Liquid–Liquid Equilibrium Behavior and Intermolecular Interactions of Water, Methyl Lactate, and Alkyl Alcohols (C6∼C9)

This work explores the liquid–liquid equilibrium (LLE) of a water + methyl lactate (ML) + alkyl alcohol system. The LLE data were acquired for water + ML + (1-hexanol, 1-heptanol, 1-octanol, and 1-nonanol) at a temperature of 303. 2 K and a pressure of 101. 3 kPa. The system’s equilibrium behavior was characterized by determining water and ML distribution coefficients across the two phases and calculating the separation factor. Moreover, activity coefficient models were utilized to regress the experimental LLE data, with binary interaction parameters subsequently derived. The model parameters were validated with the GMcalTieLinesLL tool, confirming adherence to Gibbs stability criteria. Additionally, the study encompassed an analysis of intermolecular interactions within the system, employing the σ profile, deformed charge density, interaction energy, and reduced density gradient (RDG) analysis to elucidate the interactions.