Synthesis And Analytical Properties Of Imidazole Ion Liquid/Porphyrin COF Composites

Ionic liquid as a green solvent which possess a low saturated vapor pressure,good thermal stability and chemical stability and good solubility and are widely concerned.COFs is a new kind of ordered porous crystalline material with large specific surface area,high porosity,good chemical stability and large conjugated structure,it is widely used in the fields of adsorption,catalysis,electrochemistry and gas separation.In this paper,1-octadecyl-3-triethoxy propylsilyl-imidazolium tetrafluoroborate ionic liquid modified silica gel（[ODTIm]PF6@SiO2）,Copper porphyrin 2,5-2-bromineterephthalaldehyde covalent organic framework modified multi-walled carbon nanotubes（CuP-BDB-COF@MWCNT）and ionic liquid 1-methyl-3-benzylimidazolium bromide modified CuP-BDB-COF composite（MBImBr-COF）were synthesized by chemical bonding.the structure of the obtained material was characterized and its adsorption properties were studied.The ionic liquid was grafted onto the carrier material by post-modification,which solved the problem of difficult recovery of ionic liquid and improved the adsorption capacity of the composite material.Sudan Red Ⅰ-Ⅳ is a class of azo industrial dyes,mainly used in paints,shoe polishes and floor coatings.Because of its good fat solubility,coloring ability and cheap price,it is used as a food additive by some unscrupulous businessmen.As Sudan red metabolism through the human body to produce aniline substances,the human liver and kidneys are affected by toxins,which can seriously lead to cancer.Various countries have banned the use of Sudan red as a food additive.In this paper,Sudan red in chili powder was detected by ionic liquid modified silica material as a solid phase extraction（SPE）filler by sample pretreatment technique combined with high performance liquid chromatography.In this experiment,Sudan red dyes in Chili powder were adsorbed and eluted by changing the polarity of solvent,and the qualitative and quantitative determination of Sudan red in chili powder was carried out by combining with High performance liquid chromatography,the detection of Sudan red in chili powder also showed a high sensitivity and stability.The spiked recoveries of Sudan red（Ⅰ～Ⅳ）is 87.61-109.1%.The inter-day relative standard deviation RSD is 2.45-3.03%,and the intra-day relative standard deviation RSD is 0.55-2.45%.The recoveries of the solid phase extraction packing for Sudan red in chili powder were basically unchanged after 5 cycles of using the solid phase extraction packing,indicating that the composite material has good stability.COFs are a class with some light elements such as C,H,O and N composition,which have the advantages of low density,high porosity,high specific surface area and designability.Porphyrins are a series of substituted porphyrin compounds containing heterocyclic macrocycles with large conjugated structures and good biocompatibility,which are widely used in the fields of adsorption,photocatalysis and electrocatalysis.In this paper,CuP-BDB-COF composite was prepared by solvothermal synthesis of imine Porphyrin COF with Cu-TAPP as monomer under high temperature and high pressure.Bisphenol A（BPA）is commonly used in plastic tableware,plastic water bottles,and baby bottles which can cause heart disease,diabetes and liver disease,and affect the brain development of children.In this experiment,CuP-BDB-COF was in situ compounded on the surface of NH2-MWCNT by hydrothermal method to obtain CuP-BDB-COF modified composite（CuP-BDB-COF@MWCNT）.Under the best experimental conditions,the current response of CuP-BDB-COF@MWCNT/GCE to Bisphenol A has a good linear relationship at 2 μmol/L～30μmol/L.The linear equation is Y=0.6816X+0.4837,and the linear correlation is R2=0.9989.CuP-BDBCOF@MWCNT were used as electrode materials for the rapid,simple and accurate detection of BPA in lake water by electrochemical methods.Recovery of the spiked BPA is 93.7%-99.6%.The inter-day relative standard deviation RSD is 3.9%,the intra-day relative standard deviation RSD is 2.7%.In this paper,ionic liquid 1-methyl-3-benzylimidazolium bromide were compounded with CuPDBD-COF by suziki coupling（MBImBr-COF）,then MBImBr-COF were characterized by a series of characterizations,such as crystal diffraction（XRD）,scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,elemental analysis（XPS）,and specific surface area（BET）.The analysis of the characterization results confirmed the successful modification of ionic liquids into the pore channels of porphyrin COFs.The adsorption properties of MBImBr-COF and CuP-DBD-COF were also investigated,it was found that MBImBr-COF had a significant adsorption capacity for 4-nitrophenol relative to CuP-DBDCOF.