1. Nucleation Pathways in Electrolyte Solutions

The nucleation of a solid crystalline phase from an electrolyte solution is a long-standing subject of scientific investigations; however, neither pathways nor rates can be confidently predicted from classical nucleation theory (CNT). Moreover, results from recent experimental and theoretical studies call into question underlying assumptions of that theory, such as the nature of the species that form a stable nucleus and whether that process occurs directly from solution or following a liquid–liquid separation process. Here we provide a framework for how to interpret current investigations of solid formation from electrolyte solutions by reviewing the findings of some recent investigations. These experimental and computational studies probe nucleation pathways and rates in both homogeneous and heterogeneous environments and the processes of liquid–liquid phase separation and cluster aggregation.