Predicting the Solubility of Solid Phenanthrene: A Combined Molecular Simulation and Group Contribution Approach

Abstract

A simple correction to the infinite dilution activity coefficient computed via molecular simulation for a nonelectrolyte solid solute in solution is proposed. The methodology adopts the concept that the activity coefficient may be fundamentally interpreted as a product of a residual and combinatorial term. The residual contribution is assumed to be insensitive to concentration, and the combinatorial term is modeled using the athermal Flory–Huggins theory. The proposed method uses only properties for the solute computed at infinite dilution to estimate solution‐phase properties at finite concentrations. Properties of the pure solid solute are estimated using the group contribution method of Gani and coworkers, allowing for efficient blind solubility predictions to be made. The method is applied to predict the solubility of solid phenanthrene in 17 different solvents. For all cases, the combinatorial correction lowers the predicted solubility relative to the infinite dilution approximation, and in general, improves agreement with experiment. © 2013 American Institute of Chemical Engineers AIChE J, 59: 2647–2661, 2013

Using MD Simulations To Calculate How Solvents Modulate Solubility

“…Given these, the solubility can be calculated as was done in ref. : 38 $$\text{ln}{x}_1^{\alpha }=-\beta {\mu }_1^{\alpha ,res}(T,p,x_1)-\text{ln}true(\frac{RT}{v(T,p,x_1)}true)+\text{ln}{f}_1^S(T,p)$$ where $x_1^{\alpha }$ is the equilibrium solubility of the solute in units of mole fraction, $\beta {\mu }_1^{\alpha ,res}$ is the dimensionless residual chemical potential of the solute (denoted by the subscript 1) in solvent α , ν is the molar volume of the mixture (solute 1 in solvent α ), and $f_1^S$ is the fugacity of pure solid solute.…”

“…The infinite dilution activity coefficient is directly related to the infinite dilution residual chemical potential, allowing equation 4 to be re-written as 38,62 $$\text{ln}true(\frac{c_1^{\alpha }}{c_1^{\zeta }}true)=\text{ln}true(\frac{{\gamma }_1^{\zeta ,\infty }}{{\gamma }_1^{\alpha ,\infty }}true)+\text{ln}true(\frac{v^{\zeta }(T,p)}{v^{\alpha }(T,p)}true)$$ where ${\gamma }_1^{\alpha ,\infty }$ and ${\gamma }_1^{\zeta ,\infty }$ are the infinite dilution activity coefficient of the solute in solvent α and ζ , respectively, which are computed using UNIFAC or mod-UNIFAC, and ν α and ν ζ are the molar volume of pure solvent α and ζ , respectively. In this study the molar volume term makes only a minor contribution comparing to the infinite dilution activity coefficient.…”

Improving the accuracy of computing chemical potentials in CFCMC simulations

“…Knowledge on Vapor-Liquid Equilibrium (VLE)/ reaction equilibria and chemical potentials is important for process design and modelling [1][2][3]. The past decades, force field-based molecular simulation has been developed as an attractive alternative for experiments, to accurately describe the behaviour of matter, and to obtain reliable thermodynamic and transport properties [4][5][6][7][8][9][10]. Force field-based molecular modelling is used extensively for studying phase equilibria of pure and multicomponent systems [11][12][13][14][15], describing the behaviour of guest molecules inside porous media [16][17][18][19] Supporting Information available: Force field parameters, raw data for p(λ) at λ = 0 and λ = 1, and excess chemical potentials are listed in the Supporting Information.…”

Predicting the excess solubility of acetanilide, acetaminophen, phenacetin, benzocaine, and caffeine in binary water/ethanol mixtures via molecular simulation

“…[24][25][26][27][28][29][30][31] Solubility calculation requires determining the concentration at which the chemical potential of the solute in solution is equal to that in a solid (crystalline) phase at the same temperature and pressure. The solid phase chemical potential may be computed in the complete absence of experimental thermodynamic data via molecular simulation, [24][25][26]28,29 or its value may be computed using experimental data, 27,31 group contribution methods, 30 or other predictive means. 31 For the case of predicting the solid phase chemical potential without experimental thermodynamic data, it may be necessary to use an experimental or predicted crystal structure as input to the simulations.…”