Gelation ionic liquids

Values mean minimum gel concentrations, whose unit Is g/L (gelator/ Ionic liquid). 

Thermal and ionic gelation in liquid media Desolvation in liquid media... 

Apart from these examples, nanoparticle-containing ionic liquids can also be used to impregnate a solid support from which the liquid is finally removed.1831 A solution of palladium colloids in [C4Ciim][Tf2N] was added to an orthosilicate and allowed to gelate. Afterwards, the ionic liquid was extracted with acetonitrile and the resulting aerogel used to reduce cinna-maldehyde. 

Metallomesogens are materials related to liquid crystalline ionic hquids because some of them have ionic structures [68, 69]. Gels based on ionic hquids are also one of related materials. Physical gelation of ionic liquids is accompanied by the... 

GELATION OF IONIC LIQUIDS BY LOW MOLECULAR WEIGHT GELATORS... 

With low melting point in mind, nine ionic liquids shown in Figure 26.1 were tested for gelation. The six kinds of imidazolium salts, the two kinds of ammonium... 

TABLE 26.1 Results of Gelation Test of Ionic Liquids by Gelators 1 and 2 at 25°C... 

DSSCs prepared from this quasi-solid-state ionic liquid gel were stable under light at 60 °C for 1,000 h and had an efficiency of 6.3 % under simulated AM 1.5 frill sunlight, and the gelator had no influence on the performance of the solar cell. It was proposed that, after complete dissolution of the organogelator at elevated temperatures, the gelator molecules built up nanoscale fibrils due to the formation of hydrogen bonds by the amide and urea units and thus formed a three-dimensional network. This led to gelation of the ionic liquid mixture and hindered flow of the liquid. 

Supported ionic liquid membranes (SILMs) have been recently brought into focus due to their unique properties that can prevent the loss of solvent by evaporation. Ionic liquids (ILs) are organic salts with negligible vapor pressures. They are thermally robust with a wide temperature range in the liquid state, for example, up to 300°C, compared to 100°C for water, and their polarity and hydrophilicity/ hydrophobicity can be tuned by a suitable combination of cation and anion. Noble et al. have extensively studied SILMs for CO2 separation, including the gelation of SILMs. Excellent CO2 separation performance has been reported [127-129],... 

Many anion-driven supramolecular gels have been fabricated based on ion pairing or the analog state such as a mixture of acids and bases [8d]. There are a few examples of gelator molecules that are electronically neutral anion-responsive molecules, whose anion complexes also behave as gelators. This section mainly introduces several examples of anion-driven supramolecular gel systems as ion pairs, including ionic liquids and related materials, and cationic metal complexes accompanied by counteranions. 

As in the case of the salts discussed above, appropriate pairs of cations and anions yield ionic liquids that are partially ordered but essentially nondimensional (OD) states [13]. In ionic liquids, the bulky geometries of both the cationic and the anionic species effectively prevent crystallization due to weak ionic interactions. Such ionic liquids can be converted to gelated materials. As an example, Guerrero-Sanchez and Schubert et al. investigated the gelation behavior of a quaternary ammonium ohgo(propylene oxide)-based ionic liquid 4 (Fig. 4.3a(i)) upon mixing with water... 

FIGURE 43 (a)(i) Ionic liquid 4 and (ii) a photograph of an opaque gel prepared from the aqueous solution of 4 (Reproduced from Reference 14. Copyright 2010 Royal Society of Chemistry) (b) cyclic dipeptide gelators 5a,b for ionic liquids. 

Ribot, J. C. Guerrero-Sanchez, C. Hoogenboom, R. Schubert, U. S. Aqueous gelation of ionic liquids reverse thermoresponsive ion gels. Chem. Commun. 2010, 46, 6971-6973. 

---