Preparations And Applications Of Dopamine Modified Membrane And Amidoximated Cyclodextrin Polymer Coated Magnetic Particles

For a green and sustainable future,the treatment of water pollutants is imperative.Different types of adsorption materials have great differences in the selectivity and adsorption performance of the target.In recent years,with the development of science and technology many new materials have emerged and have shown excellent performance in adsorption due to their unique structural characteristics.Aiming at the dye molecules and heavy metal ions in the water,two adsorbents were constructed using organic nanofiltration membrane and magnetic nanoparticles as the matrix,and studied on the adsorption properties of the adsorbents.The main contents are as follows:1.Based on mussel inspiration,the surface of commercial organic nanofiltration membrane（nylon-66）was coated with polydopamine.Because of the slow self-polymerization rate of polydopamine and the heterogeneity of polymerization,the trigger Cu SO₄/H₂O₂ were used to accelerate the deposition rate;the same time,a certain amount of polyethyleneimine were added to make the modified coating more uniform,and finally obtains a PDA/PEI modified organic film.The modified organic film was characterized by the water contact angle,water permeability,thermogravimetric analysis,etc.Then,the adsorption properties of the modified organic membrane were evaluated by Congo red in the aqueous solution.The results show the maximum adsorption capacity that can be achieved under optimal conditions is 124.22 mg/g,and the film material is in acid solution,alkaline solution and organic solution.This indicates that the modified membrane has the potential to be applied in the separation and enrichment of dyes.2.In order to achieve the simultaneous removal of dye molecules and heavy metal ions,an magnetic amidoximated adsorbent was designed and prepared.First,magnetic nanoparticles（Fe₃O₄）were synthesized by solvothermal method,and then Fe₃O₄ was used as the matrix.According to the principle of nucleophilic substitution,the polymer of tetrafluoroterephthalonitrile andβ-cyclodextrin was fixed on the surface of the magnetic nanoparticles to obtain the cyclodextrin polymer functionalized magnetic nanoparticles.The nanoparticles are rich in nitrile groups,which are converted into amidoxime groups to obtain the final magnetic adsorbent Fe₃O₄@P-CDP-AO.the physical and chemical properties of the material were characterized by scanning electron microscopy,transmission electron microscopy,thermogravimetric analysis and other means.At the same time,the adsorption selectivity and adsorption properties of the dye molecules and heavy metal ions in the aqueous solution of the adsorbent were studied.The results show that the adsorbent can selectively adsorb and separate dyes and heavy metal ions,indicating that the material has potential application value in water pollution treatment.