Cloud Point Phenomena in the (Aniline or N,N-Dimethylaniline + Water) Solutions, and Cosolvent Effects of Liquid Poly(ethylene glycol) Addition: Experimental Measurements and Modeling

Abstract

In this work, liquid phase behavior (cloud point phenomena) was studied for two binary and four aqueous pseudobinary systems containing aniline or N,N-dimethylaniline and poly(ethylene glycol) 200 or poly(ethylene glycol) 400, (PEG200 and PEG400, respectively) in the temperature range T = (290.15 to 351.15) K and an ambient pressure of 0.1 MPa. Experimental data (cloud-points) were obtained by the visual cloud point method. The studied systems exhibit an upper critical solution temperature (UCST) type of phase behavior and the immiscibility increases with increasing the average molar mass of poly(ethylene glycols). PEG200/PEG400 showed as a good cosolvent for aniline in water. The experimental data were correlated using non-random two-liquid model (NRTL) with one form of temperature dependent parameters.