Segment-based excess Gibbs energy model for aqueous organic electrolytes

The aqueous electrolyte nonrandom two-liquid (NRTL) model of Chen et al. is extended to represent the excess Gibbs energy of aqueous organic electroly tes. These organic electrolytes exhibit very different solution nonideality from typical aqueous electrolytes with elemental ions. The proposed extens ion is an integration of the electrolyte NRTL model for aqueous electrolyte s and the polymer NRTL model (Chen, 1993) for oligomers and polymers. Organ ic ions are treated as oligomers that consist of hydrocarbon segments and i onic segments that each exhibit distinctive physical interactions with neig hboring species. This integrated NRTL model captures the nonideal phase beh avior of aqueous organic electrolytes, including micelle formation. The mod el further provides a versatile thermodynamic framework to correlate soluti on nonideality of electrolyte systems, organic or inorganic, and complex sy stems containing both electrolytes and polymers.