abstract
This work studies the constraints of the COSMO-SAC model for predicting the liquid-liquid equilibrium (LLE) of polyethylene glycol (PEG) and water mixtures. The research extends the COSMO-SAC methodology to include polymer end groups in the σ-profile construction and employs a global optimization approach for LLE prediction across the entire composition range. The influence of various parameters, including end groups, hydrogen bond energies, and volume effects, on the LLE prediction is analyzed. The results indicate that while the COSMO-SAC model can qualitatively predict the phase behavior of PEG-water systems, including, for the first time, the closed-loop diagram, significant deviations from experimental data are observed for the LCST. The results obtained suggest that further improvements are required in both the combinatorial and residual terms to enhance the predictive accuracy of COSMO-SAC for complex polymer-solvent systems.
authors
Edgar T. de Souza; Murilo L. Alcantara; Paula Bettio Staudt; João A. P. Coutinho; Rafael de P. Soares
our authors
Murilo Leite Alcantara
Junior ResearcherProjects
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
PRR CICECO - Instituto de Materiais de Aveiro (Equipar+ CICECO)
MEDIATED BIPHASIC BATTERY (MeBattery)
Collaboratory for Emerging Technologies, CoLab (EMERGING TECHNOLOGIES)
acknowledgements
This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UID/50011/2025 (DOI 10.54499/UID/50011/2025), LA/P/0006/2020 (DOI 10.54499/LA/P/0006/2020) and UID/PRR/50011/2025 (DOI 10.54499/UID/PRR/50011/2025), financed by national funds through FCT/MCTES (PIDDAC). Additionally, this work has received funding from the European Innovation Council (EIC) under grant agreement 101046742. The EIC receives support from the European Union’s Horizon Europe research and innovation program. This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001. The first author acknowledges a CAPES scholarship through the Doctoral Sandwich Program Abroad (PDSE, Grant No. 88887.936462/2024-00).