Interface profiles in a dimerizing system

Abstract

Erratum: "Density depletion profile and solvation free energy of a colloidal particle in a polymer solution" [J.The gas-liquid density profile and surface tension are calculated for a fluid possessing hard sphere repulsion, van der Waals-like dispersion, and sticky-spot attraction. The sticky spot allows monomers to dimerize and the consequences of which are investigated. Association is treated with Wertheim's thermodynamic perturbation theory and the direct correlation functions are derived by means of the Ornstein-Zernike equations for associating systems. The primary effect of association is to shift the critical temperatures and densities from those of a nonassociating fluid. While there are small, nonmonotonic shifts in the correlation length and surface tension, accompanied by an interface composition change, these effects on the density profile seem to be subsumed in the use of the proper T/T c .

An accurate density functional theory for the vapor-liquid interface of associating chain molecules based on the statistical associating fluid theory for potentials of variable range

“…A one-site model of the type described here can be used to represent the dimerization equilibria behavior exhibited by real systems such as carboxylic acids; the thermodynamic properties of acetic acid are well known to be dominated by a dimerization equilibria. Borowko et al, 29 Peery and Evans, 32 and more recently Alejandre et al 33 have studied this model using a mean-field Wertheim DFT ͑cf. SAFT-HS MF DFT͒.…”

“…26,[29][30][31][32][33][34] Borowko et al 29 have examined the effect of dimerization on the density profile of a fluid with a single bonding site; as was also found by Blas et al, 26 the profile of the fraction of molecules not bonded is found to be shifted slightly towards the vapor phase. Pizio et al 31 undertook a study with a similar theory to examine the effect of confinement on the vapor-liquid interface for two-site associating Lennard-Jones molecules which bond to form chainlike structures.…”

“…34 Talanquer and Oxtoby 30 have used essentially the same free energy functional to study the nucleation of liquids of single-site dimerizing spherical molecules by examining the surface tension of the system. In another relevant paper, Peery and Evans 32 have studied a system of hard-core Lennard-Jones spheres with a single associating site using Wertheim's theory within a local square gradient approximation. They concluded that although molecular association has little effect on the density profile, it has a significant effect on the surface tension.…”

Surface tension and vapor-liquid phase coexistence of confined square-well fluid

“…However, for a given temperature, the interfacial width decreases with the increase of the wall width, qualitatively indicating that the vapor-liquid surface tension increases with increasing wall width. 32 Beyond H = 12, we expect a gradual increase of the surface tension as the wall width increases. The results are shown in Fig.…”

Molecular simulation study of effect of molecular association on vapor-liquid interfacial properties

“…Considerably less has been done to study inhomogeneous associating systems. Peery and Evans 7 reported a study of a dimerizing ͑one-site model͒ Lennard-Jones-based associating fluid using square gradient theory. A hybrid SAFT density functional theory ͑DFT͒ approach was used to obtain the interfacial properties of associative hard core Yukawa-based fluids.…”