Liquor ionic liquid

Transfer from Water-based to Ionic Liquid Based Liquors. In the case of water-based electrolytes, there are two economic incentives forthe above mentioned approaches the recovery of valuables and the avoidance of wastes and wastewaters. Despite the environmental attractiveness of such measures economic constraints may become an obstacle in industrial application. 

For ionic liquid based process liquors, the contrary can be assumed. Due to their relatively high prices and anticipated costs for discharge of spent liquors a breakthrough of ionic liquids in plating applications can be expected to be linked... 

Halide impurities are probably the most studied of the four general categories of impurities common to ionic liquids and, besides electrochemical analysis, two methods are currently being used to determine the level of residual halide impurities in ionic liquids [12]. The titration of the ionic hquid vnth AgN O3 is still widely used but suffers from a certain solubility of AgQ in the ionic hquid under investigation. This method can be enhanced by the Vollhard method for chlorine determination where the chloride is first precipitated with excess AgNO3 followed by back-titration of the mother liquor with aqueous potassium thiocyanate [13]. This method uses a visual endpoint through the formation of a complex between thiocyanate and an iron (III) nitrate indicator. 

Regel-Rosocka, M (2009). Extractive Removal of Zmc(II) from Chloride Liquors with Phosphonium Ionic Liquids/Toluene Mixtures as Novel Extractants, Sep. Purif. Technol, Vol.66, p>p. 19-24... 

What characterizes surfactants is their ability to adsorb onto surfaces and to modify the surface properties. At the gas/liquid interface this leads to a reduction in surface tension. Fig. 4.1 shows the dependence of surface tension on the concentration for different surfactant types [39]. It is obvious from this figure that the nonionic surfactants have a lower surface tension for the same alkyl chain length and concentration than the ionic surfactants. The second effect which can be seen from Fig. 4.1 is the discontinuity of the surface tension-concentration curves with a constant value for the surface tension above this point. The breakpoint of the curves can be correlated to the critical micelle concentration (cmc) above which the formation of micellar aggregates can be observed in the bulk phase. These micelles are characteristic for the ability of surfactants to solubilize hydrophobic substances in aqueous solution. So the concentration of surfactant in the washing liquor has at least to be right above the cmc. 

---