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

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,...

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

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.