Preparation Of Magnetic Multifunctional Polymer Nanocomposite Particles And The Research Of Properties

In recent years,due to the development of nanotechnology nanomaterials have attracted more and more attention.Thanks to their outstanding physical and chemical properties nanomaterials can be applied in many fields,including the wastewater treatment.Nanocomposite materials,in particular,composed of different nano-scale materials which have respective functions may obtain some extra performance.However,the preparation of the nanocomposite materials have some disadvantages such as long time consumption,complicated process,and poor controllability.Therefore,this paper is aimed at simplifying the preparation process and improving the application performance of nanocomposites.The details are as follows:?1?Facile fabrication of PS/Fe₃O₄@PANi nanocomposite particles and their application for the effective removal of Cu²⁺This work presents a simple and straightforward approach to fabricating multifunctional nanocompositecparticles which possess a core of a polystyrene?PS?particle,a transition layer of magnetic Fe₃O₄ cnanoparticles?NPs?,and an outer shell of adsorbable polyaniline?PANi?.In detail,the positively charged Fe₃O₄ NPs synthesized via the chemical co-precipitation method are directly loaded onto the negatively charged surfaces of the PS particles obtained by emulsifier-free emulsion polymerization through electrostatic self-assembly;subsequently,the coating of the resultant PS/Fe₃O₄ nanocomposite particles with PANi was successfully achieved by virtue of the‘‘swelling–diffusion–interfacial-polymerization method''?SDIPM?.Furthermore,the adsorption of Cu²⁺by PS/Fe₃O₄@PANi nanocomposite particles was investigated by changing the initial pH value,adsorption time,and initial concentration of the adsorbate.The adsorption data in our work follow a pseudo-second-order kinetics model and fit the Langmuir isotherm model.The PS/Fe₃O₄@PANi nanocomposite particles show that the maximum adsorption capacity is up to 181.5 mg/g at pH 5.More importantly,these nanocomposite particles can be easily recovered using an external magnetic field owing to the presence of Fe₃O₄ NPs,and the regenerated nanocomposite particles can be repeatedly used for eight cycles without significant loss of their adsorption capacity.?2?Prepartation of PS/Fe₃O₄/ZIF-8 nanocomposite particles and efficiently adsorption orgain dyesThis work presents a simple and straightforward approach to fabricating multifunctional nanocompositecparticles of PS/Fe₃O₄/ZIF-8.In detail,PS microspheres were prepared by the dispersion polymerization method and ferroferric oxide nanoparticles were prepared by co-precipitation method.Based on the thermodynamic stability,PS/Fe₃O₄ nanoparticles spontaneously form on the surface of ethylene.The addition of the above complex to the precursor solution of ZIF-8 is equivalent to the introduction of impurities in the solid.ZIF-8will nucleate heterogeneous on the surface of the PS/Fe₃O₄ nanocomposite particles to form PS/Fe₃O₄/ZIF-8 nanocomposite particles,and using the prepared composite as a seed,repeatedly feeding in the precursor solution will increase the content of ZIF-8 and finally form a shell layer.The Zn²⁺and imidazole ring based on the surface of ZIF-8 can bind with the functional groups of different dye molecules to achieve the purpose of removing the dye.Finally,the nanocomposite has good effect on methyl orange?MO?,Congo red?CR?,methylene blue?MB?All have adsorption properties,the maximum adsorption capacity of CR can reach 311.5mg/g.The nanocomposite particles can be repeatedly used 10 times without significant loss of their degradation capacity.?3?Highly efficient degradation of methylene blue by PS/Fe₃O₄/Pd@PPy nanocompositeThis work presents a simple and straightforward approach to fabricating multifunctional nanocomposite particles which possess a core of PS particle,transition layer of magnetic Fe₃O₄nanoparticles?NPs?,and an outer shell of palladuim@polypyrrole?Pd@PPy?.In detail,the positively charged Fe₃O₄ NPs synthesized by chemical co-precipitation method are directly loaded onto the negatively charged surface of PS particles obtained from emulsifier-free emulsion polymerization through electrostatic self-assembly;among them,oxidants and reducing agents are not used.Subsequently,the coating of resultant PS/Fe₃O₄ nanocomposite particles with Pd@PPy was successfully achieved by virtue of the“swelling–diffusion–interfacial-polymerization method”?SDIPM?.Furthermore,the thickness of the nanocomposite shell and the loading of Pd NPs inside the PPy can be tuned by the feed amount of pyrrole and PdCl₂.Importantly,the as-synthesized PS/Fe₃O₄/Pd@PPy nanocomposite particles also showed high catalytic activity in the degradation of methylene blue,a typical dye pollutant,with NaBH₄.The catalyst prepared by our method can degradation MB entirely in 9 min.More importantly,these nanocomposite particles can be easily recovered using an external magnetic field owing to the presence of Fe₃O₄ NPs,and the regenerated nanocomposite particles can be repeatedly used 9 times without significant loss of their degradation capacity.