Volumetric And Surface Properties Of Aqueous Solutions Of Propionate Ionic Liquids:[C₄mim][Pro] And [C₆mim][Pro] At Different Temperatures

Carboxylic acid ionic liquid has good stability,low melting point,high viscosity and conductivity and other excellent features as a new generation of green ionic liquid.It is easily to be biodegradable so that it is a friendly environmental green ionic liquid.Based on these excellent characteristics,carboxylic acid ionic liquid has attracted much attention from researchers both in the academic fields and industrial fields.Whereas data of these green ionic liquids are lacking.The main content of this paper is the supplement of physicochemical data of propionic acid ionic liquids[C4mim][Pro] and [C6mim][Pro].The propionate acid ionic liquids(PrAILs),1-alkyl-3-methylimidazolium propionate [C4mim][Pro] and [C6mim][Pro] were prepared by the neutralization method and characterized by 1H NMR spectroscopy and DSC trace.The values of density and surface tension of aqueous [C4mim][Pro] and[C6mim][Pro] have been determined at the molality range of 0.01 mol·kg-1 to 0.50mol·kg-1 in the temperature range of 288.15 K to 318.15 K.The coefficient of thermal expansion,the apparent molar volume and the parachor for these solutions were calculated.It turns out that the values of the apparent molar expansibility of solute obtained from the solution density data have been highly consistent with that calculated by Hamed-Owen euaqtion.The empirical equation for predicting the surface tension of [C4mim][Pro] and [C6mim][Pro] dilute solution is proposed according to the research of surface tension data.Based on this empirical equation the predicted values of surface tension are highly correlated with the corresponding experimental ones.We also used parachor to predict surface tension of ionic liquids.Through parachor semi-empirical method predicted surface tension for dilute solutions of [C4mim][Pro] and [C6mim][Pro] are highly correlated with the corresponding experimental values.The results have been shown that empirical equation and parachor semi-empirical method proposed in the paper are rational.