Preparation And Formation Mechanism Of Functional Polymer Magnetic Nanoparticles

Functional magnetic polymer nano-material is an advanced material. It combines the properties of polymer materials, magnetic materials and nano-materials. It has been widely applied in cell separation, targeted cancer therapy, biological and medical field, especially in cancer treatment. Cancer treatment can be divided into chemical drug therapy, radiotherapy, surgery and hyperthermia. The aim of this paper is to prepare a temperature-sensitive magnetic polymer nano-material. This material's solubility is very good in water as well as its dispersion, content of magnetic matter is high and distribution of particle size is small. Such temperature-sensitive magnetic polymer nano-material is an ideal magnetic targeting drug delivery in cancer treatment. The main research contents are as follows:(1) Fe3O4 magnetic fluid was prepared by chemical precipitation. The Fe3O4 particles were synthesized by chemical precipitation and modified with oleic acid. The resultant particles were then dissolved in octane. This is known as magnetic fluid. The dispersion of Fe3O4 magnetic particles in octane was very good, and there's no precipitation after a long time.(2) Fe3O4/PS magnetic microspheres were prepared via hybrid emulsion polymerization. In this study, hybrid emulsion polymerization is the improvement of miniemulsion polymerization. The monomers were handled in different ways, but the remaining steps were basically in the same way. The prepared particles' diameter was reduced from 70nm (one-step miniemulsion method) to 60nm, and the dispersion of particles solution was improved relatively.(3) Fe3O4/PS/PNIPAM magnetic nano-particles were synthesized by two-step soap-free emulsion polymerization. Based on the Fe3O4/PS polymerization technique, temperature-sensitive monomers (such as N-isopropyl acrylamide, N-isopropyl methacrylamide, etc.) were induced to polymerization process to synthesize a kind of temperature-sensitive magnetic material which has a higher critical solution temperature (LCST) (higher than 37℃). The particles' diameter, dispersion, magnetic material content and saturation magnetization were characterized then.(4) Fe3O4/PNIPAM magnetic nano-particles were synthesized via soap-free emulsion polymerization. As a certain concentration of the PS in the composite material which is used as targeting drug carrier can be produced toxic side effect in organism, on the basis of former research, the PS polymer should be removed from the composite material to reduce the side effect. The preparation process and principle of the temperature-sensitive magnetic polymer composite was studied then.