Aragonite and Its Composites: Preparations, Properties and Applications.

Aragonite, a metastable crystal form of calcium carbonate, exhibits the highest density and hardness among all species. Diversified forms of aragonite composites can be produced through different preparation processes, forming a relatively complete system in various application fields. Their properties and applications are determined by their multiple levels of structures and shapes. However, research information for aragonite‐related fields is currently lacking integration and clarification. This review provides a comprehensive overview on the preparation methods, properties, and potential applications of three main aragonite‐based materials: aragonite particles, nacre‐inspired mineralized aragonite composites (NMACs), and shell‐derived aragonite nanoparticles (SANPs). The formation mechanisms and versatile applications of these materials are thoroughly surveyed based on their initial precursor, reaction conditions, product forms including filler of aragonite whiskers synthesized by carbonation reaction; functional materials of NMACs fabricated by amorphous calcium carbonate‐organic matter (ACC‐OM) mediated process; biomedical materials of SANPs derived from aragonite cockle shells. Overall, this review aims to provide assistance for customized production of aragonite‐based materials as well as new research directions for both pure aragonites and its composites. [ABSTRACT FROM AUTHOR]