Vertically Aligned Carbon Nanotube Arrays on SiC Microplatelets: A High Figure-of-Merit Strategy for Achieving Large Dielectric Constant and Low Loss in Polymer Composites
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- 作者：Jinkai Yuan ; Shenghong Yao ; Weilong Li ; Alain Sylvestre ; Jinbo Bai
- 刊名：Journal of Physical Chemistry C
- 出版年：2014
- 出版时间：October 9, 2014
- 年：2014
- 卷：118
- 期：40
- 页码：22975-22983
- 全文大小：431K
- ISSN：1932-7455
文摘
Inclusion of conducting nanoparticles into polymer could result in a nonpercolated nanocomposite with largely improved dielectric constant. But the challenge always relies on lowering dielectric loss near percolation by rationally designing composite microstructure. Herein, we report a general strategy for dielectric constant enhancement employing vertically aligned carbon nanotube (CNT) arrays as filler. The CNT arrays are well distributed into poly(vinylidene fluoride) matrix with the help of SiC microplatelet support. They can naturally form effective microcapacitors in series to store charges and thus afford a dielectric constant of hundreds times higher than the virgin polymer yet maintain the loss tangent at low levels (<0.43). More importantly, such improvement is achieved at a very low loading, demonstrating the highest figure of merit ever reported for a nonpercolated system. Thanks to the thermal stability of the formed microcapacitor networks, the CNT array-based composite exhibits a giant dielectric constant of 鈭?05 and a moderate loss tangent of 鈭? at temperatures as high as 170 掳C. All these results validate the effectiveness of our strategy to realize high-performance dielectric polymer composites.