Effect of small amount of water on the dynamics properties and microstructures of ionic liquids |
| |
| Authors: | Jing Zhou Xiaomin Liu Suojiang Zhang Xiangping Zhang Guangren Yu |
| |
| Affiliation: | 1. Beijing Key Laboratory of Membrane Science and Technology & College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, P. R. China;2. Beijing Key Laboratory of Ionic Liquids Clean Process, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, P.R. China |
| |
| Abstract: | A series of systems of 1‐butyl‐3‐methylimidazolium acetate (Bmim]Ac]), 1‐butyl‐3‐methylimidazolium tetrafluoroborate (Bmim]BF4]), and 1‐butyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide (Bmim]Tf2N]) with a small amount of water were simulated. Viscosities of systems were obtained by nonequilibrium molecule dynamics simulation and the results show that the viscosities change in different ways: for Bmim]BF4] and Bmim]Tf2N], viscosities decrease rapidly in the first stage, and then decrease slowly with the increase of water content. But for Bmim]Ac], the viscosities increase first and then decrease. The unique phenomenon of Bmim]Ac] can be attributed to the formation of chain‐like structure of anion???water???anion???. Hydrogen bond (HB) interaction between ion pairs is weakened, but the number of HB between water and anions increases with increase of water content. Besides, the microstructures of water in ionic liquids‐water systems were compared and found that the distribution of water is more concentrated in Bmim]Tf2N]‐H2O system, while it is isotropy in Bmim]Ac]‐H2O system. © 2016 American Institute of Chemical Engineers AIChE J, 63: 2248–2256, 2017 |
| |
| Keywords: | ionic liquids water viscosities microstructures molecule dynamics simulation |
|
|
