Relationship Between Properties And Structers Of Biomimetic Ionic Liquids And Appliaction In Sensor

The designability is one of the important properties of ionic liquids (ILs). However, owing to the lackof the basic data, the theoretical studies and the multiformity of structures, the structure propertierelationship of ionic liquids has not been established. So the design of ionic liquids only depends on theresearcher's experiences. It is one of the choke points in the development process of ionic liquids.Meanwhile, the functionalization of ionic liquids always cause the changes of their own properties,especially the increasing of melting point and viscosity, which is harmful to the industrial application ofionic liquids. Since the main interaction in ionic liquid molecules is similar with that in biologicalmembrane molecules, the structure which helps to maintain the flowability of cell membrane is employedto design the biomimetic ionic liquids in order to reduce the melting point and viscosity. For the purpose ofgetting some insights, the relationship between structure and property of biomimetic ionic liquids isdiscussed by investigating the property and calculating the microstructure. According to the goodbiocompatibility, a novel cholesterol sensor based on biomimetic ionic liquids has been developed byimprinted technology, which has expanded the scope of application of such ionic liquids in the biology field.As a part of the National Nature Science Foundation of China (No.21173070) and the InnovatorFoundation of the Colleges and Universities of Henan Province, the major contents of the present work areas follows:(1) The design, synthesis and characterization of biomimetic ionic liquid. Homeoviscous adaptationis a homeostatic process that regulates the viscosity of membrane lipids when the environmental conditionwas changed. It is a compositional adaptation process of biomembrane. It is well known that the structureof ionic liquids with long alkyl chain is similar with the phospholipid molecules, so the homeoviscousadaptation can be used in the design of ionic liquids. The unsaturated bond and kinked tail were introducedinto the side alkyl chain in alkylimidazolium ionic liquid in order to lower the melting point. The anions ofsynthetic ionic liquid include PF6,BF4and p-toluenesulfonic acid.1H NMR was used to characterize thestructure of ionic liquids.(2) The measurements of the melting point and the quantum chemical calculations of biomimetic ionic liquid. The DSC was used to measure the melting point and glass transition temperature. The effect of saidalkyl chain structure on melting point was discussed. The B3PW91and MP2methods were employed tooptimize the structure and calculated the interaction between cations and anions of biomimetic ionic liquid.The measured results and theoretical interaction energy were combined to investigate the relationshipbetween the structure and melting point. The results show that the unsaturated bond and kinked tail isefficient in lowering the melting point of ionic liquids. The Van der Waals force between cations providesan important contribution to the melting point.(3) The application of biomimetic ionic liquid in biosensors. The syntheted ionic liquids were used asfunctional monomer in the preparation of electrochemical sensor for cholesterol detection based onmolecular imprinting self-assembled film. The electrochemical characteristics of the electrode duringmodification were studied by cyclic voltammetry and electrochemical impedance technique.