Quantum dot coding microsphere, oil field tracer agent and preparation method of oil field tracer agent

Abstract

The invention provides a quantum dot coding microsphere, a tracer agent and a preparation method thereof, and the preparation method of the quantum dot coding microsphere comprises the following steps: S1, converting a quantum dot into an alcohol phase: mixing the quantum dot with an alcohol phase ligand, and reacting to connect the quantum dot with the alcohol phase ligand to obtain an alcohol phase quantum dot; the alcohol phase ligand contains unsaturated hydrocarbon; s2, mixing the alcohol-phase quantum dots, an alcohol solvent, a monomer and an initiator to form a first mixed solution, and reacting to obtain quantum dot microspheres; and S3, mixing the quantum dot microspheres, a mixed monomer and an initiator to form a second mixed solution, and reacting to obtain the quantum dot coded microspheres.

Description

Technical Field

[0001] This application belongs to the technical field of tracers, specifically relating to a quantum dot encoded microsphere, an oilfield tracer, and a method for preparing the same. Background Technology

[0002] In the field of oilfield tracer technology, early chemical tracers (first generation), radioactive isotope tracers (second generation), and stable isotope tracers (third generation) have been gradually phased out due to their drawbacks such as toxicity, radioactivity, high cost, and interference between detection signals. Their current application rate is very low. Currently, the most widely used are fourth-generation trace substance tracers, which are mainly transition metal elements. After years of research and improvement, only about 15 types are currently available for use. Furthermore, trace substance tracers are primarily used for aqueous phase tracer applications and are not well-suited for oil phase or gas phase tracer applications. In contrast, new-generation fluorescent microsphere tracers emit fluorescence when excited by light or electricity. By utilizing different types and concentrations of fluorescent components, hundreds of different emission bands can be formed, providing an encoding function (hundreds of emission bands, i.e., hundreds of colors, hundreds of codes). Therefore, they are widely used in fields such as biomarkers, disease diagnosis, tracers, solid-phase chips, liquid-phase chips, immunochromatography, and Raman scattering. For example, by modifying the surface of fluorescent microspheres with carboxyl groups, antibodies can be coupled to the rear end, making them suitable for the biological field. Furthermore, by endowing fluorescent microspheres with properties such as hydrophilicity, lipophilicity, hydrophobicity, oleophobicity, and sustained-release, they can be applied to aqueous phase tracers, oil phase tracers, gas phase tracers, and oil-water mixture tracers, making them suitable for oilfield and natural gas tracer applications.

[0003] Fluorescent microspheres are formed by coating one or more fluorescent materials with an inorganic or organic polymer shell, the shell primarily serving to protect the fluorescent material. Fluorescent materials mainly include organic fluorescent dyes and quantum dots. Compared to organic fluorescent dyes, quantum dots possess superior optical properties such as high quantum yield, high photochemical stability, resistance to photolysis, broad excitation range, narrow emission range, and high color purity (detection signals are less prone to interference). However, current techniques for preparing quantum dot-encoded microspheres mostly employ emulsifiers or emulsion films (such as water-in-oil or oil-in-water processes) to dissolve quantum dots in oily / aqueous solvents to control the particle size. This forced particle size control method makes it difficult to control particle size uniformity and the uniformity of quantum dot content within individual microspheres (uniformity in content and particle size easily affects detection accuracy), further hindering mass production. 2. Seed microsphere methods (first forming seeds, then synthesizing microspheres) or swelling methods (first forming hollow polymer microspheres, then inserting quantum dots into the polymer microspheres) offer some improvement in uniformity. However, these methods are complex, easily damage the quantum dots, and result in low quantum dot content. They are suitable for synthesizing quantum dot microspheres with particle sizes of tens to hundreds of micrometers. Since these are used as tracers in oil fields, they also need to be heat-resistant and microbial-resistant. Samples taken from oil fields need to be purified and the tracer / microspheres extracted using organic solvents such as chloroform. However, some quantum dot microspheres are not resistant to organic solvents, which can severely affect detection accuracy.

[0004] In view of this, this application provides a quantum dot-encoded microsphere, an oilfield tracer, and a method for preparing the same, which can mass-produce quantum dot-encoded microspheres with excellent fluorescence performance and uniform particle size, and has the characteristics of resistance to organic solvents and high temperature, making it suitable for oilfield tracers. Summary of the Invention

[0005] The purpose of this application is to provide a quantum dot-encoded microsphere, an oilfield tracer, and a method for preparing the same, which can mass-produce quantum dot-encoded microspheres with excellent fluorescence performance and uniform particle size, and has the characteristics of resistance to organic solvents and high temperature, making it suitable for oilfield tracers.

[0006] A first aspect of this application provides a method for preparing quantum dot-encoded microspheres, comprising the steps of:

[0007] S1, converting quantum dots to alcohol phase: mixing quantum dots with alcohol phase ligands, reacting to link the quantum dots with the alcohol phase ligands to obtain alcohol phase quantum dots; the alcohol phase ligands contain unsaturated hydrocarbons;

[0008] S2, the alcohol phase quantum dots, alcohol solvent, monomer and initiator are mixed to form a first mixture, and the reaction is carried out to obtain quantum dot microspheres;

[0009] S3, the quantum dot microspheres, mixed monomers and initiator are mixed to form a second mixture, and the reaction is carried out to obtain quantum dot encoded microspheres.

[0010] In some embodiments, in step S1, the quantum dot is an oil-based quantum dot or an aqueous quantum dot. Preferably, the quantum dot is an oil-based quantum dot.

[0011] The quantum dots include at least one of the following: IIB-VIA group quantum dots, IIIA-VA group quantum dots, IVA-VIA group quantum dots, IVA group quantum dots, IB-IIIA-VIA group quantum dots, IB-IIB-IVA-VIA group quantum dots, VIII-VIA group quantum dots, perovskite quantum dots, or carbon quantum dots (carbon dots).

[0012] In some embodiments, the mass ratio of the added quantum dots to the alcohol phase ligand is (1.5-5):1.

[0013] Preferably, the mass ratio of the added quantum dots to the alcohol phase ligand is (2-4):1.

[0014] In some embodiments, the alcohol ligand contains a polar group, a coordinating group, and an unsaturated hydrocarbon.

[0015] Furthermore, the polar group includes at least one of hydroxyl, ether, amino, or carboxyl groups, the coordinating group includes at least one of mercapto, amino, amide, organophosphorus, or phosphate ester groups, and the unsaturated hydrocarbon includes at least one of carbon-carbon double bonds and carbon-carbon triple bonds.

[0016] Furthermore, the alcohol ligand comprises at least one of the following: polyether-polyester copolymer phosphate ester, polyether phosphate ester, polyethylene glycol phosphate ester, Triton phosphate ester, mercapto-polyethylene glycol-phosphite (DSPE-PEG-Thiol), acrylate-ω-mercapto-polyethylene glycol (AC-PEG-SH), mercapto-polyethylene glycol acrylate (HS-PEG-OPSS), mercapto-polyethylene glycol methacrylate (MAC-PEG-SH), mercapto-polyethylene glycol maleimide (HS-PEG-Alkyne), or mercapto-polyethylene glycol silane (HS-PEG-Acrylate).

[0017] In some embodiments, oily quantum dots are mixed with a nonpolar solvent, and then the alcohol phase ligand is added, and the mixture is reacted at 40-60°C for 10-24 hours to obtain a solution containing alcohol phase quantum dots.

[0018] Furthermore, the solution containing alcohol phase quantum dots is purified and extracted to obtain alcohol phase quantum dots.

[0019] In some embodiments, in step S2, the first mixture reacts, and the polymer formed by the polymerization reaction of the alcohol ligand and the monomer forms a coating layer covering the quantum dots, thereby obtaining quantum dot microspheres.

[0020] In some embodiments, the concentration of the alcohol phase quantum dots in the first mixture is 0.1-2.5 mg / ml, and the mass ratio of the monomer to the initiator is 100:(1-10):(1-15).

[0021] Preferably, in the first mixture, the concentration of the alcohol phase quantum dots is 0.5-2 mg / ml, and the mass ratio of the monomer to the initiator is 100:(2-7):(2-12).

[0022] In some embodiments, the first mixture further includes water and a dispersant.

[0023] Furthermore, in the first mixture, the weight ratio of the alcohol solvent to water is greater than the critical weight ratio for the alcohol solvent and water to form an azeotrope.

[0024] Furthermore, in the first mixture, the mass ratio of the monomer, dispersant and initiator is 100:(1-10):(1-15).

[0025] Preferably, the mass ratio of the monomer, dispersant and initiator added to the first mixture is 100:(2-7):(2-12).

[0026] In some embodiments, the alcohol phase quantum dots, alcohol solvent, water, monomer, initiator and dispersant are mixed to form a first mixture, wherein the monomer is poured in all at once; the first mixture is stirred and reacted at 55-90°C for 1-24 hours under inert gas protection.

[0027] Preferably, the alcohol phase quantum dots, alcohol solvent, water, monomer, initiator and dispersant are mixed to form a first mixture, wherein water, monomer, initiator and dispersant are added at once; the first mixture is stirred and reacted at 60-85°C for 3-24 hours under inert gas protection.

[0028] In some embodiments, the alcohol solvent is an organic alcohol. The organic alcohol includes at least one selected from methanol, ethanol, isopropanol, butanol, ethylene glycol, diethylene glycol, and 2-methoxyethanol.

[0029] In some embodiments, the monomer includes at least one of styrene, substituted styrene, and methyl methacrylate.

[0030] In some embodiments, the initiator includes at least one of azobisisobutyronitrile (AIBN), azobisisovalerate (AMBN), benzoyl peroxide (BPO), and potassium persulfate (KPS).

[0031] In some embodiments, the dispersant includes at least one of the following: polyvinylpyrrolidone (PVP), polyoxyethylene (PEO), polyethylene glycol (PEG), polyacrylic acid (PAA), polyvinyl alcohol (PVA), sodium styrene sulfonate, and polyethylene glycol octylphenyl ether (Triton X-100, X-114, X-305, etc.).

[0032] In some embodiments, in step S3, the second mixture reacts, and the mixed monomers undergo a polymerization reaction to form a crosslinked material attached to the surface of the quantum dot microspheres (i.e., the surface of the coating layer), thereby obtaining quantum dot encoded microspheres.

[0033] In some embodiments, the mixed monomer includes: a monomer, a hydrophilic monomer or a hydrophobic monomer, and a functional monomer; in the mixed monomer, the monomer accounts for 10-70% wt by mass, the hydrophilic monomer or the hydrophobic monomer accounts for 5-40% wt by mass, and the functional monomer accounts for 5-40% wt by mass.

[0034] Preferably, in the mixed monomers, the monomers account for 30-60% wt by mass, the hydrophilic or hydrophobic monomers account for 10-40% wt by mass, and the functional monomers account for 10-40% wt by mass.

[0035] Furthermore, the mixed monomer is composed of monomers, hydrophilic or hydrophobic monomers, and functional monomers.

[0036] Furthermore, the hydrophilic monomer comprises: a hydrophilic segment and a polymerizable segment; the hydrophobic monomer comprises: a hydrophobic segment and a polymerizable segment; the hydrophilic segment provides hydrophilicity to the quantum dot-encoded microspheres, the hydrophobic segment provides hydrophobicity to the quantum dot-encoded microspheres, and the polymerizable segment is capable of undergoing a polymerization reaction.

[0037] Preferably, the hydrophilic monomer includes at least one of: poly(ethylene glycol) diacrylate, acrylic acid and its derivatives, hydroxyethyl acrylate and its derivatives, and acrylamide and its derivatives.

[0038] Preferably, the hydrophobic monomer includes C12-18 olefins and their derivatives with double bonds at positions 1-2. Examples include dodecene and lauryl acrylate.

[0039] Furthermore, the functional monomer includes: a functional group and a polymerizable group.

[0040] Preferably, the functional monomer includes at least one of the following: siloxane methacrylate, α-methylstyrene, methyl methacrylate, acrylic acid, hydroxyethyl acrylate, acrylamide, and their derivatives.

[0041] In some embodiments, the quantum dot microspheres are dispersed in an emulsifier solution, an initiator is added while stirring at 60-80°C, and then an emulsifier solution containing mixed monomers is added dropwise at a rate of 1-10 ml / h, and the reaction is carried out for 10-120 min to obtain quantum dot encoded microspheres.

[0042] Preferably, the quantum dot microspheres are dispersed in an emulsifier solution, and an initiator is added all at once while stirring at 60-80°C. Then, an emulsifier solution containing mixed monomers is added dropwise at a rate of 2-5 ml / h, and the reaction is carried out for 15-60 min to obtain quantum dot encoded microspheres.

[0043] Furthermore, the emulsifier includes at least one of the following: sodium dodecyl sulfate (SDS), disodium thiodipropionate (SDPS), polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), polyacrylic acid (PAA), Tween 20 (TW20), Tween 80 (TW80), and Triton.

[0044] A second aspect of this application provides a quantum dot-encoded microsphere, comprising, from the inside out: an alcohol phase quantum dot, a coating layer covering the alcohol phase quantum dot, and a crosslinker attached to the surface of the coating layer; the alcohol phase quantum dot includes a quantum dot and an alcohol phase ligand connected to the quantum dot, the alcohol phase ligand containing an unsaturated hydrocarbon; the polymer formed by the polymerization reaction of the alcohol phase ligand with monomers forms the coating layer covering the quantum dot; and the mixed monomers undergo a polymerization reaction to form the crosslinker attached to the surface of the coating layer.

[0045] In some embodiments, the quantum dots are oil-based or water-based quantum dots. Preferably, the quantum dots are oil-based quantum dots. The quantum dots include at least one of the following: group IIB-VIA quantum dots, group IIIA-VA quantum dots, group IVA-VIA quantum dots, group IVA quantum dots, group IB-IIIA-VIA quantum dots, group IB-IIB-IVA-VIA quantum dots, group VIII-VIA quantum dots, perovskite quantum dots, or carbon quantum dots (carbon dots).

[0046] In some embodiments, the alcohol ligand contains a polar group (easily soluble in alcohol solvents), a coordinating group capable of connecting to the quantum dot surface, and an unsaturated hydrocarbon.

[0047] Furthermore, the polar group includes at least one of hydroxyl, ether, amino, and carboxyl groups, the coordinating group includes at least one of mercapto, amino, amide, organophosphorus, and phosphate ester groups, and the unsaturated hydrocarbon includes carbon-carbon double bonds and carbon-carbon triple bonds.

[0048] Furthermore, the alcohol ligand comprises at least one of the following: polyether-polyester copolymer phosphate ester, polyether phosphate ester, polyethylene glycol phosphate ester, Triton phosphate ester, mercapto-polyethylene glycol-phosphite (DSPE-PEG-Thiol), acrylate-ω-mercapto-polyethylene glycol (AC-PEG-SH), mercapto-polyethylene glycol acrylate (HS-PEG-OPSS), mercapto-polyethylene glycol methacrylate (MAC-PEG-SH), mercapto-polyethylene glycol maleimide (HS-PEG-Alkyne), or mercapto-polyethylene glycol silane (HS-PEG-Acrylate).

[0049] In some embodiments, the monomer includes at least one of styrene, substituted styrene, and methyl methacrylate.

[0050] In some embodiments, the mixed monomers include: monomers, hydrophilic or hydrophobic monomers, and functional monomers; the hydrophilic monomers include: hydrophilic segments and polymerizable segments; the hydrophobic monomers include: hydrophobic segments and polymerizable segments; the hydrophilic segments provide hydrophilicity for the quantum dot-encoded microspheres, the hydrophobic segments provide hydrophobicity for the quantum dot-encoded microspheres, and the polymerizable segments are capable of polymerization; the functional monomers include: functional groups and polymerizable groups.

[0051] The quantum dot-encoded microspheres, tracers, and their preparation methods disclosed in this application have at least the following advantages compared to existing technologies:

[0052] (1) In this application, the alcohol phase ligand used to convert quantum dots into an alcohol phase simultaneously contains polar groups, coordinating groups, and unsaturated hydrocarbons. Since the alcohol phase ligand also contains unsaturated hydrocarbons, it can undergo a polymerization reaction with the monomer under the action of an initiator. The polymer of the monomer can connect with the alcohol phase ligand, and the monomer polymer chains become increasingly longer, gradually forming a coating layer around the quantum dots, resulting in quantum dot microspheres with uniform particle size (1-8 micrometers), suitable for mass production. Furthermore, the monomer polymer is chemically bonded to the unsaturated hydrocarbons, meaning the monomer polymer is chemically bonded to the quantum dot surface, resulting in better stability of the coating layer.

[0053] (2) In the first mixture, the concentration of the alcohol phase quantum dots is 0.1-2.5 mg / ml, and the mass ratio of the monomer, dispersant, and initiator is 100:(1-10):(1-15). By adjusting the amount of alcohol phase quantum dots, monomer, initiator, and dispersant, the reaction temperature, and the time, the particle size of the formed quantum dot microspheres can be adjusted.

[0054] (3) The first mixture also includes water. By adjusting the mass ratio of the alcohol solvent to water, the particle size of the synthesized quantum dot microspheres can be finely tuned. The mass ratio of the alcohol solvent to water added to the first mixture is limited to a critical weight ratio for the alcohol solvent and water to form an azeotrope, which facilitates the recovery of alcohol solvents such as ethanol during mass production and reduces costs.

[0055] (4) The mixed monomers of this application include: monomers, hydrophilic or hydrophobic monomers, and functional monomers, consisting of three categories. The addition of the monomers allows the polymer formed by the reaction of the second mixture to readily copolymerize with the polymer (such as polystyrene) on the surface of the quantum dot microspheres. The hydrophilic or hydrophobic monomers provide hydrophilicity or hydrophobicity to the quantum dot-encoded microspheres, facilitating their application in aqueous or oil-phase tracing, and further enhancing the crosslinking degree of the polymer on top of the coating layer. The functional monomers are used to further increase the resistance of the quantum dot microspheres to organic solvents (such as chloroform) and high temperatures, and also provide binding sites for subsequent silicone coating.

[0056] (5) Quantum dot encoded microspheres: Compared with organic dyes, quantum dots have strong fluorescence, narrow half-peak width, and strong resistance to light drift. The quantum dot encoded microspheres do not interfere with each other in different detection wavelength channels and have strong fluorescence signals. Attached Figure Description

[0057] The above and other features of this application will be more fully described when read in conjunction with the following accompanying drawings. It is understood that these drawings depict only a few embodiments of the application and should not be considered as limiting the scope of the application. The application will be explained more clearly and in more detail through the use of the drawings.

[0058] Figure 1-1 This is an electron microscope image of the quantum dot-encoded microspheres prepared in Example 1 of this application.

[0059] Figure 1-2 The particle distribution map of the quantum dot-encoded microspheres prepared in Example 1 of this application was detected by flow cytometry.

[0060] Figure 1-3 Fluorescence distribution of the quantum dot-encoded microspheres prepared in Example 1 of this application, as detected by flow cytometry (Violet610).

[0061] Figure 1-4 The particle size distribution of the quantum dot-encoded microspheres prepared in Example 1 of this application is obtained by flow cytometry.

[0062] Figure 1-5 The quantum dot-encoded microspheres prepared in Example 1 of this application were analyzed using flow cytometry data.

[0063] Figure 1-6The fluorescence distribution map (B585) of the quantum dot-encoded microspheres prepared in Example 1 of this application was detected by flow cytometry.

[0064] Figure 1-7 The fluorescence distribution map (R660) of the quantum dot-encoded microspheres prepared in Example 1 of this application was detected by flow cytometry.

[0065] Figure 2-1 This is an electron microscope image of the quantum dot-encoded microspheres prepared in Example 2 of this application.

[0066] Figure 2-2 The particle distribution map of the quantum dot-encoded microspheres prepared in Example 2 of this application was detected by flow cytometry.

[0067] Figure 2-3 The fluorescence distribution map (B585) of the quantum dot-encoded microspheres prepared in Example 2 of this application was detected by flow cytometry.

[0068] Figure 2-4 The particle size distribution of the quantum dot-encoded microspheres prepared in Example 2 of this application is obtained by flow cytometry.

[0069] Figure 2-5 The quantum dot-encoded microspheres prepared in Example 2 of this application were analyzed using flow cytometry data.

[0070] Figure 2-6 The fluorescence distribution map (B525) of the quantum dot-encoded microspheres prepared in Example 2 of this application was detected by flow cytometry.

[0071] Figure 2-7 The fluorescence distribution map (R660) of the quantum dot-encoded microspheres prepared in Example 2 of this application was detected by flow cytometry.

[0072] Figure 3-1 This is an electron microscope image of the quantum dot-encoded microspheres prepared in Example 3 of this application.

[0073] Figure 3-2 The particle distribution map of the quantum dot-encoded microspheres prepared in Example 3 of this application was detected by flow cytometry.

[0074] Figure 3-3 Fluorescence distribution of the quantum dot-encoded microspheres prepared in Example 3 of this application, as detected by flow cytometry (Violet610).

[0075] Figure 3-4 The particle size distribution of the quantum dot-encoded microspheres prepared in Example 3 of this application is obtained by flow cytometry.

[0076] Figure 3-5 The quantum dot-encoded microspheres prepared in Example 3 of this application were analyzed using flow cytometry data.

[0077] Figure 4-1 This is an electron microscope image of the quantum dot-encoded microspheres prepared in Example 4 of this application.

[0078] Figure 4-2 The particle distribution map of the quantum dot-encoded microspheres prepared in Example 4 of this application is obtained by flow cytometry.

[0079] Figure 4-3 Fluorescence distribution of the quantum dot-encoded microspheres prepared in Example 4 of this application, as detected by flow cytometry (Violet610).

[0080] Figure 4-4 The particle size distribution of the quantum dot-encoded microspheres prepared in Example 4 of this application is obtained by flow cytometry.

[0081] Figure 4-5 The quantum dot-encoded microspheres prepared in Example 4 of this application were analyzed using flow cytometry data.

[0082] Figure 5-1 This is an electron microscope image of the quantum dot-encoded microspheres prepared in Example 5 of this application.

[0083] Figure 5-2 The particle distribution map of the quantum dot-encoded microspheres prepared in Example 5 of this application was detected by flow cytometry.

[0084] Figure 5-3 The fluorescence distribution of the quantum dot-encoded microspheres prepared in Example 5 of this application is detected by flow cytometry (V450).

[0085] Figure 5-4 The particle size distribution of the quantum dot-encoded microspheres prepared in Example 5 of this application is obtained by flow cytometry.

[0086] Figure 5-5 The quantum dot-encoded microspheres prepared in Example 5 of this application were analyzed using flow cytometry data.

[0087] Figure 6-1 This is an electron microscope image of the quantum dot-encoded microspheres prepared in Example 6 of this application.

[0088] Figure 6-2 The particle distribution map of the quantum dot-encoded microspheres prepared in Example 6 of this application was detected by flow cytometry using the red channel 610.

[0089] Figure 6-3 The fluorescence distribution of the quantum dot-encoded microspheres prepared in Example 6 of this application was detected by flow cytometer red channel 610 (Violet 610).

[0090] Figure 6-4The particle size distribution of the quantum dot-encoded microspheres prepared in Example 6 of this application was detected by flow cytometry using the red channel 610.

[0091] Figure 6-5 The quantum dot-encoded microspheres prepared for Example 6 of this application were detected using flow cytometry data via the red channel 610.

[0092] Figure 6-6 The particle distribution map of the quantum dot-encoded microspheres prepared in Example 6 of this application was detected by flow cytometry in the green channel 525.

[0093] Figure 6-7 The fluorescence distribution pattern (B525) of the quantum dot-encoded microspheres prepared in Example 6 of this application was detected by flow cytometry using the green channel 525.

[0094] Figure 6-8 The particle size distribution of the quantum dot-encoded microspheres prepared in Example 6 of this application was detected by flow cytometry using the green channel 525.

[0095] Figure 6-9 The quantum dot-encoded microspheres prepared for Example 6 of this application were detected using flow cytometry green channel 525.

[0096] Figure 6-10 The image shows a fluorescence microscope image of the quantum dot-encoded microspheres prepared in Example 6 of this application, detected using the red channel (EX475 / 35, DM500, EM620*50) of a fluorescence microscope.

[0097] Figure 6-11 Fluorescence microscopy images of the quantum dot-encoded microspheres prepared in Example 6 of this application, detected using the green channel (EX365 / 50, DM400, 530 / 50) of a fluorescence microscope.

[0098] Figure 7-1 Electron micrograph of the quantum dot-encoded microspheres prepared for Comparative Example 1.

[0099] Figure 7-2 Another electron microscope image of the quantum dot-encoded microspheres prepared for Comparative Example 1.

[0100] Figure 8 Electron microscopy image of the quantum dot-encoded microspheres prepared for Comparative Example 2.

[0101] Figure 9 Electron micrograph of the quantum dot-encoded microspheres prepared for Comparative Example 3.

[0102] Figure 10-1 The images show the quantum dot-encoded microspheres prepared in Example 1 before and after centrifugation during the chloroform resistance test.

[0103] Figure 10-2The images show the quantum dot-encoded microspheres prepared for Comparative Example 2 before and after centrifugation during the chloroform resistance test.

[0104] Figure 10-3 The images show the quantum dot-encoded microspheres prepared for Comparative Example 3 before and after centrifugation during the chloroform resistance test.

[0105] Figure 10-4 The image shows a fluorescence microscope image of the quantum dot-encoded microspheres prepared in Example 1 after a chloroform resistance test.

[0106] Figure 10-5 Fluorescence microscopy image of the quantum dot-encoded microspheres prepared for Comparative Example 3 after chloroform resistance test.

[0107] Figure 11-1 Fluorescence microscopy image of the quantum dot-encoded microspheres prepared in Example 1.

[0108] Figure 11-2 The image shows a fluorescence microscope image of the quantum dot-encoded microspheres prepared in Example 1 after a high-temperature resistance test.

[0109] Figure 11-3 Fluorescence microscopy image of the quantum dot-encoded microspheres prepared for Comparative Example 2.

[0110] Figure 11-4 Fluorescence microscope image of the quantum dot-encoded microspheres prepared for Comparative Example 2 after high-temperature resistance testing.

[0111] Figure 11-5 Fluorescence microscopy image of the quantum dot-encoded microspheres prepared for Comparative Example 3.

[0112] Figure 11-6 Fluorescence microscope image of the quantum dot-encoded microspheres prepared for Comparative Example 3 after high-temperature resistance testing.

[0113] Figure 12-1 The image shows an electron microscope image of the dye MF microspheres prepared in Comparative Example 4.

[0114] Figure 12-2 The particle distribution map of the dye MF microspheres prepared for Comparative Example 4 was detected by flow cytometry.

[0115] Figure 12-3 The fluorescence distribution of the dye MF microspheres prepared for Comparative Example 4 was detected by flow cytometry (R660).

[0116] Figure 12-4 The particle size distribution of the dye MF microspheres prepared for Comparative Example 4 was detected by flow cytometry.

[0117] Figure 12-5 The data were obtained by flow cytometry analysis of the dye MF microspheres prepared for Comparative Example 4.

[0118] Figure 12-6 The fluorescence distribution of the dye MF microspheres prepared for Comparative Example 4 was detected by flow cytometry (B585).

[0119] Figure 12-7 The fluorescence distribution of the dye MF microspheres prepared for Comparative Example 4 was detected by flow cytometry (R712).

[0120] Figure 13-1 The image shows an electron microscope image of the dye MF microspheres prepared in Comparative Example 5.

[0121] Figure 13-2 The particle distribution map of the dye MF microspheres prepared for Comparative Example 5 was obtained by flow cytometry.

[0122] Figure 13-3 The fluorescence distribution of the dye MF microspheres prepared for Comparative Example 5 was detected by flow cytometry (B585).

[0123] Figure 13-4 The particle size distribution of the dye MF microspheres prepared for Comparative Example 5 was obtained by flow cytometry.

[0124] Figure 13-5 The data were obtained by flow cytometry analysis of the dye MF microspheres prepared for Comparative Example 5.

[0125] Figure 13-6 The fluorescence distribution of the dye MF microspheres prepared for Comparative Example 5 was detected by flow cytometry (B525).

[0126] Figure 13-7 The fluorescence distribution of the dye MF microspheres prepared for Comparative Example 5 was detected by flow cytometry (R660). Detailed Implementation

[0127] The following embodiments are described to aid in understanding this application. These embodiments are not, and should not be, construed in any way as limiting the scope of protection of this application.

[0128] Unless otherwise defined, all terms (including technical and scientific terms) in this specification may be defined as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having meanings consistent with their meanings in the context of this disclosure and the relevant field, and will be interpreted in a non-idealized or overly formal sense unless clearly defined herein.

[0129] As used herein, the term "at least one," when modifying the entire list of elements without modifying any individual elements of the list before or after it, shall not be construed as limiting "one." "Or" means "and / or." The terms "comprising" and "including," when used in this specification, indicate the presence of the stated features, regions, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, regions, integrals, steps, operations, elements, components, and / or collections thereof. Therefore, the above wording shall be understood to mean including the stated elements, but not excluding any other elements. The term "and / or" includes any and all combinations of one or more of the associated listed items. The term "a plurality" refers to two or more. The term "connected" refers to a direct or indirect connection. It will be understood that when an element, such as a layer, film, region, or substrate, is referred to as being "on" another element, it may be directly on said other element or intermediate elements may also be present. Conversely, when an element is referred to as being "directly on" another element, no intermediate elements are present. To clearly illustrate the embodiments shown in the figures, some parts that are not actually relevant to the description may be omitted. The terms "first," "second," "third," etc., may be used herein to describe and distinguish different elements, components, regions, layers, and / or portions, but these elements, components, regions, layers, and / or portions should not be limited by these terms.

[0130] A first aspect of this application provides a method for preparing quantum dot-encoded microspheres, comprising the steps of:

[0131] S1, converting quantum dots to alcohol phase: mixing quantum dots with alcohol phase ligands, reacting to link the quantum dots with the alcohol phase ligands to obtain alcohol phase quantum dots; the alcohol phase ligands contain unsaturated hydrocarbons;

[0132] S2, the alcohol phase quantum dots, alcohol solvent, monomer and initiator are mixed to form a first mixture, and the reaction is carried out to obtain quantum dot microspheres;

[0133] S3, the quantum dot microspheres, mixed monomers and initiator are mixed to form a second mixture, and the reaction is carried out to obtain quantum dot encoded microspheres.

[0134] In some embodiments, in step S1, the quantum dot is an oil-based quantum dot or an aqueous quantum dot. Preferably, the quantum dot is an oil-based quantum dot.

[0135] In this application, the quantum dots can be either oil-based or water-based, and both can be successfully converted into alcohol-phase quantum dots. Except for carbon dots, which are inherently hydrophilic, other quantum dots are typically oil-based (with surfaces containing organic acids, organic amines, organophosphorus compounds, or thiols, etc.) obtained through direct synthesis. Water-based quantum dots are formed only through additional ligand modification. Therefore, oil-based quantum dots are preferred.

[0136] The quantum dots include at least one of the following: group IIB-VIA quantum dots, group IIIA-VA quantum dots, group IVA-VIA quantum dots, group IVA quantum dots, group IB-IIIA-VIA quantum dots, group IB-IIB-IVA-VIA quantum dots, group VIII-VIA quantum dots, perovskite quantum dots, or carbon quantum dots (carbon dots). Each quantum dot comprises a core, a shell coating the core, and ligands modified on the surface of the shell. The band width of the shell material is greater than that of the core, and the shell protects the core. The ligands enable the quantum dots to be oil-soluble or water-soluble. Oil-soluble quantum dots are synthesized by adding oil-soluble ligands to the reaction system. For example, the nuclei of group IIB-VIA quantum dots include: CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS, HgZnTeS, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe or combinations thereof. For example, the cores of group IIIA-VA quantum dots include: GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, InZnP, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, or combinations thereof. For example, group IVA-VIA quantum dot nuclei include: SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, SnPbSTe, or combinations thereof. For example, group IVA quantum dot nuclei include: Si, Ge, SiC, SiGe, or combinations thereof.For example, the cores of IB-IIIA-VIA group quantum dots include CuInSe2, CuInS2, CuInGaSe, CuInGaS, or combinations thereof. For example, the cores of IB-IIB-IVA-VIA group quantum dots include CuZnSnSe, CuZnSnS, or combinations thereof. For example, the general structural formula of perovskite quantum dots is one of ABX3, A2B2X6, or A3B3X9, where A is a monovalent amine organic cation or a monovalent inorganic metal cation (such as CH3NH3). + NH2CHNH2+, C(NH2)3 + Cs + Li + Na + K + 、Rb + B is a divalent inorganic metal cation (such as rare earth metal cations, alkaline earth metal cations, transition metal cations, and post-transition metal cations), and X is a monovalent anion (such as halogens). For example, carbon quantum dots are synthesized by carbonizing organic acids and other carbon sources under high-temperature conditions such as microwave ovens or heating, with a particle size of about 10 nm. Most carbon quantum dots are mainly composed of amorphous carbon to crystallized carbon nuclei in the form of sp... 2 Predominantly hybridized carbon. Besides the quantum dots listed, other common quantum dots are also applicable to this application and are within the scope of protection of this application. The shell is defined as the material surrounding the core and may include one or more shell layers. "Ligand" refers to any molecule or ion capable of weak or strong interactions with the quantum dot (e.g., through covalent interactions, ionic interactions, van der Waals interactions, or through interactions with any other molecules on the outer surface of the quantum dot). The oily ligands include at least one of: organic acids, organic amines, organophosphorus compounds, or thiols.

[0137] In some embodiments, the mass ratio of the added quantum dots to the alcohol phase ligand is (1.5-5):1, for example, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, or 5:1, but not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0138] Preferably, the mass ratio of the added quantum dots to the alcohol phase ligand is (2-4):1.

[0139] If the mass ratio of the alcohol phase ligand is too low, the quantum dots will not completely convert to the alcohol phase. If the mass ratio of the alcohol phase ligand is too high, the quantum dots will not be able to consume enough alcohol phase ligands, resulting in a waste of alcohol phase ligand raw materials and increased costs.

[0140] In some embodiments, the alcohol ligand contains a polar group (making it readily soluble in alcohol solvents), a coordinating group (capable of attaching to the quantum dot surface), and an unsaturated hydrocarbon (capable of polymerizing with monomers).

[0141] Furthermore, the polar group includes at least one of hydroxyl, ether, amino, or carboxyl groups; the coordinating group includes at least one of mercapto, amino, amide, organophosphorus, or phosphate ester groups; and the unsaturated hydrocarbon includes at least one of carbon-carbon double bonds and carbon-carbon triple bonds. The coordinating group is connected to the quantum dot surface either by direct chelation with metal ions on the quantum dot surface or by exchange with ligands inherent on the quantum dot surface. The polar group makes the alcohol-phase quantum dots readily soluble in alcohol solvents. The unsaturated hydrocarbon can undergo polymerization reactions with monomers.

[0142] Furthermore, the alcohol ligand includes at least one of the following: polyether-polyester copolymer phosphate ester, polyether phosphate ester, polyethylene glycol phosphate ester, Triton phosphate ester, mercapto-polyethylene glycol-phosphite (DSPE-PEG-Thiol), acrylate-ω-mercapto-polyethylene glycol (AC-PEG-SH), mercapto-polyethylene glycol acrylate (HS-PEG-OPSS), mercapto-polyethylene glycol methacrylate (MAC-PEG-SH), mercapto-polyethylene glycol maleimide (HS-PEG-Alkyne), or mercapto-polyethylene glycol silane (HS-PEG-Acrylate). In addition to the alcohol ligands listed above, alcohol ligands that simultaneously contain a polar group, a coordinating group, and an unsaturated hydrocarbon are also within the scope of protection of this application.

[0143] This application prepares quantum dot microspheres using dispersion polymerization, without employing oil-in-water or water-in-oil systems, seed polymerization, or swelling coating. Traditional dispersion polymerization involves monomers self-polymerizing into microspheres (also called polymer microspheres) in alcohol solvents or alcohol-water mixtures under the action of an initiator, forming polymer microspheres with uniform micron-sized particles (these polymer microspheres do not contain quantum dots or other fluorescent materials). If quantum dots are synthesized into quantum dot microspheres using dispersion polymerization, the surface of the quantum dots is coated with a monomer polymer. Since currently high-performance, directly synthesized quantum dots are oil-based, and dispersion polymerization is carried out in alcohol solvents or alcohol-water mixtures, it is necessary to first convert the quantum dots to an alcohol phase in batches. Therefore, the alcohol phase ligand in this application must possess a coordinating group to connect with the quantum dots, and it also needs to have polar groups such as hydroxyl groups, making it readily soluble in alcohol solvents. After the alcohol phase ligand connects with the quantum dots, the quantum dots also become readily soluble in alcohol solvents. However, the preparation of quantum dot microspheres from alcohol-phase quantum dots modified with mercaptoethanol using dispersion polymerization has not been very successful, as the polymer cannot adequately coat the quantum dots. Through extensive experimentation, the applicant discovered that because quantum dots are significantly larger than monomers, in step S2, the monomer polymerization reaction tends to self-polymerize to form polymer microspheres rather than attaching to the quantum dot surface to form a coating layer, resulting in poor coating performance. For example, mercaptoethanol can connect to quantum dots to form an alcohol phase, but during monomer polymerization, a large amount of polymer does not attach to the quantum dot surface. The alcohol-phase ligand in this application has a special design, containing unsaturated hydrocarbons (such as carbon-carbon double and triple bonds). Because the alcohol-phase ligand also contains unsaturated hydrocarbons, it can polymerize with the monomer under the action of an initiator, and the monomer polymer can form chemical bonds with the unsaturated hydrocarbons (more preferentially). The monomer polymer chains become increasingly longer, gradually entangled with the quantum dots to form a coating layer. Through dispersion polymerization, a method that can self-form micron-sized uniform microspheres, quantum dot microspheres with uniform particle size (1-8 micrometers) are obtained, suitable for mass production. Furthermore, since the polymer of the monomer is connected to the quantum dot surface through chemical bonds, the coating layer has better stability.

[0144] In some embodiments, oily quantum dots are mixed with a nonpolar solvent, and then the alcohol phase ligand is added. The mixture is reacted at 40-60°C for 10-24 hours to obtain a solution containing alcohol phase quantum dots. For example, the reaction temperature is 40°C, 42°C, 44°C, 46°C, 48°C, 50°C, 52°C, 54°C, 56°C, 58°C, or 60°C, and the reaction time is 10 hours, 12 hours, 14 hours, 16 hours, 18 hours, 20 hours, 22 hours, or 24 hours, but is not limited to the listed values. Other unlisted values ​​within the above ranges are also applicable.

[0145] The nonpolar solvent includes at least one of chloroform, benzene, carbon tetrachloride, hexane, isooctane, toluene, and dichloromethane.

[0146] Furthermore, the solution containing alcohol-phase quantum dots is purified and extracted to obtain alcohol-phase quantum dots. Purification is performed using solvents such as heptane to obtain an alcohol-phase quantum dot precipitate, which is then extracted by centrifugation to obtain the alcohol-phase quantum dots.

[0147] In some embodiments, in step S2, the first mixture reacts, and the polymer formed by the polymerization reaction of the alcohol ligand and the monomer forms a coating layer covering the quantum dots, thereby obtaining quantum dot microspheres.

[0148] In some embodiments, the concentration of the alcohol-phase quantum dots in the first mixture is 0.1-2.5 mg / ml, for example, 0.1 mg / ml, 0.2 mg / ml, 0.3 mg / ml, 0.4 mg / ml, 0.5 mg / ml, 0.6 mg / ml, 0.7 mg / ml, 0.8 mg / ml, 0.9 mg / ml, 1.0 mg / ml, 1.1 mg / ml, 1.2 mg / ml, 1.3 mg / ml, 1.4 mg / ml, 1.5 mg / ml, 1.6 mg / ml, 1.7 mg / ml, 1.8 mg / ml, 1.9 mg / ml, 2.0 mg / ml, 2.1 mg / ml, etc. The values ​​are g / ml, 2.2 mg / ml, 2.3 mg / ml, 2.4 mg / ml, or 2.5 mg / ml, but not limited to the listed values. Other unlisted values ​​within the above range are also applicable. The mass ratio of the monomer to the initiator is 100:(1-15), for example, 100:1, 100:2, 100:3, 100:4, 100:5, 100:6, 100:7, 100:8, 100:9, 100:10, 100:11, 100:12, 100:13, 100:14, or 100:15, but not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0149] Preferably, in the first mixture, the concentration of the alcohol phase quantum dots is 0.5-2 mg / ml, and the mass ratio of the monomer to the initiator is 100:(2-12).

[0150] The particle size of the formed quantum dot microspheres can be adjusted by regulating the amounts of added alcohol-phase quantum dots, monomers, initiators, dispersants, reaction temperature, and time.

[0151] In some embodiments, the first mixture further includes water.

[0152] Furthermore, the weight ratio of the added alcohol solvent to water is greater than the critical weight ratio value for the alcohol solvent and water to form an azeotrope.

[0153] In this application, firstly, the particle size of the synthesized quantum dot microspheres can be finely adjusted by regulating the mass ratio of the alcohol solvent to water. Secondly, the mass ratio of the alcohol solvent to water added to the first mixture is limited to a critical weight ratio for the alcohol solvent and water to form an azeotrope, which facilitates the recovery of alcohol solvents such as ethanol during mass production and reduces costs. For example, if the critical weight ratio for the azeotrope of ethanol and water is 95.6:4.4, it is recommended that the mass ratio of ethanol to water be slightly greater than the critical weight ratio for the azeotrope of ethanol and water, such as 95:5-90:10.

[0154] In some embodiments, the first mixture further includes a dispersant. The mass ratio of the monomer, dispersant, and initiator added to the first mixture is 100:(1-10):(1-15), for example, 100:1:1, 100:2:2, 100:3:3, 100:4:4, 100:4:5, 100:5:6, 100:5:7, 100:6:8, 100:6:9, 100:5:10, 100:6:11, 100:6:12, 100:7:13, 100:7:14, or 100:8:15, but is not limited to the listed values; other unlisted values ​​within the above range are also applicable.

[0155] Preferably, the mass ratio of the monomer, dispersant and initiator added to the first mixture is 100:(2-7):(2-12).

[0156] In some embodiments, the alcohol-phase quantum dots, alcohol solvent, water, monomer, initiator, and dispersant are mixed to form a first mixture, wherein the monomer is added in one step; the first mixture is stirred and reacted at 55-90°C for 1-24 hours under inert gas protection to obtain quantum dot microspheres. For example, the reaction temperature is 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, or 90°C, and the reaction time is 1 hour, 2 hours, 5 hours, 7 hours, 10 hours, 12 hours, 15 hours, 17 hours, 20 hours, 22 hours, or 24 hours, but is not limited to the listed values; other unlisted values ​​within the above ranges are also applicable.

[0157] Preferably, the alcohol-phase quantum dots, alcohol solvent, water, monomer, initiator and dispersant are mixed to form a first mixture, wherein water, monomer, initiator and dispersant are added at once; the first mixture is stirred and reacted at 60-85°C for 3-24 hours under inert gas protection to obtain quantum dot microspheres.

[0158] The applicant's research has found that, in the preparation of quantum dot microspheres, it is preferable to rapidly pour the monomer in one go. If the monomer is added dropwise, the resulting quantum dot microspheres tend to have poor particle size uniformity. Water, initiator, and dispersant can be added rapidly in one go, slowly, or dropwise. To simplify the operation, it is more preferable to rapidly pour water, monomer, initiator, and dispersant in one go.

[0159] In some embodiments, the alcohol solvent is an organic alcohol. The organic alcohol includes at least one selected from methanol, ethanol, isopropanol, butanol, ethylene glycol, diethylene glycol, and 2-methoxyethanol. Other organic alcohols besides those listed are also within the scope of this application.

[0160] In some embodiments, the monomer includes at least one of styrene, substituted styrene, and methyl methacrylate. In addition to the monomers listed, other monomers capable of preparing quantum dot coatings using dispersion polymerization are also within the scope of this application.

[0161] In some embodiments, the initiator includes at least one selected from azobisisobutyronitrile (AIBN), azobisisovalerate (AMBN), benzoyl peroxide (BPO), and potassium persulfate (KPS). In addition to these listed initiators, other initiators capable of initiating monomer polymerization are also within the scope of this application.

[0162] In some embodiments, the dispersant includes at least one of the following: polyvinylpyrrolidone (PVP), polyoxyethylene (PEO), polyethylene glycol (PEG), polyacrylic acid (PAA), polyvinyl alcohol (PVA), sodium styrene sulfonate, and polyethylene glycol octylphenyl ether (Triton X-100, X-114, X-305, etc.). In addition to these listed dispersants, other common dispersants are also within the scope of this application.

[0163] In some embodiments, in step S3, the second mixture reacts, and the mixed monomers undergo a polymerization reaction to form a crosslinked material attached to the surface of the quantum dot microspheres (i.e., the surface of the coating layer), thereby obtaining quantum dot encoded microspheres.

[0164] In some embodiments, the mixed monomers include: monomers, hydrophilic or hydrophobic monomers, and functional monomers; in the mixed monomers, the mass percentage of the monomers is 10-70% wt, for example, 10% wt, 15% wt, 20% wt, 25% wt, 30% wt, 35% wt, 40% wt, 45% wt, 50% wt, 55% wt, 60% wt, 65% wt, or 70% wt, but not limited to the listed values; other unlisted values ​​within the above range are also applicable. The mass percentage of the hydrophilic or hydrophobic monomers is... The mass percentage of the functional monomer is 5-40% wt, for example, 5% wt, 10% wt, 15% wt, 20% wt, 25% wt, 30% wt, 35% wt, or 40% wt, but not limited to the listed values. Other unlisted values ​​within the above range also apply.

[0165] Preferably, in the mixed monomers, the monomers account for 30-60% wt by mass, the hydrophilic or hydrophobic monomers account for 5-40% wt by mass, and the functional monomers account for 5-40% wt by mass.

[0166] Furthermore, the mixed monomer is composed of monomers, hydrophilic or hydrophobic monomers, and functional monomers.

[0167] Furthermore, the hydrophilic monomer comprises: a hydrophilic segment and a polymerizable segment; the hydrophobic monomer comprises: a hydrophobic segment and a polymerizable segment; the hydrophilic segment provides hydrophilicity to the quantum dot-encoded microspheres, the hydrophobic segment provides hydrophobicity to the quantum dot-encoded microspheres, and the polymerizable segment is capable of undergoing a polymerization reaction (the polymer resulting from this polymerization reaction can further increase the degree of crosslinking of the polymer on the basis of the coating layer).

[0168] Preferably, the hydrophilic monomer includes at least one of: poly(ethylene glycol) diacrylate, acrylic acid and its derivatives, hydroxyethyl acrylate and its derivatives, and acrylamide and its derivatives.

[0169] Preferably, the hydrophobic monomer includes C12-18 olefins and their derivatives with double bonds at positions 1-2. Examples include dodecene and lauryl acrylate. In addition to these listed examples, other hydrophilic / hydrophobic monomers are also within the scope of this application.

[0170] Furthermore, the functional monomer includes a functional group and a polymerizable group. The functional group can improve the resistance of quantum dot encoded microspheres to organic solvents, heat, acids, and alkalis, while the polymerizable group can undergo polymerization to connect to / coat the surface of the quantum dot microspheres.

[0171] Preferably, the functional monomer includes at least one of the following: siloxane methacrylate, α-methylstyrene, methyl methacrylate, acrylic acid, hydroxyethyl acrylate, acrylamide, and their derivatives. In addition to these listed functional monomers, other monomers that can increase the crosslinking degree, heat resistance, acid and alkali resistance, etc., of the coating layer are also within the scope of protection of this application.

[0172] This application designs a mixed monomer system comprising: monomers, hydrophilic or hydrophobic monomers, and functional monomers. The reason for this is that the monomers are the same as those in the first mixture (not referring to identical specific components, but rather the same range of component selection), making it easier to copolymerize with the polymer (such as polystyrene) on the surface of the quantum dot microspheres. If no monomers are present, and only hydrophilic or hydrophobic monomers and functional monomers are included, their polymers are less likely to connect with the quantum dot microspheres, or the connection efficiency is lower. The hydrophilic or hydrophobic monomers provide hydrophilicity or hydrophobicity to the quantum dot-encoded microspheres, facilitating their application in aqueous or oil-phase tracing, and further enhancing the crosslinking degree of the polymer on top of the coating layer. The functional monomers are used to further increase the resistance of the quantum dot microspheres to organic solvents (such as chloroform), high temperatures, salts, acids, and alkalis, and also provide binding sites (such as siloxy groups) for subsequent silicone coating (re-coating with a silica shell).

[0173] In some embodiments, the quantum dot microspheres are dispersed in an emulsifier solution and stirred at 60-80°C, for example, 60°C, 62°C, 64°C, 66°C, 68°C, 70°C, 72°C, 74°C, 76°C, 78°C, or 80°C, but not limited to the listed values; other unlisted values ​​within the above range are also applicable. An initiator is added, and then an emulsifier solution containing the mixed monomers is added dropwise at a rate of 1-10 ml / h, for example, 1 ml / h, 2 ml / h, 3 ml / h, 4 ml / h, 5 ml / h, 6 ml / h. 7 ml / h, 8 ml / h, 9 ml / h, or 10 ml / h, but not limited to the listed values, and other unlisted values ​​within the above range are also applicable, with a reaction time of 10-120 min, for example, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min, 90 min, 100 min, 110 min, or 120 min, but not limited to the listed values, and other unlisted values ​​within the above range are also applicable, to obtain quantum dot-encoded microspheres.

[0174] Preferably, the quantum dot microspheres are dispersed in an emulsifier solution, and an initiator is added all at once while stirring at 60-80°C. Then, an emulsifier solution containing mixed monomers is added dropwise at a rate of 2-5 ml / h, and the reaction is carried out for 15-60 min to obtain quantum dot encoded microspheres.

[0175] Furthermore, the emulsifier includes at least one selected from: sodium dodecyl sulfate (SDS), disodium thiodipropionate (SDPS), polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), polyacrylic acid (PAA), Tween 20 (TW20), Tween 80 (TW80), and Triton. In addition to these listed emulsifiers, other common emulsifiers are also within the scope of protection of this application.

[0176] A second aspect of this application provides a quantum dot-encoded microsphere, comprising, from the inside out: an alcohol phase quantum dot, a coating layer covering the alcohol phase quantum dot, and a crosslinker attached to the surface of the coating layer; the alcohol phase quantum dot includes a quantum dot and an alcohol phase ligand connected to the quantum dot, the alcohol phase ligand containing an unsaturated hydrocarbon; the polymer formed by the polymerization reaction of the alcohol phase ligand with monomers forms the coating layer covering the quantum dot; and the mixed monomers undergo a polymerization reaction to form the crosslinker attached to the surface of the coating layer.

[0177] In some embodiments, the quantum dots are oil-based or water-based quantum dots. Preferably, the quantum dots are oil-based quantum dots. The quantum dots include at least one of the following: group IIB-VIA quantum dots, group IIIA-VA quantum dots, group IVA-VIA quantum dots, group IVA quantum dots, group IB-IIIA-VIA quantum dots, group IB-IIB-IVA-VIA quantum dots, group VIII-VIA quantum dots, perovskite quantum dots, or carbon quantum dots (carbon dots).

[0178] In some embodiments, the alcohol ligand contains a polar group, a coordinating group, and an unsaturated hydrocarbon.

[0179] Furthermore, the polar group includes at least one of hydroxyl, ether, amino, and carboxyl groups, the coordinating group includes at least one of mercapto, amino, amide, organophosphorus, and phosphate ester groups, and the unsaturated hydrocarbon includes carbon-carbon double bonds and carbon-carbon triple bonds.

[0180] Furthermore, the alcohol ligand comprises at least one of the following: polyether-polyester copolymer phosphate ester, polyether phosphate ester, polyethylene glycol phosphate ester, Triton phosphate ester, mercapto-polyethylene glycol-phosphite (DSPE-PEG-Thiol), acrylate-ω-mercapto-polyethylene glycol (AC-PEG-SH), mercapto-polyethylene glycol acrylate (HS-PEG-OPSS), mercapto-polyethylene glycol methacrylate (MAC-PEG-SH), mercapto-polyethylene glycol maleimide (HS-PEG-Alkyne), or mercapto-polyethylene glycol silane (HS-PEG-Acrylate).

[0181] In some embodiments, the monomer includes at least one of styrene, substituted styrene, and methyl methacrylate.

[0182] In some embodiments, the mixed monomers include: monomers, hydrophilic or hydrophobic monomers, and functional monomers; the hydrophilic monomers include: hydrophilic segments and polymerizable segments; the hydrophobic monomers include: hydrophobic segments and polymerizable segments; the hydrophilic segments provide hydrophilicity for the quantum dot-encoded microspheres, the hydrophobic segments provide hydrophobicity for the quantum dot-encoded microspheres, and the polymerizable segments are capable of polymerization; the functional monomers include: functional groups and polymerizable groups.

[0183] The present invention will be further described in detail below with reference to specific embodiments and comparative examples. However, the present invention is not limited to the following embodiments. The implementation conditions used in the embodiments can be further adjusted according to different requirements of specific use. The conditions not specified are conventional conditions in the industry.

[0184] Example 1:

[0185] S1, Quantum Dot to Alcohol Phase Conversion: Dissolve 10g of quantum dots (red-light lnP / ZnSe / ZnSeS / ZnS quantum dots) in 50ml of chloroform, add 3g of polyether-polyester copolymer phosphate ester, and stir at 50℃ and 400rpm for 12h to obtain a solution containing alcohol phase quantum dots. Add 500ml of heptane to precipitate the alcohol phase quantum dots, centrifuge, and obtain alcohol phase quantum dots.

[0186] S2, Synthesis of quantum dot microspheres: 100 mg of the alcohol-phase quantum dots obtained in step S1 was added to 38 ml of ethanol. Then, 2 ml of water, 5 ml of styrene, 150 mg of azobisisobutyronitrile (AIBN), and 200 mg of polyvinylpyrrolidone (PVP) were added sequentially and rapidly in one step. Nitrogen gas was introduced for protection, and the mixture was stirred at 75 °C and 400 rpm for 4 hours. After centrifugation, the microspheres were washed twice with ethanol and dried to obtain quantum dot microspheres.

[0187] S3, Synthetic aqueous quantum dot-encoded microspheres:

[0188] In a 100ml three-necked flask, add 500mg of the quantum dot microspheres obtained in step S2 to 40ml of sodium dodecyl sulfate aqueous solution (concentration 2mg / ml), and stir until homogeneous. Add 400ul of polyethylene glycol. 600 Diacrylate, 400 μL methyl methacrylate, and 400 μL siloxane methacrylate were added to 10 mL of sodium dodecyl sulfate aqueous solution (2 mg / mL). The mixture was ultrasonically emulsified at 300 W for 2 min to obtain a mixed monomer solution. In a 100 mL three-necked flask under nitrogen protection, the temperature was raised to 75 °C, and the stirring speed was maintained at 400 rpm. 30 mg of potassium persulfate was rapidly added in one go, followed by dropwise addition of the mixed monomer solution at a rate of 3 mL / h. After the addition was complete, the reaction continued for 40 min. The mixture was centrifuged, washed twice with water, and dried to obtain quantum dot-encoded microspheres.

[0189] The quantum dot-encoded microspheres prepared in Example 1 were imaged using field emission transmission electron microscopy (TEM), as shown below. Figure 1-1 As shown. Flow cytometry was used to obtain its particle distribution map, as shown. Figure 1-2 As shown; fluorescence distribution map (Violet610), as follows. Figure 1-3 As shown; Particle size distribution diagram, as... Figure 1-4 As shown; and its detection data, such as Figure 1-5 As shown in the electron microscopy image and flow cytometry data from Example 1, the quantum dot-encoded microspheres exhibit uniform particle size.

[0190] Example 2:

[0191] S1, Quantum Dot to Alcohol Phase Conversion: Dissolve 10g of quantum dots (yellow-lustered CdSe / ZnSeS / ZnS quantum dots) in 50ml of chloroform, add 3g of polyether-polyester copolymer phosphate, and stir at 50℃ and 400rpm for 12h to obtain a solution containing alcohol phase quantum dots. Add 500ml of heptane to precipitate the alcohol phase quantum dots, centrifuge, and obtain alcohol phase quantum dots.

[0192] S2, Synthesis of quantum dot microspheres: 100 mg of the alcohol-phase quantum dots obtained in step S1 was added to 38 ml of ethanol. Then, 2 ml of water, 5 ml of styrene, 150 mg of azobisisobutyronitrile (AIBN), and 250 mg of PVP were added sequentially and rapidly in one step. Nitrogen gas was introduced for protection, and the mixture was stirred at 75 °C and 400 rpm for 4 hours. After centrifugation, the microspheres were washed twice with ethanol and dried to obtain quantum dot microspheres.

[0193] S3, Synthetic aqueous quantum dot-encoded microspheres:

[0194] In a 100ml three-necked flask, 500mg of the quantum dot microspheres obtained in step S2 were added to 40ml of sodium dodecyl sulfate aqueous solution (concentration 2mg / ml), and stirred until homogeneous. 400ul of hydroxyethyl acrylate, 400ul of methyl methacrylate, and 400ul of siloxane methacrylate were added to 10ml of sodium dodecyl sulfate aqueous solution (concentration 2mg / ml), and the mixture was sonicated at 300W for 2 minutes to obtain a mixed monomer solution. In a 100ml three-necked flask, under nitrogen protection, the temperature was raised to 75℃, and while maintaining a stirring speed of 400rpm, 30mg of potassium persulfate was rapidly added in one go. Then, the mixed monomer solution was added dropwise at a rate of 3ml / h, and the reaction continued for 40 minutes after the addition was complete. The mixture was centrifuged, washed twice with water, and dried to obtain quantum dot-encoded microspheres.

[0195] The quantum dot-encoded microspheres prepared in Example 2 were imaged using field emission transmission electron microscopy (TEM), as shown below. Figure 2-1 As shown. Flow cytometry was used to obtain its particle distribution map, as shown. Figure 2-2 As shown; fluorescence distribution map (B585), as follows. Figure 2-3 As shown; particle size distribution diagram, as Figure 2-4 As shown; and its detection data, such as Figure 2-5 As shown in the electron microscopy images and flow cytometry data from Example 2, the quantum dot-encoded microspheres exhibit uniform particle size.

[0197] Example 3:

[0198] S1, Quantum Dot to Alcohol Phase Conversion: Dissolve 10g of quantum dots (red-light lnP / ZnSe / ZnSeS / ZnS quantum dots) in 50ml of chloroform, add 3g of mercapto-polyethylene glycol-phosphite, and stir at 50℃ and 400rpm for 12h to obtain a solution containing alcohol phase quantum dots. Add 500ml of heptane to precipitate the alcohol phase quantum dots, centrifuge, and obtain alcohol phase quantum dots.

[0199] S2, Synthesis of quantum dot microspheres: 100 mg of the alcohol-phase quantum dots obtained in step S1 was added to 37 ml of ethanol. Then, 3 ml of water, 5 ml of styrene, 150 mg of azobisisobutyronitrile (AIBN), and 250 mg of PVP were added sequentially and rapidly in one step. Nitrogen gas was introduced for protection, and the mixture was stirred at 70 °C and 400 rpm for 4 hours. After centrifugation, the microspheres were washed twice with ethanol and dried to obtain quantum dot microspheres.

[0200] S3, Synthetic aqueous quantum dot-encoded microspheres:

[0201] In a 100ml three-necked flask, add 500mg of the quantum dot microspheres obtained in step S2 to 40ml of sodium dodecyl sulfate aqueous solution (concentration 2mg / ml), and stir until homogeneous. Add 300ul of polyethylene glycol. 600 Diacrylate, 600 μL of styrene, and 300 μL of methacrylate siloxane were added to 10 mL of sodium dodecyl sulfate aqueous solution (2 mg / mL). The mixture was sonicated at 300 W for 2 min to obtain a mixed monomer solution. In a 100 mL three-necked flask under nitrogen protection, the temperature was raised to 75 °C, and the mixture was stirred at 400 rpm. 30 mg of potassium persulfate was rapidly added in one go, followed by dropwise addition of the mixed monomer solution at a rate of 3 mL / h. After the addition was complete, the reaction continued for 40 min. The mixture was centrifuged, washed twice with water, and dried to obtain quantum dot-encoded microspheres.

[0202] The quantum dot-encoded microspheres prepared in Example 3 were imaged using field emission transmission electron microscopy (TEM), as shown below. Figure 3-1 As shown. Flow cytometry was used to obtain its particle distribution map, as shown. Figure 3-2 As shown; fluorescence distribution map (Violet610), as follows. Figure 3-3 As shown; particle size distribution diagram, as Figure 3-4 As shown; and flow cytometry detection data, such as Figure 3-5 As shown in the electron microscopy images and flow cytometry data from Example 3, the quantum dot-encoded microspheres exhibit uniform particle size.

[0203] Example 4:

[0204] S1, Quantum Dot to Alcohol Phase Conversion: Dissolve 10g of quantum dots (red-light CdSe / ZnSeS / ZnS quantum dots) in 50ml of chloroform, add 3g of mercapto-polyethylene glycol acrylate, and stir at 50℃ and 400rpm for 12h to obtain a solution containing alcohol phase quantum dots. Add 500ml of heptane to precipitate the alcohol phase quantum dots, centrifuge, and obtain alcohol phase quantum dots.

[0205] S2, Synthesis of quantum dot microspheres: 100 mg of the alcohol-phase quantum dots obtained in step S1 was added to 38 ml of ethanol. Then, 2 ml of water, 5 ml of styrene, 200 mg of azobisisobutyronitrile (AIBN), and 500 mg of PVP were added sequentially and rapidly in one step. Nitrogen gas was introduced for protection, and the mixture was stirred at 80 °C and 400 rpm for 4 hours. After centrifugation, the microspheres were washed twice with ethanol and dried to obtain quantum dot microspheres.

[0206] S3, Synthetic aqueous quantum dot-encoded microspheres:

[0207] In a 100ml three-necked flask, 500mg of the quantum dot microspheres obtained in step S2 were added to 40ml of sodium dodecyl sulfate aqueous solution (concentration 2mg / ml), and stirred until homogeneous. 300ul of lauryl acrylate, 600ul of methyl methacrylate, and 300ul of siloxane methacrylate were added to 10ml of sodium dodecyl sulfate aqueous solution (concentration 2mg / ml), and the mixture was ultrasonically emulsified at 300W for 2 minutes to obtain a mixed monomer solution. In a 100ml three-necked flask, under nitrogen protection, the temperature was raised to 75℃, and while maintaining a stirring speed of 400rpm, 30mg of potassium persulfate was rapidly added in one go. Then, the mixed monomer solution was added dropwise at a rate of 3ml / h, and the reaction continued for 40 minutes after the addition was complete. The mixture was centrifuged, washed twice with water, and dried to obtain quantum dot-encoded microspheres.

[0208] The quantum dot-encoded microspheres prepared in Example 4 were imaged using field emission transmission electron microscopy (TEM), as shown below. Figure 4-1 As shown. Flow cytometry was used to obtain its particle distribution map, as shown. Figure 4-2 As shown; fluorescence distribution map (Violet610), as follows. Figure 4-3 As shown; particle size distribution diagram, as Figure 4-4 As shown; and its detection data, such as Figure 4-5 As shown in the electron microscopy images and flow cytometry data from Example 4, the quantum dot-encoded microspheres exhibit uniform particle size.

[0209] Example 5:

[0210] S1, Quantum Dot to Alcohol Phase Conversion: Dissolve 10g of quantum dots (blue light lnP / ZnSe / ZnSeS / ZnS quantum dots) in 50ml of chloroform, add 3g of polyether-polyester copolymer phosphate ester, and stir at 50℃ and 400rpm for 12h to obtain a solution containing alcohol phase quantum dots. Add 500ml of heptane to precipitate the alcohol phase quantum dots, centrifuge, and obtain alcohol phase quantum dots.

[0211] S2, Synthesis of quantum dot microspheres: 100 mg of the alcohol-phase quantum dots obtained in step S1 was added to 35 ml of isopropanol. Then, 5 ml of water, 5 ml of methyl methacrylate, 160 mg of azobisisobutyronitrile (AIBN), and 200 mg of PVP were added sequentially and rapidly in one step. Nitrogen gas was introduced for protection, and the mixture was stirred at 75 °C and 400 rpm for 16 h. After centrifugation, the microspheres were washed twice with ethanol and dried to obtain quantum dot microspheres.

[0212] S3, Synthetic aqueous quantum dot-encoded microspheres:

[0213] In a 100ml three-necked flask, add 500mg of the quantum dot microspheres obtained in step S2 to 40ml of sodium dodecyl sulfate aqueous solution (concentration 2mg / ml), and stir until homogeneous. Add 400ul of polyethylene glycol. 200 Diacrylate, 400 μL methyl methacrylate, and 400 μL siloxane methacrylate were added to 10 mL of sodium dodecyl sulfate aqueous solution (2 mg / mL). The mixture was ultrasonically emulsified at 300 W for 2 min to obtain a mixed monomer solution. In a 100 mL three-necked flask under nitrogen protection, the temperature was raised to 75 °C, and the stirring speed was maintained at 400 rpm. 30 mg of potassium persulfate was rapidly added in one go, followed by dropwise addition of the mixed monomer solution at a rate of 3 mL / h. After the addition was complete, the reaction continued for 40 min. The mixture was centrifuged, washed twice with water, and dried to obtain quantum dot-encoded microspheres.

[0214] The quantum dot-encoded microspheres prepared in Example 5 were imaged using field emission transmission electron microscopy (TEM), as shown below. Figure 5-1 As shown. Flow cytometry was used to obtain its particle distribution map, as shown. Figure 5-2 As shown; fluorescence distribution map (V450), as... Figure 5-3 As shown; particle size distribution diagram, as Figure 5-4 As shown; and its detection data, such as Figure 5-5 As shown in the electron microscopy images and flow cytometry data from Example 5, the quantum dot-encoded microspheres exhibit uniform particle size.

[0216] Example 6:

[0217] S1, Quantum Dot to Alcohol Phase Conversion: Take 5g of red-light lnP / ZnSe / ZnSeS / ZnS quantum dots and 5g of green-light CdSe / ZnSeS / ZnS quantum dots, dissolve them in 50ml of chloroform, add 3g of polyether-polyester copolymer phosphate ester, and stir at 50℃ and 400rpm for 12h to obtain a solution containing alcohol phase quantum dots. Add 500ml of heptane to precipitate the alcohol phase quantum dots, centrifuge, and obtain alcohol phase quantum dots.

[0218] S2, Synthesis of quantum dot microspheres: 100 mg of the alcohol-phase quantum dots obtained in step S1 was added to 38 ml of ethanol. Then, 2 ml of water, 5 ml of styrene, 150 mg of azobisisobutyronitrile (AIBN), and 200 mg of PVP were added sequentially and rapidly in one step. Nitrogen gas was introduced for protection, and the mixture was stirred at 75 °C and 400 rpm for 4 hours. After centrifugation, the microspheres were washed twice with ethanol and dried to obtain quantum dot microspheres.

[0219] S3, Synthetic aqueous quantum dot-encoded microspheres:

[0220] In a 100ml three-necked flask, add 500mg of the quantum dot microspheres obtained in step S2 to 40ml of sodium dodecyl sulfate aqueous solution (concentration 2mg / ml), and stir until homogeneous. Add 400ul of polyethylene glycol. 600 Diacrylate, 400 μL methyl methacrylate, and 400 μL siloxane methacrylate were added to 10 mL of sodium dodecyl sulfate aqueous solution (2 mg / mL). The mixture was ultrasonically emulsified at 300 W for 2 min to obtain a mixed monomer solution. In a 100 mL three-necked flask under nitrogen protection, the temperature was raised to 75 °C, and the stirring speed was maintained at 400 rpm. 30 mg of potassium persulfate was rapidly added in one go, followed by dropwise addition of the mixed monomer solution at a rate of 3 mL / h. After the addition was complete, the reaction continued for 40 min. The mixture was centrifuged, washed twice with water, and dried to obtain quantum dot-encoded microspheres.

[0221] The quantum dot-encoded microspheres prepared in Example 6 were imaged using field emission transmission electron microscopy (TEM), as shown below. Figure 6-1 As shown. The particle distribution was obtained using the red channel 610 of a flow cytometer, as shown. Figure 6-2 As shown; fluorescence distribution map (Violet610), as follows. Figure 6-3 As shown; particle size distribution diagram, as Figure 6-4 As shown; and its detection data, such as Figure 6-5 The particle distribution was obtained using the green channel 525 of a flow cytometer, as shown in the figure. Figure 6-6 As shown; fluorescence distribution map (B525), as shown. Figure 6-7 As shown; particle size distribution diagram, as Figure 6-8 As shown; and its detection data, such as Figure 6-9 As shown. Images were captured using the red channel of a fluorescence microscope (EX475 / 35, DM500, EM620*50). Figure 6-10 Images were obtained using the green channel of a fluorescence microscope (EX365 / 50, DM400, 530 / 50). Figure 6-11 As can be seen from the electron micrographs, flow cytometry images and data, and fluorescence micrographs of Example 6, the quantum dot-coded microspheres prepared simultaneously have uniform particle size, and both colors can be detected well at the same time.

[0222] Comparative Example 1:

[0223] S1, Quantum Dot to Alcohol Phase Conversion: Dissolve 10g of quantum dots (red-light lnP / ZnSe / ZnSeS / ZnS quantum dots) in 50ml of chloroform, add 3g of polyether-polyester copolymer phosphate ester, and stir at 50℃ and 400rpm for 12h to obtain a solution containing alcohol phase quantum dots. Add 500ml of heptane to precipitate the alcohol phase quantum dots, centrifuge, and obtain alcohol phase quantum dots.

[0224] S2, Synthesis of quantum dot microspheres: Take 100 mg of the alcohol-phase quantum dots obtained in step S1, add them all at once to 38 ml of ethanol, 2 ml of water, 150 mg of azobisisobutyronitrile (AIBN), and 250 mg of PVP. Then, add 5 ml of styrene dropwise at a rate of 1.5 ml / h, purge with nitrogen for protection, and stir at 75 °C and 400 rpm for 4 h. Centrifuge, wash twice with ethanol, and dry to obtain quantum dot microspheres.

[0225] S3, Synthetic aqueous quantum dot-encoded microspheres:

[0226] In a 100ml three-necked flask, add 500mg of the quantum dot microspheres obtained in step S2 to 40ml of sodium dodecyl sulfate aqueous solution (concentration 2mg / ml), and stir until homogeneous. Add 400ul of polyethylene glycol. 600 Diacrylate, 400 μL methyl methacrylate, and 400 μL siloxane methacrylate were added to 10 mL of sodium dodecyl sulfate aqueous solution (2 mg / mL). The mixture was ultrasonically emulsified at 300 W for 2 min to obtain a mixed monomer solution. In a 100 mL three-necked flask under nitrogen protection, the temperature was raised to 75 °C, and the stirring speed was maintained at 400 rpm. 30 mg of potassium persulfate was rapidly added in one go, followed by dropwise addition of the mixed monomer solution at a rate of 3 mL / h. After the addition was complete, the reaction continued for 40 min. The mixture was centrifuged, washed twice with water, and dried to obtain quantum dot-encoded microspheres.

[0227] The quantum dot-encoded microspheres prepared in Comparative Example 1 were imaged using field emission transmission electron microscopy (TEM), as shown in the image. Figure 7-1 and 7-2 As shown. This quantum dot-encoded microsphere... Figure 7-1 and 7-2 It is very obvious that the particle size of its quantum dot-encoded microspheres is highly uneven and varies greatly.

[0228] Comparative Example 2:

[0229] S1, Quantum Dot to Alcohol Phase Conversion: Dissolve 10g of quantum dots (red-light lnP / ZnSe / ZnSeS / ZnS quantum dots) in 50ml of chloroform, add 3g of polyether-polyester copolymer phosphate ester, and stir at 50℃ and 400rpm for 12h to obtain a solution containing alcohol phase quantum dots. Add 500ml of heptane to precipitate the alcohol phase quantum dots, centrifuge, and obtain alcohol phase quantum dots.

[0230] S2, Synthesis of quantum dot microspheres: 100 mg of the alcohol-phase quantum dots obtained in step S1 was added to 38 ml of ethanol. Then, 2 ml of water, 5 ml of styrene, 150 mg of azobisisobutyronitrile (AIBN), and 200 mg of PVP were added sequentially and rapidly in one step. Nitrogen gas was introduced for protection, and the mixture was stirred at 75 °C and 400 rpm for 4 hours. After centrifugation, the microspheres were washed twice with ethanol and dried to obtain quantum dot microspheres.

[0231] S3, Synthetic aqueous quantum dot-encoded microspheres:

[0232] In a 100ml three-necked flask, 1g of the quantum dot microspheres obtained in step S2 was added to 50ml of sodium dodecyl sulfate aqueous solution (concentration 2mg / ml), along with 30mg of sodium bicarbonate and 30mg of potassium persulfate. The mixture was ultrasonically emulsified at 300W for 2 minutes, then nitrogen gas was introduced and the mixture was heated to 75℃. 400ul of tetrachloroethylene and 600ul of styrene were added to 10ml of sodium dodecyl sulfate aqueous solution (concentration 2mg / ml), and the mixture was ultrasonically emulsified at 300W for 2 minutes to obtain a mixed monomer solution. After the 100ml three-necked flask reached 75℃, the mixed monomer solution was added at a dropping rate of 3ml / h. After the addition was complete, the reaction continued for 40 minutes. The mixture was centrifuged, washed twice with water, and dried to obtain quantum dot-encoded microspheres.

[0233] The quantum dot-encoded microspheres prepared in Comparative Example 2 were imaged using field emission transmission electron microscopy (TEM), as shown in the image. Figure 8 As shown.

[0234] Comparative Example 3:

[0235] S1, Quantum Dot to Alcohol Phase Conversion: Dissolve 10g of quantum dots (red-light lnP / ZnSe / ZnSeS / ZnS quantum dots) in 50ml of chloroform, add 3g of polyether-polyester copolymer phosphate ester, and stir at 50℃ and 400rpm for 12h to obtain a solution containing alcohol phase quantum dots. Add 500ml of heptane to precipitate the alcohol phase quantum dots, centrifuge, and obtain alcohol phase quantum dots.

[0236] S2, Synthesis of quantum dot microspheres: 100 mg of the alcohol-phase quantum dots obtained in step S1 was added to 38 ml of ethanol. Then, 2 ml of water, 5 ml of styrene, 150 mg of azobisisobutyronitrile (AIBN), and 200 mg of PVP were added sequentially and rapidly in one step. Nitrogen gas was introduced for protection, and the mixture was stirred at 75 °C and 400 rpm for 4 hours. After centrifugation, the microspheres were washed twice with ethanol and dried to obtain quantum dot microspheres.

[0237] S3, Synthetic aqueous quantum dot-encoded microspheres:

[0238] In a 100ml three-necked flask, 1g of the quantum dot microspheres obtained in step S2 was added to 50ml of sodium dodecyl sulfate aqueous solution (concentration 2mg / ml), along with 30mg of sodium bicarbonate and 30mg of potassium persulfate. The mixture was ultrasonically emulsified at 300W for 2 minutes, then nitrogen gas was introduced and the mixture was heated to 75℃. 400ul of divinylbenzene and 600ul of styrene were added to 10ml of sodium dodecyl sulfate aqueous solution (concentration 2mg / ml), and the mixture was ultrasonically emulsified at 300W for 2 minutes to obtain a mixed monomer solution. After the 100ml three-necked flask reached 75℃, the mixed monomer solution was added at a dropping rate of 3ml / h. After the addition was complete, the reaction continued for 40 minutes. The mixture was centrifuged, washed twice with water, and dried to obtain quantum dot-encoded microspheres.

[0239] The quantum dot-encoded microspheres prepared in Comparative Example 3 were imaged using field emission transmission electron microscopy (TEM), as shown in the image. Figure 9 As shown.

[0240] from Figure 8 and Figure 9 As can be seen, the quantum dot-encoded microspheres have uniform particle size, but due to the different mixed monomers, their chloroform resistance and high-temperature resistance are poor, which is not suitable for oilfield tracer applications. Specific chloroform resistance and high-temperature resistance tests are as follows.

[0241] Chloroform resistance test:

[0242] 10 mg of each of the quantum dot-encoded microspheres obtained in Example 1, Comparative Example 2, and Comparative Example 3 was added to 3 ml of chloroform and allowed to stand for 2 hours. The photographs of Example 1, Comparative Example 2, and Comparative Example 3 before and after the chloroform resistance test and centrifugation are shown below. Figure 10-1 , Figure 10-2 , Figure 10-3 (The left image is before the chloroform resistance test, and the right image is after the chloroform resistance test and centrifugation.) From... Figure 10-2 As can be seen, the quantum dot-encoded microspheres obtained in Comparative Example 2 were completely dissolved in chloroform, meaning that these quantum dot-encoded microspheres are not chloroform-resistant and are not suitable as oilfield tracers. Figure 10-1 , Figure 10-3 As can be seen, the quantum dot-encoded microspheres obtained in Example 1 and Comparative Example 3 did not appear to dissolve significantly in chloroform to the naked eye.

[0243] Meanwhile, the morphology of the quantum dot-encoded microspheres from Example 1 after immersion in chloroform (after chloroform resistance test) was observed under a fluorescence microscope, as shown in the image. Figure 10-4 As shown; a morphological diagram of the quantum dot-encoded microspheres in Comparative Example 3 after being immersed in chloroform, as shown. Figure 10-5 As shown. From Figure 10-5As can be seen, although the quantum dot-encoded microspheres in Comparative Example 3 were not dissolved by chloroform, they exhibited swelling and aggregation. From... Figure 10-4 As can be seen, the quantum dot-encoded microspheres of Example 1 did not swell or agglomerate after being soaked in chloroform, indicating that the quantum dot-encoded microspheres of the present application have good tolerance to chloroform, a highly swelling and corrosive solvent.

[0244] High temperature resistance test:

[0245] 10 mg of each of the quantum dot-encoded microspheres obtained in Example 1, Comparative Example 2, and Comparative Example 3 was added to 10 ml of ethylene glycol and placed in an oven at 150 °C for 24 h. The morphology of the quantum dot-encoded microspheres in Example 1 before and after high-temperature treatment was observed under a fluorescence microscope, as shown in the figures below. Figure 11-1 , Figure 11-2 As shown; the morphological images of the quantum dot-encoded microspheres in Comparative Example 2 before and after high-temperature treatment are shown respectively. Figure 11-3 , Figure 11-4 As shown; the morphological images of the quantum dot-encoded microspheres in Comparative Example 3 before and after high-temperature treatment are shown respectively. Figure 11-5 , Figure 11-6 As shown.

[0246] from Figure 11-1 , Figure 11-2 As can be seen, the luminescence brightness of the quantum dot-encoded microspheres in Example 1 is basically the same before and after high-temperature treatment, indicating that the quantum dot-encoded microspheres of this application have excellent high-temperature resistance. From Figure 11-3 , Figure 11-4 It is evident that the luminescence brightness of the quantum dot-encoded microspheres in Comparative Example 2 was significantly reduced before and after high-temperature treatment, and the number of luminescent quantum dots also decreased significantly, indicating that many quantum dots had quenched, resulting in poor high-temperature resistance. Figure 11-5 , Figure 11-6 It is evident that the luminescence brightness of the quantum dot-encoded microspheres in Comparative Example 3 decreased before and after high-temperature treatment, and the number of luminescent quantum dots also decreased, indicating that some quantum dots had been quenched and the high-temperature resistance was poor.

[0247] Comparative Example 4:

[0248] In a 250 ml three-necked flask, at room temperature (25 °C), add 3.7 g formaldehyde, 2.6 g melamine, and 100 ml deionized water and mix thoroughly. Then add 60 mg Nile red and sonicate at 300 W for 1 min to mix thoroughly. Next, add 250 μL sodium hydroxide (0.1 mM) and stir at 400 rpm for 1 h. Then add 1 ml of phosphoric acid aqueous solution (phosphoric acid concentration 10%) and stir at 400 rpm for 2 h. Centrifuge, wash twice with ethanol, and dry to obtain dye MF microspheres.

[0249] The dye MF microspheres prepared in Comparative Example 4 were imaged using field emission transmission electron microscopy (TEM), as shown in the image. Figure 12-1 As shown. Flow cytometry was used to obtain its particle distribution map, as shown. Figure 12-2 As shown; fluorescence distribution map (R660), as... Figure 12-3 As shown; particle size distribution diagram, as Figure 12-4 As shown; and its detection data, such as Figure 12-5 As shown.

[0250] Comparative Example 5:

[0251] In a 250 ml three-necked flask, at room temperature (25 °C), add 3.7 g formaldehyde, 2.6 g melamine, and 100 ml deionized water and mix thoroughly. Then add 60 mg sulfonylrhodamine B and sonicate at 300 W for 1 min to mix thoroughly. Then add 250 μL sodium hydroxide (0.1 mM) and stir at 400 rpm for 1 h. Then add 1 ml of phosphoric acid aqueous solution (phosphoric acid concentration is 10%) and stir at 400 rpm for 2 h. Centrifuge, wash twice with ethanol, and dry to obtain dye MF microspheres.

[0252] The dye MF microspheres prepared in Comparative Example 5 were imaged using field emission transmission electron microscopy (TEM), as shown in the image. Figure 13-1 As shown. Flow cytometry was used to obtain its particle distribution map, as shown. Figure 13-2 As shown; fluorescence distribution map (B585), as follows. Figure 13-3 As shown; particle size distribution diagram, as Figure 13-4 As shown; and its detection data, such as Figure 13-5 As shown.

[0253] Comparative Examples 4 and 5 both consist of dye-encoded MF microspheres. As is well known, MF microspheres have hydrophilic groups on their shell surface, exhibiting hydrophilicity and strong resistance to chloroform and high temperatures. Electron microscopy images and flow cytometry data from Comparative Examples 4 and 5 show that the particle size uniformity of their dye-encoded MF microspheres is acceptable (lower than in this application). However, due to some luminescent properties of dyes, such as a larger full width at half maximum (FWHM) and weaker resistance to photodrift, dye-encoded microspheres are inferior to quantum dots. They also exhibit mutual interference and weak fluorescence signals between different detection wavelength channels. The quantum dot-encoded microspheres and dye-encoded MF microspheres prepared in Examples 1, 2, 4, and 5 were further analyzed by flow cytometry to detect their fluorescence distribution in adjacent channels at the emission peak wavelength. Example 1 yielded a fluorescence distribution map (B585), as shown... Figure 1-6 As shown; the fluorescence distribution map (R660) was obtained, as follows. Figure 1-7 As shown. Example 2 yielded a fluorescence distribution map (B525), as shown. Figure 2-6As shown; the fluorescence distribution map (R660) was obtained, as follows. Figure 2-7 As shown. Comparative Example 4 yielded the fluorescence distribution map (B585), as shown. Figure 12-6 As shown; the fluorescence distribution map (R712) was obtained, as follows. Figure 12-7 As shown. Comparative Example 5 yielded the fluorescence distribution map (B525), as shown. Figure 13-6 As shown; the fluorescence distribution map (R660) was obtained, as follows. Figure 13-7 As shown.

[0254] As can be seen from the fluorescence distribution maps detected by flow cytometry in adjacent channels at their emission peak wavelengths, Comparative Examples 4 and 5 show strong fluorescence signals detected in adjacent channels. This indicates that the dye-encoded microspheres may interfere with each other between different encoded dyes or mixed dyes, affecting detection and judgment. In contrast, Examples 1 and 2 show no or only extremely weak fluorescence signals detected in adjacent channels. This indicates that the quantum dot-encoded microspheres of this application do not interfere with each other between different encoded quantum dots or mixed quantum dots, and only have signals in the flow cytometry channel corresponding to their optimal excitation wavelength. Their encoding and decoding reliability is strong, and the fluorescence signal is also strong.

[0255] Although this application discloses several aspects and embodiments, other aspects and embodiments will be obvious to those skilled in the art. Various modifications and improvements can be made without departing from the concept of this application, and these all fall within the scope of protection of this application. The various aspects and embodiments disclosed in this application are for illustrative purposes only and are not intended to limit this application. The actual scope of protection of this application is determined by the claims.

Claims

1. A method for preparing quantum dot-encoded microspheres, characterized in that, Including the following steps: S1, converting quantum dots to alcohol phase: mixing quantum dots with alcohol phase ligands, reacting to link the quantum dots with the alcohol phase ligands to obtain alcohol phase quantum dots; the alcohol phase ligands contain unsaturated hydrocarbons; S2, the alcohol phase quantum dots, alcohol solvent, monomer and initiator are mixed to form a first mixture, and the reaction is carried out to obtain quantum dot microspheres; S3, the quantum dot microspheres, mixed monomers and initiator are mixed to form a second mixture, and the reaction is carried out to obtain quantum dot encoded microspheres.

2. The method for preparing quantum dot-encoded microspheres as described in claim 1, characterized in that, In step S1, the mass ratio of the added quantum dots to the alcohol phase ligand is (1.5-5):

1.

3. The method for preparing quantum dot-encoded microspheres as described in claim 1, characterized in that, In step S1, the alcohol phase ligand contains a polar group, a coordinating group, and an unsaturated hydrocarbon; Preferably, the polar group includes at least one of hydroxyl, ether, amino, or carboxyl groups, the coordinating group includes at least one of mercapto, amino, amide, organophosphorus, or phosphate ester groups, and the unsaturated hydrocarbon includes at least one of carbon-carbon double bonds and carbon-carbon triple bonds. Preferably, the alcohol ligand comprises at least one of the following: polyether-polyester copolymer phosphate, polyether phosphate, polyethylene glycol phosphate, Triton phosphate, mercapto-polyethylene glycol-phosphate, acrylate-ω-mercapto-polyethylene glycol, mercapto-polyethylene glycol acrylate, mercapto-polyethylene glycol methacrylate, mercapto-polyethylene glycol maleimide, or mercapto-polyethylene glycol silane.

4. The method for preparing quantum dot-encoded microspheres as described in claim 1, characterized in that, In step S2, the first mixture reacts, and the polymer formed by the polymerization reaction of the alcohol ligand and the monomer forms a coating layer for the quantum dots, thereby obtaining quantum dot microspheres.

5. The method for preparing quantum dot-encoded microspheres as described in claim 4, characterized in that, Includes one or more features selected from the following group: (1) In the first mixture, the concentration of the alcohol phase quantum dots is 0.1-2.5 mg / ml, and the mass ratio of the monomer to the initiator is 100:(1-15); (2) The first mixture further includes: water and dispersant; in the first mixture, the weight ratio of the alcohol solvent to water is greater than the critical weight ratio of the alcohol solvent to water to form an azeotrope, and the mass ratio of the monomer, dispersant and initiator is 100:(1-10):(1-15); (3) The alcohol phase quantum dots, alcohol solvent, water, monomer, initiator and dispersant are mixed to form a first mixture, wherein the monomer is poured in at once; the first mixture is stirred and reacted at 55-90°C for 1-24 hours under inert gas protection. (4) The alcohol solvent is an organic alcohol; the monomer includes at least one of styrene, substituted styrene, and methyl methacrylate; the initiator includes at least one of azobisisobutyronitrile, azobisisovalerate, benzoyl peroxide, and potassium persulfate; the dispersant includes at least one of polyvinylpyrrolidone, polyoxyethylene, polyethylene glycol, polyacrylic acid, polyvinyl alcohol, sodium styrene sulfonate, and polyethylene glycol octylphenyl ether.

6. The method for preparing quantum dot-encoded microspheres as claimed in claim 1, characterized in that, In step S3, the second mixture reacts, and the mixed monomers undergo a polymerization reaction to form a cross-linked material attached to the surface of the quantum dot microspheres, thereby obtaining quantum dot encoded microspheres.

7. The method for preparing quantum dot-encoded microspheres as described in claim 6, characterized in that, Includes one or more features selected from the following group: (1) The mixed monomers include: monomers, hydrophilic monomers or hydrophobic monomers, and functional monomers; in the mixed monomers, the mass percentage of the monomers is 10-70%wt, the mass percentage of the hydrophilic monomers or hydrophobic monomers is 5-40%wt, and the mass percentage of the functional monomers is 5-40%wt. (2) The mixed monomer is composed of monomers, hydrophilic monomers or hydrophobic monomers, and functional monomers; (3) The hydrophilic monomer includes: hydrophilic segments and polymerizable segments; the hydrophobic monomer includes: hydrophobic segments and polymerizable segments; the hydrophilic segments provide hydrophilicity to the quantum dot encoded microspheres, the hydrophobic segments provide hydrophobicity to the quantum dot encoded microspheres, and the polymerizable segments are capable of undergoing polymerization reactions; (4) The hydrophilic monomers include at least one of the following: poly(ethylene glycol) diacrylate, acrylic acid and its derivatives, hydroxyethyl acrylate and its derivatives, and acrylamide and its derivatives; the hydrophobic monomers include C12-18 olefins and their derivatives with double bonds at positions 1-2. (5) The functional monomers include: functional groups and polymerizable groups; the functional monomers include at least one of methacrylic siloxane, α-methylstyrene, methyl methacrylate, acrylic acid, hydroxyethyl acrylate, acrylamide and its derivatives.

8. A quantum dot-encoded microsphere, characterized in that, The quantum dot-encoded microspheres comprise, from the inside out: alcohol phase quantum dots, a coating layer covering the alcohol phase quantum dots, and a crosslinker attached to the surface of the coating layer; the alcohol phase quantum dots include quantum dots and alcohol phase ligands connected to the quantum dots, the alcohol phase ligands containing unsaturated hydrocarbons; the polymer formed by the polymerization reaction of the alcohol phase ligands and monomers forms the coating layer covering the quantum dots; the mixed monomers undergo a polymerization reaction to form the crosslinker attached to the surface of the coating layer.

9. The quantum dot-encoded microsphere as described in claim 8, characterized in that, Includes one or more features selected from the following group: (1) The quantum dots are oil-based quantum dots or water-based quantum dots; the quantum dots include at least one of the following: IIB-VIA group quantum dots, IIIA-VA group quantum dots, IVA-VIA group quantum dots, IVA group quantum dots, IB-IIIA-VIA group quantum dots, IB-IIB-IVA-VIA group quantum dots, VIII-VIA group quantum dots, perovskite quantum dots, or carbon quantum dots; (2) The alcohol phase ligand contains polar groups, coordinating groups and unsaturated hydrocarbons; Preferably, the polar group includes at least one of hydroxyl, ether, amino, and carboxyl groups; the coordinating group includes at least one of mercapto, amino, amide, organophosphorus, and phosphate ester groups; and the unsaturated hydrocarbon includes carbon-carbon double bonds and carbon-carbon triple bonds. Preferably, the alcohol ligand comprises at least one of the following: polyether-polyester copolymer phosphate, polyether phosphate, polyethylene glycol phosphate, Triton phosphate, mercapto-polyethylene glycol-phosphate, acrylate-ω-mercapto-polyethylene glycol, mercapto-polyethylene glycol acrylate, mercapto-polyethylene glycol methacrylate, mercapto-polyethylene glycol maleimide, or mercapto-polyethylene glycol silane; (3) The monomers include at least one of styrene, substituted styrene, and methyl methacrylate; (4) The mixed monomers include: monomers, hydrophilic monomers or hydrophobic monomers, and functional monomers; the hydrophilic monomers include: hydrophilic segments and polymerizable segments; the hydrophobic monomers include: hydrophobic segments and polymerizable segments; the hydrophilic segments provide hydrophilicity for quantum dot-encoded microspheres, the hydrophobic segments provide hydrophobicity for quantum dot-encoded microspheres, and the polymerizable segments are capable of undergoing polymerization reactions; the functional monomers include: functional groups and polymerizable groups.

10. An oilfield tracer, characterized in that, The quantum dot-encoded microspheres include those prepared by the method described in any one of claims 1-7, or those described in any one of claims 8-9.

Images