硅灰协同分散石墨烯对水泥基材料性能的影响

Effect of silica fume synergistic dispersed graphene on properties of cement-based materials

为提高石墨烯在水及水泥浆体中的分散效果,充分发挥石墨烯对水泥基材料的增强改性作用,研究了硅灰协同分散石墨烯对水泥基材料水化过程、工作性能、力学性能及水化产物微观结构的影响。并通过扫描电镜(SEM)、粒度分析、红外光谱(IR)、拉曼光谱、X射线衍射(XRD)、X射线能谱分析(EDS)等微观表征手段研究其作用机理。结果表明:硅灰可以起到楔子的作用穿插到石墨烯层间,可以消耗水泥基材料中的Ca^(2+)、减小Ca^(2+)对石墨烯分散的负面影响效应,所以硅灰协同分散提高了石墨烯在水中及水泥浆体中的分散效果,降低了水泥的流动度,缩短了凝结时间,加速了水泥水化反应,优化了水泥基材料微观结构,提高了水泥基材料的力学性能,尤其是28 d抗折强度,水泥水化产物的种类未发生变化。

In order to improve the dispersion effect of graphene in water and cement slurry and give full play to the enhancement and modification effect of graphene on cement-based materials,the effects of silica fume coordinated dispersion graphene on hydration process,working performance,mechanical properties and microstructure of hydration products of cement-based materials were studied.The mechanism was studied by scanning electron microscopy(SEM),particle size analysis,infrared spectroscopy(IR),Raman spectroscopy,X-ray diffraction(XRD),energy dispersive spectroscopy(EDS)and other microscopic characterization methods.The results show that silica fume can act as a wedge between graphene layers.The synergistic dispersion of silica fume improves the dispersion of graphene in water and cement slurry due to the consumption of Ca^(2+)in cement-based materials and the reduction of the negative effect of Ca^(2+)on graphene dispersion.The fluidity of cement is reduced and the setting time is shortened.The hydration reaction of cement was accelerated and the microstructure of cement-based materials was optimized.The mechanical properties of cement-based materials were improved,especially the 28 d flexural strength,and the types of cement hydration products did not change.