Preparation, Property And Application Of Functional Ionic Liquids

Ionic liquids have been extensively used as green solvents in organic synthesis,catalytic reaction,extraction and electrochemistry due to their unusual properties ofnegligible vapor pressure,high thermal stability,large electrochemical window,highconductivity and tunable acidity solubility.Meanwhile,ionic liquids attractedsignificant attention in the synthesis of special nano-materials because of their lowcoordination,low interface energies,low interface tensions and high orderedstructure.The most emergent issue of ionic liquid is to synthesis the ionic liquids withspecific function for special application,as well as to simplify the synthesis procedureof ionic liquid,reduce the cost and realize their large-scale application in commerce.Based on these ideas,eighteen novel ionic liquids have been prepared and themain contents are as follows:Six novel ionic liquids ([Emim][CH₃COCO₂],[Bmim][CH₃COCO₂],[Pmim][CH₃COCO₂],[Et₄N][CH₃COCO₂],[Bu₄N][CH₃COCO₂]and[Ch][CH₃COCO₂]) have been synthesized.They have been characterized by FT-IR,¹H NMR and element analysis and their composition and structures have beenconfirmed.Their glass transition temperature,conductivity,electrochemical window,thermal stability and solubility have been investigated.The results show that theirglass transition temperature is much lower than room temperature and the lowest glasstransition temperature is-77℃([Emim][CH₃COCO₂]).The decompose temperature isaround 105℃,the conductivity vary from 0.056 to 3.0mS/cm,the stableelectrochemical window is 2.3V and the solubility is excellent.Meanwhile,threecarbonates have been prepared using [Pmim][CH₃COCO₂]ionic liquid as the solvent,template and resource of CO₂.The carbonates were characterized by FT-IR,XRD,TEM and BET.These carbonates possess mesoporous structure,high surface area andspecial straw-like morphology.This exhibited the potential of ionic liquids in thesynthesis of special nano-materials.Three novel binary eutectic ionic liquids have been synthesized by simple,economical and environmentally benign process.These ionic liquids are denoted as Bu₄NBr-IM,ChCl-IM and C₂BtPF₆-IM.The formation of the binary eutectic ionicliquids is due to the interactions between the components demonstrated by the Ramanspectrum.The ionicity of the ionic liquids is high and vapor pressure is lower.Theconductivity is as high as 52 mS/cm,the viscosity is as low as 3.1cp and the stableelectrochemical window is 3.4V.Especially,they show unusual solvent properties formetal oxide,inorganic salts and solid organic compounds.This synthesis methodreduced the cost for the ionic liquids and was environmentally benign.Five novel ionic liquids based on alkyl-imidazolium and cyclictrimetaphosphimate have been prepared:[Emim]₃[PO₂NH]₃,[Bmim]₃[PO₂NH]₃,[Pmim]₃[PO₂NH]₃,[Omim]₃[PO₂NH]₃ and [Hmim]₃[PO₂NH]₃.They werecharacterized by FT-IR,¹H NMR,³¹p NMR,DSC and TG.The results show that theyare liquid at room temperature and the decompose temperature is 210℃.Meanwhile,they have higher conductivity (0.002-10.4mS/cm) and excellent solubility.Three new ionic liquids with alkyl-imidazolium cations and succinimide anionshave been obtained (EmimC₄H₄O₂N,BmimC₄H₄O₂N and HmimC₄H₄O₂N).Theirstructure and composition were confirmed by the characterization of FT-IR and ¹HNMR.Meanwhile,the melting points of the three ionic liquids(-3.15,-17.63 and-15.77℃) are determined,the conductivity vary in the range of 0.021-9.70mS/cm andthe decompose temperature is 228,225 and 220℃,respectively.Most important,theseionic liquid exhibited higher absorption capacity to CO₂ and can be recycled easily.Novel ionic liquid with functional group of aminoethyl and phosphonyl has beensynthesized and characterized.The result show that it is liquid at room temperature,decompose at 201℃and the conductivity vary in the range of 0.04-5.60mS/cm.Synchronously,the ionic liquid has been used as solvent,template and precursor tosynthesize hybrid porous nanomaterials.