Flow of Polar and Nonpolar Liquids through Nanotubes: A Computational Study

TL;DR

This study uses ab initio calculations to explore how polar and nonpolar liquids like water, methanol, and dimethyl ether flow through carbon and boron nitride nanotubes, revealing how diameter, polarity, and interactions affect flow resistance.

Contribution

It provides new insights into molecular-level flow dynamics in nanotubes, highlighting the effects of polarity, diameter, and material type on liquid transport.

Findings

Drag decreases with smaller nanotube diameter.

Higher polarity liquids experience greater drag.

Water in boron nitride nanotubes does not have higher drag than in carbon nanotubes.

Abstract

We perform ab initio density functional calculations to study the flow of water, methanol and dimethyl ether through nanotubes of carbon and boron nitride with different diameters and chiralities. The liquids we choose are important solvents, with water and methanol being polar and dimethyl ether being non-polar. In terms of activation barriers for liquid transport, we find the molecular-level drag to decrease with decreasing nanotube diameter, but to be rather independent of the chiral index. We also find molecules with higher polarity to experience higher drag during the flow. Counter-intuitively, we find the drag for water in boron nitride nanotubes not to exceed that in carbon nanotubes due to frustration in competing long-range Coulomb interactions.