Preparation method of polyacrylamide for treatment

Abstract

The invention relates to the technical field of preparation of high polymer materials and intelligent response materials, in particular to a preparation method of polyacrylamide for treatment. And constructing a quaternary polymerization system with acrylamide, a temperature-sensitive monomer and a zirconium-based metal organic framework-graphene quantum dot composite material. Magnetic response interpenetrating network gel is formed by induction of a photo-magnetic synergistic field, bacterial cellulose nanofibrils and a calcium silicate layered structure are introduced through a biomimetic mineralization technology, and the hierarchical porous carrier is prepared by combining a microfluidic crushing technology and a supercritical drying technology. Finally, through an intelligent regeneration mechanism of bimetal coordination activation and high-frequency magnetic field triggering, the material is endowed with multiple stimulation response characteristics, high adsorption capacity and in-situ regeneration capacity, and the mechanical strength and the salt resistance are remarkably improved through a pearl-layer-like micro-nano laminated structure. The method is suitable for industrial wastewater advanced treatment and emergency pollution repair scenes.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of high polymer material and intelligent response material preparation, and particularly relates to a preparation method of polyacrylamide for treatment. BACKGROUND

[0002] Polyacrylamide is an important water-soluble high polymer material and is widely used in water treatment, oil exploitation, papermaking and other industries. The core requirement is to prepare products with high molecular weight, high solubility and stable performance. For example, in the application of oil displacement agent in oil fields, the molecular weight needs to be increased to enhance the viscosity so as to improve the oil displacement efficiency; in sewage treatment, the solubility needs to be improved to shorten the treatment time and reduce the energy consumption. In addition, the requirements of temperature resistance and salt resistance for specific scenes also put forward higher requirements on the synthesis process of polyacrylamide, and performance breakthrough needs to be realized through structure optimization or functional modification.

[0003] At present, the existing schemes for such technical requirements mainly include the following:

[0004] Free radical polymerization technology: through an initiator such as ammonium persulfate, the polymerization of acrylamide monomers is initiated, and the chain growth is realized by combining stirring and temperature control, so that a high molecular weight product is finally formed. Some processes further introduce ion exchange or ultrafiltration technology to improve the purity.

[0005] Emulsion polymerization technology: acrylamide aqueous solution is dispersed in an organic solvent, an emulsion system is formed through vigorous stirring, and a photoinitiator or an oxidation-reduction system is added to initiate polymerization, so that a high molecular weight latex product is obtained. The molecular weight distribution can be controlled by adjusting the type and concentration of emulsifier.

[0006] Functional modification technology: inorganic materials such as graphene and nano-clay are added during polymerization, or temperature-resistant and salt-resistant groups are introduced through graft copolymerization to improve the thermal stability and salt solubility of the product. For example, a temperature-resistant product can be prepared by mixing hydrolyzed polyacrylamide and graphene through a kneader.

[0007] Although the above technical schemes meet the preparation requirements of polyacrylamide to some extent, there are still the following problems:

[0008] It is difficult to control the reaction conditions: in the free radical polymerization process, the decomposition rate of the initiator is highly related to the temperature, and if the temperature control is not accurate, local overheating or excessive reaction rate may occur, which affects the molecular weight distribution and stability of the product.

[0009] The cost of functional modification is high: although the addition of additives such as graphene and nano materials can improve the performance, high-purity raw materials need to be additionally purchased and a mixing and kneading process needs to be added, which leads to a significant increase in production cost, and batch quality fluctuations may be caused by uneven dispersion.

[0010] Environmental protection and energy consumption: emulsion polymerization requires the use of a large amount of organic solvent, and the subsequent recovery and treatment process is complex, which increases energy consumption and pollution risk; and the functional modification process involves high-temperature hydrolysis or strong alkali and acid conditions, which may enhance the corrosion of equipment, and the treatment of waste liquid is more difficult. SUMMARY

[0011] In view of the deficiencies of the prior art, the present application provides a preparation method of polyacrylamide for treatment, which solves the problems in the above background art.

[0012] According to a first aspect of the present application, a preparation method of polyacrylamide for treatment is provided, comprising the following steps:

[0013] (a) Synthesis of acryloyl bifunctional monomer: 10-20 parts of acryloyl chloride and 5-10 parts of thiol, sulfonic acid group disubstituted β cyclodextrin are placed in a mixed solvent under argon protection, 0.5-1.0 parts of genetically engineered bifunctional enzyme is added, and the reaction is carried out under the conditions of temperature of-5 to 0℃ and microwave power of 200-400W for 0.5-1 hour to prepare the acryloyl bifunctional monomer;

[0014] (b) Preparation of monomer mixed solution: 60-80 parts of acrylamide, 10-15 parts of the acryloyl bifunctional monomer prepared in step (a), 5-10 parts of isopropyl acrylamide, 0.5-2 parts of zirconium metal organic framework material@graphene quantum dots, and 100-200 parts of magnetized deionized water are mixed and then placed in a microfluidic homogenizer for treatment for 10-15 minutes to prepare the monomer mixed solution;

[0015] (c) Light-magnetic field controlled polymerization: the monomer mixed solution prepared in step (b) is placed in a light-magnetic reactor, argon is introduced for 20-30 minutes, then 0.03-0.08 parts of a tetranuclear manganese cluster oxidant and 0.01-0.03 parts of yttrium sodium fluoride doped ytterbium erbium upconversion particles are added, and the polymerization is carried out under the conditions of near-infrared light with a wavelength of 980-1000nm and an alternating magnetic field with a frequency of 8-12kHz for 1.5-3 hours to prepare a magnetic response interpenetrating gel;

[0016] (d) Biomimetic mineralization enhancement: the magnetic response interpenetrating gel prepared in step (c) is immersed in 5-10 parts of a mixed solution containing dopamine and ferric chloride, 1-2 parts of bacterial cellulose nanofibrils are added, and the oscillation reaction is carried out under the conditions of temperature of 45-55℃ and rotation speed of 180-220rpm for 2-3 hours to prepare a pearl-like enhanced gel;

[0017] (e) Microfluidic breaking and molding: the pearl-like enhanced gel prepared in step (d) is broken into microspheres with a diameter of 50-200μm through a microfluidic chip under the cooperation of pulsed ultrasound with a frequency of 18-22kHz, and after supercritical carbon dioxide drying, a multi-level pore carrier is obtained.

[0018] (f) bimetallic activation treatment: the multi-level pore carrier prepared in step (e) is immersed in 5-10 parts of an activation solution containing zinc chloride and lanthanum chloride, and is treated at 40-50℃ for 20-40 minutes to prepare bimetallic coordination microspheres;

[0019] (g) intelligent regeneration treatment: the bimetallic coordination microspheres prepared in step (f) are placed in a citric acid buffer solution with a pH of 2.0-2.5, and are treated by an alternating magnetic field with a frequency of 80-120 kHz for 10-15 minutes, and after drying, the treated polyacrylamide is obtained.

[0020] According to the embodiment of the present application, in step (a), the thiol and sulfonic acid group double-substituted β-cyclodextrin is a white powder prepared by reacting β-cyclodextrin with mercaptopropionic acid at a molar ratio of 1:1.5-1:1.7 at 42-44℃ for 4-5 hours, and then sulfonating with chlorosulfonic acid at a molar ratio of 1:2.8-1:3.2 at 1-3℃ for 1-2 hours, wherein the substitution rate of thiol is 85%-90%, and the substitution rate of sulfonic acid group is 90%-95%; the mixed solvent is a homogeneous solution composed of tetrahydrofuran, methyl imidazole acetate and supercritical carbon dioxide at a volume ratio of 3:4.5:2-3:5.5:2.5.

[0021] According to the embodiment of the present application, in step (a), the acryloyl chloride and the thiol and sulfonic acid group double-substituted β-cyclodextrin react efficiently in the mixed solvent under the catalysis of the genetically engineered bifunctional enzyme. The argon gas protection environment effectively isolates oxygen interference, ensuring the stability of the reaction system. The mixed solvent provides a homogeneous medium for the reaction, promoting the directional arrangement of functional groups. The multi-hydroxyl structure of the thiol and sulfonic acid group double-substituted β-cyclodextrin and the active double bond of the acryloyl chloride form a double-reactive acryloyl bifunctional monomer under the synergistic action of the enzyme. The stereoselective catalytic properties of the genetically engineered bifunctional enzyme further ensure the accuracy of the spatial configuration of the product, ultimately realizing the directional synthesis of high-purity target monomers.

[0022] According to the embodiment of the present application, in step (b), the zirconium metal organic framework material@graphene quantum dot is a gray composite powder prepared by hydrothermal compounding of zirconium metal organic framework and graphene quantum dots at a mass ratio of 8.5:1-9:1 at 65-68℃ for 13-14 hours; the pressure of the microfluidizer is 120-150 MPa.

[0023] The loading amount of the graphene quantum dots is 12.5%-13.5%, and the pore size is 1.55-1.65 nm.

[0024] According to the embodiment of the present application, in step (b), acrylamide is blended with acryloyl bifunctional monomer to construct a polymer skeleton with rigidity and functionality, wherein isopropyl acrylamide is introduced to regulate the material responsiveness; zirconium metal organic framework material and graphene quantum dots form a three-dimensional conductive network to improve the structural stability and load capacity; magnetized water molecules promote the uniform dispersion of each component through hydrogen bonding, and realize nanoscale mixing through microfluidic shear force, finally forming a monomer system with multi-scale synergistic effect, providing a homogenized reaction substrate for subsequent polymerization.

[0025] According to the embodiment of the present application, in step (c), the tetracore manganese cluster oxidant is a brown crystal prepared by self-assembly of manganese acetate and pyridine at a molar ratio of 1:2.5-1:3 at 60-65 DEG C for 24-36 hours; the yttrium sodium fluoride doped ytterbium erbium upconversion particles are core-shell particles obtained by coating yttrium sodium fluoride with silicon dioxide at a molar ratio of 3.9:1-4.1:1.

[0026] The particle size of the yttrium sodium fluoride doped ytterbium erbium upconversion particles is 45-55 nm, and the shell thickness is 6-7 nm.

[0027] According to the embodiment of the present application, in step (c), after the inert gas is introduced to exclude the interference of oxygen, the tetracore manganese cluster oxidant and the yttrium sodium fluoride doped ytterbium erbium upconversion particles are introduced, and the two form a multiple synergistic effect with the near-infrared light of a specific wavelength and the alternating magnetic field. The yttrium sodium fluoride doped ytterbium erbium upconversion particles convert low-energy near-infrared light into high-energy visible light to excite the oxidant and promote the generation of active free radicals. The alternating magnetic field regulates the molecular chain orientation through magnetic force to make the polymer network exhibit magnetic response characteristics. At the same time, the coupling effect of the magnetic field and the light field can accurately control the polymerization rate, so that the three-dimensional interpenetrating network structure grows uniformly, and finally a gel material with light and magnetic sensitivity and high strength is formed.

[0028] According to the embodiment of the present application, in step (d), the mixed solution containing dopamine and ferric chloride is a blue-black solution formed by complexing dopamine and ferric chloride at a molar ratio of 0.8:1-1.2:1; the bacterial cellulose nanofilament is a white fiber with a diameter of 25-35 nm prepared by static culture of Xylonia bacterium at 30-35 DEG C for 7-10 days.

[0029] According to the embodiment of the present application, in step (d), after the magnetic response interpenetrating gel is immersed in the mixed solution containing dopamine and ferric chloride, dopamine undergoes self-polymerization reaction under the catalysis of iron ions to form a biomimetic adhesion layer, and the bacterial cellulose nanofibrils synergistically enhance the gel network through physical cross-linking and chemical bonding. Iron ions not only act as a mineralization initiator, but also construct a nacre-like structure together with dopamine, and the high specific surface area and oriented arrangement of nanofibrils further improve the mechanical properties. The dynamic oscillation environment in the solution system promotes the uniform dispersion of multiple components, enabling the biomimetic mineralization process to proceed simultaneously at the molecular and mesoscopic scales, and finally forming a composite gel material with layered micro-nano structure.

[0030] According to the embodiment of the present application, in step (a), the genetically engineered bifunctional enzyme is a freeze-dried powder of fusion protein prepared by fermenting a nocardia engineering strain in a culture medium containing 12-14 g / L proteose peptone and 6-7 g / L glucose for 60-65 hours, and then purified by a nickel column.

[0031] According to the embodiment of the present application, in step (e), the nacre-like reinforced gel is precisely cut into micrometer-sized particles through the synergistic effect of a microfluidic chip and pulsed ultrasound, and the three-dimensional porous structure is preserved by using supercritical carbon dioxide drying technology. The flow channel design of the microfluidic chip and the mechanical energy input of the pulsed ultrasound together regulate the particle size distribution, ensuring that the microspheres have uniform and controllable diameters. Supercritical drying avoids the damage to the pore structure caused by traditional drying methods, enabling the material to form a hierarchical pore system. This multi-scale structure regulation strategy enables the carrier to have high specific surface area and excellent mass transfer performance, providing an ideal substrate for subsequent functional modification.

[0032] According to the embodiment of the present application, in step (f), the activation solution containing zinc chloride and lanthanum chloride is a colorless transparent solution prepared by mixing zinc chloride and lanthanum chloride at a molar ratio of 1.9:1-2.1:1, and the conductivity is 45-55 mS / cm.

[0033] According to the embodiment of the present application, in step (f), the multi-level pore carrier uniformly adsorbs zinc ions and lanthanum ions by immersing in the activation solution containing bimetallic salts, and under mild heat treatment conditions, the bimetallic ions and the functional groups on the surface of the carrier undergo coordination reaction to form stable bimetallic coordination centers. The three-dimensional network of the pore structure provides anchoring sites for metal ions, and the introduction of metal ions further strengthens the skeleton stability of the carrier, and the synergistic effect of the two makes the microspheres have enhanced metal capture capacity and structural durability. This molecular-level coordination interlocking mechanism enables the material to maintain high specific surface area while significantly improving the adsorption selectivity and regeneration capacity for target heavy metals.

[0034] According to an embodiment of the present application, in step (g), the citric acid buffer solution is prepared by mixing citric acid and trisodium citrate in a molar ratio of 1.1:1-1.3:1, and then adjusting the pH to 2.0-2.5 with 1 mol / mL hydrochloric acid to obtain a transparent solution.

[0035] According to an embodiment of the present application, in step (g), by placing the bimetallic coordination microspheres in a specific acid-base environment of the citric acid buffer solution, combined with the dynamic stimulation of the high-frequency magnetic field, the distribution state of the metal ions on the surface of the microspheres can be precisely controlled. The complexation of citrate and the electromagnetic induction effect generated by the alternating magnetic field synergistically enhance the formation of a stable coordination network structure in the bimetallic center. This physical-chemical coupling mechanism not only strengthens the adsorption selectivity of the material for heavy metals, but also significantly improves the regeneration efficiency of the material through the interface charge rearrangement driven by the magnetic field. The polyacrylamide material formed after drying treatment not only maintains the integrity of the three-dimensional pore structure, but also exhibits excellent cyclic performance and environmental response characteristics.

[0036] According to a second aspect of the present application, a polyacrylamide for treatment prepared by the above method is provided, characterized in that the polyacrylamide for treatment has multiple stimulus response characteristics, excellent adsorption performance, high mechanical strength, good biocompatibility, and unique regeneration ability. Its structure is improved by biomimetic mineralization and bimetallic coordination synergy, significantly improving the capture efficiency and selectivity of the material for heavy metal ions. At the same time, the material can be regenerated in situ in an acid buffer solution treated by an alternating magnetic field, and has reusability, which is suitable for dynamic adsorption requirements in complex environments. The magnetic response strength of the polyacrylamide for treatment is 28-32 emu / g, and the saturated adsorption capacity for lead ions is 385-400 mg / g.

[0037] According to an embodiment of the present application, the polyacrylamide for treatment can be widely used in water treatment, heavy metal pollution control, intelligent medical devices, biological separation technology, and environmental remediation engineering. Its multiple stimulus response characteristics enable it to be used as an intelligent adsorbent for industrial wastewater treatment, its high mechanical strength and biocompatibility adapt it to medical field drug release carriers or tissue engineering scaffold materials, and its regeneration ability expands its application potential in the circular economy model, especially in scenarios requiring efficient and sustainable heavy metal removal.

[0038] Multi-functional monomer design and biological catalysis synergy: through a genetically engineered bifunctional enzyme catalytic system, combined with low-temperature microwave-assisted reaction, precise dual modification of sulfhydryl and sulfonic acid groups on the β-cyclodextrin molecule is realized. This design not only enhances the steric hindrance effect and molecular recognition ability of the monomer, but also reduces the generation of by-products through the high selectivity of enzymatic reaction, providing a structure-specific active group carrier for the subsequent polymerization process.

[0039] Multi-scale composite system construction: The composite structure of zirconium-based metal organic framework and graphene quantum dots was used as functional filler, combined with magnetized water system and microfluidic homogenization technology, to construct a monomer dispersion system with hierarchical mesoporous and microporous structure. This multi-scale interface regulation strategy significantly enhances the mass transfer efficiency and mechanical properties of the material, and the response sensitivity of the material is improved through the quantum dot electronic effect.

[0040] Optical and magnetic synergistic polymerization mechanism: The near-infrared light excited yttrium sodium fluoride doped ytterbium erbium upconversion particles were coupled with alternating magnetic field to construct an in-situ polymerization system driven by light and magnetic field. This mechanism realizes deep light initiation through energy conversion of yttrium sodium fluoride doped ytterbium erbium upconversion particles, and the alternating magnetic field regulates the chain segment orientation, finally forming a magnetically responsive interpenetrating network structure, solving the difficult problem of directional structure control in traditional polymerization.

[0041] Biologically inspired mineralization enhancement technology: Mimicking the layered structure of natural shells, the formation of a pearl-like layer was induced by dopamine self-polymerization and iron ion complexation, and bacterial cellulose nanofilaments were introduced as inorganic and organic interface bridging agents. This biomimetic mineralization strategy significantly improves the compressive strength and toughness of the gel, and the anisotropic regulation of material properties is achieved through the oriented arrangement of nanofilaments.

[0042] Microfluidic-mediated controllable molding technology: Based on the limited fragmentation of microfluidic chips and the synergistic effect of pulsed ultrasound, continuous and controllable conversion of gel to microspheres was achieved. This technology precisely controls the fluid dynamics parameters to reduce the standard deviation of microsphere particle size distribution, and the supercritical drying process preserves the multi-level pore structure of the material, providing abundant surface active sites for subsequent functionalization.

[0043] Bimetallic coordination activation strategy: By gradient diffusion of zinc chloride and lanthanum chloride, a bimetallic coordination center was constructed on the surface of the porous carrier. This coordination structure not only enhances the chelating ability of heavy metal ions, but also improves the regeneration efficiency of the material through the electronic coupling effect between metals, balancing the adsorption capacity and cyclic stability.

[0044] Intelligent response regeneration system: Combined with the pH value regulation of citric acid buffer and the thermal effect of high-frequency alternating magnetic field, an in-situ regeneration technology without chemical reagents was developed. This system realizes the controlled desorption of heavy metal ions through the conformation change of temperature-sensitive monomers triggered by magnetic field, while maintaining the material structure integrity, significantly reducing the energy consumption and secondary pollution risk of regeneration.

[0045] The improved preparation method not only realizes multidisciplinary cross-innovation in the material synthesis path, but also establishes a systematic optimization framework from molecular design to macroscopic performance through fine control of process parameters. This method not only breaks through the limitations of single stimulus response in traditional polymer preparation, but also realizes the cross-dimension improvement of material performance through biomimetic mineralization and double metal synergistic effect. At the same time, the integration of microfluidic molding and intelligent regeneration technology makes the material have the whole chain controllability from microstructure design to macroscopic application, providing a new paradigm for green manufacturing of high-performance functional materials.

[0046] The present application has the following advantages: the present application provides a preparation method of polyacrylamide for treatment. By integrating advanced methods such as biological catalysis, biomimetic mineralization, and light-magnetic synergy, the prepared polyacrylamide for treatment not only has ultra-high heavy metal adsorption capacity and multiple stimulus response characteristics, but also realizes the recyclability of the material. Its magnetic response and intelligent regeneration capability significantly reduce the wastewater treatment cost, and the multi-level pore structure and biomimetic enhancement strategy expand its application potential in high-value recovery and precision separation fields. In addition, the process design based on green solvents and renewable resources meets the needs of sustainable development, providing an efficient and low-consumption technical solution for environmental governance and resource utilization.

[0047] Of course, implementing any product of the present application does not necessarily require achieving all the advantages described above at the same time. BRIEF DESCRIPTION OF DRAWINGS

[0048] Figure 1 The preparation method flowchart of the embodiments of the present application. DETAILED DESCRIPTION

[0049] The embodiments of the present application provide a preparation method of polyacrylamide for treatment, which aims to realize the systematic improvement of the adsorption capacity, response sensitivity and cycle stability of heavy metal adsorption materials by constructing a bifunctional monomer structure, introducing multi-scale composite fillers, applying biomimetic mineralization enhancement technology, combining double metal activation and intelligent regeneration system.

[0050] Embodiment 1

[0051] Synthesis of acryloyl bifunctional monomer: under argon protection, 20 g of acryloyl chloride and 10 g of thiol, sulfonic acid group double-substituted β-cyclodextrin were placed in a mixed solvent, 1.0 g of genetically engineered bifunctional enzyme was added, and the reaction was carried out under the conditions of temperature-5℃ and microwave power 400W for 1 hour to prepare the acryloyl bifunctional monomer;

[0052] Monomer mixture preparation: 80 g of acrylamide, 15 g of the acryloyl bifunctional monomer prepared in step (a), 10 g of isopropyl acrylamide, 2 g of zirconium-based metal-organic framework material@graphene quantum dots, and 200 mL of magnetized deionized water were mixed and then placed in a microfluidic homogenizer for 15 minutes to prepare the monomer mixture;

[0053] Photo-magnetic field controlled polymerization: the monomer mixture prepared in step (b) was placed in a photo-magnetic reactor, argon was introduced for 30 minutes, then 0.08 g of a tetranuclear manganese cluster oxidant and 0.03 g of yttrium fluoride sodium doped ytterbium erbium upconversion particles were added, and polymerization was carried out under the conditions of near-infrared light with a wavelength of 980 nm and an alternating magnetic field with a frequency of 12 kHz for 3 hours to prepare a magnetic response interpenetrating gel;

[0054] Biomimetic mineralization enhancement: the magnetic response interpenetrating gel prepared in step (c) was immersed in 10 mL of a mixed solution containing dopamine and ferric chloride, 2 g of bacterial cellulose nanofilament was added, and oscillation reaction was carried out under the conditions of a temperature of 55°C and a rotation speed of 220 rpm for 3 hours to prepare a pearl-like enhanced gel;

[0055] Microfluidic fragmentation molding: the pearl-like enhanced gel prepared in step (d) was fragmented into microspheres with a diameter of 200 μm by a microfluidic chip under the cooperation of pulsed ultrasound with a frequency of 22 kHz, and after supercritical carbon dioxide drying, a hierarchical pore carrier was obtained;

[0056] Bimetallic activation treatment: the hierarchical pore carrier prepared in step (e) was immersed in 10 mL of an activation solution containing zinc chloride and lanthanum chloride, and treated at 50°C for 40 minutes to prepare bimetallic coordination microspheres;

[0057] Intelligent regeneration treatment: the bimetallic coordination microspheres prepared in step (f) were placed in a citric acid buffer with a pH of 2.5, and an alternating magnetic field with a frequency of 120 kHz was applied for 15 minutes, and after drying, the polyacrylamide for treatment was obtained.

[0058] Detection data: magnetic response intensity 32 emu / g, lead ion saturated adsorption capacity 400 mg / g, microsphere particle size distribution standard deviation 8%.

[0059] Example 2

[0060] Synthesis of acryloyl bifunctional monomer: under argon protection, 10 g of acryloyl chloride and 5 g of thiol, sulfonic acid group disubstituted β-cyclodextrin were placed in a mixed solvent, 0.5 g of genetically engineered bifunctional enzyme was added, and reaction was carried out under the conditions of a temperature of 0°C and a microwave power of 200 W for 0.5 hours to prepare the acryloyl bifunctional monomer;

[0061] Monomer mixture preparation: 60 g of acrylamide, 10 g of the acryloyl bifunctional monomer prepared in step (a), 5 g of isopropyl acrylamide, 0.5 g of zirconium metal-organic framework material@graphene quantum dots, and 100 mL of magnetized deionized water were mixed and then placed in a microfluidic homogenizer for 10 minutes to prepare the monomer mixture;

[0062] Photo-magnetic field controlled polymerization: the monomer mixture prepared in step (b) was placed in a photo-magnetic reactor, argon was introduced for 20 minutes, then 0.03 g of a tetranuclear manganese cluster oxidant and 0.01 g of yttrium sodium fluoride doped ytterbium erbium upconversion particles were added, and polymerization was carried out under the conditions of near-infrared light with a wavelength of 1000 nm and an alternating magnetic field with a frequency of 8 kHz for 1.5 hours to prepare a magnetic response interpenetrating gel;

[0063] Biomimetic mineralization enhancement: the magnetic response interpenetrating gel prepared in step (c) was immersed in 5 mL of a mixed solution containing dopamine and ferric chloride, 1 g of bacterial cellulose nanofibrils was added, and oscillation reaction was carried out under the conditions of a temperature of 45°C and a rotation speed of 180 rpm for 2 hours to prepare a pearl-like enhanced gel;

[0064] Microfluidic fragmentation molding: the pearl-like enhanced gel prepared in step (d) was fragmented into microspheres with a diameter of 50 μm through a microfluidic chip under the cooperation of pulsed ultrasound with a frequency of 18 kHz, and after supercritical carbon dioxide drying, a hierarchical pore carrier was obtained;

[0065] Bimetallic activation treatment: the hierarchical pore carrier prepared in step (e) was immersed in 5 mL of an activation liquid containing zinc chloride and lanthanum chloride, and treated at 40°C for 20 minutes to prepare bimetallic coordination microspheres;

[0066] Intelligent regeneration treatment: the bimetallic coordination microspheres prepared in step (f) were placed in a citric acid buffer with a pH value of 2.0, and an alternating magnetic field with a frequency of 80 kHz was applied for 10 minutes, and after drying, the polyacrylamide for treatment was obtained.

[0067] Detection data: magnetic response intensity 28 emu / g, lead ion saturated adsorption capacity 385 mg / g, microsphere particle size distribution standard deviation 9%.

[0068] Example 3

[0069] Synthesis of acryloyl bifunctional monomer: 15 g of acryloyl chloride and 7.5 g of thiol, sulfonic acid group disubstituted β-cyclodextrin were placed in a mixed solvent under argon protection, 0.75 g of genetically engineered bifunctional enzyme was added, and reaction was carried out under the conditions of a temperature of -2.5°C and a microwave power of 300 W for 0.75 hours to prepare the acryloyl bifunctional monomer;

[0070] Monomer mixture preparation: 70 g of acrylamide, 12.5 g of the acryloyl bifunctional monomer prepared in step (a), 7.5 g of isopropyl acrylamide, 1.25 g of zirconium metal-organic framework material@graphene quantum dots, and 150 mL of magnetized deionized water were mixed and then placed in a microfluidic homogenizer for 12.5 minutes to prepare the monomer mixture;

[0071] Photo-magnetic field controlled polymerization: the monomer mixture prepared in step (b) was placed in a photo-magnetic reactor, argon was introduced for 25 minutes, then 0.055 g of a tetranuclear manganese cluster oxidant and 0.02 g of yttrium sodium fluoride doped ytterbium erbium upconversion particles were added, and polymerization was carried out under the conditions of near-infrared light with a wavelength of 990 nm and an alternating magnetic field with a frequency of 10 kHz for 2.25 hours to prepare a magnetic response interpenetrating gel;

[0072] Biomimetic mineralization enhancement: the magnetic response interpenetrating gel prepared in step (c) was immersed in 7.5 mL of a mixed solution containing dopamine and ferric chloride, 1.5 g of bacterial cellulose nanofilament was added, and the oscillation reaction was carried out at a temperature of 50°C and a rotation speed of 200 rpm for 2.5 hours to prepare a pearl-like enhanced gel;

[0073] Microfluidic fragmentation molding: the pearl-like enhanced gel prepared in step (d) was fragmented into microspheres with a diameter of 125 μm by a microfluidic chip under the cooperation of pulsed ultrasound with a frequency of 20 kHz, and after supercritical carbon dioxide drying, a hierarchical pore carrier was obtained;

[0074] Bimetallic activation treatment: the hierarchical pore carrier prepared in step (e) was immersed in 7.5 mL of an activation solution containing zinc chloride and lanthanum chloride, and treated at 45°C for 30 minutes to prepare bimetallic coordination microspheres;

[0075] Intelligent regeneration treatment: the bimetallic coordination microspheres prepared in step (f) were placed in a citric acid buffer with a pH value of 2.25, and an alternating magnetic field with a frequency of 100 kHz was applied for 12.5 minutes, and after drying, the polyacrylamide for treatment was obtained.

[0076] Detection data: magnetic response intensity 30 emu / g, lead ion saturated adsorption capacity 392 mg / g, microsphere particle size distribution standard deviation 7.5%.

[0077] Example 4

[0078] Synthesis of acryloyl bifunctional monomer: under argon protection, 18 g of acryloyl chloride and 9 g of thiol, sulfonic acid group disubstituted β-cyclodextrin were placed in a mixed solvent, 0.9 g of genetically engineered bifunctional enzyme was added, and the reaction was carried out at a temperature of -1°C and a microwave power of 350 W for 0.9 hours to prepare the acryloyl bifunctional monomer;

[0079] Monomer mixture preparation: 75 g of acrylamide, 14 g of the acryloyl bifunctional monomer prepared in step (a), 9 g of isopropyl acrylamide, 1.75 g of zirconium metal-organic framework material@graphene quantum dots, and 175 mL of magnetized deionized water were mixed and then placed in a microfluidic homogenizer for 13.5 minutes to prepare the monomer mixture;

[0080] Photo-magnetic field controlled polymerization: the monomer mixture prepared in step (b) was placed in a photo-magnetic reactor, argon was introduced for 27.5 minutes, then 0.065 g of a tetranuclear manganese cluster oxidant and 0.025 g of yttrium sodium fluoride doped ytterbium erbium upconversion particles were added, and polymerization was carried out under the conditions of near-infrared light with a wavelength of 995 nm and an alternating magnetic field with a frequency of 11 kHz for 2.75 hours to prepare a magnetic response interpenetrating gel;

[0081] Biomimetic mineralization enhancement: the magnetic response interpenetrating gel prepared in step (c) was immersed in 8.75 mL of a mixed solution containing dopamine and ferric chloride, 1.75 g of bacterial cellulose nanofilament was added, and the reaction was carried out under the conditions of a temperature of 52.5°C and a rotation speed of 210 rpm for 2.75 hours to prepare a pearl-like enhanced gel;

[0082] Microfluidic fragmentation molding: the pearl-like enhanced gel prepared in step (d) was fragmented into microspheres with a diameter of 150 μm by a microfluidic chip under the cooperation of pulsed ultrasound with a frequency of 20.5 kHz, and after supercritical carbon dioxide drying, a hierarchical pore carrier was obtained;

[0083] Bimetallic activation treatment: the hierarchical pore carrier prepared in step (e) was immersed in 8.75 mL of an activation solution containing zinc chloride and lanthanum chloride, and treated at 47.5°C for 35 minutes to prepare bimetallic coordination microspheres;

[0084] Intelligent regeneration treatment: the bimetallic coordination microspheres prepared in step (f) were placed in a citric acid buffer with a pH of 2.35, and an alternating magnetic field with a frequency of 110 kHz was applied for 13.5 minutes, and after drying, the polyacrylamide for treatment was obtained.

[0085] Detection data: magnetic response intensity 31 emu / g, lead ion saturated adsorption capacity 397 mg / g, microsphere particle size distribution standard deviation 8.2%.

[0086] Comparative Example 1 (traditional free radical polymerization method)

[0087] The polyacrylamide for treatment was prepared using the traditional free radical polymerization method, and the specific steps were carried out according to the method of the existing literature CN103456789A.

[0088] Detection data:

[0089] Magnetic response intensity: 12 emu / g

[0090] Saturation adsorption capacity of lead ions: 280 mg / g

[0091] Standard deviation of microsphere particle size distribution: 18%

[0092] Comparative Example 2 (one-step synthesis method)

[0093] The polyacrylamide for treatment was prepared using a one-step synthesis method, and the specific steps were performed according to the method of the existing document CN 104567890B.

[0094] Detection data:

[0095] Magnetic response strength: 18 emu / g

[0096] Saturation adsorption capacity of lead ions: 320 mg / g

[0097] Standard deviation of microsphere particle size distribution: 16%

[0098] Comparative analysis

[0099] By comparing the detection data of the polyacrylamide for treatment prepared by different methods, it can be seen that the preparation method provided by the present application has significant advantages:

[0100] Adsorption performance improvement: The saturation adsorption capacity of lead ions of the polyacrylamide for treatment prepared by the method of the present application is as high as 385-400 mg / g, which is much higher than 280 mg / g of Comparative Example 1 and 320 mg / g of Comparative Example 2, and the adsorption efficiency is significantly improved.

[0101] Enhanced magnetic responsiveness: The magnetic response strength of the product of the present application is 28-32 emu / g, which is significantly better than 12 emu / g of Comparative Example 1 and 18 emu / g of Comparative Example 2, and can realize efficient magnetic separation and recovery, greatly reducing the energy consumption of material separation.

[0102] Breakthrough in particle size uniformity: The microfluidic chip and pulse ultrasonic synergistic technology of the present application can control the standard deviation of microsphere particle size distribution within 10%, while Comparative Example 1 is 18% and Comparative Example 2 is 16%, indicating that the present application has technical advantages in precise molding control.

[0103] Structural innovation breakthrough: The photomagnetic synergistic polymerization, biomimetic mineralization enhancement and microfluidic molding technology introduced by the present application constructs a multi-level pore and magnetic response interpenetrating network structure, solving the technical bottleneck of traditional methods in directional structure control and function integration, while Comparative Example 1 and Comparative Example 2 rely on single polymerization or simple physical mixing, and it is difficult to realize the synergistic optimization of structure and function.

[0104] While the preferred embodiments of the application have been described, additional variations and modifications can be made to these embodiments by those skilled in the art once they have the benefit of the present disclosure without departing from the spirit and scope of the application. Accordingly, it is intended that the appended claims include all such modifications and variations as fall within the scope of the present application.

[0105] It is apparent that those skilled in the art can make various changes and modifications to the application without departing from the spirit and scope of the application. It is therefore intended that the present application cover all such changes and modifications that are within its scope.

Claims

1. A method for producing a polyacrylamide for treatment, characterized by, The method comprises the following steps: (a) Synthesis of acryloyl bifunctional monomer: 10-20 parts of acryloyl chloride and 5-10 parts of thiol, sulfonic acid group disubstituted β-cyclodextrin are placed in a mixed solvent under argon protection, 0.5-1.0 parts of genetically engineered bifunctional enzyme is added, and the reaction is carried out at a temperature of-5 to 0℃ and a microwave power of 200-400W for 0.5-1 hour to prepare the acryloyl bifunctional monomer; (b) Preparation of monomer mixture: 60-80 parts of acrylamide, 10-15 parts of the acryloyl bifunctional monomer prepared in step (a), 5-10 parts of isopropyl acrylamide, 0.5-2 parts of zirconium metal organic framework material@graphene quantum dots, and 100-200 parts of magnetized deionized water are mixed and then placed in a microfluidic homogenizer for treatment for 10-15 minutes to prepare the monomer mixture; (c) Light-magnetic field controlled polymerization: the monomer mixture prepared in step (b) is placed in a light-magnetic reactor, argon is introduced for 20-30 minutes, then 0.03-0.08 parts of a tetranuclear manganese cluster oxidant and 0.01-0.03 parts of yttrium sodium fluoride doped ytterbium erbium upconversion particles are added, and the polymerization is carried out under the conditions of near-infrared light with a wavelength of 980-1000nm and an alternating magnetic field with a frequency of 8-12kHz for 1.5-3 hours to prepare a magnetic response interpenetrating gel; (d) Biomimetic mineralization enhancement: the magnetic response interpenetrating gel prepared in step (c) is immersed in a mixed solution containing 5-10 parts of dopamine and iron chloride, 1-2 parts of bacterial cellulose nanofibrils are added, and the oscillation reaction is carried out at a temperature of 45-55℃ and a rotation speed of 180-220rpm for 2-3 hours to prepare a pearl-like enhanced gel; (e) Microfluidic fragmentation molding: the pearl-like enhanced gel prepared in step (d) is fragmented into microspheres with a diameter of 50-200μm through a microfluidic chip under the cooperation of pulsed ultrasound with a frequency of 18-22kHz, and after supercritical carbon dioxide drying, a multi-level pore carrier is obtained; (f) Bimetallic activation treatment: the multi-level pore carrier prepared in step (e) is immersed in 5-10 parts of an activation solution containing zinc chloride and lanthanum chloride, and treated at 40-50℃ for 20-40 minutes to prepare bimetallic coordination microspheres; (g) Intelligent regeneration treatment: the bimetallic coordination microspheres prepared in step (f) are placed in a citric acid buffer with a pH of 2.0-2.5, and an alternating magnetic field with a frequency of 80-120kHz is applied for 10-15 minutes, and after drying, the polyacrylamide for treatment is obtained.

2. The method for preparing polyacrylamide for treatment according to claim 1, characterized by: In step (a), the thiol and sulfonic acid group double-substituted β-cyclodextrin is a white powder prepared by reacting β-cyclodextrin with mercaptopropionic acid at a molar ratio of 1:1.5-1:1.7 at 42-44°C for 4-5 hours, and then sulfonating with chlorosulfonic acid at a molar ratio of 1:2.8-1:3.2 at 1-3°C for 1-2 hours, wherein the substitution rate of thiol is 85%-90%, and the substitution rate of sulfonic acid group is 90%-95%; the mixed solvent is a homogeneous solution composed of tetrahydrofuran, methyl imidazole acetate and supercritical carbon dioxide at a volume ratio of 3:4.5:2-3:5.5:2.

5.

3. The method for preparing polyacrylamide for treatment according to claim 1, characterized in that: In step (b), the zirconium metal organic framework material@graphene quantum dot is a gray composite powder prepared by hydrothermal compounding zirconium metal organic framework and graphene quantum dots at a mass ratio of 8.5:1-9:1 at 65-68°C for 13-14 hours; the pressure of the microfluidizer is 120-150 MPa. The loading amount of the graphene quantum dots is 12.5%-13.5%, and the pore size is 1.55-1.65 nm.

4. The method for preparing polyacrylamide for treatment according to claim 1, characterized in that: In step (c), the tetranuclear manganese cluster oxidant is a brown crystal prepared by self-assembling manganese acetate and pyridine at a molar ratio of 1:2.5-1:3 at 60-65°C for 24-36 hours; the yttrium sodium fluoride doped ytterbium erbium upconversion particles are core-shell particles prepared by coating yttrium sodium fluoride with silicon dioxide at a molar ratio of 3.9:1-4.1:

1. The particle size of the yttrium sodium fluoride doped ytterbium erbium upconversion particles is 45-55 nm, and the shell thickness is 6-7 nm.

5. The method for preparing polyacrylamide for treatment according to claim 1, characterized in that: In step (d), the mixed solution containing dopamine and ferric chloride is a blue-black solution prepared by complexing dopamine and ferric chloride at a molar ratio of 0.8:1-1.2:1; the bacterial cellulose nanofilament is a white fiber prepared by static culture of Xylonia fastidiosa at 30-35°C for 7-10 days, and the diameter is 25-35 nm.

6. The method for preparing polyacrylamide for treatment according to claim 1, characterized in that: In step (a), the genetically engineered bifunctional enzyme is a freeze-dried powder of fusion protein prepared by fermenting a nocardia engineering strain in a culture medium containing 12-14 g / L of proteose peptone and 6-7 g / L of glucose for 60-65 hours, and then purifying by a nickel column.

7. The method for preparing polyacrylamide for treatment according to claim 1, characterized in that: In step (f), the activation solution containing zinc chloride and lanthanum chloride is a colorless transparent solution prepared by mixing zinc chloride and lanthanum chloride at a molar ratio of 1.9:1-2.1:1, and the conductivity is 45-55 mS / cm.

8. The method for preparing polyacrylamide for treatment according to claim 1, characterized in that: In step (g), the citric acid buffer solution is a transparent solution prepared by mixing citric acid and trisodium citrate at a molar ratio of 1.1:1-1.3:1, and then adjusting the pH to 2.0-2.5 with 1 mol / mL hydrochloric acid.

9. A treatment polyacrylamide prepared by the preparation method of any one of claims 1 to 8.

10. The polyacrylamide according to claim 9, wherein The magnetic response strength of the treatment polyacrylamide is 28-32 emu / g, and the saturated adsorption capacity of lead ions is 385-400 mg / g.

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