Role of Additives in Crystal Nucleation from Solutions: A Review

Nucleation is a key step in the crystallization of solution. For regulating and controlling this process, it is thus critical to understand the nucleation mechanism under different circumstances. Note that how additives affect nucleation has not been essentially summarized. This contribution aims to explore the role of additives in theoretical models and practical applications. First, we review the development of nucleation theory: classical nucleation theory (CNT) and nonclassical nucleation theory (non-CNT). Under the framework of CNT, how additives influence the nucleation is expounded through the interactions between species involved in nucleation, along with solid–liquid interfacial energy and pre-exponential factors based on the metastable zone width (MSZW) and nucleation induction time (NIT). In non-CNT, we then discuss the effects of additives on the structural evolution of prenucleated species and competitive properties such as the Gibbs free energy change. Then, we summarize the role of multifarious additives in nucleation. Finally, how additives are adapted to treat some diseases in pathological biomineralization such as lithiasis is summarized. This review has a positive significance for comprehending the roles of additives on the nucleation in a solution milieu.