Temperature dependence and short-range electrolytic interactions within the e-PPC-SAFT framework

Understanding and modelling electrolyte systems is of interest both in an industrial context from a fundamental point view. Their importance related to their key role played traditional emerging industries, the ubiquitous presence saline solutions biological, chemical, geological environments. The development equations state has advanced greatly recent years, with aim describe properties using limited number parameters, way that allows describing accurately equilibrium these solutions. Here, we explore temperature salt concentration dependence various PPC-SAFT-based models, simple alkali halide salts (primarily NaCl). dispersion association free-energy terms characteristic SAFT-like are compared for description ion-solvent non-Coulombic interactions. Several formulations dielectric constant also investigated. In all models MSA term used account electrostatic interactions between ions Born added model molecular parameters determined by comparison experimental enthalpy solution, activity coefficient, osmotic coefficient apparent molar volume data. We find equivalent results can be obtained or without incorporating explicit treatment constant; most accurate (smallest average absolute relative deviation) when comparing data chosen found case not explicitly considered. For each approach, sensitive identified, which makes it possible reduce adjustable significantly affecting overall quality model. approach short-range yield similar results. Unfortunately, none physically meaningful correct low-temperature trend mean ionic observed experimentally.