Binghao Wang,ab Limei Liu,b Guozheng Liang*a （梁国正）,Li Yuana and Aijuan Gu*a （顾嫒娟）
a Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, Department of Materials Science and Engineering, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren-Ai Road, Suzhou, P.R. China
b Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, 199 Ren-Ai Road, Suzhou, P.R. China
J. Mater. Chem. A, 2015,3, 23162-23169
How to develop high-k materials with extremely low dielectric loss based on commercially available conductors and polymers is still a big challenge. Here we present a general method that simultaneously increases the dielectric constant ten times and decreases the dielectric loss by five orders of magnitude. By adjusting the prepolymerization time of multi-walled carbon nanotube (MWCNT) and cyanate ester (CE) blends and using the layer-by-layer casting procedure, precisely controllable dispersion and distribution of MWCNTs in polymers were achieved. Consequently, a three-layer material (PE-[g-MWCNT0.5/CE-75%]2) with an optimized prepolymerization degree, consisting of two MWCNT/CE composite layers and one polyethylene (PE) thin film, exhibits a dielectric constant of 1027 and a dielectric loss of 0.02 at 1 Hz. This is one of the best results reported for polymer composites made up of nano-carbon or ceramics to date. The mechanism behind this was elucidated by analyzing the polarization of induced charges and transport of free charges. The formation of vastly interconnected networks of space charge regions, and the existence of a conductor fault and an insulating layer are the main factors that determine an extraordinarily high dielectric constant and extremely low dielectric loss simultaneously.
链接：//pubs.rsc.org/en/content/articlelanding/2015/ta/c5ta07611k#!divAbstract
