The average free volume model for the ionic and simple liquids

TL;DR

This paper proposes an average free volume model to explain the correlation between molar volume thermal expansion and van der Waals volume in ionic liquids, validated by experimental data and comparisons with other liquids.

Contribution

The study introduces a new average free volume model considering particles as hard cores with attractive forces, explaining observed correlations in ionic and simple liquids.

Findings

Good agreement between model predictions and experimental data.

Correlation observed between molar volume thermal expansion and van der Waals volume.

Model validated with molten metals and noble gases.

Abstract

In this work, the molar volume thermal expansion coefficient of 60 room temperature ionic liquids is compared with their van der Waals volume Vw. Regular correlation can be discerned between the two quantities. An average free volume model, that considers the particles as hard core with attractive force, is proposed to explain the correlation in this study. Some typical one atom liquids (molten metals and liquid noble gases) are introduced to verify this hypothesis. Good agreement between the theory prediction and experimental data can be obtained.