Kirkwood-Buff integrals of aqueous alcohol binary mixtures

Area of Science:

• Physical Chemistry
• Thermodynamics
• Solution Chemistry

Background:

• Kirkwood-Buff integrals (KBIs) are crucial for understanding solution behavior.
• Discrepancies exist in published KBI data for aqueous alcohol mixtures.
• Accurate KBI determination is essential for validating theoretical models.

Purpose of the Study:

• To compute KBIs for binary aqueous alcohol mixtures using vapor pressure data.
• To compare these results with small angle neutron scattering (SANS) experiments.
• To assess the accuracy and reliability of different measurement techniques for KBIs.

Main Methods:

• Calculation of KBIs from experimental vapor pressure measurements.
• Comparison of calculated KBIs with existing literature values and SANS data.
• Analysis of discrepancies and agreement between different experimental approaches.

Main Results:

• Good agreement was generally observed between KBI results from vapor pressure and SANS.
• Peak position agreement was found to be more critical than magnitude agreement.
• Sources of disagreement between the methods were identified and discussed.

Conclusions:

• Both vapor pressure measurements and SANS experiments can provide accurate KBIs.
• Careful analysis of peak positions is key for validating KBI data.
• The study contributes to understanding correlations and microheterogeneity in aqueous systems via KBIs.