自感知镍纳米线/水泥基复合材料的制备及压敏性能

Fabrication and piezoresistivity of self-sensing Ni nanowire/cement composites

  • 摘要: 通过多孔氧化铝模板交流电沉积的方法制备了镍纳米线,以镍纳米线为导电填料、聚羧酸减水剂为分散剂,首次制备了新型的自感知镍纳米线/水泥基复合材料。通过SEM、TEM和XRD测试方法,研究了镍纳米线与镍纳米线水泥基复合材料的显微结构,与此同时,用四电极伏安法研究了镍纳米线水泥基复合材料的渗流阈值和压敏性。结果显示:所得的镍纳米线直径约为65 nm,长径比约为50;聚羧酸型减水剂能有效提高镍纳米线的分散性;水泥基复合材料的电阻率随镍纳米线的掺量增加呈现渗流特性,渗流阈值为0.5vol%;掺加1.0vol%镍纳米线的水泥基复合材料的应变灵敏度系数高达509.2,远高于电阻应变片的2.0,适用于混凝土结构应力监测的传感元件。

     

    Abstract: Nickel nanowires were obtained using the porous alumina template by the alternating current electro-deposition method. For the first time, the Ni nanowire/cement composites were fabricated by using the as-obtained nanowires as the conductive filler, and the polycarboxylate superplasticizer as the dispersant. The microstructures of Ni nanowires and Ni nanowires/cement composites were studied by SEM, TEM and XRD. Besides, the percolation threshold and piezoresistivity of Ni nanowires/cement composites were investigated by the four-pole method. The results indicate that the diameter of as-obtained Ni nanowires is about 65 nm and the aspect ratio is about 50. Also, the polycarboxylate superplasticizer can effectively improve the dispersion of Ni nanowires. In addition, the resistivity of cement-based composites displays the typical features of percolation phenomena with the increase of Ni nanowires content, the percolation threshold is concluded to be 0.5vol%. Furthermore, the measured gage factor of Ni nanowires/cement composites with 1.0vol% Ni nanowires is 509.2, far higher than the value of 2.0 for the resistance-strain gauge. The Ni nanowires/cement composites are promising for the application as the stress sensor in the concrete structures.

     

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