Improving ethylene glycol transport properties by caffeine – Thermodynamic and computational evidence

Abstract

In this article, detailed physicochemical characterization of ethylene glycol and caffeine + ethylene glycol mixtures is performed based on density, viscosity and refractive indices measurements in temperature range from (288.15 to 343.15) K. The apparent molar volume (Vϕ), apparent molar volume at infinite dilution (Vϕo), Masson's experimental slope (Sv), limiting apparent molar expansibility, (Eϕo), viscosity B-coefficient, thermodynamical parameters of viscous flow and molar refractions (Rm) have been evaluated from experimental measurements and results are additionally proven by molecular dynamic simulations. The addition of caffeine reduces viscosity of ethylene glycol, while caffeine molecules have high tendency to form self-aggregates due to weak interactions with ethylene glycol. Compared to aqueous solution of caffeine, caffeine + ethylene glycol mixtures are characterized with significantly lower solvation number and with more pronounced caffeine self-aggregation.