Thermodynamic Modeling of Hydrotrope Solutions
Mandana Akia and Farzaneh Feyzi
Abstract
In this research a new model for the excess Gibbs energy of hydrotrope solutions based on local composition model proposed by Chen et al. is presented. Hydrotropes are organic salts which can increase the solubility of organic and inorganic compounds in water. The proposed model has five adjustable parameters, one of them is related to long range forces and four of them are related to short range forces. Long range forces are modeled by Pitzer-Debye-Huckel equation but in our model the effect of molecular solute on dielectric constant of water has been considered. Modeling of short range forces is based on local composition concepts. The model parameters are obtained using experimental data for six hydrotropes with four solutes at different temperatures.
The solubility of molecular solutes in water in the presence of hydrotrope has been calculated for different systems. Accurate results are obtained.
