Method for preparing magnetic composite nanoparticles with core-shell structure

A technology of magnetic composite nanometer and core-shell structure, which is applied in the fields of magnetic materials, microsphere preparation, magnetic objects, etc., can solve the problems of low encapsulation rate, high cost, high polyelectrolyte price, etc., and achieve stable preparation process, structure and stability. Low requirements for performance and stable multi-layer structure

Inactive Publication Date: 2010-09-01
CHINA UNIV OF PETROLEUM (EAST CHINA) +1
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  • Summary
  • Abstract
  • Description
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  • Application Information

AI Technical Summary

Problems solved by technology

However, the polyelectrolyte used to change the positive and negative properties of the charge layer by layer in this method is expensive, high in cost, and low in encapsulation rate. At present, the technical maturity is mostly limited to the preparation of nanocomposite membranes and the preparation of multilayer core-shell structure nanoparticles. rarely reported

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] Example 1: The preparation method of magnetic composite nanoparticles with multi-layer sandwich type core-shell structure mainly includes the preparation of polymer microspheres and magnetic fluid, electrostatic self-assembly and seed emulsion polymerization and other processes. PS / Fe with three-layer sandwich core-shell structure 3 o 4 / PMMA particles as an example, the specific steps are as follows:

[0025] Take 450mL deionized water and put it in the reaction kettle, 2 , at a constant temperature of 75°C, the concentration was 1.6×10-2 mol L -1 The initiator KPS 50mL and monomer styrene 50mL were used to prepare PS microspheres. Take 4.0g Fe 3 o 4 Put the solid in 200mL deionized water, add CTAB, and ultrasonically disperse to obtain Fe 3 o 4 ferrofluid. Laser particle size analyzer (ZetasizerNano-S, Malvern Instruments.Ltd) measures particle size distribution, and the particle size of the prepared PS microsphere is about 550nm, Fe 3 o 4 The average partic...

Embodiment 2

[0029] Take 100mL of the prepared PS / Fe 3 o 4 / PMMA composite three-layer core-shell structure particle emulsion and 100mL Fe 3 o 4 Electrostatic self-assembly of ferrofluid to prepare PS / Fe 3 o 4 / PMMA / Fe 3 o 4 Four-layer core-shell structure composite nanoparticles, the average particle size is about 1180nm as measured by laser particle size analyzer. Then prepare five-layer core-shell structure composite particles by seed emulsion polymerization method, take 200mLPS / Fe 3 o 4 / PMMA / Fe 3 o 4 The composite particle emulsion was placed in a reaction kettle at a constant temperature of 75°C, and 1.6×10 -2 mol L -1 KPS 20mL. Stabilize for 10 minutes, then feed vinyl acetate (VAc) as a polymer monomer with a flow pump at a feed rate of 0.01mL·min -1 , after reacting for 5h, stop feeding and then ripen for 1h to obtain PS / Fe 3 o 4 / PMMA / Fe 3 o 4 / PVAc five-layer core-shell structure composite nanoparticles. The average particle size is about 1350nm as measured by ...

Embodiment 3

[0031] Take 200mL prepared PS / Fe 3 o 4 The composite particle emulsion was placed in a reaction kettle at a constant temperature of 75°C, and 20 mL of it was added to a concentration of 1.6×10 -2 mol L -1 The initiator azobisisobutylamidine hydrochloride (V50) was stabilized for 10 minutes, and MMA was introduced as a polymer monomer with a flow pump, and the feed rate was 0.02mL·min -1 , after reacting for 2.5h, stop feeding and then ripen for 1h to obtain PS / Fe 3 o 4 / PMMA composite three-layer core-shell structure particles. The average particle size is about 1000nm as measured by a laser particle size analyzer.

[0032] The invention combines the electrostatic self-assembly method and the seed emulsion polymerization method, does not need expensive polyelectrolyte in the preparation process, reduces the cost, and introduces a semi-continuous feeding method to control the particle size distribution of the microspheres, and obtains a multilayer core-shell structure Mag...

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Abstract

The invention discloses a method for preparing magnetic composite nanoparticles with a core-shell structure. In the method, electrostatic self-assembly and seeded emulsion polymerization are combined, wherein the electrostatic self-assembly is used to synthesize particles with the core-shell structure first and then emulsion polymerization is performed by using the particles with the core-shell structure seeds and using an initiator to prepare the magnetic composite nanoparticles with the sandwich core-shell structure which has three or more layers. The magnetic composite particles prepared by the method have a multi-layer sandwich core-shell structure, wherein in the structure, the core is a polymer microsphere, a Fe3O4 magnetic particle layer is in the middle, and different polymer layers are covered outside. The prepared particles have stable structures, strong and uniformly-distributed magnetism, smooth surfaces, controllable sizes, high stability and low cost, the thicknesses of the covering layers of the prepared particles can be controlled by nanoscale, and the adaptability of the prepared particles is high. Particles with specific surface groups can be prepared according to requirements and can be used in fields of biochemical separation, targeting preparation, immobilized enzyme, immunoassay, catalysis study and the like.

Description

technical field [0001] The invention relates to a preparation method of a magnetic composite nanometer material, in particular to a preparation method of a magnetic composite nanoparticle with a multilayer core-shell structure. Background technique [0002] Magnetic composite nanomaterials refer to the combination of polymer microspheres and nano-inorganic magnetic substances by appropriate methods to form a composite material with a special structure and magnetic properties. The material has dual characteristics of polymer microspheres and magnetic microspheres, such as surface effect, volume effect, magnetic effect, biocompatibility and functional group properties, etc., and the magnetic material is easy to purify and recycle. As a new type of functional polymer material, magnetic composite nanomaterials have been widely used in the fields of biomedicine (clinical diagnostic enzyme-labeled drugs), cytology (cell marker cell separation, etc.) and bioengineering (enzyme immo...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08L25/06C08L33/12C08K3/22H01F1/00B01J13/14
Inventor 李青松房芹芹王云芳陈金庆
Owner CHINA UNIV OF PETROLEUM (EAST CHINA)
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