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硅酸盐通报 ›› 2021, Vol. 40 ›› Issue (3): 731-740.

• 水泥混凝土 • 上一篇    下一篇

不同分散剂对复掺GO/CNFs水泥基复合材料力学和导电性能的影响

吴一晨1, 郭荣鑫1, 夏海廷1,2, 索玉霞1, 未立煌1, 陈佳敏1   

  1. 1.昆明理工大学建筑工程学院,云南省土木工程防灾重点实验室,昆明 650500;
    2.昆明理工大学民航与航空学院,昆明 650500
  • 收稿日期:2020-11-17 修回日期:2020-12-17 出版日期:2021-03-15 发布日期:2021-04-13
  • 通讯作者: 郭荣鑫,博士,教授。E-mail:guorx@kmust.edu.cn
  • 作者简介:吴一晨(1997—),女,硕士研究生。主要从事新型水泥基复合材料的研究。E-mail:1464779809@qq.com
  • 基金资助:
    国家自然科学基金(11962009)

Effects of Different Dispersants on Mechanical and Electrical Properties of GO/CNFs Cement-Based Composites

WU Yichen1, GUO Rongxin1, XIA Haiting1,2, SUO Yuxia1, WEI Lihuang1, CHEN Jiamin1   

  1. 1. Yunnan Key Laboratory of Disaster Reduction in Civil Engineering, Faculty of Civil Engineering and Mechanics, Kunming University of Science and Technology, Kunming 650500, China;
    2. Faculty of Civil Aviation and Aeronautics, Kunming University of Science and Technology, Kunming 650500, China
  • Received:2020-11-17 Revised:2020-12-17 Online:2021-03-15 Published:2021-04-13

摘要: 新型碳纳米材料氧化石墨烯(GO)和纳米碳纤维(CNFs)在分散性良好的前提下可用于改善传统水泥基材料的性能。采用聚羧酸减水剂(PCs)、十二烷基硫酸钠(SDS)、十二烷基苯磺酸钠(SDBS)3种不同分散剂对复合GO和CNFs在水泥基材料中进行分散,研究分散剂种类对复掺GO/CNFs水泥基复合材料的力学及导电性能的影响,并通过扫描电子显微镜(SEM)对不同分散剂制备的复掺GO/CNFs水泥基试件的微观结构进行分析。结果表明:当单独使用PCs作为分散剂时,在质量分数0.05%GO和0.5%CNFs掺量下,试件的抗压强度达到最大(70.1 MPa);在0.05%GO和0.3%CNFs掺量下,试件的电阻率最小(112.65 Ω·m),且在加载条件下表现出良好的电阻率-应力变化响应。而采用SDS、SDBS两种离子型分散剂时,在GO/CNFs混合分散液的配制和试件制备过程中均会产生大量绵密且难以排出的气泡,使得水泥基复合材料的内部结构疏松,抗压强度降低,电阻率变大,导电性能下降。使用PCs单独分散的GO/CNFs水泥基试件表面水化产物结构致密,而采用SDS分散时水泥基试件微观结构疏松,且仅在100倍下即可观察到表面存在大量孔隙,因此使用PCs分散GO/CNFs对水泥基复合材料性能改善的效果最好。

关键词: 水泥基复合材料, 氧化石墨烯, 纳米碳纤维, 分散剂, 复掺, 力学性能, 导电性能

Abstract: Graphene oxide (GO) and carbon nanofibers (CNFs), as two new carbon nanomaterials, can be used to improve the performance of traditional cement-based materials on the premise of good dispersion. Polycarboxylate superplasticizer (PCs), sodium dodecyl sulfate (SDS) and sodium dodecyl benzene sulfonate (SDBS) these three different dispersants were used to disperse GO and CNFs in cement-based composites. The effects of dispersants on the mechanical and electrical properties of GO/CNFs cement-based composites were studied. The microstructures of GO/CNFs cement-based composites prepared with different dispersants were analyzed by scanning electron microscope (SEM). The results show that when PCs is used as dispersant alone, the compressive strength of specimen reaches the maximum (70.1 MPa) at the mass fraction of 0.05%GO and 0.5%CNFs. When the mass fraction is 0.05%GO and 0.3%CNFs, the resistivity of specimen is the lowest (112.65 Ω·m) and shows a good resistivity-stress response under loading conditions. When SDS and SDBS are used, a large number of bubbles are generated in the preparation of GO/CNFs mixed dispersion and in the preparation of specimens, which make the internal structure of cement matrix composites loose, reduce compressive strength, increase resistivity and decrease electrical conductivity. In addition, through SEM analysis, it is seen that the hydration products of GO/CNFs cement-based composites dispersed by PCs are compact in structure, while the microstructure of cement-based composites is loose when SDS is used as dispersant, and a large number of pores in the surface is observed only at a factor of 100. Therefore, when PCs is used as dispersant, it has the best performance improvement effect on GO/CNFs cement-based composites.

Key words: cement-based composite, graphene oxide, carbon nanofibers, dispersant, double mixing, mechanical property, electrical property

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