Synthesis And Application Study Of Modified Molecularly Imprinted Polymer

Molecular imprinting technique is the technology that simulates specificity binding mode of the biological antibody-antigen.The prepolymer was formed after template combined with functional monomer.Template was removed from the polymer that prepared after initiator, crosslinking agent were added in physical or chemical method.Molecularly imprinted polymers(MIPs) have specific selective adsorption for target molecules on space structure and the binding sites.MIPs have strong physical stiffness,good resistance to high temperature,acid and alkali,which can also be recycled for reusing.The following three parts were included in this thesis:(1) Preparation and application study of aspirin MIPsAspirin MIPs was prepared by one-step swelling with aspirin as template molecule,acrylamide as functional monomers,chloroform as solvent, azodiisobutyronitrile(AIBN) as initiator,ethylene glycol methacrylate(EDGMA) as crosslinking agent.Adsorption performance was studied by the static adsorption experiment. Salicylic acid is used to study specific selective adsorption performance of MIPs as the structure analogues of aspirin.Effect of p H on the adsorption equilibrium amount of MIPs was measured with the change of pH. Scanning electron microscopy(SEM) was used to characterize the morphology of MIPs.Fourier transform infrared spectrometer(FTIR) were used to characterize the adsorption property of MIPs. Scatchard analysis shows that aspirin MIPs exist two kinds of binding sites.The biggest apparent absorption amount of high affinity binding sites is 92.08 μmol·g-1,the biggest apparent absorption amount of low affinity binding sites is 659.37 μmol·g-1.Along with the increase of pH,adsorption quantity increases,but when pH is 8,salicylic acid was generated by the hydrolysis of the AS,which affected the adsorption capacity of molecularly imprinted polymer for aspirin.(2) Preparation and characteristic research of core-shell magnetic dicamba MIPsFe3O4 nanoparticles was prepared by coprecipitation method,SiO2-NH2 was coated on the surface of Fe3O4 nanoparticles. MIPs was prepared on the surface of Fe3O4@SiO2-NH2 by using dicamba as template molecule,acrylamide as functional monomers, AIBN as initiator and EDGMA as crosslinking agent.The resultant Fe3O4@SiO2-NH2 modified dicamba MIPs is helpful for subsequent processing.It can be used to specifically adsorp psesticide residue dicamba in water.The morphology of MIPs were characterized by SEM, adsorption ability was characterized by UV and FTIR.Comparing with the structure analogue vegiben, separation factor reached 3.19.Scatchard analysis showed that the biggest apparent adsorbtion capacity of high affinity binding sites reached 69.789 μmol·g-1,the biggest apparent adsorbtion amount of low affinity binding sites is 78.160 μmol·g-1.(3) Preparation and fluorescence analysis of chitosan sponge modified rhodamine B MIPsrhodamine B MIPs were prepared using rhodamine B as template molecule,methylacrylic acid(MAA) as functional monomer,acetonitrile as solvent,AIBN as initiator,EDGMA as crosslinking agent.Then MIPs were added into the preparation of chitosan sponge.Chitosan sponge modified MIPs were characterized by SEM,and FTIR,UV and fluorescence spectrum analysis.Modified by chitosan sponge,adsorption equilibrium time of MIPs was shortened from 15 h to 10 h. The adsorption effect was also improved,the equilibrium adsorption amount increased from 0.385 μmol·L-1 to 0.564 μmol·L-1,increased by 46.53 %. Compared with the structural analogues rhodamine 6G,chitosan sponge modified rhodamine B MIPs have high specific recognition and affinity for rhodamine B.