Elucidation of Calcite Structure of Calcium Carbonate Formation Based on Hydrated Cement Mixed with Graphene Oxide and Reduced Graphene Oxide

Sarah Abduljabbar Yaseen; Ghadah Abdaljabar Yiseen; Zongjin Li

doi:10.1021/acsomega.9b00042

Elucidation of Calcite Structure of Calcium Carbonate Formation Based on Hydrated Cement Mixed with Graphene Oxide and Reduced Graphene Oxide

ACS Omega. 2019 Jun 12;4(6):10160-10170. doi: 10.1021/acsomega.9b00042. eCollection 2019 Jun 30.

Authors

Sarah Abduljabbar Yaseen¹, Ghadah Abdaljabar Yiseen², Zongjin Li³

Affiliations

¹ Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, 999077 Kowloon, Hong Kong, China.
² Department of Chemistry, College of Science, University of Baghdad, 10071 Baghdad, Iraq.
³ Institute of Applied Physics and Materials Engineering, University of Macau, 999078 Macau, China.

Abstract

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.