Pressure-dependent flow enhancement in carbon nanotubes

Hangtong Li; Zhuan Ge; Mohammad Aminpour; Liaoyong Wen; Sergio Andres Galindo-Torres

doi:10.1063/5.0179870

Pressure-dependent flow enhancement in carbon nanotubes

J Chem Phys. 2024 Feb 7;160(5):054503. doi: 10.1063/5.0179870.

Authors

Hangtong Li^{1

2}, Zhuan Ge², Mohammad Aminpour³, Liaoyong Wen⁴, Sergio Andres Galindo-Torres²

Affiliations

¹ College of Environmental and Resource Sciences, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, Zhejiang, China.
² Key Laboratory of Coastal Environment and Resources of Zhejiang Province (KLaCER), School of Engineering, Westlake University, 600 Dunyu Rd., Hangzhou 310030, Zhejiang, China.
³ Civil and Infrastructure Engineering, School of Engineering, RMIT University, Melbourne, Victoria 3001, Australia.
⁴ Key Laboratory of 3D Micro/Nano Fabrication and Characterization of Zhejiang Province, School of Engineering, Westlake University, 600 Dunyu Rd., Hangzhou 310030, Zhejiang, China.

PMID: 38341689
DOI: 10.1063/5.0179870

Abstract

It is a known and experimentally verified fact that the flow of pressure-driven nanoconfined fluids cannot be accurately described by the Navier-Stokes (NS) equations with non-slip boundary conditions, and the measured volumetric flow rates are much higher than those predicted by macroscopical continuum models. In particular, the flow enhancement factors (the ratio between the flow rates directly measured by experiments or simulations and those predicted by the non-slip NS equation) reported by previous studies have more than five orders of magnitude differences. We showcased an anomalous phenomenon in which the flow enhancement exhibits a non-monotonic correlation with fluid pressure within the carbon nanotube with a diameter of 2 nm. Molecular dynamics simulations indicate that the inconsistency of flow behaviors is attributed to the phase transition of nanoconfined fluid induced by fluid pressures. The nanomechanical mechanisms are contributed by complex hydrogen-bonding interactions and regulated water orientations. This study suggests a method for explaining the inconsistency of flow enhancements by considering the pressure-dependent molecular structures.