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

<div><p>The rheological properties of aqueous solutions of an ionic liquid as a surfactant, 1-tetradecyl-3-methylimidazolium bromide (C<sub>14</sub>mimBr), in the presence of sodium salicylate (NaSal), have been studied by rheological measurements. For these C<sub>14</sub>mimBr/NaSal systems, zero-shear viscosity as a function of NaSal concentration shows the maxima behavior. The effect of the concentration ratio, C<sub>NaSal</sub>/C<sub>C14mimBr</sub>, on the maximum was determined, and the scaling relations were obtained. Network structures could be formed in the aqueous C<sub>14</sub>mimBr solutions containing NaSal. <sup>1</sup>H NMR spectra analysis indicates that the main interaction between C<sub>14</sub>mimBr and NaSal molecules is electrostatic attraction, which leads to the formation of an ion pair.</p></div>