Study On Preparation And Application Of Polymer Magnetic Microspheres

Magnetic Polymer Microspheres (MPM) are a kind of novel functional materials, which behave properties of magnetic materials and polymer materials. MPM are quite fit for application in biological system because of their small particle size, large specific surface area, great capacity of coupling biology molecules, and good suspension in disperse system. Heretofore, MPM have exhibited extensive application prospect. In this paper, PS-MPM was prepared with monodispersity and strong magnetic responsivity on the base of others' research. The main content of this paper is such as following:1. Fe3O4 nano-particles, which can be dispersed in nano scale, were prepared by means of chemical co-precipitation method. Such influencing factors as the type of precipitant, the feeding mode, the surfactants, the reaction temperature, the curing temperature were surveyed. Some properties such as crystal structure, particle size, magnetic properties and iron content were characterized. The particle size of the product is about 16 nm with perfect crystal structure. The product exhibits superparamagnetism and strong magnetic responsivity, the saturation magnetization being 55.4emu/g and the magnetic susceptibility being 8.28 10-3emu/Oe.The particle size distribution is homogeneous with good dispersion.2. The Fe3O4 nano-particles were converted from hydrophilic to oleophylic by being modified by oleic acid. The heat change in the adsorption process of Fe3O4 nano-particles to oleic acid was measured and discussed by using microcalorimetry. The adsorption mechanism was analyzed.3. PS-MPM was prepared by improved microsuspension polymerization. Product structure, particle size and magnetic properties, were characterized and the reaction mechanism was analyzed. Such influencing factors as the indissoluble assistant, the dispersant agent, the surfactants, the amount of initiator and the stirring speed were surveyed. The product 'particle size is about15 m, with smooth surface and good dispersion. The product exhibits superparamagnetism, the saturation magnetization being 3.928 emu/g and the magnetic susceptibility being 3.249 10-3 emu/Oe. The particle size distribution is homogeneous with good dispersion. The magnetic content was 6.44%.4. Antibody, which was coated to PS-MPM by using immunology method, reacted to special corresponding antigen. The heat change in the adsorption process of antibody to MPM and the reaction process to antigen were measured by using microcalorimetry. The adsorption mechanism and the special reaction were analyzed, which established the primary base of profound study on the aspect of biology application for MPM.