Mutual and Thermal Diffusivities as well as Fluid-Phase Equilibria of Mixtures of 1-Hexanol and Carbon Dioxide

• DOI: 10.1021/acs.jpcb.0c00646
• Publication Date: 2020-02-27T17:01:05Z
• Authors: Wenchang Wu; Tobias Klein; Manuel Kerscher; Michael H. Rausch; Thomas M. Koller; Cédric Giraudet; Andreas P. Fröba
• Keywords: Hexanol

This work contributes to an improved understanding of the fluid-phase behavior and diffusion processes in mixtures 1-hexanol carbon dioxide (CO2) at temperatures around upper critical end point (UCEP) system. Raman spectroscopy dynamic light scattering were used determine composition saturation conditions as well Fick thermal diffusivities. An acceleration diffusive process up CO2 mole fractions about 0.2 was found, followed by a strong slowing-down approaching vapor–liquid–liquid equilibrium or conditions. The vanished much higher than UCEP. Experimental diffusivity data compared with predictions from molecular dynamics simulations excess Gibbs energy calculations using interaction parameters literature. Both theoretical methods not able predict that thermodynamic factor is equal zero spinodal composition, stressing need for new methodologies under such Thus, sets temperature-dependent developed nonrandom two-liquid model, which improve prediction coefficient considerably. link between nonrandomness liquid phases also discussed.