纳米碳管水泥基复合材料的DC I-V及AC阻抗特性

DC I-V and AC Impedance Characteristic of Multi-Wall Carbon Nanotubes Cement-Based Composite

结合表面活性剂及超声分散方法将0.1%的多壁纳米碳管（MWNTs）掺入水泥基体中,浇筑成型纳米碳管水泥基复合材料（MWNTs/CC）.分别采用DC电源、AC信号源供电,四电极法测试MWNTs/CC及空白参比（Plain/C）试件的DCⅠ-Ⅴ及AC阻抗模图.相比于Plain/C,MWNTs/CC试件的DCⅠ-Ⅴ曲线斜率与线性度有明显的提高;在10^2～10^3Hz的AC频率区间,其AC阻抗模也有显著的降低.表明少量长径比高、电导性佳的MWNTs纤维,在外加电场的作用下就能通过其优良的宏观隧穿效应实现在介电水泥基体中相互导通.

Multi-wall carbon nanotubes（MWNTs） with 0.1%concentration were introduced into cement matrix by surfactant ultrasonic dispersion method so as to mix cast MWNTs/cement composite（MWNTs/CC） specimens.The DCⅠ-Ⅴcharacteristics and AC impedance responses of the MWNTs/CC and reference（Plain/C） specimens were investigated by the four-electrode method under DC power,AC signal power,respectively.Compared with that of Plain/C,there exist obvious enhancements on the slope and linearity of DCⅠ-Ⅴcharacteristic of MWNTs/CC specimen;and there also exist marked decreases on AC impedance modules in-between 10~2～10~3 Hz frequency.These indicate that only a small amount of MWNTs fiber with a high aspect ratio and superior electrical conductivity can break-over conduction amongst dielectric cement matrix under power supply by its superior macro tunneling effect.