多尺度柔性钛酸钡/聚二甲基硅氧烷复合材料的制备及介电性能优化  

Preparation of Flexible Barium Titanate/Polydimethylsiloxane Composites with Hierarchical Microstructure and Optimization of Dielectric Performance

作　　者：胡海龙[1] 孟令晗 约索夫 HU Hailong;MENG Linghan;HASSAN Yusuf Abdullahi(Research Institute of Aerospace Technology,Central South University,Changsha 410083,China)

机构地区：[1]中南大学航空航天技术研究院,长沙410083

出　　处：《硅酸盐学报》2024年第4期1288-1300,共13页Journal of The Chinese Ceramic Society

基　　金：长沙自科基金项目(kq2202093);湖南省自科面上项目(2022JJ30722);中南大学人才基金项目(202045007)。

摘　　要：介电电容器具有重量轻、充放电速度快、功率密度高等优点,在航空航天储能器件领域的作用日益凸显。采用模板法与电泳沉积法相结合制备了多尺度结构的柔性复合电介质材料钛酸钡/聚二甲基硅氧烷(BTO/PDMS),研究了其微观无序、有序结构对介电性能的影响,并通过理论模拟对其介电与介电强度性能进行了系统分析,为提高复合电介质储能密度的研究提供了理论铺垫。结果表明:当BTO含量达到10.16%(质量分数)时,复合材料的相对介电常数在1000 Hz时提升到85(纯PDMS的相对介电常数仅为2.75);当BTO的体积分数在5%∼20%之间变化时,介电常数随BTO含量的增加呈线性增加;此外,通过调控BTO形貌的有序定向结构(如四方或蜂窝定向结构),介电性能得到提升,某些特定方向的介电强度性能显著提高;将聚偏氟乙烯(PVDF)和PDMS复合形成核壳结构,常数略有提升,填料与基体的介电性能差异减小,介电强度性能得到提升。Introduction Flexible and stretchable electronics have attracted much attention due to their potential applications in wearable devices,robotics,and healthcare.Among various materials,barium titanate(BTO)is a promising candidate for flexible and stretchable electronics because of its high dielectric constant,piezoelectric property,and superior thermal stability.However,the brittle nature of BTO restricts its application in flexible and stretchable devices.Polymer composites such as polydimethylsiloxane(PDMS)can be used,providing a flexibility and a stretchability for BTO-based devices.In this paper,flexible BTO/PDMS composites with a hierarchical microstructure were prepared and their dielectric performance was optimized.The hierarchical microstructure could enhance the mechanical properties,electrical conductivity,and dielectric performance of the composites.This study could provide valuable insights into the design and fabrication of flexible and stretchable electronic devices based on BTO/PDMS composites.Methods A piece of foam nickel was prepared,cleaned with acetone under ultrasound for 10 min and then washed with deionized water for several times to remove impurities on the surface.An isopropanol was used as a solvent,an appropriate amount of phenolic resin was used as a stabilizer,and an appropriate amount of aluminum nitrate nonahydrate was added to make the BTO positively charged.Little precipitation occurred after mechanical stirring and ultrasonic treatment.A uniform and stable barium titanate suspension was formed.A layer of BTO coating was deposited on the pore walls of the pretreated foam nickel by an electrophoretic deposition(EPD)process.Two copper plates were used as the poles of the electrophoretic deposition.A nickel metal foam template was fixed on a negative pole,immersing it into the EPD tank with the stable BTO suspension To prepare the samples with different BaTiO3 contents,the diameter of the BTO framework pore was controlled via adjusting the electrophoresis time.The sample was sintered

关 键 词：复合材料 多尺度结构 介电性能 有限元理论 柔性器件 

分 类 号：TB33[一般工业技术—材料科学与工程]