Ferromagnetic microsphere medium made from urea-formaldehyde resin and its preparation method

A technology of urea-formaldehyde resin and magnetic microspheres, applied in the field of ferromagnetic urea-formaldehyde resin microspheres medium and its preparation, can solve the problems of inability to re-dispersion, different settling speed, difficult separation, etc. low cost effect

Inactive Publication Date: 2005-12-21
TIANJIN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Such hydrophilic magnetic particles have different sedimentation velocities in a magnetic field, making separation difficult; another problem is that Fe 3 o 4 The powder is exposed, which may cause toxic effects on cells; another problem is due to the use of larger particles of Fe 3 o 4 Magnetic powder, even after the external magnetic field is removed, the residual magnetism of the magnetic polymer particles still aggregates together and cannot be redispersed in the solution

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] Preparation of magnetic fluid

[0024] Dissolve 112.8g FeCl separately 3 .6H 2 O, 41.2g FeCl 2 .4H 2 Pour O in 100ml water, pour it into 800ml water, place the mixed salt solution in an ice bath, cool to 6℃, add 200ml 28% ammonium hydroxide while stirring, while keeping the temperature at 6℃, the reaction produces black iron hydroxide Homogenize, heat to 90°C and keep for 30 minutes, the ferric hydroxide is converted into ferroferric oxide precipitate. The reaction equation is as follows:

[0025]

[0026] The reactants were cooled to room temperature, the ferric hydroxide homogenate was transferred to a beaker, placed on a magnetic separation device, the clear solution was discarded, and re-dispersed in 800ml of deionized water, and 112ml of 60% (by weight) was added to the washed homogenate. Calculate perchloric acid, stir for 10min, collect the upper magnetic fluid on the magnetic separation device; re-disperse the remaining homogenate in 500ml deionized water, add ...

Embodiment 2

[0034] Preparation of magnetic fluid

[0035] Dissolve 5.6g FeCl separately 3 .6H 2 O, 1.98g FeCl 2 .4H 2 O was added to 50ml of water, 10ml of 28% ammonium hydroxide was added under stirring, and the reaction produced black iron hydroxide homogenate. Heat to 60°C for 30 minutes, cool the reactants to room temperature, transfer the ferric hydroxide homogenate to a beaker, pass through a magnetic separation device, discard the clear liquid, redisperse the homogenate with 50ml of deionized water and wash three times. Add concentrated nitric acid to the slurry, adjust the pH to 1-3, and quickly stir for 30 minutes to obtain a magnetic fluid.

[0036] Preparation of magnetic microspheres

[0037] Take 30ml of the above-mentioned magnetic fluid, add 0.3g of SDS powder and 3g of urea under stirring until it is completely dissolved. Add concentrated perchloric acid to adjust the pH of the mixture to 2-2.5, then add 4ml 37% formaldehyde aqueous solution, stir vigorously for 20s, stop stir...

Embodiment 3

[0039] Dissolve 10g polyethylene glycol in 75ml water and add 8.41g FeCl respectively 3 .6H 2 O, 3.05gFeCl 2 .4H 2 O was added to 50ml of water, 15ml of 28% ammonium hydroxide was added with stirring, and the reaction produced black iron hydroxide homogenate. Heat to 60°C for 30 minutes, cool the reactants to room temperature, transfer the ferric hydroxide homogenate to a beaker, use a magnetic separation device to discard the clear liquid, redisperse the homogenate with 50ml deionized water and wash it three times. Add concentrated nitric acid to the slurry, adjust the pH to 1-3, and quickly stir for 30 minutes to obtain a magnetic fluid.

[0040] Preparation of magnetic microspheres

[0041] Take 40ml of the above-mentioned magnetic fluid and add 2.5g of urea under stirring until it is completely dissolved. Add concentrated perchloric acid to adjust the pH of the mixture to 1-2, then add 7ml 37% formaldehyde aqueous solution, stir vigorously for 20s, reduce the stirring speed to...

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Abstract

The invention discloses a ferromagnetic urea-formaldehyde resin microsphere medium and a preparation method thereof, belonging to the technology of magnetic resin microsphere medium. The base material of the microsphere medium is a urea-formaldehyde resin with a particle size of 0.5-20 μm, and Fe with a particle size of 0.1-200 nm is uniformly dispersed in the base material. 3 O 4 of nanoparticles. The preparation method adopts superparamagnetic metal oxide, urea and formaldehyde, and the preparation process includes the preparation of magnetic fluid, the peptization and separation of magnetic fluid, and the preparation of magnetic microspheres. The advantage of the present invention is that the prepared microspheres have superparamagnetic properties, Fe 3 O 4 The magnetic nanoparticles are completely coated with urea-formaldehyde resin, which avoids the poisoning effect on the separation system. The particle size distribution of the magnetic particles is uniform, the sedimentation rate in the magnetic field is consistent, and the surface is easy to be modified. The preparation method has the advantages of simple operation, easy process control, low raw material cost, good product stability and easy industrial production.

Description

Technical field [0001] The invention relates to a ferromagnetic urea-formaldehyde resin microsphere medium and a preparation method thereof, and belongs to the technology of magnetic resin microsphere medium. Background technique [0002] Biomagnetic separation technology has the characteristics of simple equipment, low production cost, convenient use and easy automation, which has attracted people's attention, and has been more and more widely used in cell screening, nucleic acid extraction, immunoassay, protein purification, etc. It plays an increasingly important role in the fields of biotechnology, biomedical diagnosis, environment and food analysis. For example, magnetic particles with surface-bound antibodies, so-called "immune magnetic beads", can be used for rapid separation of blood cells and separation and enrichment of stem cells in bone marrow; magnetic particles with surface-bound nucleic acid fragment Oligo-dT can be used for mRNA enrichment And recovery; and surfac...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08G12/12C08K3/08
Inventor 万谦宏陈磊李文斌张志超
Owner TIANJIN UNIV
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