Preparation Of Magnetic Nanoparticles Functionalized With Oxyamine Group Andsynthesis Of Multifunctional-linkers

Superparamagnetic Fe3O4 nanoparticles have been extensively used in different research area, especially in biological research. The Fe3O4 on the surface of magnetic nanoparticles without modification was easily oxidated to Fe2O3 crystal and lost magnetic properties. The surface modification can prevent the oxidation, improve the dispersity and biocompatibility, broaden the application.This article mainly adopted chemical coprecipitation method to prepare Fe3O4 magnetic nanoparticles, and surface packaged with oleic acid. The influence of rotation speed to the particle size was discussed. The surface modified Fe3O4 magnetic nanoparticles with amine and oxyamine were prepared, which were characterized by SEM、TEM、XRD、TG、FT-IR et.ac.Pentaerythritol which has four identical hydoxy groups, was choosen as backbone to introduce different functional groups to magnetic particles. Isopropylidene group was uesed to protect two hydroxyl groups, then the rest of the one or two hydroxyl can be actived by p-toluenesulfonyl chloride, introducing ethanethioyl group through substituted the p-toluenesulfonyl by thiolacetate. The side chain was elongated by tetraethylene glycol ethers to avoid the stereohindrance. Through the selective protection and deprotection and introduce different functional groups, three chemical compound have been obtained.