A molecular equation of state for alcohols which includes steric hindrance in hydrogen bonding

TL;DR

This paper introduces a novel molecular equation of state for alcohols that accounts for steric hindrance in hydrogen bonding, improving the accuracy of predictions for alcohol and water mixtures.

Contribution

It develops the first equation of state incorporating steric hindrance effects in hydrogen bonding for alcohol mixtures using Wertheim's statistical mechanics.

Findings

Enhanced prediction accuracy for hydrogen bond structures in alcohol/water mixtures.

Significant improvement over standard first-order approaches.

Validated on methanol, ethanol, and their mixtures.

Abstract

In this paper we develop the first equation of state for alcohol containing mixtures which includes the effect of steric hindrance between the two electron lone pair hydrogen bond acceptor sites on the alcohol's hydroxyl oxygen. The theory is derived for multi-component mixtures within Wertheim's multi-density statistical mechanics in a second order perturbation theory. The accuracy of the new approach is demonstrated by application to pure methanol and ethanol and binary ethanol / water mixtures. It is demonstrated that the new approach gives a substantial improvement in the prediction of hydrogen bond structure of both pure alcohol and alcohol / water mixtures as compared to standard first order approaches.