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CN-117019029-B - Preparation method of magnetic microsphere with controllable magnetic particle size

CN117019029BCN 117019029 BCN117019029 BCN 117019029BCN-117019029-B

Abstract

The invention discloses a preparation method of magnetic microspheres with controllable magnetic particle sizes, which comprises the following steps of firstly coarsening, adding polymer microspheres and ultrapure water into a three-neck flask, adding a coarsening agent, stirring, heating in a water bath at 40 ℃, separating solid and liquid after coarsening is finished, washing for multiple times, drying and storing for standby, then nitrifying, putting the coarsened polymer microspheres obtained in the step one into a beaker, adding ultrapure water, stirring, adding a nitrifying agent for two times, stirring for 48 hours, separating the solid and liquid, washing for three times, dispersing the nitrified polymer microspheres obtained in the step two into the ultrapure water, and dripping a metal precursor solution, stirring and heating to 40-90 ℃. The invention has novel design, can produce magnetic microspheres in a simpler operation environment, can stably and controllably produce magnetic microspheres with different particle diameters and different magnetic particle sizes, effectively ensures the performance and quality of the magnetic microspheres, simplifies the preparation process and reduces the production cost.

Inventors

  • GONG YI
  • KONG CAIYUN
  • HU RUI

Assignees

  • 安徽中科元贞科技有限责任公司

Dates

Publication Date
20260512
Application Date
20230803

Claims (7)

  1. 1. The preparation method of the magnetic microsphere with controllable magnetic particle size is characterized by comprising the following steps: coarsening, namely adding polymer microspheres and ultrapure water into a three-neck flask, adding a coarsening agent, stirring, heating in a water bath at 40 ℃, separating solid and liquid after coarsening, washing for multiple times, drying and storing for later use; Step two, nitrifying, namely putting the coarsened polymer microspheres obtained in the step one into a beaker, adding ultrapure water, stirring, adding 25% by weight of concentrated nitric acid, stirring for 10min, adding 10% by weight of concentrated sulfuric acid, stirring for 48h, separating solid and liquid, and washing for three times; Dispersing the nitrified polymer microsphere prepared in the step two into ultrapure water, dropwise adding a metal precursor solution compounded by ferrous sulfate and ferric sulfate, wherein the metal precursor solution contains 5 weight percent of ferrous salt, stirring and heating to 40-90 ℃; And vacuumizing the reaction kettle, introducing nitrogen, adding 1wt% of complexing agent and 0.1wt% of surfactant, slowly heating to 60 ℃, adding a buffer to adjust the pH value to 5-9, cooling to 40 ℃, adding 10wt% of reducing agent, reacting for 10min, heating to 60 ℃, adjusting the pH value to 5-9, cooling to 40 ℃, adding 10wt% of reducing agent, reacting for 30min, adding 10wt% of reducing agent, adding 50mL, 75mL, 80mL or 100mL of the total addition of complexing agent, surfactant, reducing agent and buffer, simultaneously dropwise adding a metal precursor solution containing 1wt% of ferric salt again, reacting for 30min, dropwise adding the buffer at the speed of 10mL/min, controlling the pH value to 7-10 until the reaction is finished by continuously dropwise adding the buffer, separating solid and liquid, and washing for multiple times to obtain the product.
  2. 2. The method for preparing magnetic microspheres with controllable magnetic particle size according to claim 1, wherein the polymer microspheres are polystyrene microspheres or polymethyl methacrylate microspheres.
  3. 3. The method for preparing magnetic microspheres with controllable magnetic particle size according to claim 1, wherein the roughening agent is one or more of concentrated sulfuric acid, potassium dichromate, phosphoric acid and methylsulfonic acid.
  4. 4. The method for preparing the magnetic microsphere with controllable magnetic particle size according to claim 1, wherein the reducing agent is prepared by compounding 10wt% of sodium nitrate, 5wt% of sodium citrate, 5wt% of sodium hypophosphite and ultrapure water.
  5. 5. The method for preparing magnetic microspheres with controllable magnetic particle size according to claim 1, wherein the buffer is prepared by compounding 20wt% of ethanol, 5% of hydrochloric acid, 15% of ammonia water and ultrapure water.
  6. 6. The method for preparing the magnetic microsphere with controllable magnetic particle size according to claim 1, wherein the complexing agent is prepared by compounding 0.01wt% of polyvinylpyrrolidone and 5mL of ethylenediamine.
  7. 7. The method for preparing the magnetic microsphere with controllable magnetic particle size according to claim 1, wherein the surfactant is prepared by compounding 0.1wt% of sodium dodecyl benzene sulfonate, 0.01wt% of polyvinyl alcohol and 5mL of polyethylene glycol.

Description

Preparation method of magnetic microsphere with controllable magnetic particle size Technical Field The invention relates to the technical field of nano microspheres, in particular to a preparation method of a magnetic microsphere with controllable magnetic particle size. Background The magnetic microsphere is a polymer microsphere containing magnetic nano particles and having stronger magnetic response. The preparation process includes nanometer magnet preparation, modification, dispersion, microsphere, etc. The magnetic microsphere can be widely applied to the fields of magnetic display, biomedicine, nano stealth materials, nondestructive inspection and the like. The nano magnetic material is used as a new material, and due to the unique physical and chemical properties, such as quantum size effect, small size effect, interface effect, macroscopic quantum tunneling effect and the like. So that it shows different special properties from the conventional magnetic materials in physical, chemical and other aspects. The nano-level ferroferric oxide particles have higher saturation magnetization and better biocompatibility, have no toxic or side effect, and can be used in various fields of biomedicine, such as cell marking and separation, nuclear magnetic resonance contrast agents, guiding drug carriers, tumor magnetic hyperthermia treatment and the like. The existing preparation method of the magnetic microsphere is difficult to control the particle size of the magnetic core material, easy to generate coagulation, difficult to control the size of the magnetic particles on the surface of the magnetic microsphere, uneven in distribution, limited in applicability, and complex in preparation operation due to the fact that high-temperature and high-pressure synthesis conditions are needed in most cases. Disclosure of Invention The invention aims to solve the defects that the sizes of magnetic particles on the surfaces of magnetic microspheres are difficult to control and are not uniformly distributed, the applicability of the magnetic microspheres is limited, and the preparation operation is complex due to the fact that high-temperature and high-pressure synthesis conditions are mostly needed in the prior art. In order to achieve the above purpose, the present invention adopts the following technical scheme: the preparation method of the magnetic microsphere with controllable magnetic particle size comprises the following steps: coarsening, namely adding polymer microspheres and ultrapure water into a three-neck flask, adding a coarsening agent, stirring, heating in a water bath at 40 ℃, separating solid and liquid after coarsening, washing for multiple times, drying and storing for later use; Step two, nitrifying, namely putting the coarsened polymer microspheres obtained in the step one into a beaker, adding ultrapure water and stirring, adding a nitrifying agent twice and stirring for 48 hours, separating solid and liquid, and washing for three times; And thirdly, dispersing the nitrified polymer microsphere prepared in the second step into ultrapure water, dropwise adding a metal precursor solution, stirring and heating to 40-90 ℃. And step four, vacuumizing the reaction kettle, introducing nitrogen, adding an anion reaction liquid in batches, adjusting the pH value to 5-10, adjusting the temperature to 40-100 ℃, dripping a metal precursor solution again to control the anion content, reacting for 120min, separating solid and liquid, and washing for multiple times to obtain the product. Preferably, the polymer microsphere is one or more of polystyrene microsphere, silicon dioxide microsphere, titanium dioxide microsphere, polymethyl methacrylate microsphere, melamine resin microsphere polystyrene, polymethyl methacrylate, polyethyl benzoate and styrene-acrylate copolymer. Preferably, the coarsening agent is one or more of concentrated sulfuric acid, potassium dichromate, manganese sulfate, phosphoric acid and methylsulfonic acid. Preferably, the nitrating agent is one or more of nitric acid, fuming nitric acid, sulfuric acid, glacial acetic acid, acetic anhydride, phosphoric acid, perchloric acid, acetic anhydride, trifluoroacetic acid, methanesulfonic acid and trifluoromethanesulfonic acid. Preferably, the metal precursor solution is one or more of ferric trichloride, ferric sulfate, ferric nitrate, polyaluminum ferric chloride, ferric tribromide, ferric perchlorate, ferric dihydrogen phosphate, potassium ferricyanide, ferrous sulfate, ferrous chloride and ferrous carbonate, wherein the content of ferrous salt is 0.1-20wt%. Preferably, the anion reaction liquid is prepared by mixing a reducing agent, a buffering agent, a complexing agent and a surfactant. More preferably, the reducing agent comprises one or more of sodium nitrate, potassium nitrate, ammonium nitrate, calcium nitrate, lead nitrate, cerium nitrate, sodium citrate, sodium hypophosphite, sodium borohydride, sodium chloride, sodium carbonate, sodium