Preparation And Study Of Magnetic Microspheres With Aminated Core-shell Structure

Aminated magnetic microspheres can quickly capture targets in a magnetic field due to their superparamagnetism and simple operation.They are of great value in the fields of catalysis,cell separation,protein separation,and biomedicine.In order to obtain better application effects,the prepared amino magnetic microspheres are required to be chemically stable in aqueous solutions and biological fluids,have a narrow size distribution,and are ideally spherical,superparamagnetic,and high saturation magnetization.The encapsulation method generally synthesizes functionalized magnetic nanospheres with a relatively small particle size,and it is also difficult to increase the particle size.The template method is different from the wrapping method.The particle size of the aminated magnetic microspheres prepared by the template method is easy to control,and it is easier to obtain micron-level aminated magnetic materials than the wrapping method.This subject has made the following three aspects of research content:(1).We used the template method to use the self-polymerization of dopamine to prepare a large-diameter amination two-layer core-shell magnetic microsphere with a magnetic saturation strength of 6.2 emu g^-1,and the embedded structure can be very It protects Fe₃O₄ magnetic nanoparticles from solvent pollution,prevents them from falling off,and has strong stability.(2)The optimal reaction time for preparing polystyrene seed microspheres is 4h,the optimal dosage of DVB for preparing swollen microspheres by emulsion polymerization is 3 m L,and the optimal dosage for preparing aminated three-layer core-shell magnetic microspheres TEOS is 1.2 m L.A three-layer core-shell structured magnetic microsphere with a particle size of 3.6 um was prepared by combining with the template method,and the magnetic saturation intensity was 0.3 emu g^-1.(3)We prepared hollow microspheres with a particle size of 2.1 um,good dispersibility,and uniform size by a non-template method,and then prepared an aminated hollow core-shell structure with a particle size of 2.4 um using hollow microspheres as a template The microspheres have a magnetic saturation intensity of0.85 emu g^-1.