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从具有非均匀力学和电学性质的空间电荷型压电双层膜系的模型出发 ,导出了其压电d33系数的数学表达式 .以具有优异电荷储存能力的聚四氟乙烯 (PTFE)膜作为“刚”性储电层 ,和呈现高弹性顺度的偏氟_四氟乙烯和六氟丙烯共聚物P(VDF_TFE_HFP)膜作为“柔”性层形成了具有非均匀力学和电学性质的P(VDF_TFE_HFP) PTFE驻极体压电双层膜 .利用准静态压电d33系数测量 ,热刺激放电 (thermallystimulateddischarge ,TSD)电流谱分析和在不同温度下的平均电荷重心迁移等研究了经高温栅控恒压电晕充电后形成的这种新型压电双层膜的驻极体性质及压电特性 .讨论了双层膜的厚度比对压电d33系数的影响 .实验结果说明 :经过优化其制备工艺及充电参数后形成的这类新型双层膜的压电d33系数 (约为 32pC N)明显高于久负盛名的铁电聚合物PVDF(d33=15pC N) .压电d33系数的实验测量值与由上述双层膜压电模型导出的理论计算值基本一致 .讨论了热处理工艺对这类双层膜压电稳定性的改善 .
Based on the model of the space charge piezoelectric bilayer membrane with non-uniform mechanical and electrical properties, the mathematical expression of the piezoelectric d33 coefficient is deduced.The polytetrafluoroethylene (PTFE) membrane with excellent charge storage capacity The “rigid” electrical storage layer and the PVDF-TFE-HFP membrane exhibiting a high degree of elasticity as the “soft” layer form P (VDF) with non-uniform mechanical and electrical properties (VDF_TFE_HFP) PTFE electret piezoelectric bilayer films were investigated by using quasi-static piezoelectric d33 coefficient measurement, thermally stimulated discharge (TSD) current spectrum analysis and mean charge center-of-gravity shift at different temperatures, The electret properties and piezoelectric properties of this new type of piezoelectric bilayer formed after the voltage corona charging are discussed.The influence of the thickness ratio of the bilayer film on the piezoelectric d33 coefficient is discussed.The experimental results show that after optimization of the preparation process (About 32pC N) of the novel bilayers formed after charge parameters are significantly higher than those of the prestigious ferroelectric polymer PVDF (d33 = 15pC N). The experimental measurement of the piezoelectric d33 coefficient is in agreement with The above double Theoretical values derived from the model of the piezoelectric film is substantially uniform. Discusses the improvement of heat treatment on the piezoelectric layer film such stability.