A study of the structure and thermodynamics of non-ionic microemulsion droplets: Integral equation methods (IEs) and molecular dynamics simulation (MD)

Abstract

This paper aims to explore the structural and thermodynamic properties of a bare neutral oil/water microemulsions (MEs), TX100 by using a combination of molecular dynamics simulations (MD) and Ornstein-Zernike integral equations (IEs) with the hypernetted chain closure relation (HNC), at different volume fractions ϕ (1.4%, 2.8%, 5%, 6.98%, 10%). The employed effective pair potential is a combination of a hard sphere, the van der Waals and a Yukawa type potential. Structural properties were studied by examining the radial distribution function (RDF), g(r), as a function of ϕ; increasing ϕ enhances order and correlation between droplets, manifesting as a narrow and pronounced correlation peak and a decrease in the average distance between MEs. Regarding the thermodynamic properties, as ϕ increase, the reduced pressure and internal energy increase exponentially.