PVT, viscosity, and surface tension of ethanol: New measurements and literature data evaluation

In this work, the results of density, viscosity, and surface tension measurements for ethanol are presented. Ethanol with stated mass fraction purity greater than 0.998 was further purified using molecular sieves. Density was measured within the temperature and pressure ranges, respectively, T = (278.15 to 353.15) K and p = (0.1 to 35) MPa by means of a vibrating tube densimeter, model DMA 512P from Anton Paar with an estimated uncertainty of ±0.5 kg · m⁻³. The experimental (p, ρ, T) results have been correlated by Tait equation. From this equation the isobaric expansivity, the isothermal compressibility, and the thermal pressure coefficient have been calculated. Viscosity was measured over the range T = (273.15 to 346.15) K using an Ubbelohde viscometer with a Schott–Geräte automatic measuring unit (Model AVS-470) with the associated uncertainty of ±0.001 mPa · s. The measured values were combined with selected values from the literature covering the range T = (223 K to 503) K, and the VTF model has been fitted to all the data. The surface tension of the liquid was measured using a tensiometer KSV Sigma 70 with a Du-Noüy ring for the range of T = (274.77 to 318.99) K with an uncertainty of ±0.01 mN · m⁻¹. Using these data and critically assessed data of other authors compiled from the literature, a form of the IAPWS equation was used to correlate the surface tension within the temperature range 223 K up to the critical temperature.