Li Weiwen, Ji Weiming, Torabian Isfahani Forood, Wang Yaocheng, Li Gengying, Liu Yi, Xing Feng
Guangdong Key Provincial Durability Center for Marine Structure, Shenzhen Durability Center for Civil Engineering, Department of Civil Engineering, Shenzhen University, Shenzhen 518060, China.
Department of Architecture and Civil Engineering, City University of Hong Kong, Kowloon 999077, Hong Kong, China.
Nanomaterials (Basel). 2017 Jul 14;7(7):185. doi: 10.3390/nano7070185.
Carbon nanotubes (CNTs) have shown promise for improving the mechanical performance of cement composites through crack-bridging and frictional pull-out. The interactive behaviors between CNTs and cement matrix act are crucial in optimizing the reinforcement of CNTs in cement composites. This study investigates the effects of nano-silica (NS) sol-gel on the interactive behaviors of CNTs and the cement matrix through a series of experiments and analyses. UV-visible spectrometer results show that CNTs are well-dispersed in suspension and the addition of NS has a negligible effect on the stability of CNT dispersion. Calorimetry tests and dynamic mechanical analysis demonstrate the nucleation and frictional performance of CNTs in cement matrix, respectively. The paper shows that the physical adsorption of NS on the CNT surface could result in the acceleration of cement hydration. Morphology observation confirms that a denser interface between CNTs and cement hydrates is formed. Finally, the improved interaction between CNTs and cement hydrates leads to a substantial increase in friction between CNTs and the cement matrix under periodic loading. NS may act as an ideal admixture for improving both the interactive behaviors between CNTs and cement matrix and the damping properties of cement composite.
碳纳米管（CNTs）已显示出通过裂纹桥接和摩擦拔出改善水泥基复合材料力学性能的潜力。碳纳米管与水泥基体之间的相互作用行为对于优化碳纳米管在水泥基复合材料中的增强作用至关重要。本研究通过一系列实验和分析，研究了纳米二氧化硅（NS）溶胶 - 凝胶对碳纳米管与水泥基体相互作用行为的影响。紫外可见光谱仪结果表明，碳纳米管在悬浮液中分散良好，添加纳米二氧化硅对碳纳米管分散稳定性的影响可忽略不计。量热测试和动态力学分析分别证明了碳纳米管在水泥基体中的成核和摩擦性能。本文表明，纳米二氧化硅在碳纳米管表面的物理吸附可导致水泥水化加速。形态观察证实，碳纳米管与水泥水化物之间形成了更致密的界面。最后，碳纳米管与水泥水化物之间改善的相互作用导致在周期性加载下碳纳米管与水泥基体之间的摩擦力大幅增加。纳米二氧化硅可能是一种理想的外加剂，可改善碳纳米管与水泥基体之间的相互作用行为以及水泥基复合材料的阻尼性能。
