Preparation And Study Of Novel Eu(?)and Pd(?) Ion Imprinted Polymers

Ion imprinted technology is a designable polymer material preparation technology that can highly selectively recognize target template ions.Because of its flexible design,ion imprinting technology has great development potential.Based on a large number of references,this study designs and develops a new functional monomer and a new matrix material for the preparation of ion-imprinted polymer materials.And using the synthesized new functional monomers,an ion-imprinted polymer that can be used for fluorescence detection and visual detection of Eu(?)was prepared;using the developed matrix allyl cellulose,a Pd(?)ion surface imprinted polymer with extremely high selectivity and adsorption capacity was prepared.The detailed work is as follows:Firstly,using 4,4'-dibromo-2,2'-bipyridine as raw material,a new functional monomer 4,4'-divinyl-2,2'-bipyridine used in ion imprinted technology was synthesized.Using it together with?-methacrylic acid as functional monomers,and after coordinating with Eu(?)ion from europium trichloride,under the cross-linking effect of ethylene glycol dimethacrylate,Eu(?)ion-imprinted polymer was prepared by initiate polymerization.The structure and morphology of Eu(?)ion-imprinted polymer were characterized by Fourier transform infrared spectroscopy,X-ray photoelectron spectroscopy,X-ray powder diffraction,scanning electron microscopy and transmission electron microscopy.In addition,the adsorption performance and photophysical properties of Eu(?)ion-imprinted polymer were also studied.The experimental results show that the Eu(?)ion-imprinted polymer has an adsorption capacity of 53.63 mg/g for Eu(?)ions and an imprinting factor of 1.55.Based on its fluorescent properties,Eu(?)ion imprinted polymer is used as a fluorescent probe for detecting Eu(?)ions.With the aid of a fluorescence spectrophotometer,a dual emission ratio Eu(?)ion fluorescence analysis method was established,which realizes the quantitative detection of Eu(?)ion.This method has good linearity for Eu(?)at both high(0.05-0.5 mmol/L)and low(0-0.05 mmol/L)concentrations,and its detection limit is 2.3×10^-7.Besides,based on the strong fluorescence emission of Eu(?)ion imprinted polymer,the visual detection of Eu(?)ions under ultraviolet light has been successfully realized.Secondly,a new matrix material,allyl cellulose,for ion imprinted technology was synthesized using microcrystalline cellulose as raw material.And then,4-vinylpyridine was selected as the functional monomer,Pd(?)from Na₂Pd Cl₄ was used as the template ion,and ethylene glycol dimethacrylate was used as the crosslinking agent to successfully prepare Pd(?)ion-imprinted polymers grown on the surface of allyl cellulose.Fourier transform infrared spectroscopy,X-ray powder diffraction and nuclear magnetic resonance spectroscopy were used to prove the structure of allyl cellulose,meanwhile the morphology of nano polymer particles grown on the surface of allyl cellulose was visually characterized by scanning electron microscope and transmission electron microscope.The results of equilibrium adsorption experiments show that the synthesized surface Pd(?)ion-imprinted polymer has an adsorption capacity of 80.73 mg/g for Pd(?)ions and an imprinting factor of 28.33.It has very high selectivity of Pd(?)ion which is relative to the tested several ions of Pt(IV),Fe(?),Fe(?),Pt(IV),Pr(?),Ce(?),Cd(?).For example,the selectivity coefficient for Pt(IV)ion,which has a similar structure to Pd(?)ion,reaches 18.78,and the selectivity coefficient for Fe(?)ion is as high as 1316.49.Comparing with the Pd(?)ion-imprinted polymer synthesized by direct precipitation polymerization,the Pd(?)ion-imprinted polymer synthesized based on allyl cellulose has higher adsorption speed,adsorption capacity and selectivity.