• 文献标题:   Nanoconfinement between Graphene Walls Suppresses the Near-Wall Diffusion of the Ionic Liquid [BMIM][PF6]
  • 文献类型:   Article
  • 作  者:   SHAO C, ONG WL, SHIOMI J, MCGAUGHEY AJH
  • 作者关键词:  
  • 出版物名称:   JOURNAL OF PHYSICAL CHEMISTRY B
  • ISSN:   1520-6106 EI 1520-5207
  • 通讯作者地址:  
  • 被引频次:   6
  • DOI:   10.1021/acs.jpcb.1c02562 EA APR 2021
  • 出版年:   2021

▎ 摘  要

We identify two distinct regimes for the diffusion of the ionic liquid [BMIM][PF6] confined between parallel graphene walls using molecular dynamics simulations. Within 2 nm of the wall, the cations and anions form a well-defined layered structure. In this region, the in-plane diffusion coefficients are suppressed when compared to their bulk values and increase monotonically with the distance away from the wall. Beyond 2 nm from the wall, the density profile and in-plane diffusion coefficients recover their bulk values. The channel-averaged in-plane diffusion coefficients increase monotonically with wall separation and recover the bulk values at a separation of 15 nm. A simple semianalytical model is proposed that mirrors this trend. The results also highlight the importance of applying a finite-size correction to molecular dynamics-predicted diffusion coefficients of confined liquids, which may otherwise be unusually larger than their bulk values.