Synthesis And Application Of Poly(VDAT)@Polystyrene Microspheres

Among the high polymer materials,the monodisperse,charged functional microspheres have a lot of advantages,such as large specific surface area,large cohesion function,strong adsorption,and the surface reaction ability.So the microspheres have a wide range of applications in biological medicine,biological sensing,immune technology,protein adsorption,enzyme immobilization and other fields.In addition,the big size of monodisperse polymer microspheres can also act as the growth template of ordered mesoporous and macroporous materials,then other functional materials developed and polymerized on the surface,formed the coated microspheres.At last,the coated microspheres applied to clinical examination drug release,cancer and hepatitis diagnosis,cell's marking,identification,isolation and culture,immune solid carrier and immune adsorption.The new functional monomer 2-vinyl-4,6-diamino-1,3,5-triazine?VDAT?is the main research object.The monomer has three hydrogen boning sites,so it has strong combining capacity with hydrogen bonds.The existing researches prove that PVDAT can adsorb biological macromolecules by hydrogen bonds.All these researches reacted in the organic system,and the products are gel or membrane materials.But we are trying to synthesize VDAT to functional microsphere in water.Here,we need to overcome the monomer VDAT can not dissolve in water,so at first how to make VDAT dissolve and polymerize in water.To solve this problem,we use semi-continuous precipitation polymerization to add monomer,then VDAT dissolve slightly in hot water and polymerize in it.By controlling the reaction conditions,the polymer microspheres with different size are obtained.The main content of this thesis are as follows:In this paper,we prepared the different sizes,monodisperse and negatively charged PS microsphere by dispersion polymerization method.By controlling the conditions of semi-continuous precipitation polymerization,we polymerized the PVDAT@PS coated microspheres in water.The sized of PVDAT@PS microspheres were controlled by the PS microspheres.The study found that by controlling the polymerization conditions,especially the feeding speed,we can prepare two PVDAT@PS microspheres with different surface morphology:rough and smooth surface.Trough the research process and the result,we put forward the coated mechanism.Firstly,using oleic acid modified the Fe₃O₄ particle,and prepared the modified styryl Fe₃O₄ magnetic fluids by solvent volatilization.Then the polystyrene was coated on the magnetic particle surface by dispersion polymerization.Finally,the VDAT monomer was polymerized on PS@Fe₃O₄,and formed the coated microsphere PVDAT@PS@Fe₃O₄.This topic with PVDAT@PS coated microsphere,due to its surface functional polymer PVDAT have the potential to form multiple effective hydrogen-bones,we preliminary discuss the adsorption with PVDAT@PS and the dsDNAs which are different length and different percentage of the AT base pairs.We found:the adsorption quantity are different with different dsDNAs.The adsorption is stronger with longer length and more AT base pairs.