Electrical and optical properties of MWNTs/HDPE composites in Terahertz region  

作　　者：CHEN Xiliang CHEN Xin ZHU Zhiyong 

机构地区：[1]Yellow River Conservancy Technical Institute, Kaifeng 475004, China [2]Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China [3]College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004, China

出　　处：《Nuclear Science and Techniques》2012年第3期156-162,共7页核技术（英文）

基　　金：Supported by National Natural Science Foundation of China (10675157) and (10875161);the National Basic Research Program of China (Grant No. 2010CB832903)

摘　　要：Optical and electrical properties of composites,prepared by filling of high density polyethylene(HDPE) with two kinds of multi-walled carbon nanotubes(MWNTs) differing in diameters,were explored by terahertz time-domain spectroscopy(THz-TDS) in the frequency range from 0.2 to 1.6 THz.It is found that composite with larger-diameter MWNTs possesses larger absorption coefficient and conductivity at the same concentration.The real part of the ac conductivity of the composites follows a power law dependence on frequency.And the power index is around 0.75 regardless of the MWNT concentration and diameter.The experimental data were analyzed with Cole-Cole equation under the assumption that the conductive clusters dispersed in the polymer matrix behave like dipoles and contribute mainly to the dielectric loss.It is found that both of the composites have similar values of relaxation time and distribution parameter.With increase of the MWNTs concentration,the relaxation time increases and tends to saturate at 0.7 ps after passing through the percolation threshold.Optical and electrical properties of composites, prepared by filling of high density polyethylene （HDPE） with two kinds of multi-walled carbon nanotubes （MWNTs） differing in diameters, were explored by terahertz time-domain spectroscopy （THz-TDS） in the frequency range from 0.2 to 1.6 THz. It is found that composite with larger-diameter MWNTs possesses larger absorption coefficient and conductivity at the same concentration. The real part of the ac conductivity of the composites follows a power law dependence on frequency. And the power index is around 0.75 regardless of the MWNT concentration and diameter. The experimental data were analyzed with Cole-Cole equation under the assumption that the conductive clusters dispersed in the polymer matrix behave like dipoles and contribute mainly to the dielectric loss. It is found that both of the composites have similar values of relaxation time and distribution parameter. With increase of the MWNTs concentration, the relaxation time increases and tends to saturate at 0.7 ps after passing through the percolation threshold.

关 键 词：多壁碳纳米管 复合材料 光学性能 HDPE THZ波段 太赫兹时域光谱 电气 高密度聚乙烯 

分 类 号：O484.41[理学—固体物理] TB383[理学—物理]