Formation and Stabilization of Vaterite Aggregate Grooves with Aspartic Acid (Asp) by Bubbling CO2 into a Ca(OH)2 Suspension

Abstract

Vaterite aggregate grooves are successfully obtained by the Ca(OH)2‐CO2 reaction system in the presence of aspartic acid (Asp). Then, the dynamic changes of pH, conductivity, the concentration of Ca2+ and OH– in the suspension during the reaction process are tested. Moreover, the morphologies and polymorphs of the precipitates at different reaction time are studied by the field emission scanning electron microscope (FE‐SEM) and X‐ray Diffraction (XRD). The results show that when Asp is not added in the Ca(OH)2 suspension, the precipitates are calcite, while the carbonization precipitates with Asp are vaterite. Furthermore, in the presence of Asp, the carbonization process in the Ca(OH)2 suspension has a coating‐fragmentation behavior, and vaterite aggregate grooves can be formed after 110 min. In particular, Asp plays an important role in the nucleation, crystallization, and growth of CaCO3, and then a novel formation mechanism of vaterite aggregate grooves is proposed in this paper.