摘要
采用溶胶-凝胶法制备出了钛酸钡改性炭黑的复合粒子,并观察和分析了改性粒子的颗粒成分、结构、微波介电特性及其对电磁波的吸收性能。XRD分析可知复合粒子中含有钛酸钡晶体和炭黑。TEM研究表明,溶胶-凝胶法很好地在炭黑表面包覆了一层钛酸钡绝缘层,从而使得基体中的炭黑粒子形成导电孤岛。结果表明钛酸钡改性对不同炭黑含量有着不同的影响:当炭黑体积含量较低时(<20%),钛酸钡的包覆降低了复合材料的吸波效能;当体积百分含量超过20%时,钛酸钡的包覆提高了复合材料的吸波效能。这主要是因为钛酸钡包覆炭黑粒子形成的"导电孤岛"对复合材料的电性能影响的缘故。
By using sol-gel method, the compound particle of carbon black （CB） modified by Barium titanate were prepared. The structure and morphology of coated powders were characterized, and dielectric properties and microwave absorption performance of its composite were investigated. XRD indicates that CB and barium titanate were existed in the compound particle. TEM results show that BaTiO3 nano-films were well coated on the surface of CB particles and CB particles were distributed in the matrix in the form of conducting islands. The results indicated that BaTiO3 had different effects on microwave absorption performance of the composite with different CB contents. When the volume content of filling to epoxide resin matrix is lower （〈20vol%）, the microwave absorption performance of BaTiO3/CB composite was weakened compared with that of CB composite. Contrarily, exceed 20vol% the filling to the matrix, BaTiO3 could improve microwave absorption performance of the composite greatly. The probable reasons for these were discussed based on the electromagnetic constants and morphology of the modified CB particles as well as physical model of conducting islands.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2006年第9期1404-1407,共4页
Journal of Functional Materials
基金
国家自然科学基金资助项目(50402025)
关键词
炭黑
钛酸钡
表面包覆
介电性能
吸波特性
coated
carbon black
barium titanate
dielectric properties
microwave absorption
