阅读说明：本技术 一种高度分散的Fe3O4的磁性复合水凝胶的制备方法及应用 (Highly dispersed Fe3O4Preparation method and application of magnetic composite hydrogel ) 是由 李慧迪 于 2020-12-10 设计创作，主要内容包括：本发明涉及水污染治理技术领域,且公开了一种高度分散的Fe_3O_4的磁性复合水凝胶,纳米Fe_3O_4的巯基与烯基发生高效的烯基-巯基点击化反应,将纳米Fe_3O_4通过化学键共价接枝到丙烯酸复合水凝胶中,纳米Fe_3O_4均匀分散在复合水凝胶的基体中,减少了团聚,同时在化学共价键的修饰作用下,将纳米Fe_3O_4与丙烯酸水凝胶有机结合,两者结合紧密牢固,很难发生分离和脱落,赋予了丙烯酸水凝胶优异的磁吸附和磁性回收的效果,复合水凝胶中含有丰富的羧基和氨基,在酸性介质中对Pd~(2+)等重金属离子,以及孔雀石绿等阳离子型有机染料具有很强的静电吸附和络合作用,从而起到优异的吸附效果和高效的水污染处理。(The invention relates to the technical field of water pollution treatment and discloses highly dispersed Fe 3 O 4 Magnetic composite hydrogel of (1), nano Fe 3 O 4 Mercapto and alkenyl radicals ofEfficient alkenyl-mercapto click reaction to convert nano Fe 3 O 4 Covalently grafted into acrylic acid composite hydrogel through chemical bonds, and nano Fe 3 O 4 Uniformly dispersed in the matrix of the composite hydrogel, reducing agglomeration, and simultaneously, under the modification effect of chemical covalent bonds, nano Fe is added 3 O 4 The acrylic hydrogel and the organic combination of the acrylic hydrogel are tightly and firmly combined, the separation and the falling are difficult to occur, the acrylic hydrogel is endowed with excellent magnetic attraction and magnetic recovery effects, the composite hydrogel contains abundant carboxyl and amino, and Pd is protected in an acid medium 2+ The heavy metal ions and the malachite green and other cationic organic dyes have strong electrostatic adsorption and complexation effects, thereby playing a role in excellent adsorption effect and efficient water pollution treatment.)

1. Highly dispersed Fe₃O₄The magnetic composite hydrogel is characterized in that: the highly dispersed Fe₃O₄The preparation method of the magnetic composite hydrogel comprises the following steps:

(1) adding nano Fe into deionized water₃O₄Placing the mixture in an ultrasonic treatment instrument, performing ultrasonic treatment until the mixture is uniformly dispersed, dropwise adding a sodium citrate solution, performing ultrasonic dispersion treatment, heating to 40-60 ℃, stirring and reacting for 2-4h to obtain carboxylated nano Fe₃O₄；

(2) To SOCl₂Adding carboxylated nano Fe₃O₄Heating to 60-80 ℃, and carrying out reflux reaction for 15-25h to obtain acyl chloride nano Fe₃O₄；

(3) Adding acyl chloride nano Fe into dichloromethane solvent₃O₄And dimercaptopropanol, performing ultrasonic treatment until the mixture is uniformly dispersed, adding an activator triethylamine, heating to 40-60 ℃, and performing reflux reaction for 18-36h to obtain the sulfhydrylated nano Fe₃O₄；

(4) Adding acrylic acid and acrylamide into deionized water in nitrogen atmosphere, adding sodium hydroxide to adjust the neutralization degree of the acrylic acid, and then adding sulfhydrylation nano Fe₃O₄After ultrasonic dispersion is uniform, potassium persulfate aqueous solution is dripped, the mixture is heated to 60-80 ℃, stirred and reacted for 20-40min, then N, N' -methylene bisacrylamide is added, and stirred and reacted for 5-10h to obtain highly dispersed Fe₃O₄The magnetic composite hydrogel is applied to magnetic adsorption materials and water pollution treatment.

2. Highly dispersed Fe according to claim 1₃O₄The magnetic composite hydrogel is characterized in that: the ultrasonic treatment instrument in the step (1) comprises a water bath, a heater is arranged below the water bath, and the two sides of the water bath are fixedly connected with a super-heaterThe device comprises an acoustic frequency source, a base fixedly connected below a water bath, a movable plate arranged above the base, and a large reaction bottle and a small reaction bottle arranged above the movable plate.

3. Highly dispersed Fe according to claim 1₃O₄The magnetic composite hydrogel is characterized in that: the nano Fe in the step (1)₃O₄The mass ratio of the sodium citrate to the sodium citrate is 10: 12-20.

4. Highly dispersed Fe according to claim 1₃O₄The magnetic composite hydrogel is characterized in that: SOCl in the step (2)₂And carboxylated nano Fe₃O₄The mass ratio of (A) to (B) is 40-80: 1.

5. Highly dispersed Fe according to claim 1₃O₄The magnetic composite hydrogel is characterized in that: the acyl chloride nano Fe in the step (3)₃O₄The mass ratio of the dimercaptopropanol to the triethylamine is 1:80-120: 30-50.

6. Highly dispersed Fe according to claim 1₃O₄The magnetic composite hydrogel is characterized in that: acrylic acid, acrylamide and sulfhydrylation nanometer Fe in the step (4)₃O₄The mass ratio of the potassium persulfate to the N, N' -methylene-bisacrylamide is 100:40-60:10-30:0.5-0.8: 1.5-2.

Technical Field

The invention relates to the technical field of water pollution treatment, in particular to highly dispersed Fe₃O₄The preparation method and the application of the magnetic composite hydrogel.

Background

With the rapid development of industry, a large amount of industrial wastewater and sewage are discharged into the natural water environment without being treated, so that the environment is seriously polluted, and pollutants mainly comprise organic solvent wastewater, dye wastewater and the like; and the waste water containing heavy metal ions such as copper, lead, chromium and the like seriously damage the water body environment and the biological growth environment, and the traditional water pollution treatment method mainly comprises an adsorption method, an oxidation method and a precipitation method, wherein the adsorption method is divided into physical adsorption and chemical adsorption, and the method has the advantages of simple operation, high adsorption performance, diversified adsorbents and the like, and is a common water pollution treatment method.

The traditional adsorbent mainly comprises active carbon, polyacrylamide, polyacrylic acid, ferroferric oxide magnetic adsorption materials and the like, the acrylic hydrogel is a three-dimensional gel, has strong hydrophilicity and water absorbability, can endow the hydrogel with rich carboxyl, amino and other groups by regulating and controlling a polymerization monomer, and can adsorb Cu²⁺、Pd²⁺、Cd²⁺The heavy metal ions, methylene blue, malachite green and other organic dyes have good complexation, electrostatic adsorption and the like, are novel adsorption materials widely researched, magnetic substances such as ferroferric oxide and the like can be combined with acrylic acid hydrogel, the magnetic adsorption and formation recovery effects are given to the materials, but the research difficulty is that how to solve the problem that the ferroferric oxide nano particles are easy to agglomerate and how to organically combine the ferroferric oxide with the acrylic acid hydrogel and avoid the separation and the shedding of the ferroferric oxide nano particles in a complex water body environment.

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides a high-dispersionFe₃O₄The preparation method and the application of the magnetic composite hydrogel solve the problems that ferroferric oxide and acrylic hydrogel are difficult to combine tightly and are easy to separate.

(II) technical scheme

In order to achieve the purpose, the invention provides the following technical scheme: highly dispersed Fe₃O₄The highly dispersed Fe₃O₄The preparation method of the magnetic composite hydrogel comprises the following steps:

(1) adding deionized water and nano Fe into a reaction bottle₃O₄Placing the mixture in an ultrasonic treatment instrument, performing ultrasonic treatment until the mixture is uniformly dispersed, slowly dropwise adding a sodium citrate solution, performing ultrasonic dispersion treatment, heating to 40-60 ℃, stirring and reacting for 2-4h, filtering to remove a solvent, washing with acetone and drying to obtain carboxylated nano Fe₃O₄。

(2) Adding SOCl into a reaction bottle₂And carboxylated nano Fe₃O₄Heating to 60-80 deg.C, reflux reacting for 15-25h, and distilling under reduced pressure to remove SOCl₂Washing with methanol and drying to obtain acyl chloride nano Fe₃O₄。

(3) Adding dichloromethane solvent and acyl chloride nano Fe into a reaction bottle₃O₄And dimercaptopropanol, performing ultrasonic treatment until the mixture is uniformly dispersed, adding an activator triethylamine, heating to 40-60 ℃, performing reflux reaction for 18-36h, performing reduced pressure distillation to remove the solvent, washing with methanol, and drying to obtain the sulfhydrylated nano Fe₃O₄。

(4) Adding deionized water, acrylic acid and acrylamide into a reaction bottle in a nitrogen atmosphere, adding sodium hydroxide to adjust the neutralization degree of the acrylic acid, and then adding sulfhydrylation nano Fe₃O₄Slowly dropwise adding a potassium persulfate aqueous solution after uniform ultrasonic dispersion, heating to 60-80 ℃, stirring for reaction for 20-40min, adding N, N' -methylene bisacrylamide, stirring for reaction for 5-10h, centrifugally separating to remove the solvent, washing with distilled water, dialyzing and purifying to obtain highly dispersed Fe₃O₄The magnetic composite hydrogel is applied to magnetic adsorption materials and waterPollution treatment.

Preferably, the ultrasonic treatment instrument in the step (1) comprises a water bath, a heater is arranged below the water bath, ultrasonic frequency sources are fixedly connected to two sides of the water bath, a base is fixedly connected to the lower portion of the water bath, a moving plate is arranged above the base, and a large reaction bottle and a small reaction bottle are arranged above the moving plate.

Preferably, the nano Fe in the step (1)₃O₄The mass ratio of the sodium citrate to the sodium citrate is 10: 12-20.

Preferably, the SOCl in the step (2)₂And carboxylated nano Fe₃O₄The mass ratio of (A) to (B) is 40-80: 1.

Preferably, the acyl chloride nano Fe in the step (3)₃O₄The mass ratio of the dimercaptopropanol to the triethylamine is 1:80-120: 30-50.

Preferably, the acrylic acid, the acrylamide and the sulfhydrylation nanometer Fe in the step (4)₃O₄The mass ratio of the potassium persulfate to the N, N' -methylene-bisacrylamide is 100:40-60:10-30:0.5-0.8: 1.5-2.

Drawings

FIG. 1 is a schematic view of the ultrasonic processor;

FIG. 2 is a schematic view of a base structure;

fig. 3 is a schematic diagram of moving plate adjustment.

1-ultrasonic treatment instrument; 2-water bath; 3-a heater; 4-an ultrasonic frequency source; 5-a base; 6, moving a board; 7-large reaction bottle; 8-small reaction flask.

(III) advantageous technical effects

Compared with the prior art, the invention has the following beneficial technical effects:

the highly dispersed Fe₃O₄Magnetic composite hydrogel of (1), nano Fe₃O₄Performing coordination reaction with partial carboxyl of sodium citrate to obtain carboxylated nano Fe₃O₄Carboxyl groups with SOCl₂Reacting to generate acyl chloride nano Fe₃O₄Acyl chloride group and hydroxyl of dimercaptopropanol are subjected to substitution reaction under the promotion action of triethylamine to obtain mercaptoBased nano Fe₃O₄To make nano Fe₃O₄The surface contains rich sulfydryl, thereby realizing the aim of nano Fe₃O₄Surface activation modification, in the polymerization process of acrylic acid and acrylamide, nano Fe₃O₄The rich sulfydryl on the surface and the alkenyl of acrylic acid and acrylamide generate efficient alkenyl-sulfydryl click reaction, and the nano Fe is further subjected to crosslinking under N, N' -methylene bisacrylamide₃O₄Covalently grafting the nano Fe into the acrylic acid composite hydrogel through chemical bonds₃O₄Uniformly dispersed in the matrix of the composite hydrogel, and reduces the nano Fe₃O₄The agglomeration phenomenon occurs, and the nano Fe is modified under the modification effect of chemical covalent bond₃O₄The acrylic hydrogel and the organic combination of the acrylic hydrogel are tightly and firmly combined, the separation and the falling are difficult to occur, the acrylic hydrogel is endowed with excellent magnetic attraction and magnetic recovery effects, the composite hydrogel contains abundant carboxyl and amino, and Pd is protected in an acid medium²⁺The heavy metal ions and the malachite green and other cationic organic dyes have strong electrostatic adsorption and complexation effects, thereby playing a role in excellent adsorption effect and efficient water pollution treatment.

Detailed Description

To achieve the above object, the present invention provides the following embodiments and examples: highly dispersed Fe₃O₄The preparation method of the magnetic composite hydrogel comprises the following steps:

(1) adding deionized water and nano Fe into a reaction bottle₃O₄The ultrasonic treatment instrument comprises a water bath, a heater is arranged below the water bath, ultrasonic frequency sources are fixedly connected to two sides of the water bath, a base is fixedly connected below the water bath, a movable plate is arranged above the base, a large reaction bottle and a small reaction bottle are arranged above the movable plate, ultrasonic waves are added until the ultrasonic waves are uniformly dispersed, and a sodium citrate solution is slowly dripped, wherein nano Fe₃O₄Performing ultrasonic dispersion treatment with sodium citrate at a mass ratio of 10:12-20, heating to 40-60 deg.C, stirring for reaction for 2-4h, filtering to remove solvent, washing with acetone and drying,obtaining carboxylated nano Fe₃O₄。

(2) Adding SOCl with the mass ratio of 40-80:1 into a reaction bottle₂And carboxylated nano Fe₃O₄Heating to 60-80 deg.C, reflux reacting for 15-25h, and distilling under reduced pressure to remove SOCl₂Washing with methanol and drying to obtain acyl chloride nano Fe₃O₄。

(3) Adding dichloromethane solvent and acyl chloride nano Fe into a reaction bottle₃O₄And dimercaptopropanol, performing ultrasonic treatment until the mixture is uniformly dispersed, adding an activator triethylamine in a mass ratio of 1:80-120:30-50, heating to 40-60 ℃, performing reflux reaction for 18-36h, performing reduced pressure distillation to remove the solvent, washing with methanol, and drying to obtain the sulfhydrylated nano Fe₃O₄。

(4) Adding deionized water, acrylic acid and acrylamide into a reaction bottle in a nitrogen atmosphere, adding sodium hydroxide to adjust the neutralization degree of the acrylic acid, and then adding sulfhydrylation nano Fe₃O₄Slowly dripping potassium persulfate aqueous solution after ultrasonic dispersion is uniform, heating to 60-80 ℃, stirring for reaction for 20-40min, and then adding N, N' -methylene bisacrylamide, wherein acrylic acid, acrylamide and sulfhydrylation nano Fe₃O₄Potassium persulfate and N, N' -methylene-bisacrylamide in the weight ratio of 100:40-60:10-30:0.5-0.8:1.5-2, stirring to react for 5-10 hr, centrifuging to eliminate solvent, washing with distilled water and dialyzing to purify to obtain high dispersed Fe₃O₄The magnetic composite hydrogel is applied to magnetic adsorption materials and water pollution treatment.

Example 1

(1) Adding deionized water and nano Fe into a reaction bottle₃O₄The ultrasonic treatment instrument comprises a water bath, a heater is arranged below the water bath, ultrasonic frequency sources are fixedly connected to two sides of the water bath, a base is fixedly connected below the water bath, a movable plate is arranged above the base, a large reaction bottle and a small reaction bottle are arranged above the movable plate, ultrasonic waves are added until the ultrasonic waves are uniformly dispersed, and a sodium citrate solution is slowly dripped, wherein nano Fe₃O₄The mass ratio of the sodium citrate to the sodium citrate is 10:12Ultrasonic dispersion treatment is carried out, the mixture is heated to 40 ℃, stirred and reacted for 2 hours, the solvent is removed by filtration, washed by acetone and dried to obtain the carboxylated nano Fe₃O₄。

(2) Adding SOCl with the mass ratio of 40:1 into a reaction bottle₂And carboxylated nano Fe₃O₄Heating to 60 ℃, refluxing for 15h, and distilling under reduced pressure to remove SOCl₂Washing with methanol and drying to obtain acyl chloride nano Fe₃O₄。

(3) Adding dichloromethane solvent and acyl chloride nano Fe into a reaction bottle₃O₄And dimercaptopropanol, performing ultrasonic treatment until the mixture is uniformly dispersed, adding an activator triethylamine, heating the mixture to 40 ℃ according to the mass ratio of 1:80:30, performing reflux reaction for 18 hours, performing reduced pressure distillation to remove the solvent, washing the solvent with methanol, and drying the solvent to obtain the sulfhydrylated nano Fe₃O₄。

(4) Adding deionized water, acrylic acid and acrylamide into a reaction bottle in a nitrogen atmosphere, adding sodium hydroxide to adjust the neutralization degree of the acrylic acid, and then adding sulfhydrylation nano Fe₃O₄Slowly dripping potassium persulfate aqueous solution after ultrasonic dispersion is uniform, heating to 60 ℃, stirring for reaction for 20min, and then adding N, N' -methylene bisacrylamide, wherein acrylic acid, acrylamide and sulfhydrylation nano Fe₃O₄The mass ratio of potassium persulfate to N, N' -methylene-bisacrylamide is 100:40:10:0.5:1.5, the mixture is stirred and reacted for 5 hours, the solvent is removed by centrifugal separation, and the mixture is washed by distilled water and dialyzed and purified to obtain highly dispersed Fe₃O₄The magnetic composite hydrogel of (1).

Example 2

(1) Adding deionized water and nano Fe into a reaction bottle₃O₄The ultrasonic treatment instrument comprises a water bath, a heater is arranged below the water bath, ultrasonic frequency sources are fixedly connected to two sides of the water bath, a base is fixedly connected below the water bath, a movable plate is arranged above the base, a large reaction bottle and a small reaction bottle are arranged above the movable plate, ultrasonic waves are added until the ultrasonic waves are uniformly dispersed, and a sodium citrate solution is slowly dripped, wherein nano Fe₃O₄Mass ratio to sodium citrate10:15, carrying out ultrasonic dispersion treatment, heating to 50 ℃, stirring for reaction for 3 hours, filtering to remove the solvent, washing with acetone and drying to obtain carboxylated nano Fe₃O₄。

(2) Adding SOCl with the mass ratio of 50:1 into a reaction bottle₂And carboxylated nano Fe₃O₄Heating to 60 ℃, refluxing for 25h, and distilling under reduced pressure to remove SOCl₂Washing with methanol and drying to obtain acyl chloride nano Fe₃O₄。

(3) Adding dichloromethane solvent and acyl chloride nano Fe into a reaction bottle₃O₄And dimercaptopropanol, performing ultrasonic treatment until the mixture is uniformly dispersed, adding an activator triethylamine in a mass ratio of 1:90:35, heating to 50 ℃, performing reflux reaction for 24 hours, performing reduced pressure distillation to remove the solvent, washing with methanol, and drying to obtain the sulfhydrylated nano Fe₃O₄。

(4) Adding deionized water, acrylic acid and acrylamide into a reaction bottle in a nitrogen atmosphere, adding sodium hydroxide to adjust the neutralization degree of the acrylic acid, and then adding sulfhydrylation nano Fe₃O₄Slowly dripping potassium persulfate aqueous solution after ultrasonic dispersion is uniform, heating to 70 ℃, stirring for reaction for 30min, and then adding N, N' -methylene bisacrylamide, wherein acrylic acid, acrylamide and sulfhydrylation nano Fe₃O₄The mass ratio of potassium persulfate to N, N' -methylene-bisacrylamide is 100:45:15:0.6:1.6, the mixture is stirred and reacted for 10 hours, the solvent is removed by centrifugal separation, and the mixture is washed by distilled water and dialyzed and purified to obtain highly dispersed Fe₃O₄The magnetic composite hydrogel of (1).

Example 3

(1) Adding deionized water and nano Fe into a reaction bottle₃O₄The ultrasonic treatment instrument comprises a water bath, a heater is arranged below the water bath, ultrasonic frequency sources are fixedly connected to two sides of the water bath, a base is fixedly connected below the water bath, a movable plate is arranged above the base, a large reaction bottle and a small reaction bottle are arranged above the movable plate, ultrasonic waves are added until the ultrasonic waves are uniformly dispersed, and a sodium citrate solution is slowly dripped, wherein nano Fe₃O₄With citric acidPerforming ultrasonic dispersion treatment on sodium with the mass ratio of 10:18, heating to 50 ℃, stirring for reaction for 3 hours, filtering to remove the solvent, washing with acetone and drying to obtain carboxylated nano Fe₃O₄。

(2) Adding SOCl with the mass ratio of 60:1 into a reaction bottle₂And carboxylated nano Fe₃O₄Heating to 70 ℃, refluxing for 20h, and distilling under reduced pressure to remove SOCl₂Washing with methanol and drying to obtain acyl chloride nano Fe₃O₄。

(3) Adding dichloromethane solvent and acyl chloride nano Fe into a reaction bottle₃O₄And dimercaptopropanol, performing ultrasonic treatment until the mixture is uniformly dispersed, adding an activator triethylamine, heating the mixture to 50 ℃ according to the mass ratio of 1:100:45, performing reflux reaction for 24 hours, performing reduced pressure distillation to remove the solvent, washing the solvent with methanol, and drying the solvent to obtain the sulfhydrylated nano Fe₃O₄。

(4) Adding deionized water, acrylic acid and acrylamide into a reaction bottle in a nitrogen atmosphere, adding sodium hydroxide to adjust the neutralization degree of the acrylic acid, and then adding sulfhydrylation nano Fe₃O₄Slowly dripping potassium persulfate aqueous solution after ultrasonic dispersion is uniform, heating to 70 ℃, stirring for reaction for 30min, and then adding N, N' -methylene bisacrylamide, wherein acrylic acid, acrylamide and sulfhydrylation nano Fe₃O₄The mass ratio of potassium persulfate to N, N' -methylene-bisacrylamide is 100:55:22:0.7:1.8, the mixture is stirred and reacted for 8 hours, the solvent is removed by centrifugal separation, and the mixture is washed by distilled water and dialyzed and purified to obtain highly dispersed Fe₃O₄The magnetic composite hydrogel of (1).

Example 4

(1) Adding deionized water and nano Fe into a reaction bottle₃O₄The ultrasonic treatment instrument comprises a water bath, a heater is arranged below the water bath, ultrasonic frequency sources are fixedly connected to two sides of the water bath, a base is fixedly connected below the water bath, a movable plate is arranged above the base, a large reaction bottle and a small reaction bottle are arranged above the movable plate, ultrasonic waves are added until the ultrasonic waves are uniformly dispersed, and a sodium citrate solution is slowly dripped, wherein nano Fe₃O₄Performing ultrasonic dispersion treatment with sodium citrate at a mass ratio of 10:20, heating to 60 ℃, stirring for reaction for 4h, filtering to remove the solvent, washing with acetone, and drying to obtain carboxylated nano Fe₃O₄。

(2) Adding SOCl with the mass ratio of 80:1 into a reaction bottle₂And carboxylated nano Fe₃O₄Heating to 80 ℃, refluxing for 25h, and distilling under reduced pressure to remove SOCl₂Washing with methanol and drying to obtain acyl chloride nano Fe₃O₄。

(3) Adding dichloromethane solvent and acyl chloride nano Fe into a reaction bottle₃O₄And dimercaptopropanol, performing ultrasonic treatment until the mixture is uniformly dispersed, adding an activator triethylamine, heating the mixture to 60 ℃ according to the mass ratio of 1:120:50, performing reflux reaction for 36 hours, performing reduced pressure distillation to remove the solvent, washing the product with methanol, and drying the product to obtain the sulfhydrylated nano Fe₃O₄。

(4) Adding deionized water, acrylic acid and acrylamide into a reaction bottle in a nitrogen atmosphere, adding sodium hydroxide to adjust the neutralization degree of the acrylic acid, and then adding sulfhydrylation nano Fe₃O₄Slowly dripping potassium persulfate aqueous solution after ultrasonic dispersion is uniform, heating to 80 ℃, stirring for reaction for 40min, and then adding N, N' -methylene bisacrylamide, wherein acrylic acid, acrylamide and sulfhydrylation nano Fe₃O₄The mass ratio of potassium persulfate to N, N' -methylene-bisacrylamide is 100:60:30:0.8:2, the mixture is stirred and reacted for 10 hours, the solvent is removed by centrifugal separation, and the mixture is washed by distilled water and dialyzed and purified to obtain highly dispersed Fe₃O₄The magnetic composite hydrogel of (1).

Comparative example 1

(1) Adding deionized water and nano Fe into a reaction bottle₃O₄The ultrasonic treatment instrument comprises a water bath, a heater is arranged below the water bath, ultrasonic frequency sources are fixedly connected to two sides of the water bath, a base is fixedly connected below the water bath, a movable plate is arranged above the base, a large reaction bottle and a small reaction bottle are arranged above the movable plate, ultrasonic waves are added until the ultrasonic waves are uniformly dispersed, and a sodium citrate solution is slowly dripped, wherein nano Fe₃O₄Performing ultrasonic dispersion treatment with sodium citrate at a mass ratio of 1:1, heating to 40 deg.C, stirring for reaction for 4h, filtering to remove solvent, washing with acetone, and drying to obtain carboxylated nano Fe₃O₄。

(2) Adding SOCl with the mass ratio of 30:1 into a reaction bottle₂And carboxylated nano Fe₃O₄Heating to 70 ℃, refluxing for 20h, and distilling under reduced pressure to remove SOCl₂Washing with methanol and drying to obtain acyl chloride nano Fe₃O₄。

(3) Adding dichloromethane solvent and acyl chloride nano Fe into a reaction bottle₃O₄And dimercaptopropanol, performing ultrasonic treatment until the mixture is uniformly dispersed, adding an activator triethylamine, heating the mixture to 40 ℃ according to the mass ratio of 1:70:25, performing reflux reaction for 36 hours, performing reduced pressure distillation to remove the solvent, washing the solvent with methanol, and drying the solvent to obtain the sulfhydrylated nano Fe₃O₄。

(4) Adding deionized water, acrylic acid and acrylamide into a reaction bottle in a nitrogen atmosphere, adding sodium hydroxide to adjust the neutralization degree of the acrylic acid, and then adding sulfhydrylation nano Fe₃O₄Slowly dripping potassium persulfate aqueous solution after ultrasonic dispersion is uniform, heating to 80 ℃, stirring for reaction for 20min, and then adding N, N' -methylene bisacrylamide, wherein acrylic acid, acrylamide and sulfhydrylation nano Fe₃O₄The mass ratio of potassium persulfate to N, N' -methylene-bisacrylamide is 100:30:5:0.4:1.4, the mixture is stirred and reacted for 5 hours, the solvent is removed by centrifugal separation, and the mixture is washed by distilled water and dialyzed and purified to obtain highly dispersed Fe₃O₄The magnetic composite hydrogel of (1).

Highly dispersed Fe₃O₄Magnetic composite hydrogel of (A) for Pb²⁺Adsorption Performance test

Highly dispersed Fe₃O₄Testing of adsorption performance of magnetic composite hydrogel on malachite green