The temperature of maximum density for aqueous solutions.

Area of Science:

• Physical Chemistry
• Thermodynamics
• Solution Chemistry

Background:

• The temperature of maximum density (TMD) is a key property of water and aqueous solutions, reflecting complex intermolecular interactions.
• Understanding TMD behavior is crucial for various scientific and industrial applications.

Purpose of the Study:

• To provide a comprehensive overview of experimental and theoretical advancements in the study of TMD in aqueous solutions.
• To classify and analyze existing experimental TMD data across diverse solute types and pressures.
• To evaluate the predictive capabilities of current theoretical and simulation models for TMD.

Main Methods:

• Classification of experimental TMD data based on solute type (inorganic electrolytes, non-electrolytes, organic salts, ionic liquids, amino acids, proteins).
• Analysis of experimental data under varying pressure conditions.
• Application of thermodynamic principles and qualitative/semi-quantitative arguments for data rationalization.
• Review of theoretical and simulation approaches, including scaled particle theory, to model TMD behavior.

Main Results:

• Experimental TMD data are systematically presented and categorized by solute properties.
• The influence of pressure on TMD is detailed, providing insights into solution behavior.
• Theoretical models are evaluated for their accuracy in reproducing experimental TMD observations.
• Connections between TMD and fundamental thermodynamic properties are established.

Conclusions:

• Significant progress has been made in both experimental determination and theoretical understanding of TMD in aqueous solutions.
• Current theoretical models show varying degrees of success in predicting experimental TMD data.
• Further research combining advanced experiments and theoretical/simulation developments is needed for deeper insights into TMD phenomena.