Dielectric relaxation due to interfacial polarization for heat-treated wood
Dielectric relaxation due to interfacial polarization for heat-treated wood
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DOI：
10.1016/j.carbon.2003.10.013
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发表时间：
2004
期刊：
影响因子：
10.9
通讯作者：
Hiroyuki Sugimoto;M. Norimoto
中科院分区：
文献类型：
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作者：
Hiroyuki Sugimoto;M. Norimoto
在20 Hz ~ 1 MHz和- 150 ~ 20℃的温度范围内，测量了完全干燥的杉木（Cryptomeria japonica）木块和粉末样品在高达800℃的不同温度下的介电性能。在300℃以下处理的样品中发现了由甲基运动引起的弛豫，其幅度随温度的升高而减小。当温度达到400℃时，电导率随温度升高而降低。另一种形式的松弛被认为是在500至600°C之间处理的块状试样。实验结果采用Cole-Cole圆弧定律。块体试件纵向和径向的弛豫幅度分别为60 ~ 75和24 ~ 28。在粉末试样中也观察到相同的松弛。从500℃开始，电导率开始显著提高。这些结果表明，在微观水平上，在细胞壁中形成了具有大导电性的小体积颗粒。认为这种弛豫是由界面极化引起的。
The dielectric properties of totally dried sugi (Cryptomeria japonica) wood block and powder specimens treated at various temperatures up to 800 °C were measured in the range from 20 Hz to 1 MHz and from −150 to 20 °C. Relaxation ascribed to the motion of methylol groups was detected in specimens treated at temperatures below 300 °C and its magnitude decreased with increasing temperature. The electric conductivity decreased with increasing temperature up to 400 °C. Another form of relaxation was recognized for block specimens treated at temperatures between 500 and 600 °C. Cole–Cole’s circular arc law was applied to the experimental results. The relaxation magnitude was 60–75 and 24–28 in the longitudinal and radial directions of the block specimens, respectively. Identical relaxation was also observed in the powder specimen. The electric conductivity began to increase remarkably from 500 °C. These results suggested that a small volume fraction of particles with large conductivity is formed at microscopic levels in the cell walls. It is considered that this relaxation is due to interfacial polarization.