Understanding Mineral Crystallization, Dissolution and Ion Adsorption Using Advanced Atomic Force Microscopy Techniques

Understanding the fundamental mechanisms behind mineral crystallization, dissolution, and ion adsorption is essential for advancing fields such as carbon sequestration, environmental remediation, and materials science. In this work, we utilize advanced atomic force microscopy (AFM) to explore these processes at atomic and nanoscale levels across various mineral systems. In situ AFM imaging during brucite carbonation in supercritical CO₂ (scCO₂) revealed amorphous magnesium carbonate (AMC) intermediates that acted as seeds for nesquehonite crystallization, offering new insights into crystallization pathways under elevated pressure and temperature. Another study using high-speed, high-resolution AFM focused on atomic-scale mapping of gibbsite dissolution, demonstrating that dissolution in alkaline solutions is driven by the release of aluminate dimers—a mechanism further supported by density functional tight-binding simulations. This discovery challenges traditional monomeric dissolution models and uncovers anisotropic dissolution behaviors. Additionally, high-resolution AFM was employed to visualize the surface morphologies of boehmite nanoplates, identifying intricate features such as single-step edges, intermediate-phase defects, and vertically embedded nanocrystals via a twin (010) plane. Furthermore, combining with high-resolution AFM imaging and density functional theory (DFT) simulations we confirmed the preferred binding sites for Na⁺ ions on the boehmite (010) plane under high-cation concentration conditions. These studies provide unprecedented insights into the nanoscale processes that govern mineral transformations and interactions, offering valuable knowledge for controlling material properties in technological applications.