【作者】 娄可行； 张晓青； 曹功勋； 孙转兰； 夏钟福；

【Author】 Ke-xing LOU,Xiao-qing ZHANG,Gong-xun CAO,Zhuan-lan SUN,Zhong-fu XIA Shanghai Key Laboratory of Special Artificial Microstructure Material and Technology, Department of Physics,Tongji University 20092,China

【机构】 同济大学物理系上海市特殊人工微结构材料与技术重点实验室；

【摘要】 利用模板冷压、高温热粘合工艺制备出了具有不同开孔率的有序微结构多孔聚四氟乙烯-氟化乙丙烯共聚物（PTFE-FEP）复合膜,分别通过室温恒压电晕法和接触法对复合膜进行极化,使其成为压电驻极体。采用SEM技术、介电谱、铁电分析、准静态d₃₃以及时域谱测量等表征方法,分别对材料的微观结构、机械性能、压电性以及粘弹性行为进行了研究。结果表明,极化电压对复合膜的压电活性有很大的影响,有效开孔率为0%,25%和44%的复合膜压电驻极体获得压电活性的电压阈值分别为-4000V,-3000V和-2000V,在阈值电压以上,复合膜中空间电荷密度和准静态d₃₃随着极化电压的增大显著增强。有效开孔率为0%,25%和44%的复合膜压电驻极体的反谐振频率分别在104 kHz,119 kHz和132 kHz附近,杨氏模量分别为0.9 MPa,0.58 MPa和0.53Mpa,面电荷密度分别为0.009μC/cm²,0.029μC/cm²和0.046μC/cm²。说明随着有效开孔率的增加,复合膜的杨氏模量逐渐降低,面电荷密度逐渐升高。压电响应的时域谱表明复合膜具有粘弹性行为。开孔率较高的压电驻极体表现突出的压电性,这可能是源于样品较高的面电荷密度和较低的杨氏模量。更多还原

【Abstract】 The fluorocarbon polymer films with regular void structure,made from fluoroethylenepropylene（FEP） and porous polytetrafluoroethylene（PTFE） layers were prepared by using the template patterning and fusion bonding process.After proper corona or contact charging,the films were piezoelectric.The microstructure, mechanical property,piezoelectricity and viscoelasticity of the fabricated films were studied by means of scanning electron microscope（SEM） technique,measurements of dielectric resonance spectra,and analysis of quasi-static d₃₃ coefficient in time domain.The results show that,there are threshold values of polarization about -4000 V,-3000 V and -2000 V in the films with porosities of 0,25%and 44%,respectively,and above the threshold voltage,the piezoelectric coefficient d₃₃ of the films increases significantly with the enhancement of the polarization voltage.For the films with porosities of 0,25%and 44%,the measured dielectric anti-resonance frequencies are around 104 kHz,119 kHz and 132 kHz,the calculated Young’s modulus are about 0.9 MPa,0.58 MPa and 0.53 MPa and the densities of surface charge are 0.009μC/cm², 0.029μC/cm² and 0.046μC/cm²,respectively.The piezoelectric response in time domain reflects the viscoelastic behaviors in the films.In addition,the films with large porosity show an improved piezoelectricity,which is perhaps due to the relative high density of charge and low Young’s modulus in them.更多还原