Self-Assembly of Amphiphilic Molecules or Nanoparticles Using the i-SAFT Density Functional Theory

The effects of an amphiphile (surfactant) or nanoparticle on the equilibrium structure and thermodynamic properties of systems containing chemically dissimilar species (e.g., oil and water) are largely governed by the structure of the amphiphile/nanoparticle and physical conditions of the system such as the pressure, temperature, and bulk solubility of the amphiphile/nanoparticle. Following justification of the interfacial statistical associating fluid theory (i-SAFT) density functional theory (DFT) approach against molecular simulation data for a model oil-water-surfactant system, a more extensive systematic study is carried out to analyze the role the amphiphile structure and concentration play in determining the equilibrium microstructure and interfacial tension. In addition, the surfactant-like behavior of different sized nanoparticles is characterized and compared with the surfactant behavior.