A magnetic multifunctional amphiphilic hybrid particle, its preparation method and application

Abstract

The application relates to the sewage treatment technical field, and provides a magnetic multi-effect dual-parent hybrid particle as well as a preparation method and application thereof. The magnetic multi-effect dual-parent hybrid particle comprises a core-shell separated magnetic Fe3O4 particle core and a shell layer, the shell layer is a silica / titanium dioxide hybrid shell layer with a micro-pore structure, the outer surface of the shell layer comprises a hydrophilic part and a hydrophobic part, and the inner surface of the shell layer and the surface of the magnetic Fe3O4 particle core are grafted with poly (diethylaminoethyl methacrylate). The magnetic multi-effect dual-parent hybrid particle provided by the application has excellent emulsifying performance, can realize oil-water separation, can selectively adsorb partially hydrolyzed polyacrylamide, and can efficiently treat oil-containing sewage containing partially hydrolyzed polyacrylamide in one step.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and more specifically, to a magnetic multifunctional amphiphilic hybrid particle, its preparation method, and its application. Background Technology

[0002] Polyacrylamide, as one of the most widely used water-soluble polymers, has been extensively applied in fields such as oil extraction. In particular, the viscoelasticity of partially hydrolyzed polyacrylamide (HPAM) plays a crucial role in controlling mobility and improving oil displacement efficiency in tertiary oil recovery. With the increasingly widespread application of partially hydrolyzed polyacrylamide as a polymer flooding polymer in my country's oilfield industry, the treatment of oilfield wastewater containing partially hydrolyzed polyacrylamide has also received attention. However, treating oily wastewater containing partially hydrolyzed polyacrylamide is more difficult than treating ordinary oily wastewater, and existing treatment methods generally require multiple steps to achieve compliance. How to efficiently remove partially hydrolyzed polyacrylamide while achieving oil-water separation in one step has always been a challenge in treating oily wastewater containing partially hydrolyzed polyacrylamide.

[0003] In addition, due to differences in oil wells and oil displacement operations, the pH value of the oil well discharge fluid varies greatly, with a large amount of wastewater being acidic or alkaline, which significantly increases the difficulty of its treatment. Summary of the Invention

[0004] The purpose of this invention is to provide a magnetic multifunctional amphiphilic hybrid particle and its preparation method, so as to solve the technical problem that it is difficult to treat oily wastewater containing partially hydrolyzed polyacrylamide to meet standards in one step in the prior art.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] In a first aspect, the present invention provides a magnetic multifunctional amphiphilic hybrid particle, the magnetic multifunctional amphiphilic hybrid particle comprising a core-shell separated magnetic Fe3O4 particle core and a shell layer, the shell layer being a silica / titanium dioxide hybrid shell layer with a microporous structure, the outer surface of the shell layer comprising a hydrophilic portion and a hydrophobic portion, and the inner surface of the shell layer and the surface of the magnetic Fe3O4 particle core layer being grafted with poly(diethylaminoethyl methacrylate) (PDEAEMA).

[0007] It should be noted that the "micropore structure" mentioned in this invention includes intermolecular voids in the silica / titanium dioxide macromolecular framework and defects generated during the core-shell separation process between the silica / titanium dioxide hybrid shell and the magnetic Fe3O4 particle core, and even micropores and capillaries with a pore size of 0.5 to 50 nm.

[0008] The magnetic multifunctional amphiphilic hybrid particles provided by this invention can protect the core of magnetic Fe3O4 particles by coating the core of the magnetic Fe3O4 particles with a silicon dioxide / titanium dioxide hybrid shell. Within a certain time and pH range, the core of the magnetic Fe3O4 particles can resist corrosion by hydrochloric acid, sulfuric acid, nitric acid or various alkaline reagents, thus ensuring the industrial application of the magnetic particles.

[0009] The magnetic multifunctional amphiphilic hybrid particles provided by this invention have a shell surface that includes both hydrophilic and hydrophobic portions, giving them amphiphilic properties. Compared with traditional homogeneous particles, they have more stable emulsification characteristics and can more stably and extensively emulsify oil and water phases to form stable oil-in-water emulsions, providing a stable basis for the manipulation of emulsion droplets.

[0010] Furthermore, the functional groups on the outer surface of the shell interact with partially hydrolyzed polyacrylamide via electrostatics, promoting its adsorption on the outer surface. Simultaneously, after adsorption, the wetting effect of the internal structure of the amphiphilic hybrid particles on the partially hydrolyzed polyacrylamide adsorbed on the outer surface further promotes its adsorption into the shell. The poly(diethylaminoethyl methacrylate) (PDEAEMA) grafted onto the inner surface of the shell and the core surface of the magnetic Fe3O4 particles forms a brush-like coating, increasing the specific surface area and enhancing the hydrogen bond density. The microporous structure on the silica / titanium dioxide hybrid shell provides channels for the migration and transport of partially hydrolyzed polyacrylamide, while the weakly acidic nature of the polyacrylamide also facilitates its transfer and adsorption from the outer to the inner shell, thus achieving the adsorption and migration capture of partially hydrolyzed polyacrylamide by PDEAEMA. The magnetic multifunctional amphiphilic hybrid particles provided by this invention, through the combination of their internal and external structures, significantly improve the adsorption capacity and efficiency for partially hydrolyzed polyacrylamide.

[0011] The magnetic multifunctional amphiphilic hybrid particles provided by this invention can be reused multiple times. After use, the magnetic multifunctional amphiphilic hybrid particles are washed and extracted using a benign solvent (such as ethanol) that partially hydrolyzes polyacrylamide. This removes the adsorbed partially hydrolyzed polyacrylamide, allowing the magnetic multifunctional amphiphilic hybrid particles to be reused to treat oily wastewater.

[0012] Furthermore, due to the pH sensitivity of PDEAEMA, this characteristic can be utilized to achieve repeated adsorption and desorption of partially hydrolyzed polyacrylamide by adjusting the pH, allowing the magnetic multifunctional amphiphilic hybrid particles to be reused, which greatly reduces the material cost of wastewater treatment.

[0013] According to some embodiments of the present invention, the mass ratio of silicon dioxide to titanium dioxide in the shell is 1:10 to 10:1.

[0014] According to some embodiments of the present invention, the hydrophilic portion is obtained by modifying the outer surface of an amino-containing silane coupling agent.

[0015] According to some embodiments of the present invention, the amino-containing silane coupling agent includes 3-aminopropyltriethoxysilane.

[0016] Modification with 3-aminopropyltriethoxysilane creates an amino group on the hydrophilic portion of the outer shell, which can weakly interact with partially hydrolyzed polyacrylamide containing carboxyl groups, thereby achieving the adsorption of partially hydrolyzed polyacrylamide.

[0017] According to some embodiments of the present invention, the hydrophobic portion is obtained by modifying the outer surface of the shell with an alkyl-containing silane coupling agent.

[0018] According to some embodiments of the present invention, the alkyl-containing silane coupling agent includes n-octyltriethoxysilane.

[0019] According to some embodiments of the present invention, the area of ​​the hydrophilic portion accounts for 1 / 3 to 2 / 3 of the total area of ​​the outer surface of the shell.

[0020] According to some embodiments of the present invention, the particle size of the magnetic multifunctional amphiphilic hybrid particles is 100nm < r ≤ 1000nm.

[0021] Secondly, the present invention provides a method for preparing magnetic multifunctional amphiphilic hybrid particles, comprising:

[0022] S1. Magnetic Fe3O4 particles are dispersed in an alcohol solvent, and tetraethyl orthosilicate and tetrabutyl titanate are added and stirred to obtain Fe3O4@SiO2 / TiO2 particles;

[0023] S2. Disperse Fe3O4@SiO2 / TiO2 particles in water, add paraffin wax, heat until the paraffin wax is completely melted, stir and mix, cool and filter to obtain paraffin spheres formed by Fe3O4@SiO2 / TiO2 particles embedded on the surface of paraffin wax.

[0024] S3. Disperse paraffin balls in dimethyl sulfoxide, add an amino-containing silane coupling agent, stir to react, and redisperse the obtained solid particles in an alcohol solvent to obtain hydrophilic modified particles;

[0025] S4. Disperse the hydrophilic modified particles in ethanol, add an alkyl-containing silane coupling agent, stir the reaction, and obtain amphiphilic modified particles;

[0026] S5. Mix the amphiphilic modified particles with acetic acid for 8-12 hours to obtain core-shell separated amphiphilic modified particles;

[0027] S6. The core-shell separated amphiphilic modified particles are dispersed in an alcohol solvent, and 4-(chloromethyl)phenyltrimethoxysilane is added to undergo a modification reaction; then a grafting reaction is carried out with diethylaminoethyl methacrylate to obtain magnetic multifunctional amphiphilic hybrid particles.

[0028] The method for preparing magnetic multifunctional amphiphilic hybrid particles provided by this invention uses magnetic Fe3O4 particles as a carrier. Tetrabutyl orthosilicate and tetrabutyl titanate are used to hydrolyze the surface of the magnetic Fe3O4 particles, achieving coating of the magnetic Fe3O4 particles through a sol-gel process, forming an effective silicon / titanium-coated iron core-shell structure. Paraffin wax with a phase transition temperature of 52°C is used as the oil phase. Fe3O4@SiO2 / TiO2 particles are used as solid particle emulsifiers to emulsify the oil and water phases at a temperature higher than the phase transition temperature of paraffin wax, forming a stable water-in-paraffin wax emulsion. After cooling, the paraffin wax phase solidifies and separates from the aqueous phase, yielding paraffin spheres formed by Fe3O4@SiO2 / TiO2 particles embedded in the paraffin wax surface. The Fe3O4@SiO2 / TiO2 particles are partially embedded in the paraffin wax and partially exposed. Then, the outer surface of the Fe3O4@SiO2 / TiO2 particles exposed outside the paraffin was hydrophilically modified; the paraffin was then removed to expose the portion of the Fe3O4@SiO2 / TiO2 particles previously protected by paraffin, and the outer surface of this portion was hydrophobically modified to obtain amphiphilic particles with both hydrophilic and hydrophobic parts on the particle surface. Acid etching was then performed to reduce the size of the magnetic Fe3O4 particles, causing separation from the shell and creating a hollow structure between the core and shell. Further modification with benzyl chloride [4-(chloromethyl)phenyl] was achieved on the surface of the magnetic Fe3O4 particles and the inner surface of the shell using 4-(chloromethyl)phenyl. Benzyl chloride has high reactivity and can be grafted with poly(diethylaminoethyl methacrylate) (PDEAEMA) via ATRP (atom transfer radical polymerization) to prepare magnetic multifunctional amphiphilic hybrid particles.

[0029] In this invention, tetraethyl orthosilicate and tetrabutyl titanate are hydrolyzed on the surface of magnetic Fe3O4 particles, forming a relatively dense silica / titanium dioxide hybrid shell structure on the surface of the magnetic Fe3O4 particles through a sol-gel process, thus protecting the internal magnetic Fe3O4 particles. Furthermore, the silica / titanium dioxide hybrid shell in this invention is a polymer formed by the hydrolytic condensation of tetraethyl orthosilicate and tetrabutyl titanate. Although the formed silica / titanium dioxide hybrid shell is relatively dense, intermolecular voids still exist in the macromolecular framework formed by the condensation reaction during the sol-gel process of tetraethyl orthosilicate and tetrabutyl titanate hydrolysis. This ensures the smooth progress of subsequent acid etching treatment, 4-(chloromethyl)phenyltrimethoxysilane modification, and PDEAEMA grafting processes.

[0030] In this invention, after acid etching, the magnetic Fe3O4 particles shrink, resulting in core-shell separation. This process further causes defects in the shell, which, together with the intermolecular gaps in the shell, form a microporous structure that provides a channel for the transport and migration of partially hydrolyzed polyacrylamide into the interior of the shell.

[0031] In this invention, acetic acid is used as the etching agent, which allows the etching to proceed slowly, ensuring that the etching process is controllable and making the surface of the magnetic Fe3O4 particle core smoother. If hydrochloric acid, sulfuric acid, etc. are used, it is difficult to control the etching process, which can easily lead to over-etching, resulting in the particle magnetism being too weak or even completely disappearing.

[0032] According to some embodiments of the present invention, the alcohol solvent includes at least one selected from methanol, ethanol, propanol, butanol, isopropanol, and cyclohexanol.

[0033] According to some embodiments of the present invention, the stirring speed in step S2 is 1000-5000 rpm.

[0034] In this invention, the stirring speed in step S2 directly affects the emulsification process of the particulate emulsifier (Fe3O4@SiO2 / TiO2 particles), directly leading to the stability of the emulsion interface. When the stirring speed is less than 1000 rpm, the stirring speed is too low, making it difficult for the particulate emulsifier to be delivered to the interface, thus failing to stabilize the interface and easily causing demulsification. When the stirring speed is greater than 5000 rpm, the stirring speed is too high, forcing the particulate emulsifier to be pulled at the interface, easily leading to interface instability and demulsification. Therefore, to ensure emulsification and interface stability, the stirring speed in step S2 should preferably be controlled between 1000 and 5000 rpm.

[0035] According to some embodiments of the present invention, the mixing time in step S2 is 3 to 5 minutes.

[0036] According to some embodiments of the present invention, the amino-containing silane coupling agent includes 3-aminopropyltriethoxysilane.

[0037] The local hydrophilic modification of the outer surface of Fe3O4@SiO2 / TiO2 particles was carried out in dimethyl sulfoxide using 3-aminopropyltriethoxysilane. This was achieved through a hydrolysis process to form a sol-gel composite on the outer surface of Fe3O4@SiO2 / TiO2 particles exposed to paraffin. An amino group was modified on one side of the outer surface of the Fe3O4@SiO2 / TiO2 particles.

[0038] According to some embodiments of the present invention, the alkyl-containing silane coupling agent includes n-octyltriethoxysilane.

[0039] The method of locally modifying the outer surface of Fe3O4@SiO2 / TiO2 particles with n-octyltriethoxysilane involves first removing paraffin wax with an alcohol solvent, exposing the portion of the Fe3O4@SiO2 / TiO2 particles that was embedded in paraffin wax and protected. Then, the exposed portion of the Fe3O4@SiO2 / TiO2 particles is subjected to sol-gel composite formation through the hydrolysis process of n-octyltriethoxysilane. Finally, n-octyl groups are modified on the other side of the outer surface of the Fe3O4@SiO2 / TiO2 particles.

[0040] According to some embodiments of the present invention, the mass ratio of the magnetic Fe3O4 particles, tetraethyl orthosilicate and tetrabutyl titanate is 1:(0.1-1):(0.1-1).

[0041] According to some embodiments of the present invention, the mass ratio of the magnetic Fe3O4 particles to the paraffin is 1:(10-200).

[0042] According to some embodiments of the present invention, the mass ratio of paraffin wax to water is 1:(2-10).

[0043] According to some embodiments of the present invention, the mass ratio of the magnetic Fe3O4 particles to the amino-containing silane coupling agent is 1:(0.001-0.01).

[0044] According to some embodiments of the present invention, the mass ratio of the magnetic Fe3O4 particles to the alkyl-containing silane coupling agent is 1:(0.001-0.01).

[0045] According to some embodiments of the present invention, the mass ratio of the magnetic Fe3O4 particles to the 4-(chloromethyl)phenyltrimethoxysilane is 1:(0.001-0.01).

[0046] According to some embodiments of the present invention, the mass ratio of the magnetic Fe3O4 particles to the diethylaminoethyl methacrylate is 1:(0.02-0.1).

[0047] According to some embodiments of the present invention, the particle size of the magnetic Fe3O4 particles is 100-500 nm.

[0048] According to some embodiments of the present invention, the particle size ratio of the magnetic Fe3O4 particles to the core of the magnetic Fe3O4 particles is 100:(10-99).

[0049] In this invention, if the particle size ratio of magnetic Fe3O4 particles to magnetic Fe3O4 particle cores is less than 100:99, the gaps between the shell and the magnetic Fe3O4 particle cores will be too small, affecting the adsorption capacity of the magnetic multifunctional amphiphilic hybrid particles for partially hydrolyzed polyacrylamide; if the particle size ratio of magnetic Fe3O4 particles to magnetic Fe3O4 particle cores is greater than 100:10, the size of the magnetic Fe3O4 particle cores will be too small, leading to severe magnetic attenuation and making it difficult to achieve magnetic manipulation by an external magnetic field.

[0050] According to some embodiments of the present invention, the grafting reaction includes: dissolving cuprous chloride and 2,2-bipyridine in a solvent, adding amphiphilic modified particles that have undergone modification reaction treatment and diethylaminoethyl methacrylate, and stirring the reaction under a nitrogen atmosphere and at 60-100°C.

[0051] According to some embodiments of the present invention, the solvent used in the grafting reaction includes at least one of water, tetrahydrofuran (THF), and N,N-dimethylformamide (DMF).

[0052] According to some embodiments of the present invention, the stirring reaction time in step S3 is 5 to 6 hours.

[0053] According to some embodiments of the present invention, the stirring reaction time in step S4 is 5 to 6 hours.

[0054] According to some embodiments of the present invention, the magnetic Fe3O4 particles and tetrabutyl titanate are dispersed in an alcohol solvent by ultrasonication and stirring for 12-24 hours. Preferably, the ultrasonic frequency is 60-80 Hz and / or the stirring speed is 50-100 rpm.

[0055] According to some embodiments of the present invention, the dispersion of Fe3O4@SiO2 / TiO2 particles in water is carried out by ultrasound and stirring. Preferably, the ultrasound frequency is 60-80 Hz and / or the stirring speed is 50-100 rpm.

[0056] According to some embodiments of the present invention, the dispersion of paraffin balls into dimethyl sulfoxide is carried out by stirring, preferably at a stirring speed of 50 to 100 rpm;

[0057] According to some embodiments of the present invention, the dispersion of the hydrophilic modified particles in the alcohol solvent is carried out by ultrasound and stirring. Preferably, the ultrasound frequency is 60-80 Hz and / or the stirring speed is 200-300 rpm.

[0058] According to some embodiments of the present invention, the mixing of amphiphilic modified particles with acetic acid for 8-12 hours includes: dispersing the amphiphilic modified particles in water, adding acetic acid, and mixing by means of ultrasound and stirring for 8-12 hours. Preferably, the ultrasound frequency is 60-80 Hz and / or the stirring speed is 50-100 rpm.

[0059] Thirdly, the present invention provides a magnetic multifunctional amphiphilic hybrid particle, which is prepared by the preparation method described in the second aspect.

[0060] Fourthly, the present invention provides the application of the magnetic multifunctional amphiphilic hybrid particles described in the first aspect or the magnetic multifunctional amphiphilic hybrid particles described in the third aspect in the treatment of oily wastewater containing partially hydrolyzed polyacrylamide.

[0061] The beneficial effects of this invention are at least as follows:

[0062] (1) The magnetic multifunctional amphiphilic hybrid particles provided by the present invention have excellent emulsification performance. After the droplets are emulsified and stabilized by the magnetic multifunctional amphiphilic hybrid particles, they can be controlled by an external magnetic field to achieve the enrichment and migration of oil droplets, thereby achieving oil-water separation. At the same time, they can selectively adsorb some hydrolyzed polyacrylamide, and can efficiently treat oily wastewater containing some hydrolyzed polyacrylamide in one step.

[0063] (2) The magnetic multifunctional amphiphilic hybrid particles provided by the present invention can be reused multiple times, and the adsorption capacity for partially hydrolyzed polyacrylamide will not decrease significantly, which can greatly reduce the material cost of sewage treatment.

[0064] (3) The magnetic multifunctional amphiphilic hybrid particles provided by the present invention have a silicon dioxide / titanium dioxide hybrid shell that can improve the acid and alkali resistance of the amphiphilic hybrid particles to a certain extent, making them applicable to the treatment of wastewater with more complex composition.

[0065] (4) The preparation method of magnetic multifunctional amphiphilic hybrid particles provided by the present invention is simple, the raw materials are low in cost and readily available, and can achieve industrial-scale mass production at the ton level. Detailed Implementation

[0066] To make the technical problem to be solved, the technical solution, and the beneficial effects of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely for illustrating this patent and do not limit the scope of protection of this invention in any way.

[0067] Unless otherwise defined, the technical terms used in the following embodiments have the same meaning as commonly understood by those skilled in the art. Unless otherwise specified, the reagents used in the following embodiments are conventional biochemical reagents; the raw materials, instruments, and equipment used in the following embodiments can all be obtained commercially or by existing methods; unless otherwise specified, the reagent dosages are those used in routine experimental operations; unless otherwise specified, the experimental methods are conventional methods.

[0068] Example 1

[0069] S1. 2g of magnetic Fe3O4 particles (particle size 0.2μm) were dispersed in 200mL of ethanol, and 1g of tetrabutyl titanate and 1g of tetrabutyl titanate were added at the same time. The mixture was subjected to 60Hz sonication and 100rpm top stirring to promote the dispersion of magnetic Fe3O4 particles. The process was continued for 12h to obtain Fe3O4@SiO2 / TiO2 particles.

[0070] S2. Disperse Fe3O4@SiO2 / TiO2 particles in 200 mL of water while simultaneously applying 60 Hz ultrasound and 100 rpm top-mounted stirring to promote dispersion. Increase the water temperature to 80°C, add 20 g of paraffin wax (phase transition temperature 52°C), and continue stirring until the paraffin wax is completely melted. Turn off the ultrasound and increase the stirring speed to 2000 rpm, stirring continuously for 3 min. Stop stirring and heating, cool the sample to room temperature, filter out the solidified paraffin spheres, and separate them from the water. Disperse the paraffin spheres on filter paper and allow them to air dry naturally to obtain paraffin sphere powder formed by Fe3O4@SiO2 / TiO2 particles embedded in the paraffin wax surface.

[0071] S3. Disperse the paraffin ball powder in 100 mL of dimethyl sulfoxide and slowly stir the dispersion at 50 rpm using a top-mounted stirrer. Add 20 mg of 3-aminopropyltriethoxysilane to the dispersion and continue stirring for 6 hours. Separate the paraffin ball powder and solvent using an external magnetic field, and allow the paraffin ball powder to air dry naturally. Then disperse the paraffin ball powder in 100 mL of ethanol to dissolve the paraffin. Separate the solid particles using an external magnetic field to obtain Fe3O4@SiO2 / TiO2-NH2 particles with an amino-modified surface on one side.

[0072] S4. Disperse Fe3O4@SiO2 / TiO2-NH2 particles in 100 mL of ethanol. Stir the dispersion using a top-mounted stirrer at 300 rpm, simultaneously with 60 Hz ultrasound. Add 20 mg of n-octylpropyltriethoxysilane to the dispersion and continue stirring for 6 h. Separate the solid particles using an external magnetic field and air-dry under natural conditions to obtain...

[0073] C8-Fe3O4@SiO2 / TiO2-NH2 particles.

[0074] S5. Disperse C8-Fe3O4@SiO2 / TiO2-NH2 particles in 100mL of water, add 2mL of acetic acid, and stir the dispersion for 10h using a top-mounted stirrer at 100rpm, while simultaneously adding 60Hz ultrasound to obtain core-shell separated C8-Fe3O4@SiO2 / TiO2-NH2 particles.

[0075] S6. The core-shell separated C8-Fe3O4@SiO2 / TiO2-NH2 particles were dispersed in 100 mL of ethanol, and 10 mg of 4-(chloromethyl)phenyltrimethoxysilane was added. The mixture was stirred at 100 rpm for 12 h to obtain modified C8-Fe3O4@SiO2 / TiO2-NH2 particles. 0.02 g of cuprous chloride and 0.02 g of 2,2-bipyridine were dissolved in 50 mL of DMF, and the above-mentioned modified C8-Fe3O4@SiO2 / TiO2-NH2 particles were added. At the same time, 0.1 g of DEAEMA was added, and N2 was purged for oxygen removal for 30 min. The temperature was raised to 80 °C, and the mixture was stirred at 100 rpm for 3 h. After the reaction was completed, magnetic multifunctional amphiphilic hybrid particles were obtained.

[0076] Example 2

[0077] S1. 2g of magnetic Fe3O4 particles (particle size 0.2μm) were dispersed in 200mL of ethanol, and 0.3g of tetrabutyl titanate and tetrabutyl titanate were added at the same time. The mixture was subjected to 60Hz sonication and 100rpm top stirring. The sonication and stirring were maintained to promote the dispersion of magnetic Fe3O4 particles for 12h, and Fe3O4@SiO2 / TiO2 particles were obtained.

[0078] S2. Disperse Fe3O4@SiO2 / TiO2 particles in 200 mL of water while simultaneously applying 60 Hz ultrasound and 100 rpm top-mounted stirring to promote dispersion. Raise the water temperature to 80°C, add 40 g of paraffin wax (phase transition temperature 52°C), and continue stirring until the paraffin wax is completely melted. Turn off the ultrasound and increase the stirring speed to 1000 rpm, stirring continuously for 5 min. Stop stirring and heating, cool the sample to room temperature, filter out the solidified paraffin spheres, and separate them from the water. Disperse the paraffin spheres on filter paper and air dry naturally to obtain paraffin sphere powder formed by Fe3O4@SiO2 / TiO2 particles embedded in the surface of paraffin wax.

[0079] S3. Disperse the paraffin ball powder in 100 mL of dimethyl sulfoxide and slowly stir the dispersion at 50 rpm using a top-mounted stirrer. Add 3 mg of 3-aminopropyltriethoxysilane to the dispersion and continue stirring for 6 hours. Separate the paraffin ball powder and solvent using an external magnetic field, and allow the paraffin ball powder to air dry naturally. Then disperse the paraffin ball powder in 100 mL of ethanol to dissolve the paraffin. Separate the solid particles using an external magnetic field to obtain Fe3O4@SiO2 / TiO2-NH2 particles with an amino-modified surface on one side.

[0080] S4. Disperse Fe3O4@SiO2 / TiO2-NH2 particles in 100 mL of ethanol. Stir the dispersion using a top-mounted stirrer at 300 rpm, simultaneously with 60 Hz ultrasound. Add 3 mg of n-octylpropyltriethoxysilane to the dispersion and continue stirring for 6 h. Separate the solid particles using an external magnetic field and air-dry under natural conditions to obtain...

[0081] C8-Fe3O4@SiO2 / TiO2-NH2 particles.

[0082] S5. Disperse C8-Fe3O4@SiO2 / TiO2-NH2 particles in 100mL of water, add 2mL of acetic acid, and stir the dispersion for 10h using a top-mounted stirrer at 100rpm, while simultaneously adding 60Hz ultrasound to obtain core-shell separated C8-Fe3O4@SiO2 / TiO2-NH2 particles.

[0083] S6. The core-shell separated C8-Fe3O4@SiO2 / TiO2-NH2 particles were dispersed in 100 mL of ethanol, and 3 mg of 4-(chloromethyl)phenyltrimethoxysilane was added. The mixture was stirred at 100 rpm for 12 h to obtain modified C8-Fe3O4@SiO2 / TiO2-NH2 particles. 0.02 g of cuprous chloride and 0.02 g of 2,2-bipyridine were dissolved in 50 mL of DMF, and the above-mentioned modified C8-Fe3O4@SiO2 / TiO2-NH2 particles were added. At the same time, 0.04 g of DEAEMA was added, and N2 was purged for oxygen removal for 30 min. The temperature was raised to 80 °C, and the mixture was stirred at 100 rpm for 3 h. After the reaction was completed, magnetic multifunctional amphiphilic hybrid particles were obtained.

[0084] Example 3

[0085] S1. 2g of magnetic Fe3O4 particles (particle size 0.2μm) were dispersed in 200mL of ethanol, and 2g of tetrabutyl titanate and tetrabutyl tetrabutyl titanate were added at the same time. The mixture was subjected to 60Hz sonication and 100rpm top stirring to promote the dispersion of magnetic Fe3O4 particles. The process was continued for 12h to obtain Fe3O4@SiO2 / TiO2 particles.

[0086] S2. Disperse Fe3O4@SiO2 / TiO2 particles in 200 mL of water while simultaneously applying 60 Hz ultrasound and 100 rpm top-mounted stirring to promote dispersion. Raise the water temperature to 80°C, add 20 g of paraffin wax (phase transition temperature 52°C), and continue stirring until the paraffin wax is completely melted. Turn off the ultrasound and increase the stirring speed to 5000 rpm, stirring continuously for 4 min. Stop stirring and heating, cool the sample to room temperature, filter out the solidified paraffin spheres, and separate them from the water. Disperse the paraffin spheres on filter paper and air dry naturally to obtain paraffin sphere powder formed by Fe3O4@SiO2 / TiO2 particles embedded in the surface of paraffin wax.

[0087] S3. Disperse the paraffin ball powder in 100 mL of dimethyl sulfoxide and slowly stir the dispersion at 50 rpm using a top-mounted stirrer. Add 10 mg of 3-aminopropyltriethoxysilane to the dispersion and continue stirring for 6 hours. Separate the paraffin ball powder and solvent using an external magnetic field, and allow the paraffin ball powder to air dry naturally. Then disperse the paraffin ball powder in 100 mL of ethanol to dissolve the paraffin. Separate the solid particles using an external magnetic field to obtain Fe3O4@SiO2 / TiO2-NH2 particles with an amino-modified surface on one side.

[0088] S4. Disperse Fe3O4@SiO2 / TiO2-NH2 particles in 100 mL of ethanol. Stir the dispersion using a top-mounted stirrer at 300 rpm, simultaneously with 60 Hz ultrasound. Add 10 mg of n-octylpropyltriethoxysilane to the dispersion and continue stirring for 6 h. Separate the solid particles using an external magnetic field and air-dry under natural conditions to obtain...

[0089] C8-Fe3O4@SiO2 / TiO2-NH2 particles.

[0090] S5. Disperse C8-Fe3O4@SiO2 / TiO2-NH2 particles in 100mL of water, add 2mL of acetic acid, and stir the dispersion for 10h using a top-mounted stirrer at 100rpm, while simultaneously adding 60Hz ultrasound to obtain core-shell separated C8-Fe3O4@SiO2 / TiO2-NH2 particles.

[0091] S6. The core-shell separated C8-Fe3O4@SiO2 / TiO2-NH2 particles were dispersed in 100 mL of ethanol, and 15 mg of 4-(chloromethyl)phenyltrimethoxysilane was added. The mixture was stirred at 100 rpm for 12 h to obtain modified C8-Fe3O4@SiO2 / TiO2-NH2 particles. 0.02 g of cuprous chloride and 0.02 g of 2,2-bipyridine were dissolved in 50 mL of DMF, and the above-mentioned modified C8-Fe3O4@SiO2 / TiO2-NH2 particles were added. At the same time, 0.2 g of DEAEMA was added, and N2 was purged for oxygen removal for 30 min. The temperature was raised to 80 °C, and the mixture was stirred at 100 rpm for 3 h. After the reaction was completed, magnetic multifunctional amphiphilic hybrid particles were obtained.

[0092] Example 4

[0093] S1. 2g of magnetic Fe3O4 particles (particle size 0.2μm) were dispersed in 200mL of ethanol, and 1g of tetrabutyl titanate and 1g of tetrabutyl titanate were added at the same time. The mixture was subjected to 60Hz sonication and 100rpm top stirring to promote the dispersion of magnetic Fe3O4 particles. The process was continued for 12h to obtain Fe3O4@SiO2 / TiO2 particles.

[0094] S2. Disperse Fe3O4@SiO2 / TiO2 particles in 200mL of water while simultaneously applying 60Hz ultrasound and 100rpm top-mounted stirring to promote dispersion. Raise the water temperature to 80℃, add 20g of paraffin wax (phase transition temperature 52℃), and continue stirring until the paraffin wax is completely melted. Turn off the ultrasound and increase the stirring speed to 500rpm.

[0095] Because the stirring speed is too low, the particles cannot be mechanically delivered to the oil-water interface. The silicon / titanium-coated ferromagnetic particles cannot be stably placed at the oil-water interface, and the oil and water phases cannot be stably emulsified. The water phase and the oil phase are still two phases, and it is impossible to obtain paraffin ball powder formed by silicon / titanium-coated ferromagnetic particles embedded in the surface of paraffin.

[0096] Example 5

[0097] S1. 2g of magnetic Fe3O4 particles (particle size 0.2μm) were dispersed in 200mL of ethanol, and 1g of tetrabutyl titanate and 1g of tetrabutyl titanate were added at the same time. The mixture was subjected to 60Hz sonication and 100rpm top stirring to promote the dispersion of magnetic Fe3O4 particles. The process was continued for 12h to obtain Fe3O4@SiO2 / TiO2 particles.

[0098] S2. Disperse Fe3O4@SiO2 / TiO2 particles in 200mL of water while simultaneously applying 60Hz ultrasound and 100rpm top-mounted stirring to promote dispersion. Raise the water temperature to 80℃, add 20g of paraffin wax (phase transition temperature 52℃), and continue stirring until the paraffin wax is completely melted. Turn off the ultrasound and increase the stirring speed to 6000rpm.

[0099] Due to excessive stirring speed, although the silicon / titanium-coated ferromagnetic particles were delivered to the oil-water interface by mechanical force to achieve emulsification, the excessively rapid mechanical stirring caused the particles to peel off at the interface, making the interface unstable and resulting in demulsification. As a result, it was impossible to obtain paraffin ball powder formed by silicon / titanium-coated ferromagnetic particles embedded in the surface of paraffin.

[0100] Comparative Example 1

[0101] S1. 2g of magnetic Fe3O4 particles (particle size 0.2μm) were dispersed in 200mL of ethanol, and 1g of tetrabutyl titanate and 1g of tetrabutyl titanate were added at the same time. The mixture was subjected to 60Hz sonication and 100rpm top stirring to promote the dispersion of magnetic Fe3O4 particles. The process was continued for 12h to obtain Fe3O4@SiO2 / TiO2 particles.

[0102] S2. Disperse Fe3O4@SiO2 / TiO2 particles in 200 mL of water while simultaneously applying 60 Hz ultrasound and 100 rpm top-mounted stirring to promote dispersion. Increase the water temperature to 80°C, add 20 g of paraffin wax (phase transition temperature 52°C), and continue stirring until the paraffin wax is completely melted. Turn off the ultrasound and increase the stirring speed to 2000 rpm, stirring continuously for 3 min. Stop stirring and heating, cool the sample to room temperature, filter out the solidified paraffin spheres, and separate them from the water. Disperse the paraffin spheres on filter paper and allow them to air dry naturally to obtain paraffin sphere powder formed by Fe3O4@SiO2 / TiO2 particles embedded in the paraffin wax surface.

[0103] S3. Disperse the paraffin ball powder in 100 mL of dimethyl sulfoxide and slowly stir the dispersion at 50 rpm using a top-mounted stirrer. Add 20 mg of 3-aminopropyltriethoxysilane to the dispersion and continue stirring for 6 hours. Separate the paraffin ball powder and solvent using an external magnetic field, and allow the paraffin ball powder to air dry naturally. Then disperse the paraffin ball powder in 100 mL of ethanol to dissolve the paraffin. Separate the solid particles using an external magnetic field to obtain Fe3O4@SiO2 / TiO2-NH2 particles with an amino-modified surface on one side.

[0104] S4. Disperse Fe3O4@SiO2 / TiO2-NH2 particles in 100 mL of ethanol. Stir the dispersion using a top-mounted stirrer at 300 rpm, while simultaneously applying 60 Hz ultrasound. Add 20 mg of n-octylpropyltriethoxysilane to the dispersion and continue stirring for 6 h. Separate the solid particles using an external magnetic field and air-dry them under natural conditions to obtain the granules.

[0105] Comparative Example 2

[0106] S1. 2g of magnetic Fe3O4 particles (particle size 0.2μm) were dispersed in 200mL of ethanol, and 1g of tetrabutyl titanate and 1g of tetrabutyl titanate were added at the same time. The mixture was subjected to 60Hz sonication and 100rpm top stirring to promote the dispersion of magnetic Fe3O4 particles. The process was continued for 12h to obtain Fe3O4@SiO2 / TiO2 particles.

[0107] S2. Disperse Fe3O4@SiO2 / TiO2 particles in 100mL of water, add 2mL of acetic acid, and stir the dispersion for 10h using a top-mounted stirrer at 100rpm, while simultaneously adding 60Hz ultrasound to obtain core-shell separated Fe3O4@SiO2 / TiO2 particles.

[0108] S3. Disperse the core-shell separated Fe3O4@SiO2 / TiO2 particles in 100 mL of ethanol, add 10 mg of 4-(chloromethyl)phenyltrimethoxysilane, and stir at 100 rpm for 12 h to obtain modified Fe3O4@SiO2 / TiO2 particles; dissolve 0.02 g of cuprous chloride and 0.02 g of 2,2-bipyridine in 50 mL of DMF, add the above-mentioned modified Fe3O4@SiO2 / TiO2 particles, and simultaneously add 0.1 g of DEAEMA. At the same time, purge with N2 for 30 min to remove oxygen, raise the temperature to 80 °C, and stir at 100 rpm for 3 h. After the reaction is completed, obtain the particles.

[0109] Comparative Example 3

[0110] The particles were prepared according to the preparation method of Example 1, except that acetic acid was replaced with an equal volume of dilute hydrochloric acid (pH 6).

[0111] Comparative Example 4

[0112] The granules were prepared according to the preparation method of Example 1, except that acetic acid was replaced with an equal volume of sulfuric acid.

[0113] Performance Evaluation

[0114] (a) The particle size of the particles in each embodiment and comparative example was measured using scanning electron microscopy. The results are shown in the table below:

[0115]

[0116]

[0117] (II) Wastewater Treatment Effect

[0118] One kg of each of the examples and comparative examples was added to 10 t of oily wastewater containing partially hydrolyzed polyacrylamide (COD value 2020, petroleum pollutant content 52.3 mg / L, partially hydrolyzed polyacrylamide content 103.05 mg / L). The wastewater was emulsified by stirring at 1000 rpm for 1 min using a shear mixer. Then, the migration and enrichment of oil droplets emulsified by magnetic particles were controlled by an external magnetic field. The treated wastewater was tested using the methods shown in the table below.

[0119]

[0120] The test results are shown in the table below:

[0121]

[0122] (III) Recyclability

[0123] The magnetic multi-functional amphiphilic hybrid particles are recycled by using a solvent method to wash and regenerate them. The specific processing method includes: collecting the magnetic multi-functional amphiphilic hybrid particles from Example 1 after wastewater treatment, washing them with ethanol (ethanol to particle mass ratio of 10:1), and then freeze-drying them to obtain the regenerated particles.

[0124] The treatment process of oily wastewater containing partially hydrolyzed polyacrylamide, using the regenerated particles in step (II), yielded wastewater with similar performance to that of the first wastewater treatment using the magnetic multifunctional amphiphilic hybrid particles from Example 1. These magnetic multifunctional amphiphilic hybrid particles can be recycled more than 100 times, and their removal efficiency for COD, petroleum hydrocarbons, and partially hydrolyzed polyacrylamide does not significantly decrease.

[0125] It should be noted that the embodiments described above are only for explaining the present invention and do not constitute any limitation on the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory terms, not limiting terms. Modifications can be made to the present invention within the scope of the claims, and revisions can be made to the present invention without departing from the scope and spirit of the present invention. Although the present invention described herein relates to specific methods, materials, and embodiments, it does not mean that the present invention is limited to the specific examples disclosed herein; on the contrary, the present invention can be extended to all other methods and applications with the same function.

Claims

1. A magnetic multi-effect amphiphilic hybrid particle, characterized in that, The magnetic multi-effect amphiphilic hybrid particle comprises a core-shell separated magnetic Fe3O4 particle core and a shell layer, the shell layer is a silica / titania hybrid shell layer with a fine pore structure, the outer surface of the shell layer comprises a hydrophilic part and a hydrophobic part, the inner surface of the shell layer and the surface of the magnetic Fe3O4 particle core are grafted with poly (diethylaminoethyl methacrylate) ; The fine pore structure comprises intermolecular voids present in the silica / titania macromolecular framework and defects generated in the core-shell separation process of the silica / titania hybrid shell layer from the magnetic Fe3O4 particle core, including micropores and capillary pores with a pore size of 0.5-50 nm.

2. The magnetic multi-effect amphiphilic hybrid particles according to claim 1, wherein, The hydrophilic part is obtained by modifying the outer surface of the shell layer with an amino-containing silane coupling agent; And / or, the hydrophobic part is obtained by modifying the outer surface of the shell layer with an alkyl-containing silane coupling agent.

3. The magnetic multi-effect amphiphilic hybrid particle according to claim 2, wherein, The amino-containing silane coupling agent comprises 3-aminopropyl triethoxysilane; And / or, the alkyl-containing silane coupling agent comprises n-octyl triethoxysilane.

4. The magnetic multi-effect amphiphilic hybrid particle according to any one of claims 1-3, wherein, The particle size of the magnetic multi-effect amphiphilic hybrid particle is 100 nm < r ≤ 1000 nm.

5. A method of preparing magnetic multi-effect amphiphilic hybrid particles, characterized by, Comprise: S1. Disperse the magnetic Fe3O4 particles into an alcohol solvent, add tetraethyl orthosilicate and tetra-n-butyl titanate and stir to obtain Fe3O4@SiO2 / TiO2 particles; S2. Disperse the Fe3O4@SiO2 / TiO2 particles into water, add paraffin, heat to completely melt the paraffin, stir and mix, cool and filter to obtain paraffin balls formed by embedding the surface of the paraffin with the Fe3O4@SiO2 / TiO2 particles; S3. Disperse the paraffin balls into dimethyl sulfoxide, add an amino-containing silane coupling agent, stir and react, disperse the obtained solid particles into an alcohol solvent to obtain hydrophilic modified particles; S4. Disperse the hydrophilic modified particles into ethanol, add an alkyl-containing silane coupling agent, stir and react to obtain amphiphilic modified particles; S5. Mix the amphiphilic modified particles with acetic acid for 8-12 h to obtain core-shell separated amphiphilic modified particles; S6. Disperse the core-shell separated amphiphilic modified particles into an alcohol solvent, add 4-(chloromethyl)phenyl trimethoxysilane for modification reaction, and then carry out grafting reaction with diethylaminoethyl methacrylate to prepare the magnetic multi-effect amphiphilic hybrid particle.

6. The production method according to claim 5, wherein The stirring and mixing speed in step S2 is 1000-5000 rpm; And / or, the amino-containing silane coupling agent comprises 3-aminopropyl triethoxysilane; And / or, the alkyl-containing silane coupling agent comprises n-octyl triethoxysilane.

7. The preparation method according to claim 6, characterized in that, The stirring and mixing time in step S2 is 3-5 min.

8. The production method according to any one of claims 5 to 7, characterized by, The mass ratio of the magnetic Fe3O4 particles, tetraethyl orthosilicate and tetra-n-butyl titanate is 1:(0.1-1):(0.1-1); And / or, the mass ratio of the magnetic Fe3O4 particles and the paraffin is 1:(10-200); And / or, the mass ratio of the magnetic Fe3O4 particles and the amino-containing silane coupling agent is 1:(0.001-0.01). And / or, the mass ratio of the magnetic Fe3O4 particles to the alkyl-containing silane coupling agent is 1: (0.001-0.01); And / or, the mass ratio of the magnetic Fe3O4 particles to the 4- (chloromethyl) phenyl trimethoxysilane is 1: (0.001-0.01); And / or, the mass ratio of the magnetic Fe3O4 particles to the diethylaminoethyl methacrylate is 1: (0.02~0.1).

9. The production method according to any one of claims 5 to 7, characterized by, The particle size of the magnetic Fe3O4 particles is 100~500nm; And / or, the particle size ratio of the magnetic Fe3O4 particles to the core of the magnetic Fe3O4 particles is 100: (10~99).

10. The production method according to any one of claims 5 to 7, characterized by, The grafting reaction comprises: dissolving cuprous chloride and 2,2-bipyridine in a solvent, adding the amphiphilic modified particles and diethylaminoethyl methacrylate after modification reaction treatment, and stirring and reacting under the conditions of nitrogen atmosphere and 60~100℃.

11. A magnetic multi-functional amphiphilic hybrid particle prepared by the preparation method of any one of claims 5-10.

12. The use of the magnetic multi-functional amphiphilic hybrid particle of any one of claims 1-4 or the magnetic multi-functional amphiphilic hybrid particle of claim 11 in the treatment of oil-containing wastewater containing partially hydrolyzed polyacrylamide.

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