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

Abstract

AbstractThis paper deals with the synthesis and self‐aggregation of a hydroxyl‐functionalized imidazolium‐based ionic liquid (IL) surfactant, namely 1‐hydroxyethyl‐3‐dodecylimidazolium chloride ([C2OHC12im]Cl). The molecular structure was confirmed by means of electrospray ionization mass spectrometry (ESI–MS), 1H nuclear magnetic resonance (1H NMR) and elemental analysis. Many important physicochemical parameters, such as the critical micelle concentration (CMC), the surface tension at CMC (γCMC), the adsorption efficiency (pC20), the surface pressure at CMC (ΠCMC), the maximum surface excess (Γm), the minimum molecular cross‐sectional area (Amin), the value of CMC/C20, the average number of aggregation (Nm) 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 Nm, and the critical average aggregation number (Nm,c) of imidazolium‐based IL surfactants are reported for the first time in this paper.