Pressure-sensitive properties and microstructure of carbon nanotube reinforced cement composites
Pressure-sensitive properties and microstructure of carbon nanotube reinforced cement composites
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DOI：
10.1016/j.cemconcomp.2006.12.011
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发表时间：
2007-05-01
影响因子：
10.5
通讯作者：
Zhao, Xiaohua
中科院分区：
文献类型：
--
作者：
Li, Geng Ying;Wang, Pei Ming;Zhao, Xiaohua
利用超声波能量将经过硫酸和硝酸混合溶液处理的碳纳米管均匀分散到水泥浆体中。循环压缩载荷下的电阻率和压敏性能的这种复合材料进行了分析和比较，未经处理的碳纳米管增强水泥石。结果表明，在水泥浆体中加入处理过的或未处理过的碳纳米管，水泥浆体的体积电阻率显著降低，压缩敏感性明显增强。用扫描电镜分析了水泥基复合材料的微观结构。微观观察表明，处理和未处理的碳纳米管均匀分散在水泥基体中。未处理的碳纳米管增强水泥基复合材料中，碳纳米管表面光滑，呈锯齿状，紧贴在水泥基体上，裂纹桥接，三维网络结构良好。处理后的碳纳米管增强水泥基复合材料中，碳纳米管表面被C-S-H所覆盖，从而提高了复合材料的力学强度。与未处理的碳纳米管相比，处理后的碳纳米管在水泥基复合材料中的接触点明显减少，从而导致复合材料具有更高的压敏性能和更低的电导率。(c)2007爱思唯尔有限公司版权所有。
Carbon nanotubes (CNTs) treated by using a mixed solution of H2SO4 and HNO3 were uniformly dispersed into cement paste by means of ultrasonic energy. Electrical resistivity and pressure-sensitive properties under cyclic compressive loading of this composite were analyzed and compared to that of untreated-CNT reinforced cement paste. Results show that the addition of treated or untreated CNTs to cement paste leads to a notable decrease in volume electrical resistivity and a distinct enhancement in compressive sensitivity. The microstiuctures of these cement composites were analyzed by using scanning electron microscope. The microscopic observation reveals that both treated and untreated CNTs were dispersed homogenously in the cement matrix. For untreated CNT-reinforced cement composites, the CNTs with glossy surface were zigzag and cling to cement matrix; the bridging of cracks and a well three-dimensional meshwork were also observed. For treated CNT reinforced cement composites, the surface of CNTs was covered by C-S-H, which leads to a higher mechanical strength. The contact points of the treated-CNTs in composites were much fewer than that of the untreated-CNTs in cement matrix composites, which leads to a higher compressive sensitive properties and a lower electrical conductivity. (c) 2007 Elsevier Ltd. All rights reserved.