关键词: 乙酸乙酯, 异丙醇, 黏度, 表面张力, 超额性质, 疏液性

Abstract: The viscosity(η) and surface tension(σ) of ethyl acetate(EA) + isopropanol(IPA) binary mixture were measured over the entire composition range at 298.15—323.15 K and atmospheric pressure using Ubbelohde viscometer and pendant drop method,respectively.Viscosity deviations(Δη),excess Gibbs energy of activation of viscous flow(ΔG^*E) and surface tension deviations(Δσ) were calculated from the experimental data.The excess thermodynamic properties,Δη,ΔG^*E and Δσ were correlated by the Redlich-Kister equation,and fitted parameters and standard deviations were obtained.The results show that Δη,ΔG^*E and Δσ are negative over the whole mole fraction range in the temperature range studied,and all deviations become larger as temperature decreases.The surface tension values were further used to calculate the surface entropies(S^s) and surface enthalpies(H^s) per unit surface area.The lyophobicity(β) and the surface mole fraction(x^s₂) of IPA were also derived using the extended Langmuir model.The obtained x^s₂ values indicate that the surface concentration of IPA is always higher than its bulk concentration and consequently confirm that the surface is enriched with IPA.

Key words: ethyl acetate, isopropanol, viscosity, surface tension, excess property, lyophobicity