Environmentally responsive ultra-small pore magnetic colloidal body and method for preparing same

Abstract

To provide an environmentally responsive ultra-microporous magnetic colloid body and a method for preparing the same.SOLUTION: A method for preparing an ultra-microporous magnetic colloid body includes steps such as the synthesis of Fe3O4 nanoparticles, the synthesis of Fe3O4@NH2 nanoparticles, the synthesis of PVBC chains, the preparation of PVBC-Fe3O4@NH2 composite nanoparticles, the preparation of environmentally responsive composite nanoparticles, and the preparation of an environmentally responsive colloid body with ultra-small pores. By specifically setting each step, the resulting environmentally responsive ultra-microporous magnetic colloidal body has size and morphology, multiple functions such as magnetic responsiveness, pH responsiveness, and temperature responsiveness, and can be more fully applied in areas such as controllable media transmission.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to the technical field of colloidal materials, and in particular to a method for preparing environmentally responsive ultra-small pore magnetic colloidal bodies. [Background technology]

[0002] Colloidal bodies refer to microcapsules that are composed of colloidal particles as structural elements. The preparation of colloidal bodies is generally completed by the self-assembly of colloidal particles on the surface of emulsion droplets. This kind of special hollow material has a porous shell and functional structural elements, so it is expected to have a wide range of applications in biomedicine, cell transplantation, functional food, oil industry, etc.

[0003] In existing technologies, colloid synthesis mainly uses soft template method or hard template method, and the hard template method can introduce functional material particles into the core / shell structure, but has problems such as the need to remove the template, and it is difficult to cover the surfaces of various functional material particles with a shell composed of a single layer of colloid particles. In addition, currently, when preparing colloid bodies with different functions, there is a tendency to use colloid particle elements with corresponding functions to construct the shell of the colloid, and there have been few attempts to introduce the corresponding functional materials into the cavities of the colloid bodies.

[0004] How to find colloidal bodies with ultra-small pores and multifunctionality, and their application in media transmission, still require detailed research.

[0005] Chinese Patent Application No. CN102351459A discloses a method for preparing sustained-release water-reducing agent microcapsules whose shell layer changes from dense to sparse in response to stimuli in the high pH environment of concrete. However, it is not a very small-pore magnetic colloidal body, so it cannot be applied to transmission in a medium. Summary of the Invention

[0006] The present invention provides environmentally responsive ultra-small pore magnetic colloidal bodies and a method for preparing the same.

[0007] Specifically, this is achieved by the following technical solutions:

[0008] A method for preparing environmentally responsive ultra-small pore magnetic colloidal bodies, comprising the steps of:

[0009] (1) Synthesis of Fe3O4 nanoparticles 95-105 parts by volume of an organic oil aqueous solution and 95-105 parts by volume of anhydrous ferric chloride aqueous solution are slowly mixed, then thoroughly stirred to produce a reddish-brown precipitate, stirred for 10-15 minutes, then filtered the solid-liquid mixture, collected and washed on the sieve, then dried the solid obtained after washing to obtain a wax-like substance, added the dried wax-like substance to 53-68 parts by volume of an organic solvent, then added 5-8 parts by volume of a monounsaturated fatty acid to the solution, stirred uniformly, and then placed in a hydrothermal reaction vessel and reacted at a temperature of 160-190°C for 3-6 hours, then taken out the reaction product and washed with an organic solvent, then magnetically separated with a magnet to obtain 6-12 nm Fe3O4 nanoparticles, and the obtained Fe3O4 nanoparticles are dispersed in a non-polar solvent to obtain a Fe3O4 nanoparticle dispersion.

[0010] (2) Synthesis of Fe3O4@NH2 nanoparticles 0.3-0.8% (v / v) aminosilane coupling agent and 0.005-0.02% (v / v) organic acid are added to the Fe3O4 nanoparticle dispersion obtained in step (1), and then the mixture is stirred at room temperature and reacted for 22-26 hours. After that, the mixture is separated into solid and liquid state using a magnet, the solid is washed, and freeze-dried to obtain Fe3O4@NH2 nanoparticles.

[0011] (3) Synthesis of PVBC chain Add 0.01-0.05 volume parts of initiator into 3-6 volume parts of ultra-dehydrated cationic polymerization solvent, stir with a magnetic stirrer, and after stirring for 1-5 minutes, add 1-5 volume parts of 4-chloromethylstyrene VBC monomer, continue stirring, and react for 25-35 minutes to synthesize an active PVBC polymer chain solution whose chain size is equal to the diameter of the Fe3O4@NH2 particles obtained in step (2).

[0012] (4) Preparation of PVBC-Fe3O4@NH2 composite nanoparticles The Fe3O4@NH2 nanoparticles prepared in step (2) are dispersed in an ultra-dehydrated cationic polymerization solvent, and the ratio of Fe3O4@NH2 nanoparticles to ultra-dehydrated cationic polymerization solvent is 15-25 mg: 8-12 mL. Then, the mixture is sonicated. While sonicating, the activated PVBC polymer chain solution prepared in step (3) is slowly added to the mixture, and an amount of the activated PVBC polymer chain solution is added such that the color of the system changes to light pink. Then, the sonication is continued for 0.8-1.5 hours, and the solid-liquid separation is performed with a magnet. The solid is washed with methylene chloride to obtain PVBC-Fe3O4@NH2 particles.

[0013] (5) Preparation of environmentally responsive composite nanoparticles In a sealed container, 2-4 parts by weight of the PVBC-Fe3O4@NH2 particles prepared in step (4) are mixed with 0.5-1.5 parts by weight of tris[2-(dimethylamino)ethyl]amine, 0.5-1.5 parts by weight of ultra-dehydrated isopropyl alcohol, and diethylaminoethyl methacrylate monomer, the ratio of the amount of diethylaminoethyl methacrylate monomer added to the amount of ultra-dehydrated isopropyl alcohol added is (9-11)μL:(0.8-1.2)mg, and then the container is placed in liquid nitrogen to be frozen. At the same time, an inert gas is introduced into the mixture, and after 5 to 8 minutes, the process is switched to vacuum drawing, and after 5 to 8 minutes of vacuum drawing, a thawing process is performed. The freeze-vacuum-thawing process is repeated 2 to 6 times, and 0.6 to 1.2 parts by weight of cuprous bromide is added under freezing and inert gas protection conditions, and then the freeze-vacuum-thawing process is performed again, after which the sealed container is sealed, and then the entire sealed container is placed in a thermostatic shaker at 55 to 65°C and shaken for a reaction for 10 to 13 hours, followed by solid-liquid separation with a magnet, and then the solid matter is washed to obtain pH-responsive composite nanoparticles.

[0014] Alternatively, 1.5-2.5 parts by weight of the PVBC-Fe3O4@NH2 particles prepared in step (4) are mixed with 1.5-2.5 parts by weight of tris[2-(dimethylamino)ethyl]amine, N,N-dimethylformamide, and 195-205 parts by weight of N-isopropylacrylamide monomer in a sealed container, and the ratio of the amount of N,N-dimethylformamide added to the amount of N-isopropylacrylamide added is (0.5-1.5) mL:(95-105) mg. Then, the container is placed in liquid nitrogen to freeze, and the same is cooled. Inert gas is introduced into the mixture at certain times, and after 5 to 8 minutes, the process is switched to vacuum drawing, and after 5 to 8 minutes of vacuum drawing, thawing is performed. The freezing, vacuuming, and thawing operations are repeated 2 to 6 times, and 0.6 to 1.2 parts by weight of cuprous bromide is added under freezing and inert gas protection conditions, and then the freezing, vacuuming, and thawing operations are performed again. After that, the sealed container is sealed, and the entire sealed container is placed in a thermostatic shaker at 55 to 75°C and shaken for 10 to 13 hours to react. After the treatment, the solid-liquid separation is performed with a magnet, and then the solid matter is washed to obtain temperature-responsive composite nanoparticles.

[0015] (6) Preparation of environmentally responsive colloidal bodies with extremely small pores The environmentally responsive composite nanoparticles prepared in step (5) are dispersed in a glass container containing an alkaline solution (e.g., aqueous ammonia), the ratio of the environmentally responsive composite nanoparticles to the alkaline solution is (1.5-2.5) mg: (1.8-2.6) mL, and the pH value of the alkaline solution is 8-10. Next, toluene of 8-15% of the volume of the alkaline solution is added to the glass container, and a uniform emulsion is obtained after ultrasonic treatment for 0.5-1.2 minutes. Next, an aqueous glutaraldehyde solution of 0.5-1.6 times the volume of toluene is added to the obtained emulsion, and glacial acetic acid is added to adjust the pH of the aqueous phase to 4-6. After standing for 30-60 minutes, sodium borohydride of 1-3 times the weight of the environmentally responsive composite nanoparticles is added thereto, and the mixture is reacted for 30-60 minutes to obtain an environmentally responsive colloid body with ultrafine pores.

[0016] Alternatively, the environmentally responsive composite nanoparticles prepared in step (5) are dispersed in a glass container containing an alkaline solution (e.g., aqueous ammonia), and the ratio of the environmentally responsive composite nanoparticles to the alkaline solution is (1.5-2.5) mg: (0.8-1.6) mL. Next, toluene of 8-15% of the volume of the alkaline solution is added to the glass container, and the glass container is placed in water at 45-55 ° C., and a uniform emulsion is obtained after ultrasonic treatment for 0.5-1.2 minutes. Next, an aqueous glutaraldehyde solution of 1.5-2.6 times the volume of toluene is added to the obtained emulsion, and glacial acetic acid is added to adjust the pH of the aqueous phase to 4-6. After standing for 30-60 minutes, sodium borohydride of 1-3 times the weight of the environmentally responsive composite nanoparticles is added thereto, and the mixture is reacted for 30-60 minutes to obtain an environmentally responsive colloid body with extremely small pores.

[0017] Preferably, in step (1), the organic oil aqueous solution is a sodium oleate aqueous solution, the organic solvent is ethanol, the monounsaturated fatty acid is oleic acid, the nonpolar solvent is toluene, the hydrothermal reaction kettle is a polytetrafluoroethylene hydrothermal reaction kettle, and the Fe3O4 nanoparticle dispersion is a dispersion in which 5-8 mg of Fe3O4 nanoparticles are dispersed in 28-33 mL of the nonpolar solvent.

[0018] Preferably, the molar concentration of the organic oil aqueous solution in step (1) is 0.1-0.3 M, and the molar concentration of the anhydrous ferric chloride aqueous solution is 0.1-0.3 M. In step (1), the sieve is collected and washed with deionized water, and the drying is performed in a vacuum oven, the drying temperature is 30-40° C., and the drying time is 18-24 hours.

[0019] Preferably, in step (2), the aminosilane coupling agent is 3-aminopropyltriethoxysilane and the organic acid is acetic acid.

[0020] Preferably, in step (3), the molecular weight of the PVBC polymer chain in the synthesized active PVBC polymer chain solution is 30-40 kDa.

[0021] Preferably, the super-dehydrated cationic polymerization solvent is super-dehydrated dichloromethane, the alkaline solution in step (6) is an aqueous sodium hydroxide solution or aqueous ammonia solution having a pH of 8 to 10 (preferably 9), and the initiator in step (3) is boron trifluoride diethyl ether complex.

[0022] Preferably, in step (3), an active PVBC polymer chain solution is synthesized having a chain size equal to the diameter of the Fe3O4@NH2 particles obtained in step (2), said diameter corresponding to a ratio of the chain length of the active PVBC polymer chain solution to the diameter of the Fe3O4@NH2 particles of 0.8-1.5:1.

[0023] Preferably, the inert gas in step (5) is nitrogen, the sealed container is a polymer tube, the pH-responsive composite nanoparticles are washed with isopropyl alcohol, and the temperature-responsive composite nanoparticles are washed with DMF.

[0024] The environmentally responsive ultra-small pore magnetic colloid body is obtained by the above-mentioned preparation method, and the environmentally responsive ultra-small pore magnetic colloid body has ultra-small pores formed by stacking adjacent composite nanoparticles in a hexagonal close-packed form, and the cross-sectional area of ​​the ultra-small pore diameter is 0.04×d 2 nm 2and d is the diameter of the composite nanoparticle.

[0025] The application of the environmentally responsive ultra-small pore magnetic colloidal body in media transmission integrating catalysis, concentration, directional transport, and controlled release, wherein the environmentally responsive ultra-small pore magnetic colloidal body is the ultra-small pore magnetic colloidal body prepared by the above method, or the environmentally responsive ultra-small pore magnetic colloidal body.

[0026] The beneficial effects of the present invention are as follows: The present invention provides a simple method for preparing multifunctional colloidal bodies with adjustable pore sizes through the emulsification, assembly and crosslinking of amphiphilic functional nanoparticles at the water / oil interface. By designing and preparing amphiphilic single-chain polymer nanoparticles with magnetic response or grafting pH / temperature responsive polymers through controllable living radical polymerization to prepare polymer brush nanoparticles, they can be endowed with multiple functions and realize integrated catalysis, concentration, directional transport and controlled release. Using a soft template method, multifunctional colloidal bodies with uniform size and morphology are prepared, and the pores of the colloidal bodies are generated by stacking adjacent composite nanoparticles in a hexagonal close-packed form, with a theoretical area of ​​0.04 × d 2 nm 2 (d is the diameter of the selected nanoparticle). Multifunctional colloidal bodies with ultrasmall pores can be applied in the field of controllable medium transport.

[0027] The present invention uses the prepared single-chain nanoparticles as an ATRP macromolecular initiator, and by rationally setting parameters such as the ratio, order, reaction temperature, and time of each added material during the ATRP polymerization process, an environmentally responsive polymer side chain is grafted onto the polymer main chain on one side of the particle to prepare environmentally responsive composite nanoparticles.

[0028] In the present invention, the pH value and temperature value of the dispersion are adjusted according to the different environmental responsiveness (pH / temperature) of the composite particles in the preparation process of the magnetic colloid body with ultra-small pores, so that the particles have amphiphilic properties and meet the subsequent emulsification requirements of the particles. In the crosslinking process, the type and addition ratio of the crosslinking agent and the reducing agent are reasonably set, so that the prepared colloid body is stable and the pores are reasonably controlled within the pore range required by the present invention. [Brief description of the drawings]

[0029] [Figure 1] FIG. 1 is a schematic diagram of the preparation process of environmentally responsive ultra-small pore magnetic colloidal bodies according to the present invention. [Diagram 2] 2 is a confocal laser scanning microscope photograph of environmentally responsive ultra-small pore magnetic colloid bodies prepared by the emulsion droplet soft template method of the present invention. Here, the left image in Fig. 2 is a photograph scanned using a normal light source as a laser beam, and the right image is an emulsion droplet observed in the same field of view using a laser beam and a light source with a wavelength of 488 nm, and the oil phase was previously stained with Sudan III. [Diagram 3] 3 is a scanning electron microscope (SEM) photograph of the environmentally responsive ultra-small pore magnetic colloid body prepared by the present invention, where the magnification of the left image in FIG. 3 is 45k, and the magnification of the right image is 120k. [Figure 4] FIG. 2 is a schematic diagram of the pH responsiveness of a component of a very small pore magnetic colloidal body having environmental responsiveness according to the present invention. [Diagram 5] FIG. 2 is a schematic diagram showing the magnetic and temperature responsiveness of an extremely small pore magnetic colloid body having environmental responsiveness according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] In order to make the technical problem to be solved, the technical solution and advantages of the present invention clearer, the present invention will be described in more detail below with reference to the drawings and specific embodiments.

[0031] Example 1 This example provides a pH-responsive colloidal body with ultra-small pores according to the present invention, using an emulsion droplet soft template, and the size of the colloidal body is about 2 μm. The preparation process is shown in Figure 1, and specifically includes the following steps:

[0032] (1) Synthesis of Fe3O4 nanoparticles Mix 100mL of sodium oleate aqueous solution (0.2M) and 100mL of anhydrous ferric chloride aqueous solution (0.2M) and stir thoroughly to produce a reddish brown precipitate, which is filtered, washed with deionized water, and then dried in a vacuum oven. The dried wax-like substance is dissolved in 60mL of ethanol, mixed uniformly with 6mL of oleic acid, transferred to a polytetrafluoroethylene high-pressure reaction vessel, and reacted at 180°C for 5 hours. After washing with anhydrous ethanol and separating with a magnet, it is dispersed in toluene for use; its size is approximately 10nm.

[0033] (2) Synthesis of Fe3O4@NH2 nanoparticles 6 mg of Fe3O4 nanoparticles were dispersed in toluene (30 mL) with 0.5% (v / v) 3-aminopropyltriethoxysilane and 0.01% (v / v) acetic acid, and reacted at room temperature for 24 hours with stirring. After washing with toluene and separating with a magnet, the nanoparticles were freeze-dried and prepared for use.

[0034] (3) Synthesis of PVBC chain Add 20 μL of boron trifluoride diethyl ether complex to 5 mL of ultra-dehydrated dichloromethane, add 3 mL of 4-chloromethylstyrene VBC monomer while stirring with a magnetic stirrer, and react at room temperature for 30 minutes to synthesize PVBC polymer chains with a molecular weight of 34.3 kDa, whose chain size (hydrodynamic diameter) is equal to the diameter of the Fe3O4@NH2 particles.

[0035] (4) Preparation of PVBC-Fe3O4@NH2 amphiphilic nanoparticles Disperse 20mg of Fe3O4@NH2 in 10mL of ultra-dehydrated dichloromethane. Under ultrasonic conditions, slowly add the activated PVBC chain solution in step (3) until the system begins to turn light pink, and sonicate for 1 hour. After washing with methylene chloride and collecting with a magnet, they are marked as PVBC-Fe3O4@NH2 particles.

[0036] (5) Preparation of pH-responsive PVBC-g-PDEAEMA-Fe3O4@NH2 nanoparticles In a 25 mL polymer tube, add 15 mg of the prepared PVBC-Fe3O4@NH2 composite particles, 5 mg of tris[2-(dimethylamino)ethyl]amine (Me6TREN), 5 mL of ultra-dehydrated isopropyl alcohol, and 50 μL of diethylaminoethyl methacrylate (DEAEMA) monomer, repeat the nitrogen gas-vacuum-thaw cycle three times, add 5 mg of copper bromide (CuBr) under the frozen state and nitrogen protection, repeat the cycle again, and then seal the polymer tube under vacuum. The polymer tube is placed in a thermostatic shaker at 60 °C and shaken for 12 hours to carry out the ATRP reaction. After the reaction is completed, the pH-responsive PVBC-g-PDEAEMA-Fe3O4@NH2 composite nanoparticles are washed with isopropyl alcohol and collected with a magnet.

[0037] Hydrogen Nuclear Magnetic Resonance Spectroscopy 1 If one wishes to characterize the graft length of the side chain PDEAEMA by H NMR, 31 μL of N,N-dimethylacetamide can be added to the system as a marker before the reaction to facilitate the integral calculation after the reaction.

[0038] The pH response process of PVBC-g-PDEAEMA-Fe3O4@NH2 nanoparticles is shown in Fig. 4.

[0039] (6) Preparation of magnetic and pH-responsive colloidal bodies with ultra-small pores In step (5), 2 mg of the PVBC-g-PDEAEMA-Fe3O4@NH2 nanoparticles are dispersed in 2 mL of water (pH=9), into which 0.2 mL of toluene (pre-dyed with Sudan III) is added, and ultrasonicated for 1 minute to obtain a uniform emulsion, with droplets of about 2 μm in size appearing under a laser confocal microscope, as shown in Figure 2. 0.2 mL of glutaraldehyde aqueous solution is added to the aqueous phase in the emulsion obtained above, the pH of the aqueous phase is adjusted to 5, and dynamic Schiff base bonds are formed, followed by reduction with sodium borohydride to obtain magnetic colloid bodies with ultra-small pores and pH-responsive colloid bodies.

[0040] Example 2 This example provides a temperature-responsive colloidal body with ultra-small pores according to the present invention, using an emulsion droplet soft template, the size of the colloidal body is about 1 μm, as shown in FIG. 3, specifically, the process includes the following steps:

[0041] (1) Synthesis of Fe3O4 nanoparticles Mix 100mL of sodium oleate aqueous solution (0.2M) and 100mL of anhydrous ferric chloride aqueous solution (0.2M) and stir thoroughly to produce a reddish brown precipitate, which is filtered, washed with deionized water, and then dried in a vacuum oven. The dried wax-like substance is dissolved in 60mL of ethanol, mixed uniformly with 6mL of oleic acid, transferred to a polytetrafluoroethylene high-pressure reaction vessel, and reacted at 180°C for 5 hours. After washing with anhydrous ethanol and separating with a magnet, it is dispersed in toluene for use; its size is approximately 10nm.

[0042] (2) Synthesis of Fe3O4@NH2 nanoparticles 6 mg of Fe3O4 nanoparticles were dispersed in toluene (30 mL) with 0.5% (v / v) 3-aminopropyltriethoxysilane and 0.01% (v / v) acetic acid, and reacted at room temperature for 24 hours with stirring. After washing with toluene and separating with a magnet, the nanoparticles were freeze-dried and prepared for use.

[0043] (3) Synthesis of PVBC chain Add 20 μL of boron trifluoride diethyl ether complex to 5 mL of ultra-dehydrated dichloromethane, add 3 mL of 4-chloromethylstyrene VBC monomer while stirring with a magnetic stirrer, and react at room temperature for 30 minutes to synthesize PVBC polymer chains with a molecular weight of approximately 35 kDa, whose chain size (hydrodynamic diameter) is equal to the diameter of the Fe3O4@NH2 particles.

[0044] (4) Preparation of PVBC-Fe3O4@NH2 amphiphilic nanoparticles Disperse 20mg of Fe3O4@NH2 in 10mL of ultra-dehydrated dichloromethane. Under ultrasonic conditions, slowly add the activated PVBC chain solution in step (3) until the system begins to turn light pink, and sonicate for 1 hour. After washing with methylene chloride and collecting with a magnet, they are marked as PVBC-Fe3O4@NH2 particles.

[0045] (5) Preparation of temperature-responsive PVBC-g-PNIPAM-Fe3O4@NH2 nanoparticles In a 25 mL polymer tube, add 10 mg of the prepared PVBC-Fe3O4@NH2 composite particles, 10 mg of tris[2-(dimethylamino)ethyl]amine (Me6TREN), 2 mL of N,N-dimethylformamide DMF, and 0.2 g of N-isopropylacrylamide (NIPAM) monomer, repeat the nitrogen gas-vacuum-thaw cycle three times, add 5 mg of copper bromide (CuBr) under frozen and nitrogen protection, repeat the cycle again, and then seal the polymer tube under vacuum. The polymer tube is placed in a thermostatic shaker at 70 °C and shaken for 12 hours to carry out the ATRP reaction. After the reaction is completed, the temperature-responsive PVBC-g-PNIPAM-Fe3O4@NH2 composite nanoparticles are washed with DMF and collected with a magnet.

[0046] (6) Preparation of magnetic and temperature-responsive colloidal bodies with ultra-small pores In step (5), 2 mg of the PVBC-g-PNIPAM-Fe3O4@NH2 particles are dispersed in 1 mL of hot water, 0.1 mL of toluene is added thereto, and the glass bottle is placed in hot water at 50°C and ultrasonicated for 1 minute to obtain a uniform emulsion. 0.2 mL of glutaraldehyde aqueous solution is added to the aqueous phase of the emulsion obtained above, the pH of the aqueous phase is adjusted to 5, and dynamic Schiff base bonds are formed, followed by reduction with sodium borohydride to obtain magnetic colloid bodies with ultrafine pores and temperature-responsive colloid bodies.

[0047] (Examples) The magnetic and temperature-responsive colloid with ultra-small pores of the present invention can exhibit differentiated hydrophilicity / lipophilicity at the minimum solubility LCST (about 32 ° C) of temperature-sensitive PNIPAM, and when the external temperature is lower than the LCST, it becomes hydrophilic, and when the external temperature is higher than the LCST, it becomes lipophilic. By utilizing temperature response and magnetic response, it is possible to realize magnetically controlled dispersion and collection, as well as controllable absorption and release of water-oil two-phase substances. The specific temperature response process is shown in Figure 5, where the colloid body is added to a water-oil two-phase separation system at 40 ° C, the oil phase is absorbed into the cavity, the colloid body is uniformly dispersed in the water phase, and the oil phase disappears. At the same time, an external magnet is used to collect the uniformly dispersed colloid body, and the system solution has no obvious layer structure. When the system temperature is lowered to 25 ° C, the oil phase is gradually released from the cavity and floats in the water phase, and finally an obvious layer structure is formed.

[0048] The ultra-small pore magnetic colloidal bodies described in this invention can be applied in the fields of controllable medium transmission, integrating catalysis, concentration, directional transport, and controlled release.

[0049] Well-known techniques related to the present invention will not be described in detail. The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing an environmentally responsive ultra-small pore magnetic colloidal body, the method comprising the steps of: Fe ３ O ４ Step (1) of the synthesis of nanoparticles, 95-105 parts by volume of an organic oil aqueous solution and 95-105 parts by volume of an anhydrous ferric chloride aqueous solution are slowly mixed, then thoroughly stirred to produce a reddish brown precipitate, stirred for 10-15 minutes, then filtered the solid-liquid mixture, collected and washed the residue, then dried the solid obtained after washing to obtain a waxy substance, added the dried waxy substance to 53-68 parts by volume of an organic solvent, then added 5-8 parts by volume of a monounsaturated fatty acid to the solution, stirred uniformly, and then placed in a hydrothermal reactor to react at a temperature of 160-190°C for 3-6 hours, then the reaction product is taken out and washed with an organic solvent, then magnetically separated with a magnet to obtain 6-12 nm Fe. ３ O ４ The nanoparticles were obtained, and the obtained Fe ３ O ４ The nanoparticles are dispersed in a non-polar solvent, and Fe ３ O ４ A step (1) of obtaining a nanoparticle dispersion; Fe ３ O ４ @NH ２ Step (2) of the synthesis of nanoparticles, The Fe obtained in step (1) ３ O ４ 0.3 to 0.8% (v / v) of an aminosilane coupling agent and 0.005 to 0.02% (v / v) of an organic acid are added to the nanoparticle dispersion, and then the mixture is stirred at room temperature and reacted for 22 to 26 hours. The mixture is then subjected to solid-liquid separation using a magnet, the solid matter is washed, freeze-dried, and the Fe ３ O ４ @NH ２ A step (2) of obtaining nanoparticles; Step (3) of the synthesis of a PVBC chain, Add 0.01-0.05 volume parts of initiator into 3-6 volume parts of ultra-dehydrated cationic polymerization solvent, stir with a magnetic stirrer, and stir for 1-5 minutes, then add 1-5 volume parts of 4-chloromethylstyrene VBC monomer, continue stirring, and react for 25-35 minutes, until the chain size becomes the same as the Fe obtained in step (2). ３ O ４ @NH ２ (3) synthesizing a solution of activated PVBC polymer chains equal to the diameter of the particles; PVBC-Fe ３ O ４ @NH ２ Step (4) of preparing composite nanoparticles, comprising: Fe prepared in step (2) ３ O ４ @NH ２ The nanoparticles were dispersed in a super-dehydrated cationic polymerization solvent, and Fe ３ O ４ @NH ２ The ratio of nanoparticles to super-dehydrated cationic polymerization solvent is 15-25 mg: 8-12 mL, then the mixture is sonicated, and while sonicating, the active PVBC polymer chain solution prepared in step (3) is slowly added to the mixture, and the amount of active PVBC polymer chain solution that changes the color of the system to light pink is added, and then the sonication is continued for 0.8-1.5 hours, solid-liquid separation is performed with a magnet, and the solid is washed with methylene chloride to obtain PVBC-Fe ３ O ４ @NH ２ A step (4) of obtaining particles; Step (5) of preparing environmentally responsive composite nanoparticles, In a closed container, 2 to 4 parts by weight of the PVBC-Fe ３ O ４ @NH ２ The particles are mixed with 0.5-1.5 parts by weight of tris[2-(dimethylamino)ethyl]amine, 0.5-1.5 parts by weight of ultra-dehydrated isopropyl alcohol, and diethylaminoethyl methacrylate monomer, and the ratio of the amount of diethylaminoethyl methacrylate monomer added to the amount of ultra-dehydrated isopropyl alcohol added is (9-11) μL:(0.8-1.2) mg; then, the container is put into liquid nitrogen to freeze, and at the same time, an inert gas is put into the mixture; after 5-8 minutes, the process is switched to vacuum drawing; after 5-8 minutes of vacuum drawing, the process is thawed; the freeze-vacuum-thaw operation is repeated 2-6 times; under the conditions of freezing and inert gas protection, 0.6-1.2 parts by weight of cuprous bromide is added; then, after performing the freeze-vacuum-thaw operation again, the sealed container is sealed; then, the whole sealed container is put into a thermostatic shaker at 55-65 ° C. for 10-13 hours of shaking reaction; solid-liquid separation is performed with a magnet; then, the solid matter is washed to obtain pH-responsive composite nanoparticles; Or, In a closed container, 1.5 to 2.5 parts by weight of the PVBC-Fe ３ O ４ @NH ２ The particles are mixed with 1.5-2.5 parts by weight of tris[2-(dimethylamino)ethyl]amine, N,N-dimethylformamide, and 195-205 parts by weight of N-isopropylacrylamide monomer, and the ratio of the amount of N,N-dimethylformamide added to the amount of N-isopropylacrylamide added is (0.5-1.5) mL:(95-105) mg. Then, the container is placed in liquid nitrogen to freeze, and at the same time, an inert gas is introduced into the mixture, and after 5-8 minutes, a vacuum is drawn. Step (5) of switching to the process, vacuuming for 5-8 minutes, followed by thawing, repeating the freezing, vacuuming and thawing operations 2-6 times, adding 0.6-1.2 parts by weight of cuprous bromide under freezing and inert gas protection conditions, then sealing the sealed container after performing the freezing, vacuuming and thawing operations again, then placing the entire sealed container in a thermostatic shaker at 55-75°C for shaking reaction for 10-13 hours, after processing, separating the solid and liquid with a magnet, then washing the solid matter to obtain temperature-responsive composite nanoparticles; Step (6) of preparing an environmentally responsive colloidal body having ultrasmall pores, comprising: The environmentally responsive composite nanoparticles prepared in step (5) are dispersed in a glass container containing an alkaline solution, the ratio of the environmentally responsive composite nanoparticles to the alkaline solution is (1.5-2.5) mg: (1.8-2.6) mL, and the pH value of the alkaline solution is 8-10; then, toluene of 8-15% of the volume of the alkaline solution is added into the glass container, and after ultrasonic treatment for 0.5-1.2 minutes, a uniform emulsion is obtained; then, an aqueous glutaraldehyde solution of 0.5-1.6 times the volume of toluene is added to the obtained emulsion, and glacial acetic acid is added to adjust the pH of the aqueous phase to 4-6; after standing for 30-60 minutes, sodium borohydride of 1-3 times the weight of the environmentally responsive composite nanoparticles is added thereto, and after reacting for 30-60 minutes, an environmentally responsive colloid body with ultrafine pores is obtained; Or, The environmentally responsive composite nanoparticles prepared in step (5) are dispersed in a glass container containing an alkaline solution, and the ratio of the environmentally responsive composite nanoparticles to the alkaline solution is (1.5-2.5) mg:(0.8-1.6) mL. Next, toluene of 8-15% of the volume of the alkaline solution is added to the glass container, and the glass container is placed in water at 45-55° C. and ultrasonically treated for 0.5-1.2 minutes to obtain a uniform emulsion. Next, an aqueous glutaraldehyde solution of 1.5-2.6 times the volume of toluene is added to the obtained emulsion, glacial acetic acid is added to adjust the pH of the aqueous phase to 4-6, and the mixture is allowed to stand for 30-60 minutes. Then, sodium borohydride of 1-3 times the weight of the environmentally responsive composite nanoparticles is added thereto, and the mixture is allowed to react for 30-60 minutes, after which an environmentally responsive colloid body with extremely small pores is obtained.

2. In step (1), the organic oil solution is a sodium oleate solution, the organic solvent is ethanol, the monounsaturated fatty acid is oleic acid, the non-polar solvent is toluene, the hydrothermal reaction vessel is a polytetrafluoroethylene hydrothermal reaction vessel, and the Fe ３ O ４ The nanoparticle dispersion contains 5-8 mg of Fe ３ O ４ 2. The method for preparing the environmentally responsive ultra-small pore magnetic colloid body according to claim 1, characterized in that the nanoparticles are dispersed in 28 to 33 mL of a non-polar solvent.

3. The method for preparing environmentally responsive ultra-small pore magnetic colloidal bodies according to claim 1, characterized in that in step (1), the molar concentration of the organic oil aqueous solution is 0.1-0.3 M, the molar concentration of the anhydrous ferric chloride aqueous solution is 0.1-0.3 M, and in step (1), the sieve is collected and washed with deionized water, and the drying is carried out in a vacuum oven, the drying temperature is 30-40° C., and the drying time is 18-24 hours.

4. The method for preparing an environmentally responsive ultra-small pore magnetic colloidal body according to claim 1, characterized in that in step (2), the aminosilane coupling agent is 3-aminopropyltriethoxysilane, and the organic acid is acetic acid.

5. The method for preparing environmentally responsive ultra-small pore magnetic colloidal bodies according to claim 1, characterized in that in step (3), the molecular weight of the PVBC polymer chain in the synthesized active PVBC polymer chain solution is 30-40 kDa.

6. The method for preparing an environmentally responsive ultra-small pore magnetic colloidal body according to claim 1, characterized in that the ultra-dehydrated cationic polymerization solvent is ultra-dehydrated dichloromethane, the alkaline solution in step (6) is an aqueous sodium hydroxide solution or aqueous ammonia solution with a pH of 8 to 10, and the initiator in step (3) is a boron trifluoride diethyl ether complex.

7. In step (3), the Fe obtained in step (2) ３ O ４ @NH ２ An active PVBC polymer chain solution is synthesized having a chain size equal to the diameter of the particle, said diameter being a function of the chain length of the active PVBC polymer chain solution and the Fe ３ O ４ @NH ２ The method for preparing the environmentally responsive ultra-small pore magnetic colloidal body according to claim 1, characterized in that the ratio of the particle diameter to the particle diameter is 0.8-1.5:

1.

8. The method for preparing environmentally responsive ultra-small pore magnetic colloidal bodies according to claim 1, characterized in that in step (5), the inert gas is nitrogen, the sealed container is a polymer tube, the pH-responsive composite nanoparticles are washed with isopropyl alcohol, and the temperature-responsive composite nanoparticles are washed with DMF.

9. The environmentally responsive ultra-small pore magnetic colloid body has adjacent composite nanoparticles stacked in a hexagonal close-packed form to generate ultra-small pores, and the cross-sectional area of ​​the ultra-small pore diameter is 0.04 × d ２ nm ２ The method for preparing an environmentally responsive ultra-small pore magnetic colloidal body according to any one of claims 1 to 8, characterized in that: d is the diameter of the composite nanoparticle.

10. The application of the environmentally responsive ultra-small pore magnetic colloidal body in the integrated media transmission of catalysis, concentration, directional transport and controlled release, characterized in that the environmentally responsive ultra-small pore magnetic colloidal body is an environmentally responsive ultra-small pore magnetic colloidal body obtained by the preparation method according to claim 9.

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