Premium
Effect of small amount of water on the dynamics properties and microstructures of ionic liquids
Author(s) -
Zhou Jing,
Liu Xiaomin,
Zhang Suojiang,
Zhang Xiangping,
Yu Guangren
Publication year - 2017
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.15594
Subject(s) - ionic liquid , tetrafluoroborate , hydrogen bond , chemistry , molecular dynamics , microstructure , ion , isotropy , imide , molecule , viscosity , chemical engineering , thermodynamics , crystallography , computational chemistry , organic chemistry , catalysis , physics , quantum mechanics , engineering
A series of systems of 1‐butyl‐3‐methylimidazolium acetate ([Bmim][Ac]), 1‐butyl‐3‐methylimidazolium tetrafluoroborate ([Bmim][BF 4 ]), and 1‐butyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide ([Bmim][Tf 2 N]) 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][BF 4 ] and [Bmim][Tf 2 N], 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][Tf 2 N]‐H 2 O system, while it is isotropy in [Bmim][Ac]‐H 2 O system. © 2016 American Institute of Chemical Engineers AIChE J , 63: 2248–2256, 2017