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Self-assembly of ionic liquids (ILs) surfactants in ILs solvents is important from the viewpoint of both scientific research and practical application because of the advantages of high ionic nature and possible application at high temperature. In this work, the aggregation behavior of long-chain ionic liquids 1-alkyl-3-methylimidazolium chloride [Cnmim]Cl (n = 12, 14, 16) and N-alkyl-N,N-dimethylethanolammonium [CnDMEA]Cl (n = 12, 14, 16) in a protic ionic liquid, ethanolammonium nitrate (EOAN), is investigated by surface tension measurements. The variation of micellization parameters with alkyl chain length and head group type of the ILs surfactants is analyzed and compared with that in water and in ethylammonium nitrate (EAN). It is found that the critical micelle concentration (cmc) values of the IL surfactants, such as [C12mim]Cl, in EOAN are 27 times smaller than those in EAN, and 4 times smaller than those in water. This suggests that EOAN is a better self-assembly medium for the ILs surfactants. It is also found that the contribution of head groups of the ILs surfactants to the cmc values is different in EOAN, water and EAN, while the contribution of CH2 group in the alkyl chain of the ILs surfactants is generally independent of the solvents nature.

It is a challenge to develop microemulsions which can serve as nanoreactors for the synthesis of nanoparticles and chemical reactions at high temperature. In this work, a class of novel high temperature microemulsions consisting solely of ionic liquids have been designed and prepared for the first time. It is found that nanoscale droplets formed in the ionic liquid microemulsions can be maintained up to 200 °C, and the size distribution of the droplets can be easily tuned by selection of the ionic liquids and varying compositions of the systems. By using such microemulsions as nanoreactors, porous metals such as Pt have been prepared at 180 °C without using any purposely added reductant.