By: Walter Chapman
From: Rice University
At: Instituto de Investigação Interdisciplinar, Anfiteatro
NOTE: DIFFERENT DAY OF THE WEEK!
To design and optimize processes and products in the energy, chemicals, and materials industries, engineers need computational tools to predict bulk and interfacial equilibrium properties for complex fluids in terms of temperature, pressure, composition, and molecular geometry. Systems that have been particularly challenging to model include associating or polar molecules as well as polymers and amphiphiles.
Advances in statistical mechanics based on Wertheim's theory of associating molecules have led to successful molecular models for bulk fluids of associating and polyatomic molecules such as the statistical associating fluid theory (SAFT). SAFT is widely used to predict the effects of molecular weight, polydispersity, polarity, association, and compressibility on the bulk phase behavior of mixtures containing solvents, monomers, and polymers. Extensions using density functional theory have shown success in modeling interfacial properties and molecular structure, including the behavior of fluids at hydrophilic and hydrophobic surfaces, segregation in polymer blends and polymer/colloid systems, and self-assembly of surfactants and block copolymers.
We briefly review the physical basis for the SAFT approach and the extension to interfacial systems. Some recent extensions and applications of the SAFT approach for bulk and interfacial systems are presented. These points are illustrated through comparisons with molecular simulation as well as phase equilibria data for monomers, solvents, copolymer, polymer brush, and patchy colloid systems.