Investigation of Potential Azeotrope Breakers Using DFT and COSMO Approach

Different combinations of cations (imidazolium,
pyridinium, pyrrolidinium, phosphonium, and ammonium) and anions (basic
anions, sulfate, phosphate, and borate) were studied based on the
COSMO volume and quantum chemical parameters such as highest occupied
molecular orbital/lowest unoccupied molecular orbital (HOMO/LUMO)
energies, HOMO–LUMO energy gap, global hardness and softness,
electronegativity, electrophilicity index, and chemical potential
using the density functional theory (DFT) method. Further, the sigma
profile and sigma potential for the selected cations and anions were
generated using a COSMO-RS model. The activity coefficient at infinite
dilution was also studied for the butanol–water system to find
a greater degree of nonideality. A feasible entrainer for the azeotrope
breaker for a butanol–water system is proposed.