Interactions at Aqueous Mineral Interfaces: Insights from Nonlinear Optical Spectroscopy and Atomic Force Microscopy

Many technological and environmental processes take place at mineral-water interfaces, which makes detailed knowledge of the structure and interactions at aqueous mineral interfaces essential to understand these processes. Since mineral surfaces could become charged upon contact with electrolyte solutions, the interfacial water structure and properties are also influenced by the interactions of water and ions in solution with this surface charge. A particularly promising strategy for the investigation of neutral and charged mineral-water interfaces is the combination of nonlinear optical spectroscopy with atomic force microscopy (AFM). Nonlinear optical spectroscopy provides insights into the water orientation and dynamics at the interface, while AFM can resolve the interfacial water density and forces. In this review, we discuss how nonlinear optical spectroscopy and AFM can be used to investigate mineral-water interfaces and advance our fundamental understanding of aqueous mineral interfaces.