Catanionic surface-active ionic liquids (CASAILs) of the type 1-alkyl-3-methyl-imidazolium alkylcarboxylates ([Cnmim][Cm-1COO]) and 1-alkyl-3-methyl-imidazolium 4-alkoxybenzoate ([Cnmim][ CmOBCOO]) are novel surfactants which self-assemble not only in water but also in ionic liquids. In the ChitinFluid project funded by the Carl Zeiss Foundation, we are using these kinds of complex fluids to transform chitin, which is otherwise difficult to process, into high-quality products. Surface tension isotherms of these CASAILs in water revealed low minimum surface tensions and surface head group areas of the order of 20 mNm-1 and 60 Å2, due to both the electrostatic attraction between the two oppositely charged ionic heads and the van der Waals interaction between anionic and cationic alkyl chains. Freeze-fracture electron microscopy and dynamic light scattering proved the presence of uni- and multilamellar vesicles above the critical aggregation concentration (cac). Systematic surface tension and UV/Vis spectroscopy studies showed a strong linear decrease in log(cac) with increasing anion and cation chain length due to the increasing hydrophobic effect. Based on these excellent properties, the [Cnmim][Cm-1COO]s were then investigated for their ability to efficiently stabilize ionic liquid microemulsions as promising new solvents for chitin. Studies of the phase behavior revealed that indeed only 6 wt.% of [C18mim][C17COO] are actually able to form microemulsions containing equal amounts of EAN and cyclohexane. Electrical conductivity and SANS measurements proved the presence of a bicontinuous structure with a domain size of 20 nm.