Magnetic multi-effect polymer inorganic composite amphiphilic particles, and preparation method and application thereof

Abstract

The present application relates to sewage treatment technical field, provide a kind of magnetic multi-effect polymer inorganic composite amphiphilic particle and its preparation method and application.It includes core-shell separation magnetic Fe3O4 Particle core and silica shell, and the silica shell exists micro-pore structure;The outer surface of the silica shell includes hydrophilic part and hydrophobic part, the hydrophilic part has amino, the amino grafts polydopamine, and the polydopamine is combined with gallic acid;The inner surface of the silica shell and the surface of the magnetic Fe3O4 Particle core graft poly methacrylic acid diethylaminoethyl ester.The magnetic multi-effect polymer inorganic composite amphiphilic particle provided by the present application has excellent emulsifying performance, can realize oil-water separation;It also has selective adsorption characteristics, and can efficiently treat oil-containing wastewater containing partially hydrolyzed polyacrylamide in one step.

Description

TECHNICAL FIELD

[0001] The present application relates to the sewage treatment technical field, more particularly, to a magnetic multi-effect polymer inorganic composite amphiphilic particle and a preparation method and application thereof. BACKGROUND

[0002] With the large application of partially hydrolyzed polyacrylamide as a polymer polymer in the field of oil exploitation, the treatment of oil extraction sewage containing partially hydrolyzed polyacrylamide has also been paid attention to. However, compared with ordinary oily sewage, the treatment of oily sewage containing partially hydrolyzed polyacrylamide produced by using partially hydrolyzed polyacrylamide for oil extraction is more difficult, and the existing treatment method generally needs to use multi-step treatment to realize the treatment of oily sewage containing partially hydrolyzed polyacrylamide to reach the standard. How to efficiently remove partially hydrolyzed polyacrylamide while realizing oil-water separation in one step has been a difficult problem in the treatment of oily sewage containing partially hydrolyzed polyacrylamide.

[0003] Compared with traditional surfactants and emulsifiers, the amphiphilic solid particle emulsifier has the advantages of high efficiency, low foam, non-toxicity, environmental friendliness and the like, and realizes emulsification by reducing the interfacial tension of two phases, has a high interfacial desorption energy, and realizes efficient and stable emulsification of the emulsion. The magnetic amphiphilic solid particle can make the emulsified droplets have magnetism, and then realize the manipulation of the dispersed phase droplets. On this basis, the magnetic amphiphilic solid particle can be used to realize the treatment of oily sewage, realize the emulsification of the oil phase in water, and realize the stable dispersion of the dispersed phase oil droplets, realize the migration and enrichment of the oil droplets under the manipulation of the external magnetic field, and then realize the oil-water separation. However, although the existing amphiphilic solid particle emulsifier can successfully realize oil-water separation when applied to treat the oily sewage containing partially hydrolyzed polyacrylamide, it cannot efficiently remove the partially hydrolyzed polyacrylamide at the same time in one step. SUMMARY

[0004] The present application aims to provide a magnetic multi-effect polymer inorganic composite amphiphilic particle and a preparation method thereof, so as to solve the technical problem that the oily sewage containing partially hydrolyzed polyacrylamide is difficult to be treated in one step to reach the standard in the prior art.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present application is:

[0006] In a first aspect, the present application provides a magnetic multi-effect polymer inorganic composite amphiphilic particle, which comprises a core-shell separated magnetic Fe3O4 particle core and a silica shell layer, wherein the silica shell layer has a micro-pore structure; the outer surface of the silica shell layer comprises a hydrophilic part and a hydrophobic part, the hydrophilic part has an amino group, the amino group is grafted with polydopamine, and the polydopamine is compounded with gallic acid; the inner surface of the silica shell layer and the surface of the magnetic Fe3O4 particle core are grafted with poly (diethylaminoethyl methacrylate) (PDEAEMA).

[0007] It should be noted that the "micro-pore structure" in the present application includes intermolecular gaps in the silica macromolecular skeleton and defects generated in the core-shell separation process of the silica shell layer from the magnetic Fe3O4 particle core, even micro-pores and capillary pores with a pore size of 0.5-50 nm.

[0008] The magnetic multi-effect polymer inorganic composite amphiphilic particle provided by the present application can protect the internal magnetic Fe3O4 particle core by coating a layer of silica shell layer outside the magnetic Fe3O4 particle core, and can resist corrosion of hydrochloric acid, sulfuric acid, nitric acid and the like on the internal magnetic Fe3O4 particle core within a certain period of time, thereby ensuring the industrial application of the magnetic multi-effect polymer inorganic composite amphiphilic particle.

[0009] The outer surface of the silica shell layer of the magnetic multi-effect polymer inorganic composite amphiphilic particle provided by the present application comprises a hydrophilic part and a hydrophobic part at the same time, so that the magnetic multi-effect polymer inorganic composite amphiphilic particle has amphiphilicity, has more stable emulsification characteristics compared with traditional homogeneous particles, can more stably and more widely emulsify oil-water two-phase, form a stable oil-in-water emulsion, and provide a stability basis for the manipulation of emulsion droplets.

[0010] Moreover, the functional groups on the outer surface of the silica shell of the magnetic multi-effect polymer inorganic composite amphiphilic particle have electrostatic interaction with the partially hydrolyzed polyacrylamide, which promotes the adsorption of the partially hydrolyzed polyacrylamide on the outer surface of the silica shell; and the polydopamine grafted on the amino group of the hydrophilic part and the gallic acid complexed on the polydopamine by strong hydrogen bonding both contain polyhydroxy structures and have adhesion, further increasing the adhesion and hydrogen bonding of the amphiphilic particle to the partially hydrolyzed polyacrylamide, and improving the effect of the amphiphilic particle on removing the partially hydrolyzed polyacrylamide in wastewater. After the adsorption and adhesion of the partially hydrolyzed polyacrylamide are achieved, the internal structure of the amphiphilic particle promotes the adsorption process of the partially hydrolyzed polyacrylamide into the silica shell due to the wetting effect of the partially hydrolyzed polyacrylamide adsorbed and adhered on the outer surface of the silica shell. The PDEAEMA grafted on the inner surface of the silica shell and the inner core surface of the magnetic Fe3O4 particle forms a brush-like coating, which increases the specific surface area and enhances the hydrogen bonding density. The micro-pore structure on the silica shell provides a channel for the migration and transmission of the partially hydrolyzed polyacrylamide, and the weak acidity of the partially hydrolyzed polyacrylamide is conducive to the transfer and adsorption of the partially hydrolyzed polyacrylamide from the outer surface of the silica shell to the PDEAEMA inside the silica shell, so as to realize the adsorption and migration capture of the PDEAEMA to the partially hydrolyzed polyacrylamide. The magnetic multi-effect polymer inorganic composite amphiphilic particle provided by the present application greatly improves the adsorption capacity and efficiency of the partially hydrolyzed polyacrylamide by combining the internal and external structures.

[0011] The magnetic multi-effect polymer inorganic composite amphiphilic particle provided by the present application can be recycled and reused multiple times. The recovery method can use a good solvent (such as ethanol) of the partially hydrolyzed polyacrylamide to wash and extract the used particles to remove the adsorbed partially hydrolyzed polyacrylamide; or the pH sensitivity of the PDEAEMA (the PDEAEMA shows hydrophilic properties at low pH values and shows hydrophobic properties at high pH values) can be used to realize the repeated adsorption and desorption of the partially hydrolyzed polyacrylamide.

[0012] According to some embodiments of the present application, the amino group on the hydrophilic part is obtained by modifying the outer surface of the silica shell with an amino-containing silane coupling agent.

[0013] According to some embodiments of the present application, the amino-containing silane coupling agent includes 3-aminopropyl triethoxysilane.

[0014] The modification of the outer surface of the silica shell with 3-aminopropyl triethoxysilane makes the hydrophilic part of the silica shell have an amino group, which can produce weak interaction with the partially hydrolyzed polyacrylamide with carboxyl groups, thereby realizing the adsorption of the partially hydrolyzed polyacrylamide.

[0015] According to some embodiments of the present application, the hydrophobic part is obtained by modifying the outer surface of the silica shell with an alkyl-containing silane coupling agent.

[0016] According to some embodiments of the present application, the alkyl-containing silane coupling agent comprises n-octyltriethoxysilane.

[0017] According to some embodiments of the present application, the area of the hydrophilic part accounts for 1 / 3-2 / 3 of the total surface area of the magnetic multi-functional polymer inorganic composite amphiphilic particles.

[0018] According to some embodiments of the present application, the particle size of the magnetic multi-functional polymer inorganic composite amphiphilic particles is 100 nm < r ≤ 1000 nm.

[0019] In a second aspect, the present application provides a preparation method of magnetic multi-functional polymer inorganic composite amphiphilic particles, comprising:

[0020] S1. dispersing magnetic Fe3O4 particles and tetraethyl orthosilicate into an alcohol solvent to obtain silica-coated iron magnetic particles;

[0021] S2. dispersing the silica-coated iron magnetic particles into water, adding paraffin, heating to completely melt the paraffin, stirring and mixing, and filtering after cooling to obtain paraffin balls formed by embedding the silica-coated iron magnetic particles on the surface of the paraffin;

[0022] S3. dispersing the paraffin balls into dimethyl sulfoxide, adding an amino-containing silane coupling agent, stirring and reacting, and dispersing the obtained solid particles into an alcohol solvent to obtain hydrophilic modified particles;

[0023] S4. dispersing the hydrophilic modified particles into an alcohol solvent, adding an alkyl-containing silane coupling agent, stirring and reacting to obtain amphiphilic modified particles;

[0024] S5. mixing the amphiphilic modified particles with acetic acid for 8-12 h to obtain core-shell separated amphiphilic modified particles;

[0025] S6. dispersing the core-shell separated amphiphilic modified particles into an alcohol solvent, adding 4-(chloromethyl)phenyltrimethoxysilane for modification reaction; and then adding diethylaminoethyl methacrylate (DEAEMA) for grafting reaction to obtain particles grafted with polydiethylaminoethyl methacrylate;

[0026] S7. dispersing the particles grafted with polydiethylaminoethyl methacrylate into a solvent, adding dopamine for first stirring and reaction; adding gallic acid for second stirring and reaction, and obtaining the magnetic multi-functional polymer inorganic composite amphiphilic particles after the reaction is completed.

[0027] The preparation method of the magnetic multi-effect polymer inorganic composite amphiphilic particle provided by the application comprises the processes of silica shell wrapping, hydrophilic modification, hydrophobic modification, acid etching treatment, 4-(chloromethyl)phenyl trimethoxysilane modification, grafting polydimethylaminoethyl methacrylate (PDEAEMA), grafting polydopamine and complexing gallic acid. Specifically, the magnetic Fe3O4 particle is used as a carrier, tetraethyl orthosilicate is used to realize hydrolysis on the surface of the magnetic Fe3O4 particle, and a dense silica shell structure is formed on the surface of the magnetic Fe3O4 particle through a sol-gel process to protect the magnetic Fe3O4 particle. Then, paraffin is used as an oil phase, and the silica-iron magnetic particle is used as a solid particle emulsifier to emulsify the oil and water phases when the temperature is higher than the phase transition temperature of paraffin, so as to form a stable water-paraffin emulsion. After the emulsion is cooled, the paraffin phase is solidified and separated from the water phase, so as to obtain paraffin balls in which the silica-iron magnetic particles are embedded on the surface of paraffin, and the silica-iron magnetic particles are partially embedded in paraffin and partially exposed outside paraffin. Then, the outer surface of the silica-iron magnetic particles exposed outside paraffin is subjected to hydrophilic modification. After the paraffin is removed, the part of the silica-iron magnetic particles previously protected by paraffin is exposed, and the outer surface of the part is subjected to hydrophobic modification, so as to obtain amphiphilic particles with hydrophilic and hydrophobic parts on the surface of the particles. Then, acid etching treatment is performed to reduce the size of the magnetic Fe3O4 particle, separate the silica shell and form a hollow structure between the core-shell structures. Further, 4-(chloromethyl)phenyl trimethoxysilane is used to modify benzyl chloride 【4-(chloromethyl)phenyl】 on the surface of the magnetic Fe3O4 particle and the inner surface of the silica shell. The benzyl chloride has high activity and can be used to graft PDEAEMA through ATRP (atom transfer radical polymerization). Finally, the particles are reacted with dopamine to graft polydopamine, and then gallic acid is complexed on the polydopamine through strong hydrogen bonding. The magnetic multi-effect polymer inorganic composite amphiphilic particle is prepared.

[0028] In the application, in view of the characteristics that the magnetic Fe3O4 particle is not resistant to acid solvents, tetraethyl orthosilicate is used to realize hydrolysis on the surface of the magnetic Fe3O4 particle, and a relatively dense silica shell structure is formed on the surface of the magnetic Fe3O4 particle through a sol-gel process to protect the magnetic Fe3O4 particle inside, which can resist the corrosion of hydrochloric acid, sulfuric acid and nitric acid on the inner core of the magnetic Fe3O4 particle for a certain period of time, which provides an important guarantee for the industrial application of the magnetic particle. Moreover, the silica shell in the application is a polymer formed by the hydrolysis and condensation of tetraethyl orthosilicate, which is a macromolecular skeleton composed of silicon-oxygen bonds. Although the silica shell is relatively dense, the SiO2 macromolecular skeleton formed by the condensation reaction still has intermolecular gaps in the sol-gel process of the hydrolysis of tetraethyl orthosilicate, which ensures the smooth progress of the subsequent acid etching treatment, 4-(chloromethyl)phenyl trimethoxysilane modification and grafting PDEAEMA processes.

[0029] In the present application, the magnetic Fe3O4 particles are reduced in size by acid etching, resulting in core-shell separation. This process further causes defects in the silica shell, even micro- or capillary pores, which together with the intermolecular voids in the silica shell provide channels for the transport of partially hydrolyzed polyacrylamide into the interior of the silica shell. The acid etching reagent is acetic acid, which allows slow etching to ensure controllable etching and a smoother surface of the core of the magnetic Fe3O4 particles. If hydrochloric acid or sulfuric acid is used, it is difficult to control the etching process, which can easily lead to over-etching, resulting in too weak magnetic properties or even complete loss of magnetic properties.

[0030] According to some embodiments of the present application, the alcohol solvent includes at least one of methanol, ethanol, propanol, butanol, isopropanol, and cyclohexanol.

[0031] According to some embodiments of the present application, the stirring speed in step S2 is 1000-5000 rpm.

[0032] In the present application, the stirring speed in step S2 directly affects the emulsification process of the particle emulsifier (silica-coated iron magnetic particles), directly leading to the stability of the particle emulsifier to the interface. When the stirring speed is less than 1000 rpm, the stirring speed is too low, the particle emulsifier is difficult to deliver to the interface, and the interface cannot be stabilized, which is prone to emulsion breaking. When the stirring speed is greater than 5000 rpm, the stirring speed is too high, the particle emulsifier is forced to be pulled at the interface, which is prone to interface instability and emulsion breaking. Therefore, in order to ensure emulsification and interface stability, the stirring speed in step S2 is preferably controlled to be 1000-5000 rpm.

[0033] According to some embodiments of the present application, the stirring time in step S2 is 3-5 min.

[0034] According to some embodiments of the present application, the amino-containing silane coupling agent includes 3-aminopropyl triethoxysilane.

[0035] The local hydrophilic modification of the outer surface of the silica-coated iron magnetic particles using 3-aminopropyl triethoxysilane is carried out in dimethyl sulfoxide. The sol-gel complex is realized on the exposed outer surface of the silica-coated iron magnetic particles by a hydrolysis process, and the amino group is modified on one side of the outer surface of the silica-coated iron magnetic particles, which can realize the adsorption of partially hydrolyzed polyacrylamide.

[0036] According to some embodiments of the present application, the alkyl-containing silane coupling agent includes n-octyl triethoxysilane.

[0037] The local hydrophobic modification of the outer surface of the silicon-coated iron magnetic particles with n-octyl triethoxysilane is performed by first removing the paraffin wax using an alcohol solvent, exposing the silicon-coated iron magnetic particles embedded in the paraffin wax, and then modifying the other side of the outer surface of the silicon-coated iron magnetic particles with n-octyl triethoxysilane through a sol-gel composite process.

[0038] According to some embodiments of the present application, the mass ratio of the magnetic Fe3O4 particles and tetraethyl orthosilicate is 1:(0.1-1).

[0039] According to some embodiments of the present application, the mass ratio of the magnetic Fe3O4 particles and the paraffin wax is 1:(10-200).

[0040] According to some embodiments of the present application, the mass ratio of the paraffin wax and water is 1:(2-10).

[0041] According to some embodiments of the present application, the mass ratio of the magnetic Fe3O4 particles and the amino-containing silane coupling agent is 1:(0.001-0.01).

[0042] According to some embodiments of the present application, the mass ratio of the magnetic Fe3O4 particles and the alkyl-containing silane coupling agent is 1:(0.001-0.01).

[0043] According to some embodiments of the present application, the mass ratio of the magnetic Fe3O4 particles and the 4-(chloromethyl)phenyl trimethoxysilane is 1:(0.001-0.01).

[0044] According to some embodiments of the present application, the mass ratio of the magnetic Fe3O4 particles and the diethylaminoethyl methacrylate is 1:(0.02-0.1).

[0045] According to some embodiments of the present application, the mass ratio of the magnetic Fe3O4 particles and the dopamine is 1:(0.001-0.01).

[0046] According to some embodiments of the present application, the mass ratio of the magnetic Fe3O4 particles and the gallic acid is 1:(0.001-0.01).

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

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

[0049] In the present application, if the ratio of the particle size of the magnetic Fe3O4 particles to the particle size of the core of the magnetic Fe3O4 particles is less than 100:99, it means that the gap between the silica shell and the core of the magnetic Fe3O4 particles is too small, which will affect the adsorption capacity of the magnetic multi-effect polymer inorganic composite amphiphilic particles to the partially hydrolyzed polyacrylamide; if the ratio of the particle size of the magnetic Fe3O4 particles to the particle size of the core of the magnetic Fe3O4 particles is greater than 100:10, it means that the size of the core of the magnetic Fe3O4 particles is too small, which will cause serious magnetic decay and make it difficult to realize the magnetic control of the external magnetic field.

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

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

[0052] According to some embodiments of the present application, the solvent used for dispersing the particles of the grafted polymethyl methacrylate diethylaminoethyl comprises at least one of water, tetrahydrofuran (THF), and N,N-dimethylformamide (DMF).

[0053] According to some embodiments of the present application, in the step S1, the magnetic Fe3O4 particles and tetraethyl orthosilicate are dispersed in an alcohol solvent by ultrasonic and stirring for 12-24 hours, preferably, the ultrasonic frequency is 60-80 Hz and / or the stirring speed is 50-100 rpm.

[0054] According to some embodiments of the present application, in the step S2, the silicon-coated iron magnetic particles are dispersed in water by ultrasonic and stirring, 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 application, in the step S3, the paraffin balls are dispersed in dimethyl sulfoxide by stirring, preferably, the stirring speed is 50-100 rpm.

[0056] According to some embodiments of the present application, the stirring reaction time in the step S3 is 5-6 hours.

[0057] According to some embodiments of the present application, in the step S4, the hydrophilic modified particles are dispersed in an alcohol solvent by ultrasonic and stirring, preferably, the ultrasonic frequency is 60-80 Hz and / or the stirring speed is 200-300 rpm.

[0058] According to some embodiments of the present application, the stirring reaction time in step S4 is 5-6h.

[0059] According to some embodiments of the present application, the mixing of the amphiphilic modified particles with acetic acid for 8-12h in step S5 comprises: dispersing the amphiphilic modified particles in water, adding acetic acid, and mixing for 8-12h by ultrasonic and stirring, preferably, the ultrasonic frequency is 60-80Hz and / or the stirring speed is 50-100rpm.

[0060] According to some embodiments of the present application, the first stirring reaction time in step S7 is 5-6h.

[0061] According to some embodiments of the present application, the second stirring reaction time in step S7 is 5-6h.

[0062] In a third aspect, the present application provides a magnetic multi-effect polymer inorganic composite amphiphilic particle, which is prepared by the preparation method of the second aspect.

[0063] In a fourth aspect, the present application provides an application of the magnetic multi-effect polymer inorganic composite amphiphilic particle of the first aspect or the magnetic multi-effect polymer inorganic composite amphiphilic particle of the third aspect in treating oil-containing wastewater containing partially hydrolyzed polyacrylamide.

[0064] The present application has at least the following beneficial effects:

[0065] (1) The magnetic multi-effect polymer inorganic composite amphiphilic particle provided by the present application has a wide size distribution window, can realize sub-micron / micron distribution, and has uniform particle size, excellent emulsification performance, and the liquid droplets emulsified by the particle can be controlled by an external magnetic field to realize the enrichment and migration of oil droplets, thereby realizing oil-water separation.

[0066] (2) The magnetic multi-effect polymer inorganic composite amphiphilic particle provided by the present application has a core-shell separation structure, the poly (diethylaminoethyl methacrylate) grafted in the cavity between the core and the shell has a good adsorption effect on partially hydrolyzed polyacrylamide, the amino group on the surface of the particle and the polydopamine grafted on the amino group also have the ability to adsorb partially hydrolyzed polyacrylamide, and the gallic acid complexed with the polydopamine can construct stronger adhesion and hydrogen bond effect, further improving the removal effect and efficiency of partially hydrolyzed polyacrylamide in the oil-containing wastewater, thereby realizing one-step efficient treatment of the oil-containing wastewater containing partially hydrolyzed polyacrylamide.

[0067] (3) The magnetic multi-effect polymer inorganic composite amphiphilic particle provided by the application can realize repeated adsorption and desorption of partially hydrolyzed polyacrylamide, so that the magnetic multi-effect polymer inorganic composite amphiphilic particle can be repeatedly used multiple times, and the adsorption capacity for partially hydrolyzed polyacrylamide will not decrease obviously, which can greatly reduce the material cost of wastewater treatment.

[0068] (4) The preparation method of the magnetic multi-effect polymer inorganic composite amphiphilic particle provided by the application has simple process, low raw material cost and easy availability, and can realize industrialized ton-level batch production. DETAILED DESCRIPTION

[0069] In order to make the technical problems, technical solutions and beneficial effects of the application clearer, the application will be further described in detail below in combination with specific examples. It should be understood that the specific examples described herein are only used to illustrate the patent in detail, and do not limit the protection scope of the application in any way.

[0070] Unless otherwise defined, the technical terms used in the following examples have the same meanings as generally understood by those skilled in the art to which the application belongs. The reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the raw materials, instruments and equipment used in the following examples can be purchased on the market or obtained by existing methods; the reagent amount, unless otherwise specified, is the reagent amount in conventional experimental operation; and the experimental method, unless otherwise specified, is a conventional method.

[0071] Example 1

[0072] S1. 2.0 g of magnetic Fe3O4 particles (particle size of 0.2 μm) were dispersed in 200 mL of ethanol, and 1.0 g of tetraethyl orthosilicate was added, and 60 Hz ultrasonic and 100 rpm overhead stirring were additionally added to promote the dispersion of the magnetic Fe3O4 particles. The ultrasonic and stirring were maintained for 12 h, and the silicon-coated iron magnetic particles were separated.

[0073] S2. The silicon-coated iron magnetic particles were dispersed in 200 mL of water, and 60 Hz ultrasonic and 100 rpm overhead stirring were additionally added to promote the dispersion of the silicon-coated iron magnetic particles. The water temperature was increased to 80℃, 20 g of paraffin (phase transition temperature of 52℃) was added, and the stirring was continued until the paraffin was completely melted. The ultrasonic was turned off and the stirring speed was increased to 2000 rpm, and the stirring was continued for 3 min. The stirring and heating were stopped, and the sample was cooled to room temperature. The solidified paraffin balls were filtered out and separated from the water. The paraffin balls were dispersed on filter paper and naturally air-dried to obtain paraffin ball powder formed by the silicon-coated iron magnetic particles embedded on the surface of the paraffin.

[0074] S3. The paraffin wax ball powder was dispersed in 100 mL of dimethyl sulfoxide, and the dispersion was stirred slowly by a overhead stirrer at a speed of 50 rpm. 20 mg of 3- aminopropyltriethoxysilane was added to the dispersion, and the stirring was continued for 6 h. The paraffin wax ball powder and the solvent were separated by an external magnetic field, and the paraffin wax ball powder was dried naturally. The paraffin wax ball powder was dispersed in 100 mL of ethanol, and the paraffin wax was dissolved. The solid particles were separated by an external magnetic field to obtain Fe3O4@SiO2-NH2 particles with amino groups modified on one side of the surface.

[0075] S4. The Fe3O4@SiO2-NH2 particles were dispersed in 100 mL of ethanol, and the dispersion was stirred by a overhead stirrer at a speed of 300 rpm, while 60 Hz ultrasound was added. 20 mg of n-octyltriethoxysilane was added to the dispersion, and the stirring was continued for 6 h. The solid particles were separated by an external magnetic field to obtain C8-Fe3O4@SiO2-NH2 particles.

[0076] S5. The C8-Fe3O4@SiO2-NH2 particles were dispersed in 100 mL of water, and 2 mL of acetic acid was added. The dispersion was stirred by a overhead stirrer for 10 h at a speed of 100 rpm, while 60 Hz ultrasound was added. The C8-Fe3O4@SiO2-NH2 particles with core-shell separation were obtained.

[0077] S6. The C8-Fe3O4@SiO2-NH2 particles with core-shell separation were dispersed in 100 mL of ethanol, and 10 mg of 4-(chloromethyl)phenyltrimethoxysilane was added. The stirring was continued for 12 h at a speed of 100 rpm. The C8-Fe3O4@SiO2-NH2 particles treated by modification were obtained. 0.02 g of cuprous chloride and 0.02 g of 2,2-bipyridine were dissolved in 50 mL of DMF, and the C8-Fe3O4@SiO2-NH2 particles treated by modification were added. 0.1 g of DEAEMA was added, and N2 was introduced to remove oxygen for 30 min. The temperature was increased to 80 °C, and the stirring was continued for 3 h at a speed of 100 rpm. The particles grafted with poly (diethylaminoethyl methacrylate) were obtained.

[0078] S7. The particles grafted with poly (diethylaminoethyl methacrylate) were dispersed in a solvent, and 20 mg of dopamine was added. The reaction was stirred for 6 h. Then, 20 mg of gallic acid was added, and the reaction was stirred for 6 h. The magnetic multi-functional polymer inorganic composite amphiphilic particles were obtained after the reaction was completed.

[0079] Example 2

[0080] S1. 2.0 g of magnetic Fe3O4 particles (0.2 μm in size) were dispersed in 200 mL of ethanol, while 0.3 g of tetraethyl orthosilicate was added, 80 Hz ultrasound and 80 rpm overhead stirring were added, the ultrasound and stirring were kept to promote the dispersion of the magnetic Fe3O4 particles, and the process was continued for 24 h. The silicon-coated iron magnetic particles were separated.

[0081] S2. The silicon-coated iron magnetic particles were dispersed in 200 mL of water, while 80 Hz ultrasound and 80 rpm overhead stirring were added, the ultrasound and stirring were kept to promote the dispersion of the silicon-coated iron magnetic particles. The water temperature was raised to 80 °C, 50 g of paraffin (52 °C in phase transition temperature) was added, and the stirring was continued until the paraffin was completely melted. The ultrasound was turned off and the stirring speed was increased to 1000 rpm, and the stirring was continued for 5 min. The stirring and heating were stopped, and the sample was cooled to room temperature. The solidified paraffin balls were filtered off and separated from the water. The paraffin balls were dispersed on filter paper and naturally air-dried, obtaining paraffin ball powder in which the silicon-coated iron magnetic particles were embedded on the surface of the paraffin.

[0082] S3. The paraffin ball powder was dispersed in 100 mL of dimethyl sulfoxide, and the dispersion was slowly stirred using an overhead stirrer at a speed of 80 rpm. 3 mg of 3- aminopropyltriethoxysilane was added to the dispersion, and the stirring was continued for 5 h. The paraffin ball powder and the solvent were separated using an external magnetic field, and the paraffin ball powder was air-dried in a natural state. The paraffin ball powder was again dispersed in 100 mL of ethanol, the paraffin was dissolved, and the solid particles were separated using an external magnetic field, obtaining Fe3O4@SiO2-NH2 particles with amino-modified surfaces on one side.

[0083] S4. The Fe3O4@SiO2-NH2 particles were dispersed in 100 mL of ethanol, and the dispersion was stirred using an overhead stirrer at a speed of 300 rpm, while 80 Hz ultrasound was added. 3 mg of n-octyltriethoxysilane was added to the dispersion, and the stirring was continued for 5 h. The solid particles were separated using an external magnetic field, obtaining C8-Fe3O4@SiO2-NH2 particles.

[0084] S5. The C8-Fe3O4@SiO2-NH2 particles were dispersed in 100 mL of water, 2 mL of acetic acid was added, and the dispersion was stirred using an overhead stirrer for 8 h at a speed of 80 rpm, while 80 Hz ultrasound was added. Core-shell separated C8-Fe3O4@SiO2-NH2 particles were obtained;

[0085] S6. The C8-Fe3O4@SiO2-NH2 particles with core-shell separation were dispersed in 100 mL of ethanol, 3 mg of 4-(chloromethyl)phenyl trimethoxysilane was added, and stirring was performed at 80 rpm for 12 h to obtain modified C8-Fe3O4@SiO2-NH2 particles; 0.02 g of cuprous chloride and 0.02 g of 2,2-bipyridine were dissolved in 50 mL of DMF, the above modified C8-Fe3O4@SiO2-NH2 particles were added, 0.04 g of DEAEMA was added, and N2 was introduced to remove oxygen for 30 min, and the temperature was increased to 80°C, and stirring was performed at 80 rpm for 3 h to obtain particles grafted with poly(diethylaminoethyl methacrylate);

[0086] S7. The particles grafted with poly(diethylaminoethyl methacrylate) were dispersed in a solvent, 3 mg of dopamine was added, and stirring was performed for 6 h, 3 mg of gallic acid was further added, and stirring was performed for 6 h, and the magnetic multi-functional polymer inorganic composite amphiphilic particles were obtained after the reaction was completed.

[0087] Example 3

[0088] S1. 2.0 g of magnetic Fe3O4 particles (with a particle size of 0.2 μm) were dispersed in 200 mL of ethanol, and 2.0 g of tetraethyl orthosilicate was added, and 80 Hz ultrasonic and 60 rpm overhead stirring were additionally performed to promote the dispersion of the magnetic Fe3O4 particles, and the ultrasonic and stirring were maintained for 12 h, and the silicon-coated iron magnetic particles were separated.

[0089] S2. The silicon-coated iron magnetic particles were dispersed in 200 mL of water, and 80 Hz ultrasonic and 60 rpm overhead stirring were additionally performed to promote the dispersion of the silicon-coated iron magnetic particles. The water temperature was increased to 80°C, 20 g of paraffin (with a phase transition temperature of 52°C) was added, and stirring was continuously performed until the paraffin was completely melted. The ultrasonic was turned off and the stirring speed was increased to 5000 rpm, and the stirring was continuously performed for 4 min. The stirring and heating were stopped, the sample was cooled to room temperature, and the solidified paraffin balls were filtered out and separated from the water. The paraffin balls were dispersed on filter paper and naturally air-dried to obtain paraffin ball powder in which the silicon-coated iron magnetic particles were embedded on the surface of the paraffin.

[0090] S3. The paraffin ball powder was dispersed in 100 mL of dimethyl sulfoxide, and the dispersion was slowly stirred by using an overhead stirrer at a speed of 60 rpm. 10 mg of 3-aminopropyl triethoxysilane was added to the dispersion, and the stirring was continuously performed for 6 h. The paraffin ball powder and the solvent were separated by using an external magnetic field, and the paraffin ball powder was air-dried in a natural state. The paraffin ball powder was further dispersed in 100 mL of ethanol, the paraffin was dissolved, the solid particles were separated by using an external magnetic field, and Fe3O4@SiO2-NH2 particles with amino-modified surfaces on one side were obtained.

[0091] S4. Disperse Fe3O4@SiO2-NH2 particles into 100 mL ethanol, stir the dispersion with an overhead stirrer at 200 rpm, while adding 80 Hz ultrasound. Add 10 mg of n-octyltriethoxysilane to the dispersion, continue stirring for 6 h, separate the solid particles with an external magnetic field, and obtain C8-Fe3O4@SiO2-NH2 particles.

[0092] S5. Disperse C8-Fe3O4@SiO2-NH2 particles in 100 mL water, add 2 mL of acetic acid, stir the dispersion with an overhead stirrer at 60 rpm for 12 h, while adding 80 Hz ultrasound, and obtain core-shell separated C8-Fe3O4@SiO2-NH2 particles.

[0093] S6. Disperse core-shell separated C8-Fe3O4@SiO2-NH2 particles in 100 mL ethanol, add 15 mg of 4-(chloromethyl)phenyltrimethoxysilane, and stir at 60 rpm for 12 h to obtain modified C8-Fe3O4@SiO2-NH2 particles; dissolve 0.02 g of cuprous chloride and 0.02 g of 2,2-bipyridine in 50 mL of DMF, add the above modified C8-Fe3O4@SiO2-NH2 particles, add 0.2 g of DEAEMA, and pass N2 to remove oxygen for 30 min, then heat to 80°C, and stir at 60 rpm for 3 h to obtain particles grafted with poly(diethylaminoethyl methacrylate);

[0094] S7. Disperse the particles grafted with poly(diethylaminoethyl methacrylate) into a solvent, add 10 mg of dopamine, stir the reaction for 6 h, then add 10 mg of gallic acid, stir the reaction for 6 h, and obtain magnetic multi-functional polymer inorganic composite amphiphilic particles after the reaction is completed.

[0095] Example 4

[0096] S1. Disperse 2.0 g of magnetic Fe3O4 particles (particle size of 0.2 μm) into 200 mL of ethanol, while adding 1.0 g of tetraethyl orthosilicate, and add 60 Hz ultrasound and 100 rpm overhead stirring to promote dispersion of the magnetic Fe3O4 particles, and continue for 12 h, and separate to obtain silicon-coated iron magnetic particles.

[0097] S2. Disperse the silica-coated magnetic particles into 200 mL water while adding 60 Hz ultrasound and 100 rpm overhead stirring, keep the ultrasound and stirring to promote the dispersion of the silica-coated magnetic particles. Increase the water temperature to 80 °C, add 20 g paraffin wax (phase transition temperature is 52 °C), continue stirring until the paraffin wax is completely melted. Turn off the ultrasound and increase the stirring speed to 6000 rpm. Because the stirring speed is too high, the silica-coated magnetic particles are mechanically delivered to the oil-water interface to achieve emulsification, but the fast mechanical stirring causes the particles to be stripped from the interface, making the interface unstable, resulting in demulsification, and the silica-coated magnetic particle-embedded paraffin wax powder cannot be prepared.

[0098] Example 5

[0099] S1. Disperse 2.0 g of magnetic Fe3O4 particles (particle size is 0.2 μm) into 200 mL of ethanol, while adding 1.0 g of tetraethyl orthosilicate, and adding 60 Hz ultrasound and 100 rpm overhead stirring, keep the ultrasound and stirring to promote the dispersion of the magnetic Fe3O4 particles, continue for 12 h, and separate the silica-coated magnetic particles.

[0100] S2. Disperse the silica-coated magnetic particles into 200 mL water while adding 60 Hz ultrasound and 100 rpm overhead stirring, keep the ultrasound and stirring to promote the dispersion of the silica-coated magnetic particles. Increase the water temperature to 80 °C, add 20 g paraffin wax (phase transition temperature is 52 °C), continue stirring until the paraffin wax is completely melted. Turn off the ultrasound and increase the stirring speed to 6000 rpm. Because the stirring speed is too high, the silica-coated magnetic particles are mechanically delivered to the oil-water interface to achieve emulsification, but the fast mechanical stirring causes the particles to be stripped from the interface, making the interface unstable, resulting in demulsification, and the silica-coated magnetic particle-embedded paraffin wax powder cannot be prepared.

[0101] Comparative Example 1

[0102] S1. Disperse 2.0 g of magnetic Fe3O4 particles (particle size is 0.2 μm) into 200 mL of ethanol, while adding 1.0 g of tetraethyl orthosilicate, and adding 60 Hz ultrasound and 100 rpm overhead stirring, keep the ultrasound and stirring to promote the dispersion of the magnetic Fe3O4 particles, continue for 12 h, and separate the silica-coated magnetic particles.

[0103] S2. Disperse the silicon-coated magnetic particles into 200 mL water, while adding 60 Hz ultrasound and 100 rpm overhead stirring, keeping the ultrasound and stirring to promote the dispersion of the silicon-coated magnetic particles. Increase the water temperature to 80 °C, add 20 g of paraffin wax (phase transition temperature of 52 °C), continue stirring until the paraffin wax is completely melted. Turn off the ultrasound and increase the stirring speed to 2000 rpm, continue stirring for 3 min. Stop stirring and heating, cool the sample to room temperature, filter out the solidified paraffin wax balls, separate them from the water. Disperse the paraffin wax balls on filter paper, air dry to obtain paraffin wax ball powder with silicon-coated magnetic particles embedded in the surface of the paraffin wax.

[0104] S3. Disperse the paraffin wax ball powder into 100 mL dimethyl sulfoxide, slowly stir the dispersion with an overhead stirrer at a speed of 50 rpm. Add 20 mg of 3- aminopropyltriethoxysilane to the dispersion, continue stirring for 6 h. Use an external magnetic field to separate the paraffin wax ball powder and the solvent, and air dry the paraffin wax ball powder. Disperse the paraffin wax ball powder in 100 mL ethanol again, dissolve the paraffin wax, separate the solid particles using an external magnetic field, and obtain Fe3O4@SiO2-NH2 particles with amino groups modified on one side of the surface.

[0105] S4. Disperse the Fe3O4@SiO2-NH2 particles into 100 mL ethanol, stir the dispersion with an overhead stirrer at a speed of 300 rpm, while adding 60 Hz ultrasound. Add 20 mg of n-octyltriethoxysilane to the dispersion, continue stirring for 6 h, and separate the solid particles using an external magnetic field to obtain C8-Fe3O4@SiO2-NH2 particles.

[0106] S5. Disperse the C8-Fe3O4@SiO2-NH2 particles in a solvent, add 20 mg of dopamine, stir for 6 h, then add 20 mg of gallic acid, stir for 6 h, to obtain the particles.

[0107] Comparative Example 2

[0108] S1. Disperse 2.0 g of magnetic Fe3O4 particles (particle size of 0.2 μm) into 200 mL of ethanol, while adding 1.0 g of tetraethyl orthosilicate, adding 60 Hz ultrasound and 100 rpm overhead stirring, keeping the ultrasound and stirring to promote the dispersion of the magnetic Fe3O4 particles, for 12 h, and separating to obtain silicon-coated magnetic particles.

[0109] S2. Disperse the silicon-coated magnetic particles in 100 mL of water, add 2 mL of acetic acid, stir the dispersion with an overhead stirrer at a speed of 100 rpm for 10 h, while adding 60 Hz ultrasound, to obtain silicon-coated magnetic particles with core-shell separation;

[0110] S3. The core-shell separated silicon-coated iron magnetic particles were dispersed in 100 mL of ethanol, 10 mg of 4-(chloromethyl)phenyltrimethoxysilane was added, and stirring was carried out at 100 rpm for 12 h to obtain modified silicon-coated iron magnetic particles; 0.02 g of cuprous chloride and 0.02 g of 2,2-bipyridine were dissolved in 50 mL of DMF, the above modified silicon-coated iron magnetic particles were added, 0.1 g of DEAEMA was added, oxygen was removed by N2 for 30 min, the temperature was raised to 80°C, and stirring was carried out at 100 rpm for 3 h. After the reaction was completed, the particles were obtained.

[0111] Comparative Example 3

[0112] The particles were prepared according to the preparation method of Example 1, except that acetic acid was replaced by an equal volume of dilute hydrochloric acid (PH 6).

[0113] Comparative Example 4

[0114] The particles were prepared according to the preparation method of Example 1, except that acetic acid was replaced by an equal volume of sulfuric acid.

[0115] Performance evaluation

[0116] (I) The particle size of the particles of each example and comparative example was measured by scanning electron microscopy, and the results are shown in the following table:

[0117] Group Particle diameter (nm) Example 1 300 Example 2 218 Example 3 280 Comparative Example 1 300 Comparative Example 2 220 Comparative Example 3 300 Comparative Example 4 300

[0118] (II) Wastewater treatment effect

[0119] 1 kg of the particles prepared in each example and comparative example was added to 10 t of oil-containing wastewater containing partially hydrolyzed polyacrylamide (COD value was 2020, oil pollutant content was 52.3 mg / L, and partially hydrolyzed polyacrylamide content was 103.05 mg / L), and the oil-containing wastewater was emulsified by using a shearing machine to stir at a speed of 1000 rpm for 1 min; then the migration and enrichment of the magnetic particle emulsified oil droplets were realized by external magnetic field control. The treated wastewater was detected, and the detection method is shown in the following table:

[0120]

[0121] The detection results are shown in the following table:

[0122]

[0123] (III) Recycling performance

[0124] The magnetic multi-effect polymer inorganic composite amphiphilic particles of Example 1 were regenerated. The specific method included: collecting the magnetic multi-effect polymer inorganic composite amphiphilic particles of Example 1 after wastewater treatment, washing with ethanol, the mass ratio of ethanol to the amphiphilic particles was 10:1, and then freeze-drying treatment after washing to obtain the regenerated particles.

[0125] The process of treating wastewater containing partially hydrolyzed polyacrylamide and oil in (ii) was repeated using the regenerated particles, and the indicators of the treated wastewater were similar to the treatment effect of the magnetic multi-effect polymer inorganic composite amphiphilic particles of Example 1 in the first wastewater treatment. The recycling number of the magnetic multi-effect polymer inorganic composite amphiphilic particles can reach more than 100 times, and the removal effect of COD, oil and partially hydrolyzed polyacrylamide will not be significantly worse.

[0126] It should be noted that the above-described examples are only used to explain the present application and do not constitute any limitation on the present application. The present application is described by referring to typical examples, but it should be understood that the words used therein are descriptive and explanatory words, rather than limiting words. The present application can be modified as specified within the scope of the claims of the present application, and the present application can be revised without departing from the scope and spirit of the present application. Although the present application described therein relates to specific methods, materials and examples, it does not mean that the present application is limited to the specific examples disclosed therein, on the contrary, the present application can be extended to all other methods and applications with the same function.

Claims

1. A magnetic multi-functional polymer inorganic composite amphiphilic particle, characterized in that, The magnetic multifunctional polymer inorganic composite amphiphilic particles comprise a core-shell separated magnetic Fe3O4 particle core and a silica shell, wherein the silica shell has a microporous structure; the outer surface of the silica shell comprises a hydrophilic portion and a hydrophobic portion, wherein the hydrophilic portion has an amino group, the amino group is grafted with polydopamine, and gallic acid is composited on the polydopamine; the inner surface of the silica shell and the surface of the magnetic Fe3O4 particle core are grafted with poly(diethylaminoethyl methacrylate).

2. The magnetic multi-functional polymer inorganic composite amphiphilic particles according to claim 1, characterized in that, The amino groups on the hydrophilic portion are obtained by modifying the outer surface of the silica shell with an amino-containing silane coupling agent; And / or, the hydrophobic portion is obtained by modifying the outer surface of the silica shell with an alkyl-containing silane coupling agent; And / or, the particle size of the magnetic multifunctional polymer inorganic composite amphiphilic particles is 100nm < r ≤ 1000nm.

3. The magnetic multi-functional polymer inorganic composite amphiphilic particles according to claim 2, characterized in that, The amino-containing silane coupling agent includes 3-aminopropyltriethoxysilane; And / or, the alkyl-containing silane coupling agent includes n-octyltriethoxysilane.

4. A method for preparing magnetic multifunctional polymer inorganic composite amphiphilic particles, characterized in that, include: S1. Magnetic Fe3O4 particles and tetraethyl orthosilicate are dispersed in an alcohol solvent to obtain silicon-coated iron magnetic particles; S2. Disperse silicon-coated ferromagnetic 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 silicon-coated ferromagnetic particles embedded on the surface of paraffin wax. 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. S4. Disperse the hydrophilic modified particles in an alcohol solvent, add an alkyl-containing silane coupling agent, stir the reaction, and obtain amphiphilic modified particles; S5. Mix the amphiphilic modified particles with acetic acid for 8-12 hours to obtain core-shell separated amphiphilic modified particles; 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 particles grafted with diethylaminoethyl methacrylate. S7. Disperse the grafted poly(diethylaminoethyl methacrylate) particles in a solvent, add dopamine, and stir for the first reaction; then add gallic acid and stir for the second reaction. After the reaction is completed, the magnetic multifunctional polymer inorganic composite amphiphilic particles are obtained.

5. The preparation method according to claim 4, characterized in that, The stirring speed in step S2 is 1000~5000 rpm.

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

7. The preparation method according to any one of claims 4-6, characterized in that, The amino-containing silane coupling agent includes 3-aminopropyltriethoxysilane; And / or, the alkyl-containing silane coupling agent includes n-octyltriethoxysilane.

8. The preparation method according to any one of claims 4-6, characterized in that, The mass ratio of the magnetic Fe3O4 particles to tetraethyl orthosilicate is 1:(0.1~1). And / or, the mass ratio of the magnetic Fe3O4 particles to the paraffin is 1:(10~200); And / or, the mass ratio of the magnetic Fe3O4 particles to 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)phenyltrimethoxysilane 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). And / or, the mass ratio of the magnetic Fe3O4 particles to the dopamine is 1:(0.001-0.01). And / or, the mass ratio of the magnetic Fe3O4 particles to the gallic acid is 1:(0.001-0.01).

9. The preparation method according to any one of claims 4-6, characterized in that, The magnetic Fe3O4 particles have a particle size of 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 preparation method according to any one of claims 4-6, characterized in that, The grafting reaction includes: dissolving cuprous chloride and 2,2-bipyridine in a solvent, adding amphiphilic modified particles that have undergone modification treatment and diethylaminoethyl methacrylate, and stirring the reaction under a nitrogen atmosphere and at 60~100°C.

11. A magnetic multifunctional polymer inorganic composite amphiphilic particle, prepared by any one of claims 4-10.

12. The application of the magnetic multifunctional polymer inorganic composite amphiphilic particles according to any one of claims 1-3 or the magnetic multifunctional polymer inorganic composite amphiphilic particles according to claim 11 in the treatment of oily wastewater containing partially hydrolyzed polyacrylamide.

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