Polymorphism and thermal stability of nesquehonite (MgCO3·3H2O) regulated by magnesium L-aspartate: For CO2 mineral sequestration

Abstract

Prepared by hydrothermal method, the nesquehonite (MgCO₃·3H₂O) was characterized through different testing and analysis techniques. The study investigated the influence of l-aspartic acid regulation on the morphology, structure, and thermal stability of the nesquehonite. SEM and DSC results indicated that the sample had larger size and higher thermal stability. Building on it, the reaction mechanism using magnesium l-aspartate as a reactant was further explored, confirming that the formation of O-Mg coordination bonds induced nucleation self-assembly of crystals, effectively enhancing thermal stability. Compared to conventional methods, the initial decomposition temperature of the crystals prepared in this study increased by 42.5 %. This study provides a theoretical basis for the indirect mineralization of CO₂ to produce magnesium carbonates. Furthermore, the direct incorporation of biomolecular polymeric salts offers a novel perspective for understanding the role of organic additives in the process of crystals mineralization.