碳纳米管（CNTs）水泥砂浆复合材料实验研究

发布时间：2018-01-06 05:24

本文关键词：碳纳米管（CNTs）水泥砂浆复合材料实验研究　出处：《清华大学》2013年硕士论文　论文类型：学位论文

【摘要】：碳纳米管（CNTs）作为一种新型纳米纤维材料，以其优异的力学、电学性能，是现在材料研究领域的一个热点。学者研究发现，在金属、陶瓷中掺加一定比例的碳纳米管，能够有效增加基体材料的韧性。水泥作为与陶瓷性能类似的脆性材料，在水泥基体中掺加一定量的CNTs，对于改善基体的固有脆性会发挥良好的效果。本文主要研究CNTs水泥砂浆复合材料的实验室制备方法，包括CNTs在水溶液中的分散性能、CNTs水泥砂浆的浇注工艺以及CNTs水泥砂浆的配合比。在此基础上，对分别添加普通CNTs、带有官能团（-COOH/-OH）的CNTs、附着SiO_2的CNTs的水泥砂浆试件进行了实验研究，并且研究了不同掺量的CNTs对于实验结果的影响。实验采用了抗压强度和抗折强度用来评估试件的力学性能；压汞实验和扫描电镜来评估试件的微观结构。结果表明，添加普通CNTs的试件力学性能下降了70%。CNTs掺量的变化对于试件的影响不大，CNTs自身直径的变化（10-20nm~40-60nm）对于试件性能的略有影响，直径较大的CNTs试件力学性能提高了5%。试件整体孔隙率上升了100%，平均孔径大幅上升，电镜照片显示在水泥基体中存在大量孔隙，主要是因为分散剂SDS的加入带来了大量气泡影响了实验结果；带有官能团（-COOH/-OH）CNTs的试件的力学性能提升了15%，含有羧基（-COOH）CNTs的试件的平均强度要比含有羟基（-OH）CNTs的试件更高。整体孔隙率基本不变，但平均孔径下降了30%，，电镜照片显示CNTs在水泥基体中起到了桥连微裂缝，填充微孔隙的作用；添加附着SiO_2的CNTs的试件力学性能略有上升，电镜照片显示纳米SiO_2薄膜成功地附着在CNTs表面，平均厚度为50nm，CNTs在水泥基体中形成网状连接水泥的水化产物。
[Abstract]:Carbon nanotubes (CNTs) as a new nanofiber material, with its excellent mechanical and electrical properties, is a hot spot in the field of material research. Adding a certain proportion of carbon nanotubes to ceramics can effectively increase the toughness of the matrix materials. Cement, as a brittle material similar to ceramic properties, adds a certain amount of CNTs to the cement matrix. It has a good effect on improving the inherent brittleness of the matrix. In this paper, the laboratory preparation methods of CNTs cement mortar composites are studied, including the dispersion properties of CNTs in aqueous solution. The pouring process of CNTs cement mortar and the mix ratio of CNTs cement mortar. On this basis, the CNTs with normal CNTs and functional group (-COOH / -OH) was added respectively. The cement mortar specimens with CNTs attached to SiO_2 were studied experimentally. The influence of different CNTs content on the experimental results was studied. The compressive strength and the flexural strength were used to evaluate the mechanical properties of the specimens. Mercury injection experiments and scanning electron microscopy (SEM) were used to evaluate the microstructure of the specimens. The results showed that the mechanical properties of the specimens with the addition of ordinary CNTs decreased by 70. the change of the content of CNTs had little effect on the specimens. The variation of the diameter of CNTs (10-20nm) 40-60nm) has a slight effect on the properties of the specimen. The mechanical properties of CNTs specimens with larger diameters were improved by 5%. The overall porosity of the specimens increased by 100 and the average pore size increased significantly. The SEM photos showed that there were a large number of pores in the cement matrix. The main reason is that the addition of dispersant SDS brings a lot of bubbles to affect the experimental results. The mechanical properties of the specimens with functional groups were improved by 15%. The average strength of the CNTs containing carboxyl group was higher than that of the sample containing hydroxyl group. The overall porosity was almost unchanged, but the average pore size decreased by 30%. Electron microscopic photographs show that CNTs acts as a bridge to connect microcracks and fill in micropores in cement matrix. The mechanical properties of the CNTs added with SiO_2 increased slightly, and the SEM photos showed that the nanocrystalline SiO_2 films were successfully adhered to the surface of CNTs with an average thickness of 50 nm. CNTs forms hydration products of reticular joint cement in cement matrix.
【学位授予单位】：清华大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU578.1;TU599

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