摘要
以油酸为有机配体,采用两相方法合成了油溶性的超小尺寸纳米晶体纳米ZrO_2(nano ZrO_2),并对nano ZrO_2表面包覆的油酸改性使纳米晶体与聚酰胺酸(PAA)接枝,通过旋膜法热亚胺化后形成nano ZrO_2/聚酰亚胺(PI)复合超薄膜。利用TEM、XRD、FTIR和SEM等对nano ZrO_2及nano ZrO_2/PI复合超薄膜进行表征,并对nano ZrO_2/PI复合超薄膜的介电性能进行了探究。结果显示,nano ZrO_2尺寸均一(5.0nm左右),为锐钛矿晶型,其晶体结构和尺寸不受改性接枝影响。nano ZrO_2在复合超薄膜中分散良好。电学研究表明,复合超薄膜的介电性能受nano ZrO_2与PAA质量比及制膜热亚胺化温度的影响。当PAA∶ZrO_2质量比为2∶3、热亚胺化温度为320℃时,介电常数达到最大,几乎是纯PI薄膜的2倍。两相法-改性接枝-热亚胺化制备PI复合超薄膜的方法简单高效,能够避免无机粒子在PI基体内的团聚并提高介电性能,对于PI基复合薄膜的制备、应用及推广具有重要意义。
Oleic acid-capped nanocrystals （nano ZrO2） were fabricated via two-phase approach, modified and graf- ted onto polyamic acid （PAA）. After the imidization of nano ZrO2/PAA, nano ZrO2/polyamide （PI） ultra-thin composite films were finally obtained. The nanoerystals and nano ZrO2/PI ultra-thin composite films were character- ized by TEM, XRD, FTIR and SEM, and the dielectric properties of the nano ZrO2/PI ultra-thin composite films were also exploited. The results demonstrate the nano-size （about 5.0 nm） and mono-dispersity o{ ZrO2, the mor- phology and crystallinity of the nanocrystals are not negatively influenced by modification or grafting. The nanocrys- tals are homogenously dispersed in the bulk of PI. The dielectric properties of nano ZrO2/PI ultra-thin composite films are influenced by the mass fraction of nanocrystals and the filming condition （i. e. , imidization temperature）. With a PAA：ZrO2 mass ratio of 2 ： 3 and aimidization temperature of 320℃, the dielectric constant exhibites the maximum, around twice that of pure PI thin films. Overall, nano ZrO2/PI ultra-thin composite film fabrication method （general nanocrystal preparation-modification-grafting-imidization） exhibites its efficiency, feasibility, flexi- bility and versatility. This method can be extended by evolving other nanoparticles with high dielectric constant, tai- lor the properties by tuning the content of nanoparticles and filming condition, and obtain high dielectric constant composite films with low cost and pollution.
作者
程凤梅
马明月
李海东
CHENG Fengmei;MA Mingyue;LI Haidong(College of Material and Textile Engineering,Jiaxing University,Jiaxing 314001,China;School of Materials Science and Engineering,Changzhou University,Changzhou 213164,China)
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2018年第7期1725-1730,共6页
Acta Materiae Compositae Sinica
基金
浙江省自然科学基金(LY16E030008)
关键词
ZRO2
纳米晶体
改性
聚酰亚胺
超薄膜
介电常数
ZrO2
nanocrystal
modification
polyamide
ultra thin films
dielectric constant
