Chapter 4

Ionic Liquid-Based Surfactants

Synthesis, Molecular Structure, Micellar Properties and Applications

Paula D. Galgano

Paula D. Galgano

Nitro Química, São Paulo, Brazil

Search for more papers by this author
Omar A. El Seoud

Omar A. El Seoud

Institute of Chemistry, University of São Paulo, São Paulo, Brazil

Search for more papers by this author
First published: 31 July 2015
Citations: 7

Summary

The favorable properties of ionic liquids (ILs), for example, negligible vapor pressure, polarity, high chemical and thermal stability, as well as molecular structural versatility, are expected to be carried over to their surface-active counterparts, ionic liquid-based surfactants (ILBSs; ILs with long-chain “tails”); this has been verified experimentally for several 1,3-dialkylimidazolium chlorides, bromides, and tetrafluoroborates. The impetus for studying ILBSs is the enormous potential for their applications, for example, in the biomedical and nanotechnological fields. The progress in these applications rests on a clear understanding of the relationship between surfactant molecular structure and properties of its solution. This article is focused on the imidazole-based ILBSs, including syntheses, determination of the properties of their solutions, and comparison between their micellar properties and those of “conventional” cationic surfactants, for example, pyridine-based cationics, and of some of their main applications. The most frequently employed schemes for the synthesis and purification of ILBSs are given; the following micellar properties are listed, where available: the critical micelle concentration, counterion dissociation constant, surfactant aggregation number, and thermodynamic parameters of aggregation. The applications of the ILBSs are briefly discussed.

The full text of this article hosted at iucr.org is unavailable due to technical difficulties.