Yaseen Sarah Abduljabbar, Yiseen Ghadah Abdaljabar, Li Zongjin
Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, 999077 Kowloon, Hong Kong, China.
Department of Chemistry, College of Science, University of Baghdad, 10071 Baghdad, Iraq.
ACS Omega. 2019 Jun 12;4(6):10160-10170. doi: 10.1021/acsomega.9b00042. eCollection 2019 Jun 30.
In this study, the carbonation of Portland cement by direct chemical interaction with graphene oxide (GO) and reduced graphene oxide (rGO) at 7 and 28 days was examined. During the carbonation reaction, the calcium-bearing phases (calcium hydroxide, calcium silicate hydrate, and ettringite) formed calcium carbonate polymorphs, along with amorphous silica gel, gypsum, and alumina gel. These reaction products were examined using XRD (X-ray diffraction), XPS (energy-dispersive spectrometry), and FTIR (Fourier transform infrared). XRD patterns showed that the intensities of the calcium hydroxide and calcium carbonate peaks in the hydrated cement mixed with GO and/or rGO are higher than the corresponding peaks in the hydrated cement without any additives. The morphology of the reaction products was also characterized by SEM (scanning electron microscopy) measurements, which showed that a needle-like phase of calcium carbonate develops on the hydrated cement. The obtained microstructure parameters enabled the development of a more precise carbonation model.
在本研究中，考察了波特兰水泥在7天和28天时通过与氧化石墨烯（GO）和还原氧化石墨烯（rGO）直接化学相互作用而发生的碳酸化。在碳酸化反应过程中，含钙相（氢氧化钙、硅酸钙水合物和钙矾石）形成了碳酸钙多晶型物，同时还有无定形硅胶、石膏和氧化铝凝胶。使用X射线衍射（XRD）、能量色散光谱（XPS）和傅里叶变换红外光谱（FTIR）对这些反应产物进行了检测。XRD图谱显示，与GO和/或rGO混合的水化水泥中氢氧化钙和碳酸钙峰的强度高于未添加任何添加剂的水化水泥中的相应峰。反应产物的形态也通过扫描电子显微镜（SEM）测量进行了表征，结果表明在水化水泥上形成了针状碳酸钙相。所获得的微观结构参数有助于建立更精确的碳酸化模型。
