Study On Viscosity Database Of Ionic Liquids

Based on the unique physicochemical properties, studies of ionic liquids (ILs) have a rapid development in recent years, especially in the current advocacy of clean technology and sustainable development, ILs are widely recognized and accepted as the "real green solvents", and have been applied to the chemical-related fields such as catalytic reaction, organic synthesis, extraction separation and electrochemistry. Unfortunately, however, the high viscosity of ionic liquid (two or more orders of magnitude of conventional molecular solvents) has become the bottleneck in its industrial application. Therefore, how to reduce the viscosity of ILs is the key issue. Viscosity data of ionic liquids are essentially important for both theoretical study and industrial application, and up to now many ionic liquids have been synthesized and a great number of data on their properties have been reported. There are several existing database on ionic liquids, such as Merck, DDB (Dortmund Date Bank), NIST (National Institute of Standards and Technology), Crossfire Gmelin/Beilstein, ILs database from IPE and delph-IL, but the type of the data and information in them are not comprehensive. So establishing a completed, comprehensive and detailed viscosity database of ILs is of great significance, which is also important for the synthesis and rational design of ILs with low viscosity.Based on the above considerations, the following work has been done in this paper:1. A database for the viscosity of pure ILs and their binary/ternary mixtures with organic solvents is established by performing a comprehensive collection from the worldwide published scientific literature sources covering the period from1970to2010. In this database there are totally306cations,108anions and5045data entries, and the viscosity data for binary and ternary system of ILs are also involved. The data information of viscosity includes basic information (name, ID, abbreviation, formula, mol weight, structural formula, CAS number), sample information (sample sources, initial and final purity, purification method, purity analysis) and viscosity information (temperature, pressure, viscosity value, measurement methods or model, reference).2. According to the viscosity data in our data base, we studied the impact of various factors on viscosity, including temperature, pressure, length of side chain substituents, cation, anion and impurities.3. The results of QSPR studies on ILs viscosity are summarized, and then we concluded the factors which have important effects on the viscosity of ILs by comparing the results of direct observation on ILs viscosity with the results of QSPR study.