Uncovering the Solvent-Solute Interaction Mechanism in Nucleation of Erythritol Based on Metastable Zone Widths: Experimental Kinetics and Molecular Dynamics Simulations

Thepolythermal method (PTM) was employed to measure metastablezone width (MSZW) of erythritol (ERT) in solvents containing differenthydrogen bond acceptor (HBA) capacities. The nucleation behavior ofERT was explained by modified Sangwal's theory. In order tofurther uncover the effect of interaction mechanism between solventand solute molecules on the nucleation rate of ERT, the molecularelectrostatic potential surface (MEPS), Hirshfeld surface (HS) analysis,and radial distribution function (RDF) were calculated and analyzed.It was found that the strength of solvent-solute interactionwas mainly related to the HBA ability of the solvent: the greaterthe HBA ability was, the stronger the hydrogen bond between the solventand solute molecules would be, resulting in more difficulty for thesolute to separate from the solvent, which then widens the MSZW andleads to a lower nucleation rate, a smaller critical nucleation size,and a longer induction time. Additionally, the induction time underdifferent supersaturation ratios was measured to analyze the nucleationmechanism of ERT. At a high supersaturation ratio, the nucleationmechanism was homogeneous, while at a low supersaturation ratio, thenucleation mechanism was heterogeneous. The calculated interface energybased on the classical nucleation theory was compared with the interfaceenergy calculated by modified Sangwal's theory. The two calculatedvalues were in good agreement, which further lay the foundation forthe application of modified Sangwal's theory.