Long Wu-Jian, Li Hao-Dao, Fang Chang-Le, Xing Feng
Guangdong Provincial Key Laboratory of Durability for Marine Civil Engineering, Shenzhen Durability Center for Civil Engineering, College of Civil Engineering, Shenzhen University, Shenzhen 518060, China.
Nanomaterials (Basel). 2018 Jan 9;8(1):31. doi: 10.3390/nano8010031.
The properties of graphene oxide (GO)-based cement paste can be significantly affected by the state of GO dispersion. In this study, the effects of uniformly dispersed and re-agglomerated GO on the rheological, mechanical properties and microstructure of cement paste were systematically investigated. Two distinct dispersion states can be achieved by altering the mixing sequence: Polycarboxylate-ether (PCE) mixed with GO-cement or cement mixed with GO-PCE. The experimental results showed that the yield stress and plastic viscosity increased with the uniformly dispersed GO when compared to those of re-agglomerated GO cement paste. Moreover, the 3-day compressive and flexural strengths of uniformly dispersed GO paste were 8% and 27%, respectively, higher than those of re-agglomerated GO pastes. The results of X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy analyses demonstrated that uniformly dispersed GO more effectively promotes the formation of hydration products in hardened cement paste. Furthermore, a porosity analysis using mercury intrusion porosimetry revealed that the homogeneous dispersion of GO can better inhibit the formation of large-size pores and optimize the pore size distribution at 3 and 7 days than the re-agglomerated GO.
氧化石墨烯（GO）基水泥浆体的性能会受到GO分散状态的显著影响。在本研究中，系统研究了均匀分散和重新团聚的GO对水泥浆体流变性能、力学性能和微观结构的影响。通过改变混合顺序可实现两种不同的分散状态：聚羧酸醚（PCE）与GO-水泥混合或水泥与GO-PCE混合。实验结果表明，与重新团聚的GO水泥浆体相比，均匀分散的GO会使屈服应力和塑性粘度增加。此外，均匀分散的GO浆体的3天抗压强度和抗折强度分别比重新团聚的GO浆体高8%和27%。X射线衍射、傅里叶变换红外光谱和扫描电子显微镜分析结果表明，均匀分散的GO能更有效地促进硬化水泥浆体中水化产物的形成。此外，压汞法孔隙率分析表明，与重新团聚的GO相比，GO的均匀分散在3天和7天时能更好地抑制大尺寸孔隙的形成并优化孔径分布。
