A kind of nano silicon dioxide microsphere and preparation method thereof

Abstract

The invention discloses a nanosilicon dioxide pellet. The nanosilicon dioxide pellet comprises a silicon dioxide shell body and a polymer nuclear body which is wrapped inside the silicon dioxide shell body. The grain size of the silicon dioxide shell body is 50-1000 nm and the shell thickness of the silicon dioxide shell body is 5-75 nm. The nanosilicon dioxide pellet has a uniform size distribution, a controllable pellet size, shell thickness and cavity rate and good biocompatibility; in addition, the nanosilicon dioxide pellet has good heat stability, a high mechanical property and very good water dispersibility. The invention also discloses a preparing method of the nanosilicon dioxide pellet. The preparing method is a soap-free emulsion polymerization method and is simple to operate; a nano composite pellet with a nuclear shell structure can be synthesized in a large scale, that is, the polymer nuclear body and the silicon dioxide shell body can be formed at the same time; meanwhile, the preparing process is simple and efficient, and the product yield and the product purity are high, and thus the cost is reduced sharply.

Description

technical field [0001] The invention relates to the technical field of preparation of organic / inorganic nano-composite microspheres, in particular to a nano-silica microsphere and a preparation method thereof. Background technique [0002] In recent years, organic / inorganic nanocomposite microspheres have received more and more attention, because they have the plasticity, ease of processing, light weight of organic materials and the rigidity, heat resistance, wear resistance, and resistance of inorganic materials. Chemical corrosiveness, easy modification, and various functional properties, such as magnetic properties, electrical conductivity, etc. As a kind of organic / inorganic composite materials, polymer / silica nanocomposite microspheres with core-shell structure have been widely used in the fields of biomedicine, catalysis, electronic devices and colloidal interface research. The silica hollow microspheres show great application prospects in the fields of drug encapsula...

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Problems solved by technology

However, due to the use of persulfates (such as potassium persulfate or ammonium persulfate) in traditional soap-free emulsion polymerization systems, the surface of polymer microspheres is usually negatively charged, and the electrostatic repulsion with the silica shell greatly limits Further deposition of silica on its surface

[0009] Literature (Macromolecules 2016,49,1552.) also mentions the one-step synthesis of polystyrene / silica core-shell nanocomposite particles by miniemulsion polymerization of styrene stabilized by hyperbranched polyethoxysiloxane, but this This method needs to use high-speed shear emulsification equipment to obtain fine emulsion, otherwise the polymer will agglomerate later, and the ideal core-shell structure cannot be obtained. More importantly, this method can only be used for hydrophobic and weakly polar monomers such as styrene. Not suitable for highly polar and water-soluble monomers such as methacrylates, acrylates, acrylonitrile and methacrylonitrile

[0010] In short, there is no simple and efficient method in the prior art that can prepare nano-silica composite microspheres with a core-shell structure on a large scale

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