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Indexed by:期刊论文

Date of Publication:2021-01-10

Journal:ACS SUSTAINABLE CHEMISTRY & ENGINEERING

Volume:8

Issue:39

Page Number:14718-14731

ISSN No.:2168-0485

Key Words:tricalcium silicate; carbonation; calcium carbonate; crystal growth; heat of carbonation; quantitative analysis

Abstract:Accelerated carbonation is expected to be a potential technique for sustainable development of cement-based materials, where the strength is significantly increased in several hours and greenhouse gas CO2 is stored permanently. Tricalcium silicate (C3S) is the most dominant composition in Portland cement, and the investigation regarding the gas-solid carbonation process of pure C3S is beneficial for further in-depth understanding of carbonation of complex C3S-containing systems. Besides, the vital roles of calcium carbonate in promoting mechanical properties during the diagenesis process are proposed in terms of the calcite growth process induced by carbonation. Multitechnique approaches, such as carbonation heat (via isothermal calorimetry), Rietveld refinement, etc., suggested that rhombic calcite was covered by spherical nanoparticles, formed from the transformation of amorphous calcium carbonate, and the rate of reaction was controlled by the solution environment. The particle size of calcite increased greatly in the leveled reaction stage (i.e., stage III). A combined effect of the strong mechanical bond and lamellar stack formed among calcite particles compacted the microstructure significantly. Changes in the crystallite size (from 43.9 to 107.9 nm), particle size (from 302.2 to 2077.6 nm), thermodynamic stability, lattice volume, and bond length were observed during the growth process of calcite. These findings provide a possibility to control the polymorphs, microstructures, or specific particle sizes of calcium carbonate for industrial applications and are beneficial for understanding and imitation of diagenesis paths in natural processes.