Correlation between Macroscopic Diffusion Rates and Microscopic Interactions in Ethylene Glycol-Based Solvents

An evaluation of molecular interactions is important for estimating macroscopic properties, such as solubility and diffusivity. In this study, for several types of ethylene glycol-based absorbents, we discuss the correlation between a macroscopic property (molecular diffusivity) and a microscopic criterion (residence time) using molecular dynamics simulations for pure solvent systems and CO2-loaded solvent systems. The negative correlations between the diffusivity and the residence time can be divided into categories, depending on the number of constituent hydroxy groups of the solvent molecules. The disparity between the categories arises from whether hydrogen bonding can be formed between the solvent molecules. This study leads to the systematic estimation of the molecular diffusivity from the theoretical prediction of the residence time. We believe that the residence time is suitable as a criterion to evaluate macroscopic properties.

Automated summary

This study investigates the correlation between macroscopic properties and microscopic criteria in ethylene glycol-based absorbents through molecular dynamics simulations. The negative correlation between diffusivity and residence time can be categorized based on the number of hydroxy groups in the solvent molecules, with disparities arising from potential hydrogen bonding. The study proposes using residence time as a criterion for evaluating macroscopic properties.