Method for preparing Fe3O4 powder with controllable form by using local magnetic field change

A form and powder technology, applied in the field of nano-powder preparation and application, can solve the problems of high cost, poor environmental friendliness, complex process, etc., and achieve the effects of using less raw materials, good environmental friendliness, and simple operation

Inactive Publication Date: 2019-03-12
HEFEI UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, these methods all have problems such as high cost, complicated process and poor environmental friendliness.

Method used

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  • Method for preparing Fe3O4 powder with controllable form by using local magnetic field change
  • Method for preparing Fe3O4 powder with controllable form by using local magnetic field change
  • Method for preparing Fe3O4 powder with controllable form by using local magnetic field change

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] Example 1: Magnon size versus Fe 3 o 4 The effect of particle assembly

[0020] Preparation of Fe with Controllable Morphology by Using Local Magnetic Field 3 o 4 The steps of powder are as follows:

[0021] 1), divide into three groups of experiments altogether, each group takes by weighing 0.27g ferrous sulfate (FeSO 4 ·7H 2 O) and 1.5g of sodium citrate (Na 3 Cit) is put into the deionized water of 60mL, stirring and dissolving is mixed with ferrous citrate aqueous solution;

[0022] 2), drop an appropriate amount of ammonia water in the prepared ferrous citrate aqueous solution to adjust its pH value to 10;

[0023] 3), transfer each group of prepared alkaline ferrous citrate aqueous solution into a polytetrafluoroethylene reaction kettle, add 1cm small magnets, 2cm medium magnets and 3cm large magnets respectively, and seal;

[0024] 4) Put the reaction kettle into an oven at 180°C for 24 hours, take out the precipitate and wash and dry it to obtain differe...

Embodiment 2

[0030] Example 2: Reaction time to Fe 3 o 4 The effect of particle assembly

[0031] It was found that the reaction time has a great influence on the final Fe 3 o 4 The morphology of the powder also has a great influence. When other reaction conditions remain unchanged, Fe can be effectively regulated by changing the reaction time. 3 o 4Powder form. The alkaline ferrous citrate aqueous solution that is prepared with embodiment 1 is equally divided into two parts, carries out hydrothermal reaction after all adding medium model magneton, and setting reaction time is respectively 12h and 48h, and the form of the product that obtains is as follows image 3 shown. Depend on image 3 a It can be seen that when the reaction is 12h, the product is spherical Fe 3 o 4 Mainly, a small number of small-sized particles aggregated into straight particle chains. image 3 b is the Fe obtained from the reaction for 48h 3 o 4 From the SEM image of the product, it can be seen that th...

Embodiment 3

[0032] Embodiment 3: Different forms of Fe 3 o 4 Study on Magnetic Properties of Powder

[0033] Utilize two kinds of forms Fe prepared in embodiment 2 3 o 4 The product was tested for its magnetic properties at room temperature, and the results were as follows Figure 4 As shown, as the reaction time is different, the obtained Fe 3 o 4 The hysteresis loops of the powder all present S-type. When the external field is scanned from -15000Oe to 15000Oe, the Fe prepared after 12h 3 o 4 Nanoparticles ( Figure 4 The hysteresis curve of a) does not see obvious hysteresis, indicating that the obtained Fe 3 o 4 Smaller particles exhibit superparamagnetic phenomena. And the Fe obtained after 48h 3 o 4 particle chain ( Figure 4 b) The saturation magnetization (M s ) is significantly higher than Fe 3 o 4 nanoparticles. Experiments have shown that different forms of Fe 3 o 4 The magnetic properties of powders at room temperature are very different.

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Abstract

The invention discloses a method for preparing Fe3O4 powder with a controllable form by using a local magnetic field change, and relates to the technical field of preparation and application of nanometer powder. The method controls the change of a local magnetic field by magneton with different sizes, and obtains Fe3O4 powder materials with various forms by a hydrothermal reaction in a reaction system composed of ferrous sulfate (FeSO4.7H2O), sodium citrate (Na3Cit) and ammonia water; as the size of the magneton is changed from small to large, the prepared Fe3O4 powder material is gradually transformed from the nano-particle to a particle aggregate through a particle chain, and the morphology of the Fe3O4 powder can be prepared in a controllable mode. The method has the characteristics ofbeing simple in operation, environmentally friendly, high in saturation magnetization of the obtained chain-type Fe3O4 powder and easy in magnetic separation. The method uses the single ferrous sulfate as an iron source to prepare Fe3O4, fewer raw materials are used, no other by-products are produced, and environmental friendliness is good.

Description

technical field [0001] The invention relates to the technical field of nano powder preparation and application, in particular to a form-controllable Fe powder prepared by changing a local magnetic field. 3 o 4 powder method. Background technique [0002] Fe 3 o 4 It has ferrimagnetism and is a cubic inverse spinel structure, which has good environmental friendliness and wide application. Therefore, the Fe 3 o 4 There are many reports on the preparation and application of ferrite powder. Currently, Fe 3 o 4 The preparation methods mainly include grinding method, hydrogen reduction method, pyrolysis method, chemical precipitation method, γ-ray irradiation method, sol-gel method, microemulsion method, etc. However, the above-mentioned methods all have problems such as high cost, complicated process and poor environmental friendliness. [0003] In recent years, studies have found that nanocrystals can have some special structures and shapes when they are formed in an e...

Claims

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Application Information

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IPC IPC(8): C01G49/08B82Y40/00
CPCB82Y40/00C01G49/08C01P2002/72C01P2004/03C01P2006/42
Inventor 韩成良杜慧慧朱乐城沈寿国杨昌林
Owner HEFEI UNIV
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