Controllable Preparation Of Magnetic Surface Molecularly Imprinted Polymer For Extraction Of Tetrabromobisphenol A

As the largest consumption of brominated flame retardant?BFR?,Tetrabromobisphenol A?TBBPA?are a potential endocrine disrupting chemicals and pollution widely used as additives in manufacturing polymers including polycarbonate plastic and epoxy resins.Because of its wide and dispersive use,endocrine disrupting and toxic properties,TBBPA can pollute the environment and ecosystem through various means and have potential health risks to the people.Molecular imprinted polymers?MIPs?are an emerging molecular recognition technique,which can form the specific recognition sites in synthetic polymers by using templates or imprinted molecules that are complementary to the spatial structure of the template.The template molecules were selectively adsorbed by recognition sites in the mixture.Compared with other materials,MIPs have the characteristics of conformational preconditioning,specific recognition and extensive practicability.Meanwhile,MIPs are now drawing more and more attention since they are highly specific,chemically stable,easily prepared and low in cost,and overcome the interference of analytes with similar structures or functional groups and be able to selectively bind template molecules from complex chemical matrices.The surface molecular imprinting confines almost all recognition sites to the surface,which is more favorable for the removal and recombination of template molecules.Metal-organic frameworks?MOFs?are a new type of porous materials that have developed rapidly over the past decade.MOFs are three-dimensional structure of crystalline materials composed of metal ions or metal clusters that are connected by organic linkers.Because of its adjustable pore size,large specific surface area,structure diversity,unsaturated metal coordination and surface modification energy,MOFs are becoming a research hotspot in field of material,chemical and environmental.In view of the advantages of molecularly imprinted polymers,MOFs and magnetic nanoparticles,the paper is devoted to the study of two kinds of preparation methods of TBBPA molecular imprinting.Magnetic molecularly imprinted composites with controllable morphology,high adsorption abilities,faster kinetics and strong magnetic response were prepared.Moreover,the composites were used for the removal and enrichment of TBBPA in water.The research content mainly as follows:1.Preparation of magnetic surface molecular imprinted polymers microspheres for selective and efficient adsorption of Tetrabromobisphenol AFirstly,Fe₃O₄ nanoparticles were synthesized as the magnetic core by solvothermal method,which made the molecularly imprinted polymers material magnetic-responsive and easily separate from the solution.Secondly,Fe₃O₄ was coated by SiO2 via stober method and then modified by MPS.4-vinyl pyridine?4-VP?,TBBPA and ethylene glycol dimethacrylate?EGDMA?were respectively chosen as functional monomer,template molecule and cross-linker to fabricate MIPs with magnetic core-shell Fe₃O₄@SiO2 as the support to prepare magnetic molecularly imprinted polymers.The prepared magnetic molecular imprints were used to adsorption of TBBPA and compared with its nonprintable polymer.At the same time,the selective adsorption capacity and reusability of the magnetic molecular imprints were evaluated in detail.The results showed that the obtained materials have good binding ability to the template molecules?58.67 mg g-1?,fast adsorption rate?30 min?and high selectivity and good reusability.2.Preparation and application of tetrabromobisphenol A molecular imprinted based on core-shell magnetic metal–organic frameworks in water sampleMagnetic nanoparticle molecularly imprinted polymers with good selectivity to tetrabromobisphenol A were prepared on the surface of MOFs.This work reports a novel metal–organic framework?MOF?-based metal affinity platform for the rapid and highly specific separation of TBBPA using zeolitic imidazolate framework-8 coated magnetic nanocomposites,which can be carried out in aqueous solution at room temperature.Fe₃O₄@ZIF-8@MIPs showed a good monodispersity,saturation magnetization was 38.4 emu g-1,BET area was 185.9 m2 g-1,pore volume and pore size were 0.47 m3 g-1 and 99.15 ?,respectively.Due to the higher density of the low coordination Zn atom on the surface of ZIF-8,Fe₃O₄@ ZIF-8 itself has an adsorption capacity to TBBPA and the maximum amount of adsorption?Qmax?is 117.6 mg g-1.The results showed that Fe₃O₄@ZIF-8@MIPs had a good selectivity to TBBPA.In addition,Fe₃O₄@ZIF-8@MIPs showed excellent recoverability,recovery rate of 85.0% after 5 times,and fast adsorption kinetics?15 min?for TBBPA.