Pressure effects in the properties of simple monohydric alcohols. Lessons from molecular dynamics simulations of united atom type UAM-EW model

TL;DR

This study uses molecular dynamics simulations to analyze how pressure affects properties of simple monohydric alcohols, evaluating a specific force field against experimental data across various pressures.

Contribution

It applies and assesses a united atom force field for alcohols under pressure, providing insights into their microscopic and macroscopic behavior.

Findings

Density increases with pressure for all alcohols.

Simulated properties agree well with experimental data.

Pressure influences microscopic structure and dielectric properties.

Abstract

We explore the pressure dependence of a set of properties of simple monohydric alcohols, namely of methanol, ethanol and 1-propanol, by using isobaric-isothermal molecular dynamics computer simulations. A recently proposed united atom, non-polarizable force field for each of alcohols [V. Garc\'{i}a-Melgarejo et al., J. Mol. Liq., 323, 114576 (2021)] is applied. Accuracy of the force field is evaluated by comparing the simulation results and available experimental data from the literature. Specifically, the density of alcohols upon increasing pressure, the isothermal compressibility, the static dielectric constant and self-diffusion coefficient are investigated starting from 1 bar up to 3 kbar. Evolution of the microscopic structure under pressure is discussed in terms of the pair distribution functions and some coordination numbers. Conclusions of the present modelling and necessary developments to consider in future work are commented on.