Homogeneous nucleation temperatures in aqueous mixed salt solutions

Area of Science:

• Physical Chemistry
• Solution Chemistry
• Thermodynamics

Background:

• Homogeneous nucleation temperature (TH) is crucial for understanding phase transitions in solutions.
• Aqueous mixed salt systems present complex interactions influencing nucleation phenomena.
• Previous studies have not comprehensively addressed TH in diverse mixed salt environments.

Purpose of the Study:

• To measure and analyze homogeneous nucleation temperature (TH) in aqueous mixed salt systems.
• To develop an empirical model for predicting TH based on system composition and ionic strength.
• To investigate the relationship between TH and various physicochemical properties like viscosity and ion mobility.

Main Methods:

• Experimental measurement of homogeneous nucleation temperature (TH) in aqueous mixed salt solutions.
• Analysis of TH data using a novel empirical equation correlating TH with ionic strength and composition.
• Correlation of the empirical parameter q0 with viscosity B-coefficients and self-diffusion coefficients (D0).

Main Results:

• Homogeneous nucleation temperature (TH,m) in mixed salt systems can be predicted by a linear summation model.
• The empirical parameter q0, reflecting ionic interactions, is directly related to viscosity B-coefficients.
• A linear correlation was established between q0 and the self-diffusion coefficient (D0) of ionic solutes.
• q0 also correlates well with the rotational correlation time of ionic species.

Conclusions:

• The study provides a predictive model for homogeneous nucleation temperature in mixed salt solutions.
• Ionic interactions, quantified by q0, play a significant role in determining TH,m.
• The findings enable the computation of TH,m for salt mixtures lacking common ions using data from mixtures with common ions.