聚酰亚胺纳米复合绝缘体系中TiO2颗粒团聚现象的微观作用机制研究  

Research on Microscopic Mechanism of TiO2 Particles Aggregation Phenomenon in Polyimide Nanocomposite Insulating System

作　　者：黄旭炜 李庆民[1] 邹亮[2] HUANG Xuwei;LI Qingmin;ZOU Liang(Beijing Key Laboratory of High Voltage&EMC,North China Electric Power University,Beijing 102206,China;School of Electrical Engineering,Shandong University,Jinan 250061,China)

机构地区：[1]华北电力大学高电压与电磁兼容北京市重点实验室,北京102206 [2]山东大学电气工程学院,山东济南250061

出　　处：《绝缘材料》2020年第2期14-21,共8页Insulating Materials

基　　金：国家自然科学基金资助项目(51929701、51737005);中央高校基本科研业务费专项资金(2017XS005);国家留学基金(201706730018)

摘　　要：为研究聚酰亚胺-二氧化钛(PI-TiO2)复合材料中纳米颗粒团聚现象的微观作用机制,利用反应分子动力学构建并计算了含有不同纳米颗粒尺寸和数量的PI-TiO2复合仿真体系中纳米颗粒的运动过程,结合微观运动过程中化学键与氢键的变化趋势,分析了聚酰亚胺基体中纳米颗粒发生团聚现象的作用机理。结果表明:由于边沿缺位原子的非饱和性,TiO2纳米颗粒将与氢键受力的聚酰亚胺分子发生相向运动,并与之形成Ti-O-C桥接化学结构,这是导致纳米颗粒团聚的主要原因。基于体系能量分解的研究表明,纳米颗粒是在电荷转移能、静电势能及分子间作用能等微观能量的共同作用下趋于团聚。最后,利用原位聚合法制备了含不同TiO2质量分数的PI-TiO2纳米复合薄膜,根据扫描电子显微镜(SEM)测试中呈现的团聚分布特征,验证了上述团聚现象的发生机理。In order to study the microscopic mechanism of nanoparticle aggregation phenomenon in polyimide-titanium dioxide(PI-TiO2)composites,the motion processes of nanoparticles in PI-TiO2 composite simulation systems containing different sizes and quantities of particles were constructed and calculated using reaction molecular dynamics.Combining with the change trends of chemical bonds and hydrogen bonds during the microscopic motion process,the mechanism of nanoparticles aggregation phenomenon in the polyimide matrix was analyzed.The results show that due to the unsaturation of the edge-deficient atoms,the TiO2 nanoparticles will move toward the hydrogen-bond drived polyimide molecules and then form Ti-O-C bridging chemical structurs,which is the main cause for the nanoparticles aggregation.The research based on system energy decomposition shows that the nanoparticles tend to aggregate under the combined action of charge transfer energy,electrostatic potential energy,and intermolecular interaction energy.Finally,PI-TiO2 nanocomposite films with different mass fraction of TiO2 were prepared by in-situ polymerization method,and the mechanism of above aggregation phonomenon was verified according to the aggregation distribution characteristics observed by scanning electron microscopy(SEM).

关 键 词：纳米二氧化钛 团聚 聚酰亚胺纳米复合薄膜 反应分子动力学 原位聚合法 

分 类 号：TM215[一般工业技术—材料科学与工程]