Fan Jie, Li Gengying, Deng Sijie, Deng Chengwei, Wang Zhongkun, Zhang Zhijun
School of Civil Engineering, Guizhou Institute of Technology, Guiyang 550003, China.
College of Water Conservancy and Civil Engineering, South China Agricultural University, Guangzhou 510642, China.
Materials (Basel). 2020 Jun 22;13(12):2807. doi: 10.3390/ma13122807.
Carbon nanotubes (CNTs) are considered as one of the ideal modifiers of cement materials, since CNTs can improve the mechanical properties of cement paste effectively. However, the interfacial interaction between CNTs and the cement matrix is weak. Moreover, it is difficult to disperse CNTs within cement paste. To overcome these shortages, in this study, CNTs were firstly dispersed into a styrene-acrylic emulsion (SAE). Then the homo-dispersion CNT/SAE emulsion was incorporated into cement paste. The effect of the CNT/SAE hybrid-system on the mechanical properties and microstructure of cement paste was studied. For purposes of comparison, the properties of cement paste mono incorporating CNTs or SAE are also investigated. The results show that CNT/SAE network films could be observed in cement paste by using a field emission scanning electron microscope (FESEM). These network films could bridge the cracks and refine the pores of a cement matrix. Infrared analysis and Raman spectroscopy show that the CNT/SAE hybrid modifier has stronger interfacial adhesion and better load transfer ability over the mono adding of CNTs and SAE emulsion. As a result, the hybrid addition of CNT/SAE significantly improved the flexural strength of cement paste. Especially, the addition of 0.1% CNTs and 15% SAE by mass of cement improved the 28-day flexural strength of cement paste by 21% and 25% as compared to the mono addition of CNTs or SAE, respectively.
碳纳米管（CNTs）被认为是水泥材料理想的改性剂之一，因为碳纳米管能够有效改善水泥浆体的力学性能。然而，碳纳米管与水泥基体之间的界面相互作用较弱。此外，碳纳米管在水泥浆体中难以分散。为克服这些不足，本研究首先将碳纳米管分散到苯丙乳液（SAE）中。然后将均匀分散的碳纳米管/苯丙乳液掺入水泥浆体中。研究了碳纳米管/苯丙乳液复合体系对水泥浆体力学性能和微观结构的影响。为作比较，还研究了单独掺入碳纳米管或苯丙乳液的水泥浆体的性能。结果表明，通过场发射扫描电子显微镜（FESEM）可观察到水泥浆体中的碳纳米管/苯丙乳液网络膜。这些网络膜能够弥合水泥基体中的裂缝并细化孔隙。红外分析和拉曼光谱表明，与单独添加碳纳米管和苯丙乳液相比，碳纳米管/苯丙乳液复合改性剂具有更强的界面粘结力和更好的荷载传递能力。因此，碳纳米管/苯丙乳液复合添加显著提高了水泥浆体的抗折强度。特别是，与单独添加碳纳米管或苯丙乳液相比，按水泥质量计添加0.1%的碳纳米管和15%的苯丙乳液分别使水泥浆体28天抗折强度提高了21%和25%。
