Synthesis and Self‐Aggregation of a Hydroxyl‐Functionalized Imidazolium‐Based Ionic Liquid Surfactant in Aqueous Solution

Abstract

Abstract This paper deals with the synthesis and self‐aggregation of a hydroxyl‐functionalized imidazolium‐based ionic liquid (IL) surfactant, namely 1‐hydroxyethyl‐3‐dodecylimidazolium chloride ([C 2 OHC 12 im]Cl). The molecular structure was confirmed by means of electrospray ionization mass spectrometry (ESI–MS), 1 H nuclear magnetic resonance ( 1 H NMR) and elemental analysis. Many important physicochemical parameters, such as the critical micelle concentration (CMC), the surface tension at CMC (γ CMC ), the adsorption efficiency (p C 20 ), the surface pressure at CMC (Π CMC ), the maximum surface excess (Γ m ), the minimum molecular cross‐sectional area ( A min ), the value of CMC/ C 20 , the average number of aggregation ( N m ) and the micellar microenvironment polarity were determined by surface tension‐concentration curves, fluorescence spectra, and electrical conductivity. The phenomena of the second CMC, the concentration dependence of N m , and the critical average aggregation number ( N m ,c ) of imidazolium‐based IL surfactants are reported for the first time in this paper.