of large piezoelectricity, flexibility, low cost, low acoustic impedence, and so on. In this study, we invented a new precess to prepare ferroelectrets with controllable micro-structure. The mechanical and electrical properties, physical model, and the relation between the microstructure and their piezoelectic effects for the fabricated films were systematically investigated. In addition, flexible film sensors based on ferroelectrets were also explored.The results show that the invented preparation process by using finely designed template is an effective mothod to control the micro-structure and piezoelectricity of ferroelectrets. The piezoelectric effect and thermal stabality in the fabricated films with templates, made of polytetrafluoroethylene and tetrafluoroethylene-hexafluoropolypropylene copolymer, are significantly improved compared with polypropylene ferroelectrets.For example, the working temperature increases to 150 oC from 60 oC for the fabricated fluoro-polymer ferroelectrets.The improved physical model consists of both electrical and machanical features of ferroelectrets. The developed film sensors based on ferroelectrets are with large sensitivity and flexibility.

英文关键词： ferroelectrets; regular microstructure; physical model; piezoelectricity; film sensors