Study On Synthesis Of [C₆mim][Ala] Ionic Liquid And Its Aqueous Solution Viscosity

Ionic liquid is an ionic fluid or low temperature molten salt which consists of cation and anion. Varieties and amount of ionic liquids have been depended by the ways of the anion and cation combination. Ionic liquid also possesses some characteristics such as good conductivity, low melting point, wide chemical window, strong dissolution ability and so on. In order to optimize and adjust the ionic chemical structure of ionic liquids, it is essential to study the physical and chemical properties of ionic liquids from a fundamental research of the viscosity of ionic liquids.The experiments adopt acid and alkali neutralization method which is a kind of two step synthesis method to synthesize [C6mim][Ala] alanine ionic liquid. In the range of 288.15-328.15K temperature, ubbelohde viscometer is used to measure density and viscosity of different concentrations [C6mim][Ala] aqueous solution. The density and viscosity data measured by the experiment combined with Jones-Dole equation fitting the experimental data obtain the B coefficient of viscosity at different temperatures. Thus, it shows clearly that the ionic liquid has a destructive effect on the structure of the solvent water as the solute.On the basis of transition state theory of Eyring liquid viscosity, semi-empirical method is put forward to predict the viscosity of ion liquid aqueous solution. We can get a good linear correlation by comparing the experimental value with the estimate value of viscosity of [C6mim][Ala] ionic liquid. Therefore, we can consider that this is a feasible method to estimate viscosity of ionic liquid aqueous solution of. And we can also judge whether the theoretical model of the prediction is in line with the fact which is meaningful to apply this prediction to produce the ionic liquid in practice. At last, ionic liquids making a contribution to the free energy, activation entropy and enthalpy of activation of flow is also calculated.