Rheological Behavior of Aqueous Solutions of An Ionic Liquid As A Surfactant

The rheological properties of aqueous solutions of an ionic liquid as a surfactant, 1-tetradecyl-3-methylimidazolium bromide (C14mimBr), in the presence of sodium salicylate (NaSal), have been studied by rheological measurements. For these C14mimBr/NaSal systems, zero-shear viscosity as a function of NaSal concentration shows the maxima behavior. The effect of the concentration ratio, CNaSal/CC14mimBr, on the maximum was determined, and the scaling relations were obtained. Network structures could be formed in the aqueous C14mimBr solutions containing NaSal. 1H NMR spectra analysis indicates that the main interaction between C14mimBr and NaSal molecules is electrostatic attraction, which leads to the formation of an ion pair.