Micelle-ionic liquid solution

Blesic, M., Marques, M.H., Plechkova, N.V., Seddon, K.R., Rebelo, L.RN., and Lopes, A., Self-aggregation of ionic liquids Micelle formation in aqueous solution. Green Chem., 9, 481-490, 2007. 

In this study we restrict our consideration by a class of ionic liquids that can be properly described based on the classical multicomponent models of charged and neutral particles. The simplest nontrivial example is a binary mixture of positive and negative particles disposed in a medium with dielectric constant e that is widely used for the description of molten salts [4-6], More complicated cases can be related to ionic solutions being neutral multicomponent systems formed by a solute of positive and negative ions immersed in a neutral solvent. This kind of systems widely varies in complexity [7], ranging from electrolyte solutions where cations and anions have a comparable size and charge, to highly asymmetric macromolecular ionic liquids in which macroions (polymers, micelles, proteins, etc) and microscopic counterions coexist. Thus, the importance of this system in many theoretical and applied fields is out of any doubt. 

An important common feature of macroion solutions is that they are characterized by at least two distinct length scales determined by the size of macroions (an order up to lOnm in the case of ionic micellar solutions) and size of the species of primary solvent (water molecules and salt ions, i.e. few Angstroms). Considering practical colloidal macro-dispersions, like foams, gels, emulsions, etc., usually we are dealing with as many as four distinct length scales molecular scale (up to lnm) that characterizes the species of the primary solvent (water or simple electrolytes) submicroscopic or nano scale (up to lOOnm) that characterizes nanoparticles or surfactant aggregates called micelles microscopic or mesoscopic scale (up to lOO m) that encompasses liquid droplets or bubbles in emulsion and foam systems as well as other colloidal suspensions, and macroscopic scale (the walls of container etc). 

Figure 4.34 Solubilisation of cellulose, (a) By Cd-tren (b) A -methylmorpholine A -oxide (c) fringe micelles formed in apparently simple solutions (d) ionic liquids capable of solubilising cellulose and other polysaccharides.

Ammonium salts are well-known cationic surfactants. These amphiphilic molecules aggregate in aqueous solution to micelles and at higher concentrations to lyotropic (typical member is CTAB, eetyltimethylammonium bromide) (or thermotropie) mesophases. Beside this ammonium salts are used as phase transfer catalysts and as ionic liquids (ILs) in synthesis of nanopartickle catalysts [70-74],... 

Another responsiveness which could be of interest in the field of drug delivery is that to the medium ionic strength. Investigations by NMR showed that diblock copolymers comprising imidazolium-based ionic liquid monomers exhibited salt-responsive behavior in aqueous solution, i.e., anionic exchange induced micellization. ... 

Wang Z, Lai H, Wu P (2012) Influence of PIL segment on solution properties of poly (N-isopropylacrylamide)-b-poly(ionic liquid) copolymer micelles, thermal phase behavira-and microdynamics. Soft Matter 8 11644—11653... 

Self-aggregation of ionic liquids micelle formation in aqueous solution. Green Chem., 9,481-490. 

Dong, B. Li, N. Zheng, L. Q. Yu, L. Inoue, T. (2007). Surface adsorption and micelle formation of surface active ionic liquids in aqueous solution. Langmuir, 23, 4178-4182. 

Dong, B. Zhang, J. Zheng, L. Q. Wang, S. Q. Li, X. W. Inoue, T. R. (2008a). Salt-induced viscoelastic wormlike micelles formed in surface active ionic liquid aqueous solution.. Colloid Interface Sci, 319,338-343. 

Jungnickel, C Luczak, J. Ranke, J. Fernandez, J. F. Muller, A. Thoming, J. (2008). Micelle formation of imidazolium ionic liquids in aqueous solution. Colloid Surf. A-Physicochem. Eng. Asp., 316, 278-284. 

Luczak, J. Jungnickel, C. Joskowska, M. Thoming, J. Hupka, J. (2009). Thermodynamics of micellization of imidazolium ionic liquids in aqueous solutions. J. Colloid Interface Sci, 336,111-116. 

Miskolczy, Z. Sebok-Nagy, K Biczok, L. Gokturk, S. (2004). Aggregation and micelle formation of ionic liquids in aqueous solution. Chem. Phys. Lett., 400, 296-300. 

Sifaoui, H. Lugowska, K. Domanska, U. Modaressi, A. Rogalski, M. (2007). Ammonium ionic liquid as modulator of the critical micelle concentration of ammonium surfactant at aqueous solution Conductimetric and dynamic light scattering (DLS) studies. /. Colloid Interface Set., 314,643-650. 

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