Formation Mechanism of the Spiral-Like Structure of a Hydrogen Bond Network Confined in a Fluorinated Nanochannel: A Molecular Dynamics Simulation

Abstract

The structure of the hydrogen bond network inside of the proton conductive channel is of significant importance to proton transfer confined in a nanochannel. In order to investigate the independent effects of fluorination and confinement dimension on the hydrogen bond network, a one-dimensional carbon nanotube decorated with fluorine was built to mimic the environment of the proton conductive channel in the perfluorosulfonic membrane (Phys. Chem. Chem. Phys. 2016, 18 (35), 24198−24209). It was found that a fluorinated nanochannel helps to form a spiral-like sequential hydrogen bond network with few branched hydrogen bonds in the central region, which is believed to promote unidirectional proton transfer along the channel axis without random movement. To explore the mechanism of the formation of the spiral-like hydrogen bond structure, molecular dynamics simulation was conducted to analyze the hydrogen bonding properties of water and a hydrated proton confined in the fluorinated CNT with chirality of (10,1...