resumo
In this work, we showcase the potential of the SAFT-gamma-Mie equation of state to obtain, in a top-down approach, coarse-grained molecular models capable of describing micelliza-tion phenomena. For this purpose, we selected polyethylene oxide (PEO)/polypropylene oxide (PPO) triblock copolymers in aqueous solutions as a case study. The model was fitted to reproduce the thermophysical properties-liquid densities and vapor pressures-of small PEO/PPO oligomers as well as the activity coefficients or liquid-liquid phase diagrams of their binary mixtures with water. At low concentrations, the MD simulations show the formation of spherical micelles of morphology comparable to experiments, with the characteristic star-shaped or flower-shaped morphology depending on the polymer block sequence. The local structure and molecular conformations were analyzed, showing distinctions between the two types of aggregates. At higher concentrations, depending on the co-polymer sequence, the molecules form larger micelles or coalesce into larger aggregates when signs of phase separation are observed, as expected.
palavras-chave
EQUATION-OF-STATE; GLYCOL DIMETHYL ETHER; TRIBLOCK COPOLYMERS; BEHAVIOR; FLUIDS
categoria
Engineering
autores
Silva, GMC; Pérez-Sanchéz, G; Pantano, DA; Loehlé, S; Coutinho, JAP
nossos autores
Germán Pérez-Sánchez
Investigador Júnior
Gonçalo Miguel Carvalho da Silva
Investigador Júnior
Grupos
G4 - Materiais Renováveis e Economia Circular
G6 - Materiais Virtuais e Inteligência Artificial
Projectos
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
agradecimentos
The authors acknowledge the funding from the TotalEnergies OneTech Solaize Research Center through a research partnership. This work was partly developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020, and LA/P/0006/2020, financed by national funds through the FCT/MCTES (PIDDAC). G. Perez-Sanchez acknowledges the national funds (OE), through FCT-Fundacao para a Ciencia e a Tecnologia, I.P., in the scope of the framework contract foreseen in numbers 4, 5, and 6 of Article 23 of the Decree-Law 57/2016, August 29th, changed by Law 57/2017, July 19th.