The Structure And Properties Of Microemulsions Composed Of The Protic Ionic Liquids And The Ionic Liquids Surfactants

The ionic liquid microemulsion shares the advantages of ionic liquid and microemulsion.In theory,the microemulsion system can be formed completely,which composed of three different ionic liquids.More importantly,this system has a very high ion environment,nonvolatile and ultrastable in extreme temperatures.As a part of the project supported by the National Natural Science Foundation of China（No.21473050）,in this study,we have designed and synthesized a series of ionic liquids,such as hydroxyl functionalized protic ionic liquids and amphiphilic ionic liquids.Then we investigated the structure,properties and morphology of this kind of microemulsion system,and provide the basis of its application.The main contents of this paper is as follows.1.Ethanolammonium nitrate（EOAN）,ethylammonium nitrate（EAN）and amphiphilic ionic liquids including imidazolium-based ILs [Cnmim]Cl（n=12,14,16）and cholinium-based ILs [CnDMEA]Cl（n=12,14,16）were prepared.The aggregation behavior of these ILs surfactants in EOAN and EAN was investigated by surface tension measurements,the aggregation parameters and thermodynamic parameters were calculated based on the cmc values.The effect of length of alkyl chain of ILs surfactants,temperature and structure of solvent on the cmc values were discussed in detail.Finally,the size and morphology of aggregates in EOAN were characterized and analyzed by the DLS and Cryo-TEM.2.The microemulsion systems which is composed of three different ionic liquids EOAN+[Cnmim]Cl/[CnDMEA]Cl（n=12,14）+[Cnmim][Tf₂N]（n=2,4,6,8,10）were constructed.The phase equilibrium properties,microstructure and size distribution were studied by phase diagram,electrical conductivity,dynamic light scattering measurements.The morphology of this system was characterized by Cryo-TEM.Finally,the microstructure of this microemulsion in extreme temperature were analyzed by small angle x-ray scattering method.3.1-ethyl-3-methyl imidazole ethyl sulfate salt（[C₂mim]EtSO₄）was selected as polar phase,AOT-type ionic liquids（[Cnmim]AOT（n=4,8）and [CnDMEA]AOT（n=1,4,8））were selected as surfactant,and quaternary phosphonium salt（P44414Tf₂N）was selected as nonpolar phase.The phase equilibrium properties of this new ternary system were studied preliminarily at different temperatures.The aggregation behavior of the AOT-type ionic liquid surfactant in [C₂mim]EtSO₄ was analyzed by DLS method.