Surface functionalized hollow polymer microspheres, and methods and applications thereof

Abstract

The application relates to the technical field of high polymer materials, and discloses a surface functionalized hollow high polymer microsphere, which specifically comprises the following steps: (1) stirring and reacting styrene, a functional monomer, an initiator, an active ingredient and deionized water to obtain an emulsion, which is prepared for use; (2) swelling the emulsion with an organic solvent to obtain a precipitate, which is the surface functionalized hollow high polymer microsphere. The application uses styrene and glycidyl methacrylate as comonomers, uses mineral salts and other active ingredients as additives, systematically controls the ball-forming mode of polymerization, uses a soap-free emulsion polymerization method to prepare monodisperse solid high polymer microspheres with a unique structure, and uses an organic solvent to swell the high polymer microspheres to obtain hollow high polymer microspheres, the hollow high polymer microspheres have the characteristics of uniform particle size, good sphericity, no concave and damaged surface, high loading capacity, high specific surface area, low density and the like, and have wide application in the fields of catalyst preparation, heat and sound insulation materials, photoelectric materials and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymer materials, in particular to a surface functionalized hollow high polymer microsphere and a preparation method and application thereof. BACKGROUND

[0002] High polymer microspheres are important functional high polymer materials at present. Early high polymer microspheres are mainly applied to bulk product fields such as coatings, plastic additives, building materials, paper surface processing, etc. In recent years, the application fields of high polymer microspheres are continuously expanding, and the research in the fields of biomedical and biochemical engineering is particularly popular, specifically including embedding of toxic or biologically active substances, loading of fluorescent dyes, enzyme immobilization, etc. Due to the transfer of the application of high polymer microspheres from bulk products to high-end fields, higher requirements are put forward for the performance of high polymer microspheres, specifically including particle size and monodispersity of microspheres, thermal stability and resistance to organic solvents, etc. However, traditional high polymer microspheres are mostly solid structures. In order to expand the application range of high polymer microspheres, it is necessary to study hollow high polymer microspheres. Compared with traditional solid high polymer microspheres, hollow high polymer microspheres have the advantages of low density and large specific surface area, can adsorb or load more active substances, and have broad application prospects in drug control and release, energy storage materials, loading of fluorescent dyes, etc. Therefore, it has important scientific significance and practical value to design and controllably synthesize hollow high polymer microspheres.

[0003] At present, the preparation methods of traditional hollow high polymer microspheres mainly include self-assembly method, emulsion method, template method, etc. Among them, the template method becomes the most commonly used method for preparing hollow microspheres due to its good predictability, high repeatability and stable performance, etc. The template method for preparing hollow high polymer microspheres is divided into soft template method and hard template method. The soft template method is to use soft vesicles or micelles as templates, so that the polymerization reaction occurs on the surface of the template, thereby preparing hollow high polymer microspheres. However, the hollow high polymer microspheres synthesized by this method have irregular shapes, and the particle size distribution is usually uneven. In addition, a large amount of surfactant needs to be added during the preparation of hollow high polymer microspheres by the soft template method, which limits the application of the soft template method. The hard template method is to use stable high polymers or inorganic nanoparticles as cores, and the polymerization reaction occurs on the surface of the template. Finally, the template is removed by calcination or solvent etching, etc.

[0004] At the same time, the preparation process of the hollow microspheres prepared by the prior art is relatively complex, and the surface structure of the microspheres is easily damaged during the preparation process, for example, causing the surface of the microspheres to be concave or form large holes, which is easy to cause the internal functional substances to leak or directly contact with the external environment, etc. In addition, the functional groups on the surface of the prepared microspheres are limited, and it is difficult to perform biological coupling and chemical modification and other functional designs according to the application target.

[0005] Therefore, providing a surface functionalized and internally hollow monodisperse polymer microsphere and a preparation method thereof is a technical problem to be solved in the art. SUMMARY

[0006] The present application aims to provide a surface functionalized hollow polymer microsphere and a preparation method and application thereof. The present application first prepares monodisperse solid polymer microspheres by using a soap-free emulsion polymerization method, and then swells the solid polymer microspheres by using an organic solvent to obtain hollow polymer microspheres. The prepared product has good sphericity, no surface depression, uniform particle size, high loading capacity, and high surface area and low density.

[0007] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme:

[0008] A preparation method of a surface functionalized hollow polymer microsphere, specifically comprising the following steps:

[0009] (1) stirring and reacting styrene, a functional monomer, an initiator, an active ingredient and deionized water to obtain an emulsion, for standby use;

[0010] (2) swelling the emulsion by using an organic solvent, and obtaining the surface functionalized hollow polymer microspheres after centrifugation.

[0011] The functional monomer used in the present application has a hydrophilic epoxy functional group. In the process of soap-free emulsion polymerization, the hydrophilic functional group is preferentially distributed on the outside of the microspheres, and the hydrophobic functional group is more distributed in the inside of the microspheres. Among them, the hydrophilic polyglycidyl methacrylate does not dissolve in the organic solvent basically, mainly because the cross-linking occurs in the continuous reaction of the glycidyl methacrylate on the outside of the microspheres, and the polystyrene distributed in the inside is easily dissolved in the organic solvent.

[0012] In a general polymerization reaction, the two kinds of monomers tend to be randomly copolymerized, resulting in more surface of the microspheres being destroyed in the process of swelling in the organic solvent, and the high-quality hollow structure cannot be formed. However, in the reaction liquid of styrene and glycidyl methacrylate, the active ingredient is added in the present application, so as to change the polymerization tendency between the monomers, that is, more polyglycidyl methacrylate tends to be distributed on the outside of the microspheres, and more polystyrene tends to be distributed in the inside of the microspheres, and the morphology of the microspheres is basically unchanged in the swelling process. Furthermore, by controlling the reaction conditions, the functionalized hollow polymer microspheres with uniform particle size and monodispersity can be prepared.

[0013] Preferably, the mass ratio of the active ingredient to the deionized water in step (1) is 0.003-0.3:100;

[0014] The volume ratio of the styrene, the functional monomer and the deionized water is 3-10:1.2-6:100.

[0015] The mass ratio of the initiator and the deionized water is 0.05-0.4:100.

[0016] Wherein, the microspheres without adding functional monomers have linear structure and are difficult to stably exist in high-concentration organic solvents; and the high-molecular microspheres synthesized by adding a higher amount of functional monomers can stably exist in high-concentration organic solvents for a long time, the functional monomer amount in a suitable ratio can make the microspheres in a hollow structure, increasing the functional monomer amount can reduce the hollow degree of the microspheres, and a substantial reduction in the functional monomer amount can cause the microspheres to be damaged or dissolved to a large extent in the organic solvent.

[0017] Moreover, the hollow high-molecular microspheres with complete surfaces after swelling can be obtained by adding an appropriate amount of active ingredients in the reaction solution, and increasing the active ingredient amount can also increase the hollow degree of the microspheres, but excessive active ingredients can cause the microspheres to be adhered during the preparation and swelling process.

[0018] Preferably, the preparation method is carried out in an inert gas atmosphere.

[0019] Preferably, the temperature of the reaction in step (1) is 63-75℃, and the time is 4-16h; and the stirring speed is 150-600rpm.

[0020] Preferably, the temperature of the reaction in step (1) is 70℃.

[0021] Preferably, the active ingredients in step (1) include mineral salts and / or biological macromolecules.

[0022] The functional monomer is glycidyl methacrylate.

[0023] The initiator is any one of potassium persulfate, sodium persulfate and ammonium persulfate.

[0024] Preferably, the volume ratio of the emulsion and the organic solvent in step (2) is greater than 1, and the swelling time is greater than 1min.

[0025] Preferably, the volume ratio of the emulsion and the organic solvent in step (2) is greater than 3, and the swelling time is greater than 5min.

[0026] In the present application, the swelling time is shorter, the higher the amount of organic solvent, the greater the hollow degree of the microspheres, and the faster the swelling speed, and extending the swelling time does not significantly change the morphology of the microspheres.

[0027] Preferably, the organic solvent in step (2) is at least one of tetrahydrofuran, acetone, diethyl ether, ethyl acetate, cyclohexane, toluene, xylene and mesitylene.

[0028] Preferably, the mineral salt comprises at least one of calcium salt, phosphorus salt, magnesium salt, potassium salt, sodium salt, iron salt, zinc salt, copper salt, manganese salt, iodine salt, selenium salt and molybdenum salt.

[0029] The biological macromolecule comprises at least one of amino acid, nucleotide, polysaccharide, vitamin and protein.

[0030] Preferably, the prepared hollow high polymer microspheres are washed by water, ethanol or ethanol / water mixture alternately after centrifugation and discarding supernatant.

[0031] A surface functionalized hollow high polymer microsphere prepared by the preparation method.

[0032] Preferably, the particle size of the hollow high polymer microsphere is 100-1000 nm.

[0033] The application of the surface functionalized hollow high polymer microsphere prepared by the preparation method in the preparation of catalyst, heat and sound insulation material, photoelectric material, magnetic material, drug microcapsule material.

[0034] The application of the surface functionalized hollow high polymer microsphere prepared by the preparation method in the fields of aerospace, oil exploitation, ocean exploration, communication, ship, automobile, rail transportation, building material, chemical industry, electronics, medical treatment, environmental protection, cosmetics, sports goods.

[0035] The controllable preparation of high-quality hollow high polymer nanometer microspheres fills the blank in the research field, and the method has epoch-making significance, not only in that it will open up the exploration of the scientific principle behind the micro-preparation method, reveal the new mechanism of polymer material synthesis and open up a new path, but also greatly promote the rapid development of multiple neck technologies.

[0036] Notably, the hollow high polymer microspheres prepared by the application have good sphericity, no surface depression and uniform particle size, and have characteristics such as high surface area and low density, and the size of the hollow microspheres is in the nanometer scale, which has a wider application range than micron hollow spheres, and has high strength, heat preservation, fireproofing, corrosion resistance, insulation, wear resistance, good flowability and easy filling, thereby having a wide application prospect in the fields of catalyst carrier, heat and sound insulation material, photoelectric material, magnetic material, drug microcapsule material, aerospace, oil exploitation, ocean exploration, communication, ship, automobile, rail transportation, building material, chemical industry, electronics, medical treatment, environmental protection, cosmetics, sports goods, etc.

[0037] (1) Application in materials for aviation, aerospace and submarine

[0038] The addition of nanoscale hollow polymer microspheres to the base resin can effectively reduce the material density while maintaining the strength of the material, and can be applied to the field of special functional materials such as aviation, aerospace and submarine.

[0039] (2) Application in oil exploitation

[0040] Hollow polymer nanospheres have low density, high strength and do not absorb water, and have irreplaceable advantages in the application of ultra-deep well and ultra-low density cement slurry. Drilling fluid containing hollow polymer nanospheres has good rheological properties and inhibition, large adjustable density range, uniform and stable dispersion, can ensure the consistency of wellbore density, and at the same time solves the problem that the measurement instrument cannot effectively transmit signals in multiphase flow. In addition, hollow polymer nanospheres can be combined with radionuclides to play an important role in drilling and exploitation applications.

[0041] (3) Application in automobile lightweighting

[0042] By replacing traditional fillers, hollow polymer nanospheres can reduce the weight of molded parts without sacrificing strength or aesthetics. The application of hollow polymer nanospheres in automobile lightweighting mainly has the following ways: (a) hollow polymer nanospheres are applied to automobile modified engineering plastics; (b) hollow polymer nanospheres are applied to low-density SMC (Sheet molding compound) composite materials; (c) hollow polymer nanospheres are applied to damping materials; (d) hollow polymer nanospheres are applied to automobile sealant; (e) carbon fiber composite materials, chassis armor, special putty and other materials are also application paths of hollow polymer nanospheres in automobile lightweighting.

[0043] (4) Application in adhesives

[0044] There are many types of adhesives with different components, mainly including silicone adhesives, polyurethane adhesives, epoxy adhesives, EVA (ethylene vinyl acetate copolymer adhesive) adhesives, etc., and the base materials of most of them are various types of resins. The application of hollow polymer nanospheres in adhesives mainly has the following ways: (a) hollow polymer nanospheres are applied to special structure glue; (b) hollow polymer nanospheres are applied to bonding and packaging glue.

[0045] (5) Application in 5G communication

[0046] PCB (printed circuit board, printed circuit board) is the basis of 5G wireless communication equipment, and the development of high-performance high-frequency low-dielectric PCB products must choose resin matrix and fiber reinforced materials with low dielectric constant and low dielectric loss factor. The hollow high polymer nanometer microspheres are filled with gas, and the dielectric constant of the gas is close to 1. In addition to the polystyrene shell, the dielectric constant of the hollow high polymer nanometer microspheres is extremely low, which can effectively improve the dielectric properties of the material. At the same time, its light weight, low thermal conductivity, non-toxic, non-combustible, good chemical stability, high dispersion and other advantages make the material's impact resistance, creep resistance and heat resistance, dimensional stability, insulation performance, rigidity and stress damping ability are improved. Therefore, hollow high polymer nanometer microspheres are the best choice for filling materials for PCB substrate materials in the 5G era.

[0047] (6) Application in agricultural and plastic films

[0048] Hollow high polymer nanometer microspheres as plastic film opening agents can solve the problem of opening agent accumulation on the surface of the film, and can achieve good opening and smoothness of the film, improve the processing performance of the film and not affect the transparency of the film. Hollow high polymer nanometer microspheres as functional additives for film products can effectively reduce the dielectric constant of the film in the communication field; glass film for building has good heat insulation effect; used for preservative film can improve the preservation performance.

[0049] (7) Application in the environmental protection industry

[0050] Hollow high polymer nanometer microspheres as special pore-forming fillers combined with ceramic materials can be applied to various scenes including airplanes and industrial exhaust treatment.

[0051] (8) Application in the medical industry

[0052] Hollow high polymer nanometer microspheres have many advantages and are very suitable for the medical and health industry to improve the performance of existing technology. For example, ultrasound enhancement, drug delivery, interventional surgery, embolization and occlusion, biological imaging, in vitro detection, medical devices, stent materials, catheter materials, etc.

[0053] (9) Application in the sports industry

[0054] With the light weight of hollow polymer nanometer microspheres, when preparing composite sports products, adding hollow polymer nanometer microspheres can not only reduce the amount of organic matter and thus reduce VOC (volatile organic compounds) emissions, but also make the sports products have stable size standards, wear resistance, light weight, and good weather resistance, which is more conducive to athletes achieving good results. For example, light weight basketball boards (low density SMC products), light weight water skiing boards (main materials are panel + composite foam sandwich structure), ski boards (HGM modified engineering plastics), etc.

[0055] (10) Application in the emulsion explosive industry

[0056] After special treatment of the surface of hollow polymer nanometer microspheres, they can be closely combined with the oil film of the external phase of emulsion explosives, supporting them to play the role of stabilizer. When the external initiation effect occurs, each hollow polymer nanometer microsphere is adiabatically compressed, the local temperature rises rapidly, and when the temperature is high enough, it will cause intense exothermic chemical reactions such as oil phase combustion and oxidant decomposition, play a sensitizing role, and greatly improve the detonation performance of the explosive and the storage stability.

[0057] (11) Application in the green building materials industry

[0058] The application of hollow polymer nanometer microspheres in the green building materials industry mainly has the following ways: (a) hollow polymer nanometer microspheres are applied to thermal insulation coatings; (b) hollow polymer nanometer microspheres are applied to composite doors and windows; (c) hollow polymer nanometer microspheres are applied to artificial marble; (d) hollow polymer nanometer microspheres are applied to engineered wood, furniture, bathroom, etc.

[0059] (12) Application in the electrical energy and transportation industry

[0060] The application of hollow polymer nanometer microspheres in the electrical energy and transportation industry mainly has the following ways: (a) electric meter box, electric appliance cabinet, switch box; (b) new energy vehicle charging pile, battery box; (c) train window frame, toilet assembly, bathroom, wallboard, washbasin, shower tray, seat, tea table top, carriage wallboard, roof, electronic components, switch equipment, etc.

[0061] (13) Application in other aspects

[0062] In addition to the above several main application directions, hollow polymer nanometer microspheres also have wide application prospects in the fields of functional polymer microbead products, thermal, light, electrical, wave-absorbing, shielding and other material preparation, composite material towers, silicone rubber products, wind power blades, liquid crystal display spacer materials, medical immunodetection, biological functional materials, wave-absorbing materials, 3D printing materials, liquid metal materials, photocatalyst carrier materials, etc.

[0063] The hollow polystyrene microspheres of the present application have the characteristics of small density, large specific surface area, controllable hollow degree and high loading capacity, and can be widely applied in the fields of catalyst carrier, heat and sound insulation material, photoelectric material, magnetic material, drug microcapsule material, aerospace, oil exploitation, ocean exploration, communication, ship, automobile, rail transportation, building material, chemical industry, electronics, medical treatment, environmental protection, cosmetics, sports goods and the like.

[0064] Compared with the prior art, the present application has the following beneficial effects:

[0065] (1) In the present application, the surface of the polystyrene microspheres is designed and functionally modified, and glycidyl methacrylate is added in the polymerization process, so that the microsphere surface contains a large number of epoxy groups and hydroxyl groups, has good hydrophilicity, and achieves the purpose of adjusting the polarity of the microsphere surface; part of the epoxy groups gradually crosslink during the hydrolysis process on the surface of the microspheres, which can increase the organic solvent resistance of the microspheres, and the addition of nutrient active substances in the reaction solution can make the hydrophilic glycidyl methacrylate preferentially distribute on the outside of the microspheres, and the liposoluble polystyrene is more distributed in the inside of the microspheres during the preparation process, so that a microsphere with a core-shell structure is finally synthesized; when organic solvent immersion swelling is carried out, the polystyrene in the inside is easy to dissolve, so that the hollow of the microspheres is realized, and a hollow structure high polymer microsphere is obtained. In addition, the functional groups on the surface of the microspheres can be coupled with most biomolecules through reaction, which can be widely applied in the field of biomedicine.

[0066] (2) The functionalized hollow high polymer microspheres prepared in the present application have a large internal space, can embed more functional substances, and have good stability; at the same time, the hollow high polymer microspheres prepared have uniform particle size, and the surface does not have recesses or damage, can effectively coat functional substances, and is not easy to cause leakage.

[0067] (3) The preparation method of the present application is simple and controllable, the particle size and the pore size of the core of the microspheres can be controlled by adjusting the process parameters such as the ratio of styrene monomer and functional monomer, the initiation temperature, the amount and type of initiator, the amount of active ingredient, the amount and type of organic solvent, etc., so as to realize the preparation concept of controllable morphology and size, and at the same time, the preparation conditions are easy to realize, which is conducive to the process scale-up research and easy to realize industrialized production.

[0068] (5) The hollow high polymer microspheres obtained in the present application have good sphericity, no recess on the surface and uniform particle size, and have the characteristics of high surface area and low density. BRIEF DESCRIPTION OF DRAWINGS

[0069] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced. The drawings in the description are only examples of the embodiments of the present application.

[0070] Figure 1 Transmission electron microscope image of the solid high polymer microspheres prepared in Example 1 of the present application;

[0071] Figure 2 Transmission electron microscope image of the hollow high polymer microspheres after swelling treatment prepared in Example 1 of the present application;

[0072] Figure 3 Scanning electron microscope image of the solid high polymer microspheres prepared in Example 1 of the present application;

[0073] Figure 4 Scanning electron microscope image of the hollow high polymer microspheres after swelling treatment prepared in Example 1 of the present application;

[0074] Figure 5 Particle size and distribution diagram of the hollow high polymer microspheres after swelling treatment prepared in Example 1 of the present application;

[0075] Figure 6 Morphology diagram of the hollow spheres when the initiator temperature is 73℃ and 70℃ respectively in Example 4 of the present application;

[0076] Figure 7 Morphology diagram of the hollow high polymer microspheres prepared in Example 22 of the present application under different solvent ratios and different swelling times;

[0077] Figure 8 Coupling effect diagram of the microspheres in Example 27 of the present application and the dye containing amino group;

[0078] Figure 9 Color comparison diagram of the blank polystyrene microspheres and the microspheres in Example 27 of the present application in the test tube. DETAILED DESCRIPTION

[0079] The embodiments of the present application will be described below, examples of which are shown in the accompanying drawings. The embodiments described with reference to the drawings are exemplary and are intended to explain the present application, and are not understood as limiting the present application.

[0080] Example 1

[0081] A preparation method of surface functionalized hollow high polymer microspheres, specifically comprising the following steps:

[0082] Into a 250 mL three-necked flask, 3 mL of styrene and 1.8 mL of glycidyl methacrylate were added, 110 mg of potassium persulfate, 100 mg of sodium chloride and 100 mL of deionized water were added, mechanical stirring was started and the rotation speed was set to 350 rpm, the condensate water was opened, and after 15 min of inert gas, it was heated to 70°C at room temperature, and after 8 h of reaction, the reaction solution showed a milky white color, the emulsion and tetrahydrofuran were mixed according to the volume ratio 1:5 for 5 min, and then the upper liquid was discarded after centrifugation, and then washed with ethanol and water alternately once, to obtain the surface functionalized hollow polymer microspheres.

[0083] The product of Example 1 was tested by transmission electron microscopy (TEM, Transmission Electron Microscope): on the HT7700 transmission electron microscope of Japan Hitachi Company, the prepared polymer microspheres were diluted 1000 times and then dropped onto the copper support net covered with carbon film, and then dried naturally at room temperature for characterization, and the results are as follows Figures 1-2 , wherein, Figure 1 is the transmission electron microscopy of the solid polymer microspheres before swelling treatment, it can be seen that the solid microspheres are regular spherical, and the diameter is about 275 nm, Figure 2 is the transmission electron microscopy of the prepared hollow polymer microspheres after swelling treatment, it can be seen that the hollow polymer microspheres after swelling are complete in shape, and the shape is still spherical, and there is no depression or damage on the surface, which shows that the polymer microspheres do not change in morphology in tetrahydrofuran solvent, and the diameter is about 270 nm.

[0084] The product of Example 1 was tested by scanning electron microscopy (SEM, Scanning Electron Microscope): on the Ultra 55 field emission scanning electron microscope of Germany Zeiss Company, the synthesized polymer microsphere emulsion was diluted 1000 times and then dropped onto a silicon wafer, and then dried naturally at room temperature; due to the poor conductivity of the polymer material, in order to prevent the accumulation of electric charge before sampling, the sample was treated by gold ion sputtering, and the results are as follows Figures 3-4 , wherein Figure 3 is the scanning electron microscopy of the solid polymer microspheres before swelling treatment, it can be seen that the solid microspheres are regular spherical, Figure 4 is the scanning electron microscopy of the prepared hollow polymer microspheres after swelling treatment, it can be seen that the shape is still spherical after swelling, and there is no depression or damage on the surface, which also shows that the polymer microspheres do not change in morphology in tetrahydrofuran solvent.

[0085] The particle size and distribution of the product of Example 1 were tested: the hollow polymer microsphere solution was diluted 1000 times with deionized water, and placed in a cuvette, and the particle size of the hollow microspheres was measured at 25°C using a Zetasizer ZS-90 from the British Malvern Company. The instrument used an excitation light of 633 nm red light, and the angle between the incident light and the detector was 90°. The instrument was set to have a holding time of 2 min during testing, and the zeta potential testing temperature was 25°C. The particle size distribution of the hollow polymer microspheres is shown in Figure 5 As can be seen, the size of the microspheres is substantially uniform, and the coefficient of variation of the particle size distribution is 0.05, indicating monodispersity.

[0086] Example 2

[0087] 3 mL of styrene and 1.8 mL of glycidyl methacrylate were added to a 250 mL three-necked flask, 110 mg of potassium persulfate, 10 mg of sodium chloride and 100 mL of deionized water were added, mechanical stirring was started and the stirring speed was set to 350 rpm, the condensate was turned on, and the temperature was heated to 70°C at room temperature. After 16 h of reaction, the reaction solution was milky white. The emulsion and acetone were mixed at a volume ratio of 1:5 for 10 min, the upper liquid was discarded after centrifugation, and then the hollow polymer microspheres with a particle size of 254 nm and a complete surface were prepared by washing with ethanol and water.

[0088] Example 3

[0089] 3 mL of styrene and 3 mL of glycidyl methacrylate were added to a 250 mL three-necked flask, 110 mg of potassium persulfate, 30 mg of sodium chloride and 100 mL of deionized water were added, mechanical stirring was started and the stirring speed was set to 350 rpm, the condensate was turned on, and the temperature was heated to 70°C at room temperature. After 16 h of reaction, the reaction solution was milky white. The emulsion and tetrahydrofuran were mixed at a volume ratio of 1:5 for 10 min, the upper liquid was discarded after centrifugation, and then the hollow polymer microspheres with a particle size of 322 nm and a complete surface were prepared by washing with water.

[0090] Example 4

[0091] 3 mL of styrene and 1.8 mL of glycidyl methacrylate were added to a 250 mL three-necked flask, 110 mg of potassium persulfate, 30 mg of sodium chloride and 100 mL of deionized water were added, mechanical stirring was started and the stirring speed was set to 350 rpm, the condensate was turned on, and the temperature was heated to 70°C at room temperature. After 16 h of reaction, the reaction solution was milky white. The emulsion and tetrahydrofuran were mixed at a volume ratio of 1:5 for 10 min, the upper liquid was discarded after centrifugation, and then the hollow polymer microspheres with a particle size of 322 nm and a complete surface were prepared by washing with water.

[0092] According to the relevant parameters, due to the temperature rise of the polymerization of the present embodiment, the polymerization between monomers is more inclined to random copolymerization, when the initiation temperature reaches 73℃, reference Figure 7 The right of the figure is the lower degree of hollow inside the hollow microspheres prepared at 73℃ (compared with the left 70℃ condition, the size of the cavity is obviously reduced), and the reason is that at a higher temperature, a large amount of initiator is simultaneously decomposed, the reaction is violent, and the random polymerization is inclined, the composition inside and outside the microspheres has no obvious difference, and the hollow structure cannot be formed.

[0093] Example 5

[0094] 3mL of styrene and 1.8mL of glycidyl methacrylate were added to a 250mL three-necked flask, 110mg of potassium persulfate, 30mg of sodium bromide and 100mL of deionized water were added, mechanical stirring was started and the speed was set to 350rpm, the condensate was opened, and the inert gas was introduced for 15min, then heated to 70℃ at room temperature, after 8h of reaction, the reaction solution showed a milky white color, the emulsion and tetrahydrofuran were mixed according to the volume ratio of 1:5 for 10min, then the upper liquid was discarded after centrifugation, and then washed with water by centrifugation, to prepare surface-intact hollow polymer microspheres with a particle size of 254nm.

[0095] Example 6

[0096] 3mL of styrene and 1.8mL of glycidyl methacrylate were added to a 250mL three-necked flask, 110mg of potassium persulfate, 30mg of sodium bromide and 100mL of deionized water were added, mechanical stirring was started and the speed was set to 350rpm, the condensate was opened, and the inert gas was introduced for 15min, then heated to 70℃ at room temperature, after 8h of reaction, the reaction solution showed a milky white color, the emulsion and tetrahydrofuran were mixed according to the volume ratio of 1:5 for 10min, then the upper liquid was discarded after centrifugation, and then washed with water by centrifugation, to prepare surface-intact hollow polymer microspheres with a particle size of 254nm.

[0097] Example 7

[0098] 3mL of styrene and 1.8mL of glycidyl methacrylate were added to a 250mL three-necked flask, 110mg of potassium persulfate, 30mg of sodium bromide and 100mL of deionized water were added, mechanical stirring was started and the speed was set to 350rpm, the condensate was opened, and the inert gas was introduced for 15min, then heated to 70℃ at room temperature, after 8h of reaction, the reaction solution showed a milky white color, the emulsion and tetrahydrofuran were mixed according to the volume ratio of 1:5 for 10min, then the upper liquid was discarded after centrifugation, and then washed with water by centrifugation, to prepare surface-intact hollow polymer microspheres with a particle size of 254nm.

[0099] Example 8

[0100] Into a 250 mL three-necked flask, 3 mL of styrene and 1.8 mL of glycidyl methacrylate were added, 110 mg of potassium persulfate, 10 mg of sodium chloride, 5 mg of amino acid, 5 mg of vitamin and 100 mL of deionized water were added, mechanical stirring was started and the rotating speed was set at 350 rpm, the condensate water was opened, after 15 min of inert gas purging, heating was started at room temperature to 70 °C, after 12 h of reaction, the reaction solution appeared milky white, the emulsion and tetrahydrofuran were mixed at a volume ratio of 1:5 for 10 min, the upper liquid was discarded after centrifugation, and then washed with ethanol and water alternately once to prepare surface-intact hollow polymer microspheres with a particle size of 250 nm.

[0101] Example 9

[0102] Into a 250 mL three-necked flask, 3 mL of styrene and 1.8 mL of glycidyl methacrylate were added, 110 mg of potassium persulfate, 3 mg of calcium chloride and 100 mL of deionized water were added, mechanical stirring was started and the rotating speed was set at 350 rpm, the condensate water was opened, after 15 min of inert gas purging, heating was started at room temperature to 70 °C, after 12 h of reaction, the reaction solution appeared milky white, the emulsion and tetrahydrofuran were mixed at a volume ratio of 1:5 for 10 min, the upper liquid was discarded after centrifugation, and then washed with ethanol and water alternately once to prepare surface-intact hollow polymer microspheres with a particle size of 254 nm.

[0103] Example 10

[0104] Into a 250 mL three-necked flask, 3 mL of styrene and 1.8 mL of glycidyl methacrylate were added, 110 mg of potassium persulfate, 300 mg of potassium chloride and 100 mL of deionized water were added, mechanical stirring was started and the rotating speed was set at 350 rpm, the condensate water was opened, after 15 min of inert gas purging, heating was started at room temperature to 70 °C, after 12 h of reaction, the reaction solution appeared milky white, the emulsion and tetrahydrofuran were mixed at a volume ratio of 1:5 for 10 min, the upper liquid was discarded after centrifugation, and then washed with ethanol and water alternately once to prepare surface-intact hollow polymer microspheres with a particle size of 333 nm.

[0105] Example 11

[0106] Into a 250 mL three-necked flask, 3 mL of styrene and 1.8 mL of glycidyl methacrylate were added, 110 mg of potassium persulfate, 300 mg of sodium chloride and 100 mL of deionized water were added, mechanical stirring was started and the rotation speed was set to 350 rpm, the condensate water was opened, after 15 min of inert gas purging, heating to 70°C at room temperature, after 12 h of reaction, the reaction solution showed milky white, the emulsion and tetrahydrofuran were mixed according to the volume ratio 1:5 for 10 min, the upper liquid was discarded after centrifugation, and then washed with ethanol and water alternately once to prepare surface-intact hollow polymer microspheres with a particle size of 423 nm.

[0107] Example 12

[0108] Into a 250 mL three-necked flask, 3 mL of styrene and 1.8 mL of glycidyl methacrylate were added, 110 mg of potassium persulfate, 300 mg of sodium chloride and 100 mL of deionized water were added, mechanical stirring was started and the rotation speed was set to 350 rpm, the condensate water was opened, after 15 min of inert gas purging, heating to 70°C at room temperature, after 12 h of reaction, the reaction solution showed milky white, the emulsion and tetrahydrofuran were mixed according to the volume ratio 1:5 for 10 min, the upper liquid was discarded after centrifugation, and then washed with ethanol and water alternately once to prepare surface-intact hollow polymer microspheres with a particle size of 423 nm.

[0109] Example 13

[0110] Into a 250 mL three-necked flask, 3 mL of styrene and 1.8 mL of glycidyl methacrylate were added, 110 mg of potassium persulfate, 300 mg of sodium chloride and 100 mL of deionized water were added, mechanical stirring was started and the rotation speed was set to 350 rpm, the condensate water was opened, after 15 min of inert gas purging, heating to 70°C at room temperature, after 12 h of reaction, the reaction solution showed milky white, the emulsion and tetrahydrofuran were mixed according to the volume ratio 1:5 for 10 min, the upper liquid was discarded after centrifugation, and then washed with ethanol and water alternately once to prepare surface-intact hollow polymer microspheres with a particle size of 423 nm.

[0111] Example 14

[0112] Into a 250 mL three-necked flask, 3 mL of styrene and 1.2 mL of glycidyl methacrylate were added, 110 mg of potassium persulfate, 10 mg of sodium chloride and 100 mL of deionized water were added, mechanical stirring was started and the rotation speed was set to 350 rpm, the condensate water was opened, after 15 min of inert gas purging, heating to 70°C at room temperature, after 12 h of reaction, the reaction solution showed milky white, the emulsion and tetrahydrofuran were mixed according to the volume ratio 1:5 for 10 min, the upper liquid was discarded after centrifugation, and then washed with ethanol and water alternately once to prepare surface-intact hollow polymer microspheres with a particle size of 244 nm.

[0113] Example 15

[0114] Into a 250 mL three-necked flask, 5 mL of styrene and 3 mL of glycidyl methacrylate were added, 110 mg of potassium persulfate, 30 mg of sodium chloride and 100 mL of deionized water were added, mechanical stirring was started and the rotation speed was set to 350 rpm, the condensate water was opened, after 15 min of inert gas purging, heating to 70°C at room temperature, after 12 h of reaction, the reaction solution showed milky white, the emulsion and tetrahydrofuran were mixed according to the volume ratio 1:5 for 10 min, the upper liquid was discarded after centrifugation, and then washed with ethanol and water alternately once to prepare surface-intact hollow polymer microspheres with a particle size of 298 nm.

[0115] Example 16

[0116] Into a 250 mL three-necked flask, 4 mL of styrene and 2 mL of glycidyl methacrylate were added, 110 mg of potassium persulfate, 30 mg of sodium chloride and 100 mL of deionized water were added, mechanical stirring was started and the rotation speed was set to 350 rpm, the condensate water was opened, after 15 min of inert gas purging, heating to 70°C at room temperature, after 12 h of reaction, the reaction solution showed milky white, the emulsion and tetrahydrofuran were mixed according to the volume ratio 1:5 for 10 min, the upper liquid was discarded after centrifugation, and then washed with ethanol and water alternately once to prepare surface-intact hollow polymer microspheres with a particle size of 281 nm.

[0117] Example 17

[0118] Into a 250 mL three-necked flask, 3 mL of styrene and 1.8 mL of glycidyl methacrylate were added, 110 mg of potassium persulfate, 30 mg of sodium chloride and 100 mL of deionized water were added, mechanical stirring was started and the rotation speed was set to 200 rpm, the condensate water was opened, after 15 min of inert gas purging, heating to 70°C at room temperature, after 12 h of reaction, the reaction solution showed milky white, the emulsion and tetrahydrofuran were mixed according to the volume ratio 1:5 for 10 min, the upper liquid was discarded after centrifugation, and then washed with ethanol and water alternately once to prepare surface-intact hollow polymer microspheres with a particle size of 215 nm.

[0119] Example 18

[0120] Into a 250 mL three-necked flask, 3 mL of styrene and 1.8 mL of glycidyl methacrylate were added, 110 mg of potassium persulfate, 30 mg of sodium chloride and 100 mL of deionized water were added, mechanical stirring was started and the rotation speed was set to 200 rpm, the condensate water was opened, after 15 min of inert gas purging, heating to 70°C at room temperature, after 12 h of reaction, the reaction solution showed milky white, the emulsion and tetrahydrofuran were mixed according to the volume ratio 1:5 for 10 min, the upper liquid was discarded after centrifugation, and then washed with ethanol and water alternately once to prepare surface-intact hollow polymer microspheres with a particle size of 215 nm.

[0121] Example 19

[0122] Into a 250 mL three-necked flask, 3 mL of styrene and 1.8 mL of glycidyl methacrylate were added, 110 mg of potassium persulfate, 30 mg of sodium chloride and 100 mL of deionized water were added, mechanical stirring was started and the rotation speed was set to 200 rpm, the condensate water was opened, after 15 min of inert gas purging, heating to 70°C at room temperature, after 12 h of reaction, the reaction solution showed milky white, the emulsion and tetrahydrofuran were mixed according to the volume ratio 1:5 for 10 min, the upper liquid was discarded after centrifugation, and then washed with ethanol and water alternately once to prepare surface-intact hollow polymer microspheres with a particle size of 215 nm.

[0123] Example 20

[0124] Into a 250 mL three-necked flask, 3 mL of styrene and 1.8 mL of glycidyl methacrylate were added, 110 mg of potassium persulfate, 30 mg of sodium chloride and 100 mL of deionized water were added, mechanical stirring was started and the rotating speed was set to 500 rpm, the condensate water was opened, inert gas was introduced for 15 min, then heated to 70°C at room temperature, the reaction was carried out for 12 h, the reaction solution was milky white, the emulsion and tetrahydrofuran were mixed at a volume ratio of 1:5 for 10 min, the upper liquid was discarded after centrifugation, then washed with ethanol and water alternately once, and the surface-intact hollow polymer microspheres with a particle size of 302 nm were prepared.

[0125] Example 21

[0126] Into a 250 mL three-necked flask, 3 mL of styrene and 1.8 mL of glycidyl methacrylate were added, 110 mg of potassium persulfate, 30 mg of sodium chloride and 100 mL of deionized water were added, mechanical stirring was started and the rotating speed was set to 500 rpm, the condensate water was opened, inert gas was introduced for 15 min, then heated to 70°C at room temperature, the reaction was carried out for 12 h, the reaction solution was milky white, the emulsion and tetrahydrofuran were mixed at a volume ratio of 1:5 for 10 min, the upper liquid was discarded after centrifugation, then washed with ethanol and water alternately once, and the surface-intact hollow polymer microspheres with a particle size of 302 nm were prepared.

[0127] Comparative Examples 1-14

[0128] Into a 250 mL three-necked flask, different proportions of styrene and glycidyl methacrylate were added, 110 mg of potassium persulfate and 100 mL of deionized water were added, a certain amount of mineral salt was added or not, mechanical stirring was started and the rotating speed was set to 350 rpm, the condensate water was opened, inert gas was introduced for 15 min, then heated to the set temperature at room temperature, the reaction was carried out for 12 h, the reaction solution was milky white, the emulsion and tetrahydrofuran were mixed at a volume ratio of 1:5 for 10 min, the upper liquid was discarded after centrifugation, then washed with ethanol and water alternately once; the specific parameters of each comparative example reaction are shown in Table 1, and the obtained polymer microspheres were tested by transmission electron microscopy, the particle size and swelling results were observed, see Table 1.

[0129] Table 1 Preparation parameters and swelling results of polymer microspheres prepared in Comparative Examples 1-14

[0130]

[0131] In the field of polymer microspheres, the polymer chains of microspheres without the addition of functional monomers are linear structures, which are difficult to stably exist in high-concentration organic solvents; as can be seen from Comparative Example 8 in Table 1, when the addition amount of styrene St is 0, the prepared polymer microspheres have excellent stability and do not change in organic solvents, and solid microspheres can be obtained; when a higher amount of glycidyl methacrylate (abbreviated as GMA) is added, the synthesized polymer microspheres can stably exist in high-concentration organic solvents for a long time without a crosslinking agent, and solid microspheres can be obtained, namely Comparative Examples 3, 4, and 5; the GMA amount in a suitable proportion can enable the microspheres to be in a hollow structure, but further reduction of the GMA amount will cause the microspheres to be damaged or dissolved to a large extent in organic solvents, namely the hollow polymer microspheres are not firm. By adding an appropriate amount of mineral salt such as sodium chloride to the reaction solution, hollow polymer microspheres with an intact surface after swelling can be obtained, and it is found that the addition of mineral salt can increase the GMA amount limit of the hollow polymer microspheres, and increasing the amount of mineral salt can also increase the hollow degree of the microspheres, but increasing the GMA amount can reduce the hollow degree of the microspheres, and excessive mineral salt can cause the microspheres to be adhered during the preparation and swelling processes. When the initiation temperature reaches 77°C and 81°C, the microspheres do not hollow during the swelling process in organic solvents, and reducing the initiation temperature can cause the microspheres to precipitate during the preparation process and the hollow microspheres and solid microspheres to coexist after swelling.

[0132] Comparative Example 15

[0133] 3 mL of styrene and 1.8 mL of hydroxyethyl methacrylate were added to a 250 mL three-necked flask, 110 mg of potassium persulfate, 30 mg of sodium chloride, and 100 mL of deionized water were added, mechanical stirring was started and the stirring speed was set to 350 rpm, the condensate water was opened, and inert gas was introduced for 15 min, then the temperature was heated to 70°C at room temperature, and the reaction was carried out for 12 h. After that, the emulsion and tetrahydrofuran were mixed at a volume ratio of 1:5 for 10 min, and the obtained polymer microspheres were aggregated, and the qualified target product could not be obtained.

[0134] Comparative Example 16

[0135] The preparation method was the same as that of Comparative Example 15, and the hydroxyethyl methacrylate monomer was replaced by ethylene glycol dimethacrylate. The obtained polymer microspheres were aggregated, and the qualified target product could not be obtained.

[0136] Comparative Example 17

[0137] The preparation method was the same as that of Comparative Example 15, and the hydroxyethyl methacrylate monomer was replaced by acrylic acid. The obtained polymer microspheres were dissolved, and the qualified target product could not be obtained.

[0138] Comparative Example 18

[0139] The preparation method is same as that of Comparative Example 15, except that the hydroxyethyl methacrylate monomer is replaced by methacrylic acid, and the obtained high molecular microspheres are agglomerated, and the qualified target product cannot be obtained.

[0140] From the above related comparative examples, it can be seen that the hollow high molecular microspheres containing epoxy groups on the surface are successfully prepared by adjusting the process parameters such as the amount of styrene, the type and amount of functional monomer, the initiation temperature, the type and amount of initiator, the type and amount of active ingredient, the amount and type of organic solvent, etc. In the present application, the functional monomer GMA and the active ingredient are indispensable. When the content of the functional monomer is low, the microspheres are difficult to stably exist in the high-concentration organic solvent, and the hollow high molecular microspheres with uniform particle size cannot be obtained.

[0141] Example 22

[0142] The solid high molecular microsphere emulsion prepared in Example 1 is mixed with tetrahydrofuran according to the volume ratio of 1:1, 1:3, 1:5, 1:10, and swelled for 5 min, 20 min, 12 h and 24 h, the upper liquid is discarded by centrifugation, and the transmission electron microscopy test is carried out without centrifugation, and the results are shown in Figure 6 .

[0143] As shown in Figure 6 , when swelled in a higher content of tetrahydrofuran (the volume ratio of microsphere emulsion to tetrahydrofuran is 1:5 and 1:10), the microspheres swelled for 20 min, 12 h and 24 h have no obvious difference in morphology, and have high monodispersity. In addition, when swelled in a lower content of tetrahydrofuran (the volume ratio of microsphere emulsion to tetrahydrofuran is 1:1 and 1:3), the microspheres are adhered to each other, mainly because the low content of tetrahydrofuran cannot effectively dissolve the polystyrene swelled from the inside of the microspheres, which adheres to the surface of the microspheres, resulting in the agglomeration of the microspheres.

[0144] Example 23

[0145] The hollow polystyrene microspheres prepared by the preparation method of Example 1 are added to PBS buffer solution (8g NaCl, 0.2g KCl, 0.24g KH2PO4, 1.44g Na2HPO4) containing amoxicillin, and stirred at 35℃ at a speed of 200rpm for 24h, and the drug concentration is 100μg / mL. The results prove that the drug loading capacity is 2 times higher than that of the solid spheres.

[0146] The hollow polystyrene microspheres of the present application are smooth in appearance, good in sphericity, uniform in particle size, excellent in swelling performance, high in drug loading capacity and have sustained release effect. At the same time, the hollow polystyrene microspheres are biodegradable, non-toxic and harmless, and are an ideal drug carrier.

[0147] Effect of partial reagent dosage on hollow polymer microspheres

[0148] In the soap-free emulsion polymerization system, the dosage and concentration of monomers and other reagents directly affect the performance of the microspheres. It is crucial to scale up the reaction to obtain higher yield while ensuring that the performance of the microspheres is sufficient in the field of large-scale production.

[0149] The experiment was designed and carried out according to Example 1, with the difference being that the dosage of some reagents was adjusted according to Table 2, wherein the active ingredient of the additive was an aqueous solution containing 50 mg of sodium nitrate. As can be seen from Table 2, when the concentration of monomers and other reagents is low (Entry 1), the particle size of the microspheres is small, and the microspheres are solid after swelling. This may be due to the fact that the distribution of the two polymer chains in the microspheres has no clear boundary, and when the volume of the microspheres is small, the degree of uneven distribution of the polymer chains that make up the microspheres is not sufficient to make the internal components of the microspheres mostly PS polymer chains, and the internal structure cannot be dissolved in THF solvent, so the microspheres are formed as solid structures.

[0150] When the total content of monomers and other reagents increases (Table 2, Entries 2 to 9), the particle size of the microspheres increases continuously, and the degree of hollow inside the microspheres after swelling increases accordingly. The morphology of the microspheres is still spherical, and is stable for a long time, without agglomeration within 1000 nm (Entries 2 to 8); when the particle size further increases, partial agglomeration occurs (Entry 9).

[0151] Effect of partial reagent dosage on hollow polymer microspheres

[0152]

[0153] Example 25

[0154] Add 3 mL of styrene and 3 mL of glycidyl methacrylate to a 500 mL three-necked flask, add 200 mg of ammonium persulfate, 20 mg of sodium chloride, and 200 mL of deionized water, start mechanical stirring and set the speed to 150 rpm, open the condensate water, and introduce inert gas nitrogen / argon (volume ratio 1:1) for 20 minutes, heat to 70°C at room temperature, and react for 6 hours. The reaction solution appears milky white. Mix the emulsion, toluene, and ethyl acetate in a volume ratio of 1:3:1, stir for 5 minutes, centrifuge and discard the upper liquid, then wash with ethanol and water, respectively, to obtain surface-intact hollow polymer microspheres with a particle size of 168 nm.

[0155] Example 26

[0156] Into a 2000 mL four-necked flask, 30 mL of styrene and 18 mL of glycidyl methacrylate were added, 1000 mg of sodium persulfate, 200 mg of sodium chloride, 100 mg of potassium carbonate, 100 mg of sodium bisulfate and 1000 mL of deionized water were added, mechanical stirring was started and the stirring speed was set to 300 rpm, the condensate water was opened, and inert gas argon was introduced for 30 minutes, heated to 70°C at room temperature, and reacted for 8 hours. After the reaction solution appeared milky white, the emulsion and toluene, acetone were mixed according to the volume ratio 1:1:4 and stirred for 8 min, then the upper liquid was discarded after centrifugation, and then washed with ethanol and water respectively to obtain hollow polymer microspheres with a particle size of 260 nm and a complete surface.

[0157] Example 27 Coupling experiment of hollow polymer microspheres and amino-containing dyes

[0158] A small amount of amino-containing dye (4-(6-methyl-1,2,4,5-tetrazine-3-yl) phenyl) methylamine hydrochloride was taken and dissolved in 2 mL of deionized water, then evenly divided into two centrifuge tubes, 0.5 mL of microsphere emulsion was added to the centrifuge tube and shaken (as shown in Figure 8 , where the left control group added ordinary polystyrene microspheres, which were polymerized with styrene as monomer, and did not contain other functional monomers; the right experimental group added the hollow microspheres obtained in Example 1), centrifuged after overnight reaction, and then washed twice with deionized water after discarding the supernatant; the dye (pink) used in this experiment contains an amino structure and can undergo nucleophilic reaction with epoxy groups, and the reference Figure 9 , compared with the blank polystyrene microspheres (colorless, sample at the bottom of the left tube 1), it was found that the microspheres of the present application were successfully dyed (pink, sample at the bottom of the right tube 2), further proving that the epoxy groups exist on the surface of the microspheres and can successfully undergo coupling reaction with amino groups.

[0159] Example 28 Preparation of luminescent hollow polymer microspheres

[0160] 0.2 g of Eu(III) complex Eu(TTA)3(TPPO )2 was weighed and dissolved in 20 mL of acetone to prepare a 1 g / 100 μL concentration of Eu(III) complex acetone solution, 20 μL of Eu(III) complex acetone solution was taken in a 2 mL glass bottle, then 180 μL of acetone solution was added and mixed evenly, 600 μL of deionized water was added, and after mixing, 200 μL of hollow microsphere emulsion with a solid content of 0.5% (obtained in Example 26) was added, the emulsion was centrifuged after mixing, the supernatant was discarded, and then deionized water was added and ultrasonic dispersed, and after repeated washing, it was stored at room temperature;

[0161] The hollow microspheres prepared by the application are stronger than conventional polymer microspheres in terms of dye loading, because the hollow microspheres prepared by the application contain more cavities inside, which enhances the ability of adsorbing dyes, and more hydrophilic polymer chains exist outside, which protects the oil-soluble Eu(III) complex dyes. Tests show that under the excitation of 365 nm ultraviolet light, the luminescent hollow microspheres emit characteristic peaks of Eu, in which the main peak is bright red light at 615 nm.

[0162] Example 29: Preparation of luminescent hollow polymer microspheres by a simple wet chemical method

[0163] 3 mL of styrene and 1.8 mL of glycidyl methacrylate were added to a 1000 mL three-necked flask, 110 mg of sodium persulfate, 100 mg of sodium chloride and 100 mL of deionized water were added, mechanical stirring was started and the rotation speed was set to 350 rpm, the condensate water was opened, and after 15 min of inert gas was introduced, it was heated to 70°C at room temperature, and after 12 h of reaction, the reaction solution was milky white; 300 mL of tetrahydrofuran solution containing 150 mg of complex Eu(TTA)3(TPPO)2 was added, and after stirring and mixing, the emulsion was centrifuged, and the supernatant was discarded, then deionized water was added and ultrasonic dispersion was carried out, and after repeated washing at room temperature, the luminescent hollow polymer microspheres with a particle size of 265 nm and a complete surface were prepared.

[0164] The preparation method of the application is simple, and directly integrates the synthesis of hollow polymer microspheres and the loading of luminescent dyes. Tests show that under the excitation of 365 nm ultraviolet light, the prepared luminescent hollow microspheres emit characteristic peaks of Eu, in which the main peak is bright red light at 615 nm.

[0165] The above examples are only used to illustrate the technical solutions of the application, and not to limit them; although the application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing examples, or make equivalent substitutions for part of the technical features; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the application.

Claims

1. A method for preparing surface-functionalized hollow polymer microspheres, characterized in that, Specifically, the following steps are included: (1) Styrene, functional monomer, initiator, active ingredient and deionized water are stirred and reacted to obtain an emulsion for later use; (2) The emulsion is swollen with an organic solvent, and the precipitate obtained after centrifugation is the surface-functionalized hollow polymer microspheres; In step (1), the mass ratio of the active ingredient to the deionized water is 0.003-0.3:100; the volume ratio of the styrene, the functional monomer, and the deionized water is 3-10:1.2-6:100; the mass ratio of the initiator to the deionized water is 0.05-0.4:100; the reaction temperature is 63-75℃, and the reaction time is 4-16h. The active ingredient is a mineral salt or a combination of mineral salts and biological macromolecules; The functional monomer is glycidyl methacrylate; The mineral salts include at least one of calcium salts, phosphate salts, magnesium salts, potassium salts, sodium salts, iron salts, zinc salts, copper salts, manganese salts, iodine salts, selenium salts, and molybdenum salts; the biological macromolecules include at least one of amino acids, nucleotides, polysaccharides, vitamins, and proteins.

2. The method for preparing surface-functionalized hollow polymer microspheres according to claim 1, characterized in that, The stirring speed in step (1) is 150-600 rpm.

3. The method for preparing surface-functionalized hollow polymer microspheres according to claim 1, characterized in that, The initiator mentioned in step (1) is any one of potassium persulfate, sodium persulfate, and ammonium persulfate.

4. The method for preparing surface-functionalized hollow polymer microspheres according to claim 1, characterized in that, In step (2), the volume ratio of the emulsion to the organic solvent is greater than 1, and the swelling time is greater than 1 min.

5. The method for preparing surface-functionalized hollow polymer microspheres according to claim 1, characterized in that, The organic solvent mentioned in step (2) is at least one of tetrahydrofuran, acetone, diethyl ether, ethyl acetate, cyclohexane, toluene, xylene, and trimethylbenzene.

6. A surface-functionalized hollow polymer microsphere obtained by the preparation method according to any one of claims 1-5.

7. The surface-functionalized hollow polymer microsphere according to claim 6, characterized in that, The hollow polymer microspheres have a particle size of 100-1000 nm.

8. The application of a surface-functionalized hollow polymer microsphere obtained by the preparation method according to any one of claims 1-5 in the preparation of catalysts, heat and sound insulation materials, optoelectronic materials, magnetic materials, and drug microcapsule materials.

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