Preparation And Characterization Of Magnetic Polymer Microsphere

Magnetic polymer microspheres are composites particles combining polymers and inorganic magnetic particles together with a certain structure. Compared with conventional microspheres, Magnetic polymer microspheres with superparamagnetic can be quickly separated from the mixture under the influence of external magnetic field.This dissertation focuses on the preparation of magnetic polymer microspheres, factors and characterization of the microspheres on the adsorption of BSA. Microspheres characterized by SEM、TEM、IR、XRD、VSM、UV Spectrophotometer and Laser Particle Size Analyzer.Magnetic Fe₃O₄ particles were prepared by coprecipitation with a diameter range 4nm～8nm ,with narrow size distribution and showed irregular square. While reaction temperature 60℃and aging temperature at 80℃nanometer magnetic iron oxide have the highest levels, corresponding to the stronger magnetic response.Magnetic polystyrene microspheres prepared by Soap-free emulsion polymerization with a diameter of about 10nm 20nm to combine polystyrene with Fe₃O₄ together .The impact of the reactor, the amount of initiator and different phase dispersion were investigated.Based on the preparation of nano-magnetic polystyrene microspheres, we prepared PSt-MMA/VAc microspheres by seed emulsion polymerization which have excellent performance such as stability, uniform distribution and strong magnetic response to introduced functional groups in microsphere surface with diameter is 20nm～50nm and narrow size distribution. Of the monomer amount, stirring speed, ultrasonic vibration and centrifugal effects were studied. Determinate the nano-magnetic polymer microspheres saponification value. By saponification reaction to the introduction of magnetic polymer microsphere surface hydroxyl and characterization of surface functional groups of the number of particles.We have determinaten hysteresis curve of the magnetic polymer composite microspheres. Under external magnetic field, saturation magnetization of particles down a lot, but still showed superparamagnetic characteristics.Determination of the magnetic polymer microspheres on the adsorption properties of BSA. With the increase in the amount of monomer, nano-magnetic microsphere surface was introduced more ester functional groups, an increase of protein adsorption. When the seed emulsion polymerization using VAc, the ester group easily converted to hydroxyl, microspheres for protein adsorption capacity enhanced.