CN101525157B - A kind of preparation method of water-soluble ferrite nanoparticles - Google Patents

Abstract

In order to overcome the defects of the prior art and promote the application of ferrite nanoparticles in the field of biomedicine, the invention discloses a preparation method of monodisperse, highly crystalline and water-soluble ferrite nanoparticles. The method is to add iron triacetylacetonate and acetylacetonate salt of divalent metal cations into tetraethylene glycol, which acts as both a solvent and a ligand on the surface of ferrite nanoparticles, and then carry out gradient heating and separation. paragraph response. Because the oxygen atom in the tetraethylene glycol and the metal ion in the ferrite have a coordination effect, the invention prepares the water-soluble ferrite nano-particles. Moreover, monodisperse, highly crystalline ferrite nanoparticles exhibiting good superparamagnetism were produced under the process conditions. In addition, the invention also has the advantages of simple operation, readily available raw materials, low cost, mild conditions, low requirements for equipment, environmentally friendly production process, no pollution by-products, and large-scale industrial production.

Description

A kind of preparation method of water-soluble ferrite nanoparticles

technical field

The invention relates to a method for preparing ferrite nanoparticles, in particular to a method for preparing water-soluble ferrite nanoparticles, and belongs to the technical field of nanomaterials. the

Background technique

Ferrites of manganese, zinc, cobalt, and nickel are important functional materials. Among them, Mn-Zn and Ni-Zn ferrite are currently the world's largest high-frequency soft magnets, and are often used as magnetic materials for high-frequency transformers, inductors and recording heads. Ferrite is also an important catalyst, which has been used in ammonia synthesis, Fischer-Tropsch synthesis, and oxidative dehydrogenation reactions of ethylbenzene and butene, etc. It has broad application prospects in the fields of chemical and chemical synthesis. Due to their superparamagnetism, ferrite nanoparticles also have a wide range of applications in the field of biomedicine. For example, the research as a magnetic resonance contrast agent has received a lot of attention, but to be applied in the field of biomedicine, ferrite nanoparticles must be The particles are monodisperse, highly crystalline and water-soluble, which allows for good reproducibility under biological conditions, high saturation magnetic susceptibility and good biocompatibility. the

At present, the methods for preparing ferrite nanoparticles mainly include chemical co-precipitation method, hydrothermal method, sol-gel method, spray pyrolysis method, microemulsion method, phase inversion method, supercritical method, shock wave synthesis method, microwave field Under wet synthesis, explosion method, high energy ball milling method and self-propagating high temperature synthesis method, etc. The defects of the above method are mainly: complex process, large environmental pollution, harsh reaction conditions, expensive special reaction device, high production cost, wide particle size distribution of nanoparticles, and easy agglomeration of the obtained product. The disadvantage is that most of the ferrite nanoparticles obtained by these methods are insoluble in water, have poor biocompatibility, and poor crystal phase, and cannot well meet the application requirements in the biomedical field. Therefore, it is of great significance to study a preparation method of monodisperse, highly crystalline and water-soluble ferrite nanoparticles for promoting the application of ferrite nanoparticles in the field of biomedicine. the

Contents of the invention

The purpose of the present invention is to provide a preparation method of monodisperse, highly crystalline and water-soluble ferrite nanoparticles, so as to overcome the defects of the prior art and promote the application of ferrite nanoparticles in the field of biomedicine. the

For realizing above-mentioned purpose of the invention, the technical scheme that the present invention adopts is as follows:

The preparation method of the water-soluble ferrite nanoparticles provided by the present invention, the specific operation is as follows: the acetylacetonate salt of iron triacetylacetonate and divalent metal cations is added to tetraethylene glycol, and the ratio of iron triacetylacetonate and divalent metal cations is controlled. The molar ratio is 2:1, and the molar concentration of iron triacetylacetonate in tetraethylene glycol is 0.04-0.2mol/L; perform anhydrous and oxygen-free operation, and heat the reaction system under the protection of an inert gas. When the temperature rises to 100-140 ℃, heat preservation reaction for 1 to 3 hours; then continue to heat up, when the temperature rises to 200 to 220 ℃, heat preservation reaction for 1 to 3 hours; then continue to heat up, when the temperature rises to 285 to 305 ℃, heat preservation reaction 3 hours; after the reaction is complete, cool naturally to room temperature, centrifuge, wash the precipitate with absolute ethanol, and vacuum-dry at 15-30°C for 10-20 hours. the

The divalent metal cation is preferably any one of Mn ²⁺ , Ni ²⁺ , Co ²⁺ , Zn ²⁺ or Cu ²⁺ .

In the preparation method of the present invention, the selected tetraethylene glycol not only acts as a solvent, but also acts as a ligand on the surface of ferrite nanoparticles, because the oxygen atoms in tetraethylene glycol and the metal ions in ferrite produce The complexation effect is obtained, so water-soluble ferrite nanoparticles are produced; due to the process of combining gradient heating and segmented reaction in the present invention, monodisperse, high-crystalline, and better superparamagnetic particles are produced. ferrite nanoparticles. Compared with the prior art, the present invention also has beneficial effects such as simple operation, readily available raw materials, low cost, mild conditions, low requirements for equipment, environmentally friendly production process, no pollution by-products, and large-scale industrial production. the

Description of drawings

Fig. 1 is the transmission electron microscope (TEM) photograph of the MnFe ₂ O ₄ nanoparticles prepared by embodiment 1;

Fig. 2 is the _high -resolution transmission electron microscope (HR-TEM) photograph of the _MnFe2O4 nanoparticle prepared by embodiment 1;

FIG. 3 is an X-ray diffraction (XRD) spectrum of the MnFe ₂ O ₄ nanoparticles prepared in Example 1.

Detailed ways

The present invention will be further described below by embodiment, and its purpose is only to understand content of the present invention better but not limit the protection scope of the present invention. the

Example 1

The preparation method of the water-soluble ferrite nanoparticles provided in this example is as follows: add 2 mmol of iron triacetylacetonate and 1 mmol of manganese acetylacetonate to 30 ml of tetraethylene glycol; Heating the reaction system, when the temperature rises to 120°C, heat preservation reaction for 2 hours; then continue to heat up, when the temperature rises to 210°C, heat preservation reaction for 2 hours; then continue to heat up, when the temperature rises to 295°C, heat preservation reaction 2 hours; after the reaction is complete, naturally cool to room temperature, centrifuge, wash the precipitate with absolute ethanol, and vacuum-dry at 25°C for 15 hours to obtain black water-soluble MnFe ₂ O ₄ nanoparticles.

Fig. 1 is the transmission electron microscope (TEM) photograph of the _MnFe2O4 nanoparticle prepared in this embodiment, it can be seen from the figure: the _{prepared MnFe2O4} nanoparticle is uniform in size, and _has good monodispersity, average The size is about 9nm, which belongs to the size range of superparamagnetism.

Fig. 2 is a high-resolution transmission electron microscope (HR-TEM) photograph of the MnFe ₂ O ₄ nanoparticles prepared in this example. It can be seen from the figure that the prepared MnFe ₂ O ₄ nanoparticles are single crystals.

Fig. 3 is an X-ray diffraction (XRD) spectrum of the MnFe ₂ O ₄ nanoparticles prepared in this example, which further illustrates that the product prepared in this example is a MnFe ₂ O ₄ nano single crystal.

Example 2

The preparation method of the water-soluble ferrite nanoparticles provided in this example is as follows: add 2 mmol of iron triacetylacetonate and 1 mmol of manganese acetylacetonate to 10 ml of tetraethylene glycol; Heating the reaction system at lower temperature, when the temperature rises to 140°C, heat preservation reaction for 1 hour; then continue to heat up, when the temperature rises to 220°C, heat preservation reaction for 1 hour; then continue to heat up, when the temperature rises to 305°C, heat preservation reaction 1 hour; after the reaction is complete, naturally cool to room temperature, centrifuge, wash the precipitate with absolute ethanol, and vacuum-dry at 30° C. for 10 hours to obtain black water-soluble MnFe ₂ O ₄ nanoparticles.

Experimental results show that the product prepared in this example is NiFe ₂ O ₄ nano single crystal with good monodispersity and an average size of about 11 nm.

Example 3

The preparation method of the water-soluble ferrite nanoparticles provided in this example is as follows: add 2 mmol of iron triacetylacetonate and 1 mmol of manganese acetylacetonate to 50 ml of tetraethylene glycol; Heating the reaction system, when the temperature rises to 100°C, heat preservation reaction for 3 hours; then continue to heat up, when the temperature rises to 200°C, heat preservation reaction for 3 hours; then continue to heat up, when the temperature rises to 285°C, heat preservation reaction 3 hours; after the reaction is complete, cool naturally to room temperature, centrifuge, wash the precipitate with absolute ethanol, and vacuum-dry at 15° C. for 20 hours to obtain black water-soluble MnFe ₂ O ₄ nanoparticles.

Experimental results show that the product prepared in this example is NiFe ₂ O ₄ nano single crystal with good monodispersity and an average size of about 10 nm.

Example 4

The preparation method of this example is the same as that described in Example 1, except that the manganese acetylacetonate used is replaced by nickel acetylacetonate. the

Experimental results show that the product prepared in this example is NiFe ₂ O ₄ nano single crystal with good monodispersity and an average size of about 12 nm.

Example 5

The preparation method of this example is the same as that described in Example 1, except that the manganese acetylacetonate used is replaced by cobalt acetylacetonate. the

Experimental results show that the product prepared in this example is a CoFe ₂ O ₄ nano single crystal with good monodispersity and an average size of about 10 nm.

Example 6

The preparation method of this example is the same as that described in Example 1, except that the manganese acetylacetonate used is replaced by zinc acetylacetonate. the

Experimental results show that the product prepared in this example is a ZnFe ₂ O ₄ nano single crystal with good monodispersity and an average size of about 12 nm.

Example 7

The preparation method of this example is the same as that described in Example 1, except that the manganese acetylacetonate used is replaced by copper acetylacetonate. the

Experimental results show that the product prepared in this example is CuFe ₂ O ₄ nano single crystal with good monodispersity and an average size of about 8 nm.

Claims (2)

1. the preparation method of a water-soluble ferrite nano-particle, it is characterized in that, the concrete operations of described method are as follows: the acetylacetonate of praseodynium iron and divalent metal is added in the Tetraglycol 99, the mol ratio of control praseodynium iron and divalent metal is 2: 1, and the volumetric molar concentration of praseodynium iron in Tetraglycol 99 is 0.04～0.2mol/L; Carry out the anhydrous and oxygen-free operation, reacting by heating system under protection of inert gas, when temperature is raised to 100～140 ℃, insulation reaction 1～3 hour; Then continue to heat up, when temperature is raised to 200～220 ℃, insulation reaction 1～3 hour; Then continue again to heat up, when temperature is raised to 285～305 ℃, insulation reaction 1～3 hour; Reaction is finished, and naturally cools to room temperature, and centrifugation with the absolute ethanol washing precipitation, got final product in 15～30 ℃ of vacuum-dryings in 10～20 hours.

2. the preparation method of water-soluble ferrite nano-particle according to claim 1 is characterized in that, described divalent metal is Mn ²⁺, Ni ²⁺, Co ²⁺, Zn ²⁺Or Cu ²⁺In any.

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