作　　者： ; ; ; ; ; ;

机构地区： 中国科学院深圳先进技术研究院

出　　处： 《陶瓷学报》 2011年第3期358-363,共6页

摘　　要： 利用液相化学还原法制备了Ni微纳米颗粒,通过研磨和热压工艺制备了镍填充聚偏氟乙烯(PVDF)复合材料。研究了Ni/PVDF复合材料在10 7～10 9Hz频率范围内的介电性能和20℃～200℃范围内冷却过程中的热学性能。结果表明:在10 7Hz测试频率下,其渗流域值fc=0.275,渗流效应明显。在相同测试频率下,复合材料介电常数和介电损耗均随着Ni颗粒体积分数的增大而增大;在Ni颗粒含量不超过23.1vol%时,在同一体积分数下,介电常数和介电损耗均随着测试频率的增加而减小。Ni颗粒含量为27.1vol%时,在测试频率小于3.5×108Hz时,复合材料介电常数和介电损耗随着测试频率的增加而减小;大于3.5×108Hz时,其介电损耗随着测试频率的增加而逐渐增大,介电常数显著下降。随着Ni颗粒体积分数的增大,复合材料的结晶峰温度升高,结晶焓和结晶度减小。 The Ni particles were synthesized by aqueous chemical reduction and filled in PVDF matrix and formed Ni/PVDF composites via a grinding and the hot-molding technique.Dependence of dielectric properties of the composites between 10 7~ 10 9Hz on Ni volume fraction are studied.The thermal properties of the composites on Ni contents from 20℃ to 200℃ during the cooling cycle are also studied.The results show that within a general frequency range from 10 7-10 9 Hz,the dielectric permittivity and loss tangent increase with the filler content.The percolation threshold of the composites is 0.275 at 10 7Hz.The dielectric constant and loss tangent of the composites decrease with the increase of frequency when the content of Ni particles is below 23.1vol%.When the content is 27.1vol%,the loss tangent has a minimum value at about 3.5×10 8 Hz and when the frequency is above 3.5×10 8Hz,the dielectric constant decreases quickly.With the increase of Ni contents,the peak crystallization temperature of the composites increases,while the crystallization enthalpy and crystallinity of the composites go down.

关 键 词： 镍 复合材料 热学性能 高频

领　　域： [化学工程] [化学工程]