Unexpected effect of an empty cavity on water transport through a combined carbon nanotube

School of Material Science and Physics, China University of Mining and Technology - Xuzhou 221116, China

^(a) xwmeng@cumt.edu.cn (corresponding author)

Received: 8 July 2021
Accepted: 21 October 2021

Abstract

Controlling water transport via an empty cavity can achieve unexpected properties for various applications. In this paper, water transport through a combined carbon nanotube with an empty cavity is studied by molecular dynamics simulations. It is found that the occupancy of water molecules and the transfer rate of water molecules through the combined carbon nanotube can be affected by the size of the cavity unexpectedly under a relatively low pressure difference. The occupancy of water molecules in the combined carbon nanotube and the average transfer rate begin to decrease significantly if the size of the cavity reaches a critical radius of 0.733 nm. The energy gap between water molecules and the combined carbon nanotube is adopted to explain the effect of the empty cavity on water properties in the combined carbon nanotube. Our findings may pave a way for understanding the effect of the empty cavity on water dynamics in the carbon nanotube and offering another way to control water properties at the nanoscale.