Preparation And Application Of Magnetic Polymer Microspheres

In this paper, magnetic fluid was prepared by co-precipitation with homogeneous size distribution, good dispersion, high magnetic responsiveness. To the need of green chemistry, the magnetic particles were dispersed by electrostatic stabilization with nitric acid instead of traditional surfactant method.Most commercial magnetic beads are polystyrene matrix. In this paper, magnetic polystyrene microspheres with carboxyl group were prepared by dispersion polymerization. For high magnetic responsiveness, the magnetic fluid was modified by silane coupling reagent (CH2=CH2-Si(OC2H5)).A novel method was invented to prepare magnetic urea-formaldehyde resin-based polymer microspheres, which were prepared by polymerization with urea and formaldehyde as monomer, magnetite as core and then were coated with Si-OH groups using a sol-gel approach. Amino and expoxy groups are introduced by covalent binding on coated urea-formaldehyde resin-based microspheres. The carboxyl group is introduced by the reaction of microspheres with epoxy and iminodiacetic acid.The prepared magnetic polystyrene microspheres with carboxyl group, urea-formaldehyde resin-based beads with carboxyl, expoxy, hydroxy groups were employed to simplify the isolation of genomic DNA from calf thymus.