纳米碳管水泥基复合材料的电阻性能

Properties of electrical resistivity of fiber-reinforced cement composites with multi-walled carbon nanotubes

摘要:

以水泥为基体、多壁纳米碳管(MWNTs)为增强组分,采用表面活性剂超声分散方法,混合成型制备了MWNTs纤维增强水泥基材料(FRCs).探讨了各组FRCs试件体积电阻率(ρv)随MWNTs质量分数(w),含水率(X),荷载(σ)的变化规律.结果表明:FRCs的ρv随w增加而逐渐降低,当w达2%时,ρv只有1.83kΩ·cm左右;除w为2%的NFC5外,其他组FRCs的X对其ρv影响显著,尤其是水分扩散梯度较大时;除空白NFC0试件外,五组FRCs试件均有一定的压敏效应,但只有w为0.5%的NFC3试件的相对ρv变化(Δρv)随着σ持续增加呈现明显而均匀的变化,且能很好地表征试件内部微裂缝发展特征过程.

Abstract:

Fiber-reinforced cement composites(FRCs) with multi-walled carbon nanotubes(MWNTs) loadings were fabricated with ultrasonic surfactant dispersion and subsequently casting-mix method.The effect of different MWNTs loadings(w),wets(X) and pressures(σ) on the volume resistivity(ρv) of six groups of FRCs was investigated respectively.Results show that the ρv of FRC steadily falls down with the increment of w,and it is only a round 1.83 kΩ·cm with w being 2% ;except for NFC5 group with w being 2%,those ρv of other five groups of specimens are all sensitive to the correspondent X,especially when the diffusion gradient of water is rather high;except for the plain NFC0,there exist somewhat pressure-sensitive features for other five groups of specimens.However,only the fractional change in ρv(Δρv) of NFC3 group with w being 0.5% has distinct and steady descending trend,and it well exhibits the characteristics of micro cracks during occurring,developing and merging with the increment of σ.