Abstract

Water in a nanoconfined geometry has attracted great interest from the viewpoint of not only basic science but also nanofluidic applications. Here, the rotational dynamics of water inside single-walled carbon nanotubes (SWCNTs) with mean diameters larger than ca. 1.4 nm were investigated systematically using 2H nuclear magnetic resonance spectroscopy with high-purity SWCNTs and molecular dynamics calculations. The results were compared with those for hydrophilic pores. It was found that faster water dynamics could be achieved by increasing the hydrophobicity of the pore walls and decreasing the pore diameters. These results suggest a strategy that paves the way for emerging high-performance filtration/separation devices. Upon cooling below 220 K, it was found that water undergoes a transition from fast to slow dynamics states. These results strongly suggest that the observed transition is linked to a liquid-liquid crossover or transition proposed in a two-liquid states scenario for bulk water.

Details

Title
Rotational dynamics and dynamical transition of water inside hydrophobic pores of carbon nanotubes
Author
Kyakuno, Haruka 1 ; Matsuda, Kazuyuki 2 ; Nakai, Yusuke 3 ; Ichimura, Ryota 3 ; Saito, Takeshi 4 ; Miyata, Yasumitsu 5 ; Hata, Kenji 6 ; Maniwa, Yutaka 3 

 Department of Physics, Graduate School of Science and Engineering, Tokyo Metropolitan University, Hachioji, Japan; Institute of Physics, Faculty of Engineering, Kanagawa University, Yokohama, Japan 
 Institute of Physics, Faculty of Engineering, Kanagawa University, Yokohama, Japan 
 Department of Physics, Graduate School of Science and Engineering, Tokyo Metropolitan University, Hachioji, Japan 
 Nanomaterials Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan 
 Department of Physics, Graduate School of Science and Engineering, Tokyo Metropolitan University, Hachioji, Japan; JST, CREST, Kawaguchi, Japan 
 CNT-application Research Center, National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan 
Pages
1-11
Publication year
2017
Publication date
Nov 2017
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2127646287
Copyright
© 2017. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.