Method for preparing silicon dioxide magnetic composite microballoon with core-shell structure

Abstract

The invention belongs to the field of the synthesis of magnetic nano materials, and relates to a method for preparing a silicon dioxide magnetic composite microballoon with a core-shell structure. The method comprises the following steps: adding magnetic iron oxide nano particles monodispersed in water into the mixing solution of alcohol and ultrapure water, and stirring for 0.3-2h; then adding 0.01-1ml of tetraethyl silicate in the mixture, and stirring for 0.3-2h; then adding 0.5-5ml of stronger ammonia water, continuing to stir for 2-24h, and obtaining the solution of the silicon dioxide magnetic composite microballoon with the core-shell structure; and using applied magnetic field for separating the microballon from the solution. In the invention, by proportioning the quantity of the reactant reasonably, and setting the reaction conditions reasonably, one or a plurality of the iron oxide magnetic nano particle(s) are covered in each produced silicon dioxide microballoon, and the microballoon has good balling performance and monodispersity, has controllable shell layer thickness and narrow particle size distribution, and is easy to clean, simple and convenient in operation, low in cost, less in waste, and high in productivity.

Description

technical field [0001] The invention belongs to the field of synthesis of magnetic nanometer materials, and relates to a method for preparing silicon dioxide magnetic composite microspheres with a core-shell structure. Background technique [0002] Magnetic nanoparticles have some special magnetic properties, such as: superparamagnetism, high saturation magnetization, etc., and have broad application prospects in biomedical fields such as targeted drug carriers, cell separation, nuclear magnetic resonance, immune detection, and biomolecular purification. . In recent years, core-shell composite materials with magnetic nanoparticles as the core and silica as the shell have attracted widespread attention. This is because silica has good biocompatibility and anti-decomposition ability. After the surface of nanoparticles is coated with a layer of silica, it can greatly shield the interaction of magnetic dipoles, so that the particles have good water dispersibility, chemical stab...

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Problems solved by technology

[0004] In order to solve the preparation method of silica magnetic composite microspheres with a core-shell structure described in the background technology, the operation is cumbersome, the particle size is difficult to control, the surface of the prepared microspheres is rough, and the core agglomeration phenomenon is serious, which is not conducive to downstream biological applications. Technical problem, the present invention provides a preparation of silica magnetic composite microspheres with a core-shell structure that is easy to operate, low in cost, narrow in particle size distribution, good in sphericity and monodispersity, controllable in shell thickness, and easy to clean method, the core of the composite microspheres prepared by this method is ferric oxide with hydrophilic groups such as nonanoic acid or azelaic acid attached to the surface, any one or both of ferric ferric oxide magnetic iron oxide nanoparticles mix of species

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