How Structurally Similar Additives Affect the Dimensionless Interfacial Tension for Inducing Nucleation: The Case Study of Succinic Acid

Abstract

Additives play a crucial role in regulating metastable zone widths (MSZWs) during the nucleation process, where solid−liquid interfacial tension is one of the important factors. In this work, we explored how glutaric acid, heptanedioic acid, and azelaic acid, as major byproducts, which have similar structures to succinic acid and act as an additive, affected nucleation behaviors of succinic acid. By measuring the MSZWs, classical nucleation theory and the newly defined dimensionless interfacial tension γ eff were employed to evaluate the nucleation ability in the presence of additives. Our results show that when increasing the carbon chain length and concentration of additives, this leads to an increase in the impurity coverage θ and adsorption heat Q diff , which causes γ eff to rise. Therefore, it suppresses the formation of crystal nuclei and leads to an increase in the nucleation energy barrier, which further widens the MSZWs. By using impurities in the production of succinic acid as additives, we highlight that the conception of the dimensionless interfacial tension γ eff may open the door to provide a possible method for evaluating and predicting the effect of additives on the solid−liquid interfacial tension during the nucleation process of succinic acid.