CN107376870A - A kind of preparation method of magnetic polymer dye sorbent - Google Patents

Abstract

The invention relates to a preparation method of a magnetic polymer dye adsorbent, which uses an improved chemical co-precipitation method to prepare magnetic nanoparticles, and then uses γ-chloropropyltrimethoxysilane and polyethyleneimine to modify its surface respectively. Obtain polyethyleneimine-modified magnetic nanoparticles, and finally copolymerize polyethyleneimine-modified magnetic nanoparticles and functional monomers to prepare magnetic polymer dye adsorbents with multi-level cross-linked structures and various adsorption groups , the saturation magnetization is 3.5-15.5 emu/g, the remanence and coercive force tend to be zero, and it has paramagnetism and magnetic responsiveness. For the initial concentration of 100-1000mg/L dye aqueous solution, the dye adsorption capacity reaches 50-600mg /g, 60-150 minutes to reach adsorption equilibrium, the dye adsorption capacity after 5 regeneration cycles exceeds 90% of the first adsorption capacity, which can be widely used in dye adsorption separation and dye wastewater pollution treatment, etc.

Description

A kind of preparation method of magnetic polymer dye adsorbent

1. Technical field

The invention relates to a preparation method of a magnetic polymer dye adsorbent. The magnetic polymer dye adsorbent prepared by the invention is suitable for the adsorption and separation of dyes, and can be widely used in dye adsorption, dye separation and purification, and dye environmental pollution control.

2. Background technology

Dye wastewater mainly comes from dye and dye intermediate production industries and different industries such as textile, leather, paper, rubber, plastic, cosmetics, pharmaceuticals and food. It has complex composition, large changes in water quantity and quality, high chroma, COD and BOD concentration It is one of the most difficult industrial wastewater to treat due to the characteristics of high concentration, high suspended solids, and many refractory biodegradable substances. In addition, dye wastewater not only has obvious chroma, which affects the senses, but also contains toxic and harmful pollutants to the water body or human body. If the dye wastewater is discharged directly without treatment, it will cause damage to the ecological environment of the water body, and toxic and harmful substances will enter the food chain. , will affect the health of the human body, so the environmental protection and efficient treatment of dye wastewater has become an urgent problem to be solved in today's society.

At present, the methods for treating dye wastewater mainly include chemical, biological, and physical methods. The sedimentation flocculation method is simple to operate and low in cost, but the large amount of sludge produced increases the operating cost. Electrolysis consumes a lot of electricity and metal electrodes when treating wastewater. Photocatalytic oxidation is only effective for low-concentration dye wastewater. The selectivity of the biological method is relatively single, and the microorganisms are sensitive to the environment. The adsorption method is simple in operation, low in cost and good in effect, and the adsorbent is easy to recycle. Commonly used adsorbents include activated carbon, minerals, and resin adsorbents. Activated carbon has strong adsorption capacity and high removal rate, but the cost is high, and it is generally only used for the treatment or advanced treatment of printing and dyeing wastewater with low concentration. Minerals include natural zeolite, bentonite, etc., which have good ion exchange capacity and adsorption performance, but low activity and difficult regeneration. The resin adsorbent has high treatment efficiency, can be regenerated under certain conditions, and can still maintain high efficiency after regeneration, which is suitable for the treatment of dye wastewater.

Traditional adsorbents such as ion exchange resins, adsorption resins, carbonaceous adsorbents, and natural mesoporous mineral materials, etc., these adsorbent materials can only be separated by traditional methods such as centrifugation, filtration, and precipitation after adsorbing dyes, which is not only time-consuming and labor-intensive, but also energy-saving. Environmental protection, easy to damage the structure of the adsorption material, which will affect the regeneration and utilization of the adsorption material. In recent years, the emergence of nanomaterials and nanotechnology has greatly promoted the progress and development of dye processing technology. Magnetic nanomaterials are widely used in the field of dye adsorption and removal due to their unique advantages such as large specific surface area, abundant active sites and high magnetic properties. great application potential. The magnetic nano-adsorbent can adsorb the dye pollutants in the water body. After the adsorption is completed, the adsorbent and the mother liquor can be separated quickly and effectively through magnetic separation under the action of an external magnetic field. The cost is low and the operation is simple, which solves the problem of conventional The problem of difficult solid-liquid separation and recovery separation of adsorbents.

Li et al. synthesized magnetic poly(acrylic acid-acrylamide-butyl methacrylate) hydrogel by in-situ co-precipitation method, which has good adsorption and removal performance for cationic dyes crystal violet and basic fuchsin. Xu et al. synthesized amino-modified magnetic nanoparticles by solvothermal method, and then added polyacrylic acid and amino-modified magnetic nanoparticles for chemical grafting to prepare magnetic polymer adsorbents. The adsorption rate of rhodamine R6G was fast, and the adsorption capacity was 55.8mg/ g. He et al first synthesized hyperbranched polyglycerol-coated magnetic Fe3O4 nanoparticles, and then added succinic anhydride to obtain carboxylated modified hyperbranched coated magnetic Fe3O4 nanoparticles, which have high adsorption efficiency, fast adsorption rate and good repeatability for cationic dyes. Zhou et al first prepared Fe3O4/SiO2 nanoparticles with a core-shell structure, then added hyperbranched polymers for surface modification, and finally added succinic anhydride to obtain carboxylated modified hyperbranched coated magnetic Fe3O4/SiO2 nanoparticles, Rhodamine R6G and crystal violet adsorption capacity reached 0.37mmol/g and 0.60 mmol/g, respectively. Chen et al. synthesized amino-modified Fe3O4 nanoparticles by a solvothermal method, and then added crosslinking agents glutaraldehyde and polyethyleneimine to generate a magnetic polyethyleneimine adsorbent with a three-dimensional network structure. Acidic alizarin red, methyl The adsorption capacities of orange, methylene blue, sunset yellow, nuclear fast red and alizarin green were 145.7 mg/g, 127.5 mg/g, 137.0 mg/g, 118.3 mg/g and 126.8 mg/g, respectively.

Wen et al. used 1,2-dibromoethane to cross-link polyethyleneimine to synthesize polyethyleneimine nanogels, and then prepared magnetic polyethyleneimine nanocomposite hydrogels by in-situ precipitation method. The removal rate of anionic dye CR More than 99%. Cheng et al. used a one-step synthesis method to synthesize magnetic polyvinyl alcohol/graphene oxide hydrogel. The adsorption capacities of methylene blue and methyl violet were 231.12 mg/g and 204.74 mg/g, respectively. Shanehsaz et al. prepared magnetic polypyrrole adsorbent by oxidative polymerization method, and the adsorption capacity of reactive blue RB19 reached 112.36 mg/g.

Hosseinadeh et al. used a one-pot synthesis method to prepare magnetic cellulose/polyacrylic acid hydrogels based on carboxymethyl cellulose and polyacrylic acid, and the adsorption capacity of dye crystal violet reached 189 mg/g. Beyki et al. used magnetic Fe3O4-cellulose with a core-shell structure as a matrix, and added epichlorohydrin and 1-methylimidazole to prepare a magnetic cellulose ionic liquid adsorbent. The adsorption capacity of Congo red dye reached 131 mg/g. Luo et al cross-linked γ-Fe2O3, cellulose and activated carbon with epichlorohydrin to obtain a magnetic cellulose/activated carbon adsorbent, and the removal rates of methyl orange and methylene blue exceeded 99%. Chang et al. covalently grafted starch with multi-layered carbon nanotubes, and then used starch as a template to grow magnetic nanoparticles on the surface of starch-grafted carbon nanotubes to obtain magnetic starch/carbon nanotube adsorption materials with methyl orange and methylene blue adsorption capacity. Respectively 135.8mg/g and 94.1mg/g. Pourjavadi et al first synthesized magnetic Fe3O4@SiO2 nanoparticles, then added starch and acrylic acid monomers for graft copolymerization to prepare magnetic starch grafted polyacrylic acid hydrogels, and the removal rate of crystal violet dye was close to 90%. Baldikova et al. used sodium citrate-sodium hydroxide to modify wheat straw, and then prepared magnetic wheat straw adsorbent by microwave synthesis. The adsorption capacities of acridine orange and methyl green were 208.3mg/g and 384.6mg/g, respectively.

Although magnetic polymer dye adsorbents have attracted more and more attention and gradually become a research hotspot at home and abroad, how to effectively improve the compatibility between magnetic nanoparticles and polymer matrix, avoid the agglomeration of magnetic nanoparticles and inhibit the magnetic nanoparticle The macroscopic phase separation of particles and polymer matrix remains a key scientific and bottleneck technical issue affecting the magnetic properties and dye adsorption performance of magnetic polymer dye adsorbents.

3. Contents of the invention

In view of this, the object of the present invention is to provide a preparation method of magnetic polymer dye adsorbent. Firstly, magnetic nanoparticles were prepared by improved chemical co-precipitation method, and then the surface was modified with γ-chloropropyltrimethoxysilane and polyethyleneimine respectively to obtain polyethyleneimine-modified magnetic nanoparticles. Ethyleneimine modified magnetic nanoparticles and functional monomers are copolymerized to prepare a magnetic polymer dye adsorbent with a multi-layered cross-linked structure and a variety of dye adsorption groups. Through polyethyleneimine modified magnetic nanoparticles, the improvement The compatibility of magnetic nanoparticles and polymer matrix, through the physical entanglement and hydrogen bonding of polyethyleneimine macromolecular chains grafted on the surface of magnetic nanoparticles and polymer matrix, avoids the agglomeration of magnetic nanoparticles and inhibits the magnetic nanoparticles. The macroscopic phase separation of particles and polymer matrix realizes the magnetic intelligent separation of magnetic polymer dye adsorption, which better solves the shortcomings of ordinary dye adsorbents, such as difficult solid-liquid separation and easy to produce secondary pollution.

According to the purpose of the present invention, a kind of preparation method of magnetic polymer dye adsorbent is proposed, and its feature has following processing steps:

a) Add FeCl3·6H2O, FeCl2·4H2O and deionized water into a three-necked flask, stir evenly, heat up to 50-80°C after nitrogen protection for 30 minutes, then add dropwise ammonia solution with a mass concentration of 25-30%, ammonia solution After the dropwise addition is completed, react at a constant temperature under nitrogen protection for 3-6 hours, cool down to room temperature, wash with deionized water for 3-5 times, and separate with a magnet to obtain magnetic nanoparticles; FeCl3 6H2O, FeCl2 4H2O, ammonia with a mass concentration of 25-30% The mass ratio of aqueous solution to deionized water is 10-30:5-10:25-60:100-200;

b) Add magnetic nanoparticles, γ-chloropropyltrimethoxysilane and deionized water into a three-necked flask and stir evenly. After 30 minutes of nitrogen protection, the temperature is raised to 50-80°C, and then dropwise added 25-30% of the mass concentration Ammonia solution, nitrogen protection, constant temperature reaction for 3-6 hours, then cooling down to room temperature, washing with deionized water for 3-5 times, and magnetic separation to obtain chloropropyl-modified nano-magnetic particles; magnetic nanoparticles, γ-chloropropyltrimethoxysilane , the mass ratio of ammonia solution with a mass concentration of 25-30% and deionized water is 1-5:2-15:2-15:100-200;

c) Add chloropropyl-modified nano-magnetic particles, polyethyleneimine and deionized water into a three-necked flask and stir evenly, raise the temperature to 40-70°C, react at constant temperature under nitrogen protection for 2-5 hours, then cool down to room temperature, and deionized water Wash 3 to 5 times and separate with magnet to obtain polyethyleneimine-modified nano-magnetic particles; the mass ratio of chloropropyl-modified nano-magnetic particles, polyethyleneimine and deionized water is 1-5:1-5:100 ~200;

d) Dissolve NaOH in 200mL deionized water, slowly add acrylic acid to the NaOH aqueous solution in an ice bath, and stir for 0.5-2h to obtain a partially neutralized acrylic acid aqueous solution; polyethyleneimine modified magnetic nanoparticles, acrylamide and Add the cross-linking agent to partially neutralize the aqueous acrylic acid solution, stir evenly, raise the temperature to 50-60°C, add a redox initiator, initiate the polymerization reaction for 3-5 hours, and finally wash the product with absolute ethanol for 3-5 times, magnetically separate , dried at 80°C, crushed to obtain a magnetic polymer dye adsorbent; the molar ratio of acrylic acid to NaOH is 1:0.5-0.8; the mass ratio of acrylic acid to acrylamide is 1-5:1-5; the crosslinking agent accounts for acrylic acid 0.1% to 0.8% of the total mass of acrylic acid and acrylamide monomers; redox initiators account for 0.1% to 2.0% of the total mass of acrylic acid and acrylamide monomers; polyethyleneimine modified magnetic nanoparticles account for acrylic acid and acrylamide monomers 5-30% of the total body weight;

e) The saturation magnetization of the magnetic polymer dye adsorbent is 3.5-15.5emu/g, the remanence and coercive force tend to be zero, and it has paramagnetism and magnetic responsiveness. For the dye aqueous solution with an initial concentration of 100-1000mg/L, The dye adsorption capacity reaches 50-600 mg/g, and the adsorption equilibrium is reached in 60-150 minutes. The dye adsorption capacity after 5 regeneration cycles exceeds 90% of the first adsorption capacity.

The crosslinking agent used in the present invention is selected from N,N'-methylenebisacrylamide, ethylene glycol diacrylate, ethylene glycol diacrylate, ethylene glycol diacrylate, 1,3 -Propylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, glycidyl methacrylate and polyethylene glycol diacrylate.

The redox initiator used in the present invention includes an oxidizing agent and a reducing agent, the oxidizing agent is selected from ammonium persulfate, potassium persulfate and sodium persulfate, and the reducing agent is selected from sodium bisulfite, sodium sulfite, sodium thiosulfate and ferrous sulfate.

The methylene blue used in the present invention, cationic blue FGL, cationic orange R, cationic bright yellow 7GL, cationic pink FG, methyl green, crystal violet, methyl orange, reactive black RB5, Congo red, alizarin red, sunset yellow, alizarin Green, acid chrome blue K and eosin Y.

Advantage and effect of the present invention are:

1) The polymerization reaction is carried out directly in the aqueous solution, without environmental pollution, the method is simple and easy, and no nitrogen protection is required, so the nitrogen device is omitted, and the investment cost of the equipment is reduced.

2) The magnetic nanoparticles are modified by polyethyleneimine to improve the compatibility between the magnetic nanoparticles and the polymer matrix, and the physical entanglement of the polyethyleneimine macromolecular chains grafted on the surface of the magnetic nanoparticles and the polymer matrix Hydrogen bonding, avoiding the agglomeration of magnetic nanoparticles, inhibiting the macroscopic phase separation of magnetic nanoparticles and polymer matrix, realizing the magnetic intelligent separation of dye adsorption by magnetic polymer dye adsorbent, better solving the problem of solid-liquid separation of ordinary dye adsorbents, Easy to produce the disadvantage of secondary pollution.

3) Copolymerize polyethyleneimine-modified magnetic nanoparticles and functional monomers to prepare a magnetic polymer dye adsorbent with a multi-level cross-linked structure and a variety of dye adsorption groups. Through the synergy of various adsorption groups effect, further improving the adsorption performance of magnetic polymer adsorbent dyes;

The magnetic hysteresis performance, dye adsorption rate, adsorption capacity and regeneration recycling performance of the magnetic polymer dye adsorbent of the present invention are measured as follows.

The hysteresis performance of magnetic polymer dye adsorbent was measured by LDJ-9600 vibrating magnetometer (VSM).

Put the dye solution with a concentration of 100-1000mg/L and 0.2g dry and finely ground magnetic polymer dye adsorbent into a 250mL Erlenmeyer flask, then place it in a shaker to oscillate for adsorption, take a sample after shaking for a certain period of time, and use ultraviolet /Visible spectrophotometer measures the absorbance of the sample at the maximum absorption wavelength of the dye. Each sample is measured 3 times to get the average value. The dye adsorption capacity q _t and adsorption capacity q _e are respectively calculated according to the following formula:

q _t (mg/g)＝{(C ₀ -C _t )V}/m (1)

q _e (mg/g)={(C ₀ -C _e )V}/m (2)

Among them, C ₀ , C _t , and C _e are the initial concentration of the dye, the concentration of the dye for a certain period of oscillation adsorption, and the equilibrium concentration of the dye adsorption (mg.L-1), V is the solution volume (L), and m is the magnetic polymer dye adsorption The mass (g) of the agent.

The magnetic polymer dye adsorbent saturated with adsorbed dye is desorbed with 50 mL of 0.5 mol/L hydrochloric acid solution, and after desorbing for a certain period of time, the dye concentration in the solution is measured with a UV/visible spectrophotometer until the desorption equilibrium is reached. The desorbed magnetic polymer dye adsorbent was dried and pulverized, and then the dye was adsorbed again under the same conditions, and the dye adsorption capacity of the magnetic polymer dye adsorbent was measured by UV/visible spectrophotometer, and compared with the first time The adsorption capacity of the dye was compared to characterize the regeneration and recycling performance of the magnetic polymer dye adsorbent, and the regeneration cycle was repeated for 5 times to evaluate the regeneration and recycling performance of the magnetic polymer dye adsorbent.

4. Specific implementation

In order to better understand the present invention, the content of the present invention will be further described below in conjunction with the examples, but the content of the present invention is not limited to the following examples.

Example 1:

Add 19.6g FeCl3 6H2O and 7.2g FeCl2 4H2O and 150mL deionized water into a three-necked flask, stir evenly, and heat up to 60°C after nitrogen protection for 30min, then add 50g of ammonia solution with a mass concentration of 25-30% dropwise, After the ammonia solution was added dropwise, react at a constant temperature under nitrogen protection for 5 hours, cool down to room temperature, wash with deionized water three times, and separate with a magnet to obtain magnetic nanoparticles; 1g of magnetic nanoparticles, 2g of γ-chloropropyltrimethoxysilane and 100mL of deionized Add water into the three-necked flask and stir evenly, heat up to 60°C after nitrogen protection for 30 minutes, then add dropwise 2 g of ammonia solution with a mass concentration of 25-30%, react at constant temperature under nitrogen protection for 5 hours, cool down to room temperature, and wash with deionized water for 5 times. Magnet separation to obtain chloropropyl modified nano magnetic particles. Add 1g of chloropropyl-modified nano-magnetic particles, 1g of polyethyleneimine and 100mL of deionized water into a three-necked flask and stir evenly, raise the temperature to 40°C, keep the temperature under nitrogen protection for 5 hours, cool down to room temperature, and wash with deionized water for 3 times , separated by a magnet to obtain polyethyleneimine-modified nano magnetic particles.

Dissolve 9g NaOH in 200mL deionized water, slowly add 24g acrylic acid to the NaOH aqueous solution dropwise in an ice bath, and stir for 2 hours to obtain a partially neutralized acrylic acid aqueous solution; 12g polyethyleneimine modified nano-magnetic particles, 16g acrylamide and Add 0.12g of ethylene glycol diacrylate to partially neutralize the aqueous solution of acrylic acid, stir evenly, raise the temperature to 60°C, add 0.48g of ammonium persulfate and 0.16g of sodium bisulfite, initiate the polymerization reaction for 3 hours, and finally wash the product with anhydrous Washed with ethanol for 3 times, magnetically separated, dried at 80°C, and pulverized to obtain a magnetic polymer dye adsorbent with a saturation magnetization of 15.5emu/g, remanence and coercive force tending to zero, with paramagnetism and magnetic responsiveness ; For the aqueous solutions of crystal violet, cationic bright yellow 7GL, sunset yellow and alizarin green with an initial concentration of 100mg/L, the adsorption capacities of the magnetic polymer dye adsorbents crystal violet, cationic bright yellow 7GL, methyl orange and alizarin green respectively reached 95mg/g, 86mg/g, 74mg/g and 50mg/g reached adsorption equilibrium in 150 minutes, and the adsorption capacity of crystal violet, cationic bright yellow 7GL, methyl orange and Congo red after 5 regeneration cycles exceeded 90% of the first adsorption capacity.

Example 2:

Add 30g FeCl3 6H2O and 10g FeCl2 4H2O and 200mL deionized water into a three-necked flask, stir evenly, protect with nitrogen for 30 minutes, then raise the temperature to 70°C, then add 60g of ammonia solution with a mass concentration of 25-30% dropwise, and add the ammonia solution dropwise After completion, the reaction was carried out under constant temperature under nitrogen protection for 4 hours, cooled to room temperature, washed with deionized water for 5 times, and separated by a magnet to obtain magnetic nanoparticles; 5g of magnetic nanoparticles, 15g of γ-chloropropyltrimethoxysilane and 200mL of deionized water were added to the three-hole Stir evenly in the flask, heat up to 70°C after nitrogen protection for 30 minutes, then add dropwise 15 g of ammonia solution with a mass concentration of 25-30%, react at constant temperature under nitrogen protection for 4 hours, cool down to room temperature, wash with deionized water for about 5 times, and separate with a magnet to obtain Chloropropyl modified nano magnetic particles. Add 2.5g of chloropropyl-modified nano-magnetic particles, 3g of polyethyleneimine and 150mL of deionized water into a three-necked flask and stir evenly, raise the temperature to 70°C, react at a constant temperature under nitrogen protection for 2 hours, then cool down to room temperature, and wash with deionized water for 5 Second, magnet separation to obtain polyethyleneimine modified nano magnetic particles.

Dissolve 7.2g NaOH in 200mL of deionized water, slowly add 20g of acrylic acid to the NaOH aqueous solution in an ice bath, and stir for 2 hours to obtain a partially neutralized acrylic acid aqueous solution; 6g of polyethyleneimine modified nano-magnetic particles, 20g of acrylamide Add 0.08g of ethylene glycol diacrylate to partially neutralize the aqueous acrylic acid solution, stir evenly, raise the temperature to 60°C, add 0.36g of sodium persulfate and 0.12g of sodium bisulfite, initiate the polymerization reaction for 3 hours, and finally the product Wash 5 times with absolute ethanol, magnetically separate, dry at 80°C, and pulverize to obtain a magnetic polymer dye adsorbent. The saturation magnetization is 8.6emu/g, and the remanence and coercive force tend to be zero. It has paramagnetism and Magnetic responsiveness; for the aqueous solution of methylene blue, methyl green, reactive black RB5 and alizarin red with an initial concentration of 300mg/L, the adsorption capacities of the magnetic polymer dye adsorbents methylene blue, methyl green, reactive black RB5 and alizarin red respectively reach 175mg/g, 154mg/g, 141mg/g and 126mg/g, 120min reached adsorption equilibrium, and the adsorption capacities of methylene blue, methyl green, reactive black RB5 and alizarin red after 5 regeneration cycles all exceeded the first adsorption capacity 90% of.

Example 3:

Add 10g FeCl3 6H2O and 5g FeCl2 4H2O and 100mL deionized water into a three-necked flask, stir evenly, protect with nitrogen for 30 minutes, then raise the temperature to 80°C, then add 25g of ammonia solution with a mass concentration of 25-30% dropwise, and add the ammonia solution dropwise After completion, the reaction was carried out at constant temperature under nitrogen protection for 3 hours, cooled to room temperature, washed with deionized water for 4 times, and separated by a magnet to obtain magnetic nanoparticles; 3 g of magnetic nanoparticles, 8 g of γ-chloropropyltrimethoxysilane and 150 mL of deionized water were added to the Stir evenly in the flask, heat up to 80°C under nitrogen protection for 30 minutes, then add dropwise 10 g of ammonia solution with a mass concentration of 25 to 30%, react at a constant temperature under nitrogen protection for 3 hours, then cool down to room temperature, wash with deionized water for 3 times, and separate with a magnet to obtain Chloropropyl modified nano magnetic particles. Add 5g of chloropropyl-modified nano-magnetic particles, 5g of polyethyleneimine and 200mL of deionized water into a three-necked flask and stir evenly, raise the temperature to 60°C, react at constant temperature under nitrogen protection for 3 hours, then cool down to room temperature, and wash with deionized water for 5 times , separated by a magnet to obtain polyethyleneimine-modified nano magnetic particles.

Dissolve 5.4g NaOH in 200mL of deionized water, slowly add 16g of acrylic acid to NaOH aqueous solution in an ice bath, and stir for 2 hours to obtain a partially neutralized acrylic acid aqueous solution; 8g polyethyleneimine modified nano-magnetic particles, 24g acrylamide Add 0.10g of ethylene glycol diacrylate to partially neutralize the aqueous acrylic acid solution, stir evenly, raise the temperature to 50°C, add 0.54g of potassium persulfate and 0.18g of sodium thiosulfate, initiate the polymerization reaction for 5 hours, and finally the product Wash 3 times with absolute ethanol, magnetically separate, dry at 80°C, and pulverize to obtain a magnetic polymer dye adsorbent. The saturation magnetization is 11.2emu/g, the remanence and coercive force tend to be zero, and it has paramagnetism and Magnetic responsiveness: For the aqueous solution of crystal violet, methylene blue, sunset yellow and alizarin green with an initial concentration of 600mg/L, the adsorption capacities of the magnetic polymer dye adsorbent crystal violet, methylene blue, sunset yellow and alizarin green respectively reach 334mg/g, 278mg/g, 185mg/g and 142mg/g reached adsorption equilibrium in 100 minutes, and the adsorption capacity of crystal violet, methylene blue, sunset yellow and alizarin green after 5 regeneration cycles exceeded 90% of the first adsorption capacity.

Example 4:

Add 15gFeCl3·6H2O and 6gFeCl2·4H2O and 150mL deionized water into a three-necked flask, stir evenly, protect with nitrogen for 30 minutes, then raise the temperature to 50°C, then add 35g of ammonia solution with a mass concentration of 25-30% dropwise, and add the ammonia solution dropwise After the completion of the reaction at constant temperature under nitrogen protection for 6 hours, cool down to room temperature, wash with deionized water 5 times, and separate with a magnet to obtain magnetic nanoparticles; 2.5g of magnetic nanoparticles, 5g of γ-chloropropyltrimethoxysilane and 100mL of deionized water were added to Stir evenly in a three-necked flask, heat up to 50°C after nitrogen protection for 30 minutes, then dropwise add 6 g of ammonia solution with a mass concentration of 25 to 30%, react at a constant temperature under nitrogen protection for 6 hours, then cool down to room temperature, wash with deionized water for 5 times, and separate with a magnet. The chloropropyl modified nano magnetic particles are obtained. Add chloropropyl-modified nano-magnetic particles, polyethyleneimine and deionized water into a three-necked flask, stir evenly, raise the temperature to 50°C, and react at constant temperature under nitrogen protection for 4 hours, then cool down to room temperature, wash with deionized water 3 times, and separate with a magnet. , to obtain polyethyleneimine modified nano-magnetic particles.

Dissolve 9g NaOH in 200mL deionized water, slowly add 24g acrylic acid to the NaOH aqueous solution dropwise in an ice bath, and stir for 2 hours to obtain a partially neutralized acrylic acid aqueous solution; 2g polyethyleneimine modified nano-magnetic particles, 16g acrylamide and Add 0.16g of 1,3-propanediol diacrylate to partially neutralize the aqueous acrylic acid solution, stir evenly, raise the temperature to 50°C, add 0.60g of potassium persulfate and 0.20g of sodium sulfite, initiate polymerization for 5 hours, and finally dissolve the product with absolute ethanol Wash 5 times, magnetically separate, dry at 80°C, and pulverize to obtain a magnetic polymer dye adsorbent with a saturation magnetization of 3.5emu/g, remanence and coercive force tending to zero, and having paramagnetism and magnetic responsiveness; For the aqueous solutions of Cationic Bright Yellow 7GL, Reactive Black RB5, Alizarin Red and Sunset Yellow with an initial concentration of 800mg/L, the adsorption capacity of the magnetic polymer dye adsorbents Cationic Bright Yellow 7GL, Reactive Black RB5, Alizarin Red and Sunset Yellow reached 457mg/L respectively. g, 320mg/g, 277mg/g and 216mg/g, the adsorption equilibrium was reached in 80 minutes, and the adsorption capacities of cationic bright yellow 7GL, reactive black RB5, alizarin red and sunset yellow after five regeneration cycles all exceeded the first adsorption capacity 90%.

Example 5:

Add 20g FeCl3 6H2O and 8g FeCl2 4H2O and 200mL deionized water into a three-necked flask, stir evenly, protect with nitrogen for 30 minutes, then heat up to 70°C, then add 50g of ammonia solution with a mass concentration of 25-30% dropwise, and add dropwise the ammonia solution After completion, the reaction was carried out under constant temperature under nitrogen protection for 4 hours, cooled to room temperature, washed with deionized water for 4 times, and separated by magnet to obtain magnetic nanoparticles; 4g of magnetic nanoparticles, 12g of γ-chloropropyltrimethoxysilane and 200mL of deionized water were added to the Stir evenly in the flask, heat up to 80°C after nitrogen protection for 30 minutes, then dropwise add 12 g of ammonia solution with a mass concentration of 25 to 30%, react at constant temperature under nitrogen protection for 3 hours, then cool down to room temperature, wash with deionized water for 3 times, and separate with a magnet to obtain Chloropropyl modified nano magnetic particles. Add 3g of chloropropyl-modified nano-magnetic particles, 2g of polyethyleneimine and 150mL of deionized water into a three-necked flask and stir evenly, raise the temperature to 40°C, react at constant temperature under nitrogen protection for 5h, then cool down to room temperature, and wash with deionized water 5 times , separated by a magnet to obtain polyethyleneimine-modified nano magnetic particles.

Dissolve 8g NaOH in 200mL deionized water, slowly add 24g acrylic acid to the NaOH aqueous solution dropwise in an ice bath, and stir for 2 hours to obtain a partially neutralized acrylic acid aqueous solution; 4g polyethyleneimine modified nano-magnetic particles, 18g acrylamide and Add 0.10g of N,N'-methylenebisacrylamide to partially neutralize the aqueous acrylic acid solution, stir evenly, raise the temperature to 50°C, add 0.62g of ammonium persulfate and 0.21g of sodium bisulfite, initiate the polymerization reaction for 5 hours, and finally The product was washed 3 times with absolute ethanol, magnetically separated, dried at 80°C, and crushed to obtain a magnetic polymer dye adsorbent with a saturation magnetization of 5.9emu/g, remanence and coercivity tending to zero, and a smooth Magnetic properties and magnetic responsivity; for aqueous solutions of crystal violet, cationic bright yellow 7GL, reactive black RB5 and methyl orange at an initial concentration of 1000 mg/L, magnetic polymer dye adsorbents crystal violet, cationic bright yellow 7GL, reactive black RB5 and methyl orange The adsorption capacity reaches 600mg/g, 517mg/g, 476mg/g and 414mg/g respectively, and the adsorption equilibrium is reached in 60 minutes. The adsorption capacity of crystal violet, cationic bright yellow 7GL, reactive black RB5 and methyl orange after 5 regeneration cycles exceeds 90% of the first adsorption capacity.

Claims (4)

1. a preparation method of magnetic polymer dye adsorbent is characterized in that following processing steps are arranged: Add FeCl3·6H2O, FeCl2·4H2O and deionized water into a three-necked flask, stir evenly, protect with nitrogen for 30 minutes, then heat up to 50-80°C, then add dropwise an ammonia solution with a mass concentration of 25-30%. After the addition is completed, react at a constant temperature under nitrogen protection for 3-6 hours, cool down to room temperature, wash with deionized water for 3-5 times, and separate with a magnet to obtain magnetic nanoparticles; FeCl3 6H2O, FeCl2 4H2O, ammonia solution with a mass concentration of 25-30% The mass ratio with deionized water is 10～30:5～10:25～60:100～200; Add magnetic nanoparticles, γ-chloropropyltrimethoxysilane and deionized water into a three-necked flask and stir evenly. After 30 minutes of nitrogen protection, the temperature is raised to 50-80°C, and then ammonia with a mass concentration of 25-30% is added dropwise. Aqueous solution, nitrogen protection constant temperature reaction for 3 to 6 hours, then cooling to room temperature, washing with deionized water for 3 to 5 times, and magnetic separation to obtain chloropropyl modified nano-magnetic particles; magnetic nanoparticles, γ-chloropropyl trimethoxysilane, The mass ratio of ammonia solution with a mass concentration of 25-30% and deionized water is 1-5: 2-15: 2-15: 100-200; Add chloropropyl-modified nano-magnetic particles, polyethyleneimine and deionized water into a three-necked flask, stir evenly, heat up to 40-70°C, react at constant temperature under nitrogen protection for 2-5 hours, then cool down to room temperature, and wash with deionized water 3 to 5 times, magnet separation to obtain polyethyleneimine modified nano-magnetic particles; the mass ratio of chloropropyl-modified nano-magnetic particles, polyethyleneimine and deionized water is 1～5: 1～5:100～ 200; Dissolve NaOH in 200mL deionized water, slowly add acrylic acid to the NaOH aqueous solution in an ice bath, and stir for 0.5-2 hours to obtain a partially neutralized acrylic acid aqueous solution; polyethyleneimine modified magnetic nanoparticles, acrylamide and cross-linked Add the agent to partially neutralize the aqueous acrylic acid solution, stir evenly, raise the temperature to 50-60°C, add the redox initiator, initiate the polymerization reaction for 3-5 hours, and finally wash the product with absolute ethanol 3-5 times, magnetically separate, 80 Dry at ℃ and pulverize to obtain a magnetic polymer dye adsorbent; the molar ratio of acrylic acid to NaOH is 1:0.5-0.8; the mass ratio of acrylic acid to acrylamide is 1-5:1-5; 0.1% to 0.8% of the total mass of amide monomers; redox initiators account for 0.1% to 2.0% of the total mass of acrylic acid and acrylamide monomers; the molar ratio of oxidizing and reducing agents is 1 to 2:1; Amine-modified magnetic nanoparticles account for 5-30% of the total mass of acrylic acid and acrylamide monomers; The saturation magnetization of the magnetic polymer dye adsorbent is 3.5-15.5 emu/g, the remanence and coercive force tend to be zero, and it has paramagnetism and magnetic responsiveness. For the dye aqueous solution with an initial concentration of 100-1000mg/L, the dye adsorption The capacity reaches 50-600 mg/g, and the adsorption equilibrium is reached in 60-150 minutes. The dye adsorption capacity after 5 regeneration cycles exceeds 90% of the first adsorption capacity. 2. the preparation method of a kind of magnetic polymer dye adsorbent according to claim 1 is characterized in that: described crosslinking agent is selected from N, N'-methylenebisacrylamide, ethylene glycol bisacrylic acid ester, ethylene glycol diacrylate, diethylene glycol diacrylate, 1,3-propanediol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, glycidyl methacrylate and Polyethylene glycol diacrylate. 3. the preparation method of a kind of magnetic polymer dye adsorbent according to claim 1 is characterized in that: described redox initiator comprises oxidizing agent and reducing agent, and oxidizing agent is selected from ammonium persulfate, potassium persulfate and persulfate Sodium sulfate, reducing agent is selected from sodium bisulfite, sodium sulfite, sodium thiosulfate and ferrous sulfate. 4. the preparation method of a kind of magnetic polymer dye adsorbent according to claim 1 is characterized in that: described dyestuff is selected from methylene blue, cationic blue FGL, cationic orange R, cationic bright yellow 7GL, cationic pink FG, formazan Base Green, Crystal Violet, Methyl Orange, Reactive Black RB5, Congo Red, Alizarin Red, Sunset Yellow, Alizarin Green, Acid Chrome Blue K, and Eosin Y.