Experimental Determination and Modeling of Density, Viscosity, and Surface Tension for Sulfolane + Ethyl Acetate and + n‑Propyl Acetate

The density, viscosity, and surface tension for the binary mixtures of sulfolane + ethyl acetate and + n-propyl acetate were measured at the atmospheric pressure and temperature ranging from 308.15 to 328.15 K. The linear equation and Andrade model were successfully used to correlate the experimental density and viscosity, respectively. On the basis of the experimental data, the viscosity energy barrier and the surface entropy/enthalpy were further obtained. The calculation of the molecular interaction energy using the Dmol3 module in Materials Studio software shows that the interaction energy in sulfolane + ethyl acetate is slightly greater than one in sulfolane + n-propyl acetate, which is consistent with the experimental observation. In addition, each experimental property of density, viscosity, and surface tension can well be reproduced by the square-well chain fluid with variable range (SWCF-VR) equation of state with one different binary adjustable parameter.