Nanoparticles containing suspended conjugated structures and emulsion thereof

Abstract

The present invention relates to a nanoparticle containing a pendant conjugated structure. The nanoparticle containing a pendant conjugated structure comprises an oxidative cross-linking product of a block polymer containing the following polymer segment a and polymer segment b: (A) a repeating unit polymer segment a containing at least one conjugated monomer, the repeating unit structural formula of the conjugated monomer is shown as formula (I): and (B) a repeating unit polymer segment b containing at least one hydrophilic monomer, the repeating unit structural formula of the hydrophilic monomer is shown as formula (II): The present invention obtains nanoparticles containing hydrophilic segments and conjugated segments and an emulsion thereof by a method of PISA combined with carbon-carbon cross-coupling polymerization. The preparation method is simple, the polymer solid content in the emulsion is high, the conjugated structure ratio is high, the particle size uniformity of the nanoparticles is good, the emulsion is stable, and the conductive performance is excellent.

Description

Technical Field

[0001] The invention belongs to the field of polymer materials, and in particular relates to nanoparticles containing a suspended conjugated structure and an emulsion thereof. Background Art

[0002] Conjugated polymers such as polyacetylene (PA), polyfluorene (PF), polythiophene (PT), polyfluorenebenzene (PFP), poly-phenylene vinylene (PPV), poly-p-phenylene vinylene (PPE) and polypentadiene (PDA) are widely used in the field of optoelectronic materials due to their special optoelectronic properties.

[0003] However, since most conjugated polymers are hydrophobic, they cannot be used in aqueous environments. Therefore, nanoparticles containing conjugated polymers can be prepared. However, the aqueous nanoemulsions obtained by conventional methods have a low solids content (usually less than 1%), which limits the optical and electrical properties of the conjugated polymers. Summary of the Invention

[0004] In view of this, the present invention proposes the following technical solution: through the PISA combined with carbon-carbon cross-coupling polymerization method, nanoparticles containing hydrophilic segments and conjugated segments and their emulsions are obtained. The polymer solid content in the emulsion is high, the proportion of conjugated structures is high, the particle size uniformity of the nanoparticles is good, the emulsion is stable and has excellent conductive properties.

[0005] Unless otherwise specified, the % in the present invention refers to molar percentage, and the content ratio refers to molar ratio.

[0006] In a first aspect, the present invention provides a nanoparticle containing a pendant conjugated structure, wherein the nanoparticle containing a pendant conjugated structure comprises an oxidative cross-linking product of a block polymer containing the following polymer segment a and polymer segment b:

[0007] (A) a polymeric segment a comprising a repeating unit of at least one conjugated monomer, wherein the repeating unit structure of the conjugated monomer is as shown in formula (I):

[0008] and,

[0009] (B) a polymeric segment b comprising a repeating unit of at least one hydrophilic monomer, wherein the repeating unit structural formula of the hydrophilic monomer is as shown in formula (II):

[0010]

[0011] in:

[0012] Each R1 may be the same or different and is independently selected from H or methyl;

[0013] Each R2 may be the same or different and is independently selected from -R4-Q;

[0014] Each R4 can be the same or different and is independently selected from a chemical bond or C 1-10 unsubstituted or substituted with 1-4 R s Substituted alkyl, alkenyl or alkoxy, said R s Selected from halogen, C 1-6 Alkyl, C 1-6 at least one of an alkoxy group or a cyano group;

[0015] Each Q is independently selected from a group containing at least one cyclic conjugated structure, that is, Q may include any other non-conjugated group in addition to the group containing the cyclic conjugated structure; the group containing the cyclic conjugated structure is selected from at least one of benzene, thiophene, pyrrole, thiazole, oxazole, imidazole, pyrazole, pyridine or pyrimidine groups;

[0016] Each R3 can be the same or different and is independently selected from -CH2-CH2-N(CH3)2, -CH2-CH2-N(CH2CH3)2, -CH2-CH(CH3)-OH, -CH(CH3)-CH2-OH,

[0017] -CH2-CH2-O-CH2-CH2-OH, -CH2-CH2-O-CH2-CH2-O-CH3;

[0018] In the block copolymer, the content of the repeating unit of the conjugated monomer is 50-99.5 mol%;

[0019] In the block copolymer, the content of the repeating unit of the hydrophilic monomer is 0.5-50 mol%;

[0020] The weight average molecular weight of the block polymer is 5-50 kg / mol; the particle size of the nanoparticles is 30-3000 nm.

[0021] Preferably, each R4 can be the same or different and is independently selected from a chemical bond or C 1-6 unsubstituted or replaced by 1-2 R s Substituted alkyl, alkenyl or alkoxy, said R s Selected from C 1-6 Alkyl, C 1-4 At least one of an alkoxy group or a cyano group.

[0022] Preferably, each R4 can be the same or different and is independently selected from a chemical bond or C 1-4 an alkyl or alkoxy group.

[0023] Preferably, each Q is independently selected from a group containing at least one cyclic conjugated structure, and the group containing the cyclic conjugated structure is selected from at least one of benzene, thiophene, and pyrrole groups.

[0024] Each R3 can be the same or different and is independently selected from -CH2-CH2-N(CH3)2, -CH2-CH2-N(CH2CH3)2, -CH2-CH(CH3)-OH, -CH(CH3)-CH2-OH,

[0025] -CH2-CH2-O-CH2-CH2-OH, -CH2-CH2-O-CH2-CH2-O-CH3.

[0026] Preferably, the R2 is selected from at least one of the following groups:

[0027]

[0028]

[0029] Preferably, the conjugated monomer is

[0030] At least one of; the hydrophilic monomer is

[0031]

[0032] Preferably, in the block copolymer, the content of the repeating units of the conjugated monomer is 60-99 mol%, 70-95 mol%, 80-94 mol% or 85-93 mol%.

[0033] Preferably, the content of the repeating unit of the hydrophilic monomer is 1-40 mol%, 5-30 mol%, 6-20 mol% or 7-15 mol%.

[0034] Preferably, the block copolymer has a weight average molecular weight of 7-43 kg / mol.

[0035] Preferably, the particle size of the nanoparticles is 50-1000 nm, 100-500 nm, 150-300 nm or 200-280 nm.

[0036] In a second aspect, the present invention provides a method for preparing any of the aforementioned nanoparticles containing a pendant conjugated structure, comprising the following steps:

[0037] (S1) using a living free radical polymerization method to obtain a macroinitiator comprising a hydrophilic monomer and a segment b;

[0038] (S2) polymerizing the macroinitiator and conjugated monomer of step S1 using a polymerization-induced self-assembly method to obtain the block copolymer comprising segment a and segment b; and,

[0039] (S3) In the presence of an oxidizing catalyst, the block copolymer of step S2 is oxidatively crosslinked to obtain nanoparticles containing a pendant conjugated structure.

[0040] Preferably, in step S2, the molar ratio of the macroinitiator to the conjugated monomer is 1:40-1:300.

[0041] Preferably, in step S3, the molar ratio of the block copolymer to the oxidizing catalyst is 1:m-1:10m, where m is the average degree of polymerization of the conjugated monomer in segment a.

[0042] Preferably, in step S2, the molar ratio of the macroinitiator to the conjugated monomer is 1:200-1:300.

[0043] Preferably, in step S3, the molar ratio of the block copolymer to the oxidizing catalyst is 1:5m-1:10m, where m is the average degree of polymerization of the conjugated monomer in segment a.

[0044] Preferably, the living radical polymerization method in step S1 is RAFT.

[0045] Preferably, the step S1 comprises: polymerizing the hydrophilic monomer of the present invention under the action of a RAFT chain transfer agent and an initiator to obtain a macroinitiator.

[0046] Preferably, the step S2 comprises: polymerizing the macromolecular initiator obtained in step S1 and the conjugated monomer of the present invention under the action of an initiator to obtain the block copolymer.

[0047] The block copolymer is a nanoparticle with the morphology of micelles, nanowires, sheets, vesicles, etc., and a particle size of 30-3000 nm, preferably 100-500 nm.

[0048] Preferably, step S3 comprises: subjecting the block copolymer obtained in step S2 to intramolecular and intermolecular oxidative polymerization (i.e., carbon-carbon cross-coupling polymerization) under the action of an oxidative catalyst to obtain the nanoparticles containing the pendant conjugated structure of the present invention.

[0049] Preferably, the RAFT chain transfer agent may be a common dithioester or trithioester, for example, 4-cyanopentanoic acid dithiobenzoic acid or protonated 2-cyanopropyl N-methyl-N-(4-pyridine)aminodithiocarbonate.

[0050] Preferably, the initiator includes an azo initiator, a peroxide initiator or a photoinitiator, etc. For example, the initiator can be: azobisisobutyronitrile (AIBN), azobisisoheptanenitrile (ABVN), hydrogen peroxide, dibenzoyl peroxide (BPO), diethylhexyl peroxydicarbonate (EHP), potassium persulfate, ammonium persulfate, Eosin Y, methyl vinyl ketone, benzoin, benzophenone and fluorescein, etc.

[0051] Preferably, the molar ratio of the RAFT chain transfer agent to the initiator in step S1 is 20:1-5:1, preferably 10:1.

[0052] Preferably, the molar ratio of the hydrophilic monomer to the RAFT chain transfer agent in step S1 is 10:1-50:1, preferably 40:1.

[0053] Preferably, the initiators in step S1 and step S2 may be the same or different.

[0054] Preferably, the polymerization reaction solvent in step S1 and step S2 is at least one of THF, ether, toluene, methanol or ethanol.

[0055] Preferably, the polymerization temperature in step S1 and step S2 may be 0-70° C., and the polymerization time may be 2-24 h.

[0056] Preferably, the oxidizing catalyst in step S3 can be a chemical oxidative coupling catalyst: NiCl2, ferric chloride (FeCl3), 2-chloro-2-phenylacetophenone, Pd / Cu, etc.; electrochemical oxidative coupling: electrode charging and discharging acts as a catalyst; metal catalyst: nickel, palladium, etc.; transition metal reagent; such as at least one of NiCl2(bpy), Ni(COD)2, NiBr2(PPh3)2, NiCl2, PdCl2(bpy)CoCl2, FeCl2, etc.

[0057] On the third aspect, the present invention provides a nanoemulsion comprising:

[0058] (1) The nanoparticles containing a pendant conjugated structure according to any one of the preceding claims; and

[0059] (2) aqueous solvents;

[0060] The solid content of the nanoemulsion is 3 wt%-30 wt%.

[0061] Preferably, the solid content of the nanoemulsion is 5wt-30wt% or 10wt-25wt%.

[0062] Preferably, the nanoparticles are obtained by the aforementioned method for preparing nanoparticles.

[0063] Nanoemulsions can be prepared by conventional methods, for example by dispersing nanoparticles in an aqueous solvent.

[0064] The aqueous solvent of the present invention refers to water alone, or a mixed solvent consisting of water and an organic solvent, wherein the content of the organic solvent in the solvent (water and organic solvent) does not exceed 20wt%, for example, not more than 15wt%, 10wt%, 5wt%, 3wt%, or 1wt%. The organic solvent is preferably a water-soluble organic solvent, and illustratively, the organic solvent includes, but is not limited to, water-miscible solvents such as ethanol, acetone, and dimethyl sulfoxide.

[0065] Preferably, the nanoemulsion of the present invention does not contain a dispersant and / or an emulsifier and / or a surfactant.

[0066] In a fourth aspect, the present invention provides applications of the aforementioned nanoparticles or nanoemulsions containing suspended conjugated structures in the fields of biomedicine, electronic materials, or optoelectronic materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 : Schematic diagram of the dynamic light scattering particle size results of the block polymer of Example 1 of the present invention.

[0068] Figure 2 : Transmission electron micrograph of the block polymer of Example 1 of the present invention.

[0069] Figure 3 : Schematic diagram of the dynamic light scattering particle size results of the nanoparticles of Example 2 of the present invention.

[0070] Figure 4 : Transmission electron micrograph of the nanoparticles of Example 2 of the present invention.

[0071] Figure 5 : Photograph of the polymer alcohol phase emulsion of Example 1 of the present invention.

[0072] Figure 6 : Photograph of the aqueous polymer emulsion of Example 1 of the present invention.

[0073] Figure 7 : Photograph of the aqueous emulsion of nanoparticles of Example 2 of the present invention.

[0074] Figure 8 : Ultraviolet absorption and fluorescence emission spectra of the comparative example block polymer of the present invention.

[0075] Figure 9 : Emulsion photo of the comparative block polymer of the present invention.

[0076] Figure 10 : Schematic diagram of the dynamic light scattering particle size results of the comparative example block polymer of the present invention.

[0077] Figure 11 : Ultraviolet absorption spectra of the block polymer of Example 1 and the nanoparticles of Example 2 of the present invention.

[0078] Figure 12 : Fluorescence emission spectra of the block polymer of Example 1 and the nanoparticles of Example 2 of the present invention.

[0079] Figure 13 : Cyclic voltammetry curve of the nanoparticles of Example 2 of the present invention.

[0080] Figure 14 : Cyclic voltammetry curve of the comparative example block polymer of the present invention. DETAILED DESCRIPTION

[0081] In the following description, numerous specific details are provided to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without one or more of these details. In other instances, certain technical features well known in the art are not described to avoid confusion with the present invention.

[0082] Example

[0083] All raw materials and reagents were purchased from Aldrich and used directly.

[0084] Test equipment

[0085]

[0086] Synthesis example 1

[0087] Synthesis of 2-(2-hydroxyethoxy)ethyl methacrylate (HEO2MA)

[0088] Diethylene glycol (31.8g, 0.30mol) and triethylamine (16.2g, 0.16mol) were added to 100mL of dichloromethane. At 0°C, methacryloyl chloride (15.6g, 0.15mol) was slowly added dropwise to the above system, the system was restored to room temperature, and the reaction was continued for 16 hours. After the reaction was completed, the solid in the system was filtered out, the organic phase was washed three times with a saturated sodium chloride solution, dried over anhydrous sodium sulfate overnight, filtered, and most of the solvent was removed under reduced pressure. The crude product was purified by silica gel column chromatography (eluent ratio: ethyl acetate: dichloromethane = 1:3) to obtain 10.2g of a yellow oily liquid with a yield of 62%. The structural formula is as follows:

[0089]

[0090] Synthesis example 2

[0091] Synthesis of 3-Thienylmethacrylate (TPMA)

[0092] Thiophene-3-ethanol (10g, 0.078mol) and triethylamine (15.8g, 0.16mol) were dissolved in 250ml of dichloromethane. The mixture was cooled to 0°C and methacryloyl chloride (12.2g, 0.12mol) was slowly added dropwise to the solution. The reaction was continued for 24 hours after the system returned to room temperature. After the reaction was completed, the solids in the system were filtered out, the organic phase was washed three times with a saturated sodium chloride solution, dried over anhydrous sodium sulfate overnight, filtered, and most of the solvent was removed under reduced pressure. The crude product was purified by silica gel column chromatography with an eluent ratio of ethyl acetate: petroleum ether = 1:14 to obtain 7.1g of a light yellow oily liquid with a yield of 71%. The structural formula is as follows:

[0093]

[0094] Synthesis example 3

[0095] Synthesis of 3-Thienyl Methyl Methacrylate

[0096] 3-Thiophene methanol (3g, 1eq) and triethylamine (4.24g, 1.2eq) were dissolved in 140ml of toluene. The mixed system was cooled to 0°C, and methacryloyl chloride (4.38g, 1.2eq) was slowly added dropwise to the above solution. After the system returned to room temperature, the reaction was continued for 24 hours. After the reaction was completed, 250ml of distilled water was poured into the flask to dissolve the white precipitate. First, the aqueous phase was extracted three times with 100ml of diethyl ether, and finally washed with 1M HCl (4×200ml) and saturated NaCl solution (200ml), dried over anhydrous sodium sulfate overnight, filtered, and most of the solvent was removed under reduced pressure. The crude product was purified by Al2O3 column chromatography using CH2Cl2 as the eluent. The product was a light yellow liquid with a yield of 67%. The structural formula is as follows:

[0097]

[0098] Synthesis example 4

[0099] Synthesis of (9-fluorenyl)methyl methacrylate (9FMMA)

[0100] 9-Fluorenylmethanol (5.04 g, 0.026 mol) and triethylamine (15.8 g, 0.16 mol) were dissolved in 100 ml of anhydrous tetrahydrofuran. The mixture was cooled to 0°C and methacryloyl chloride (12.2 g, 0.12 mol) was slowly added dropwise to the solution. The reaction was allowed to return to room temperature and continued for 24 hours. After 24 hours, the reaction was quenched with water and extracted with ether. The crude product was purified by silica gel column chromatography to obtain 0.70 g (10% yield) of (9-fluorenyl)-methyl methacrylate (9FMMA) as a light yellow oil with the following structural formula:

[0101]

[0102] Synthesis example 5

[0103] Macromolecular chain transfer agent PHEO2MA with an average degree of polymerization of 30 30 Synthesis

[0104] HEO2MA (1.74 g, 10 mmol), 4-cyano-4-(thiobenzoyl)valeric acid (CPADB) (46.5 mg, 0.17 mmol), and AIBN (2.73 mg, 0.017 mmol) were weighed and dissolved in anhydrous THF (2.68 mL). The reaction system was transferred to a Schlenk tube. After three cycles of freezing-vacuuming-dissolving, the Schlenk tube was placed at 70°C. After reacting for 6 hours, the Schlenk tube was quickly placed in liquid nitrogen to quench the reaction. After diluting the reaction solution with THF, it was slowly added dropwise to a large amount of vigorously stirred n-hexane solution. The product was collected by filtration and the solid was dried in a vacuum oven overnight. A red solid poly (2-(2-hydroxyethoxy)ethyl methacrylate) (PHEO2MA) was obtained. 30 )1.3g, yield 74%.

[0105] Synthesis example 6

[0106] Macromolecular chain transfer agent PHEO2MA with an average degree of polymerization of 44 44 Synthesis

[0107] HEO2MA (1.74 g, 10 mmol), CPADB (70 mg, 0.25 mmol), and AIBN (4.1 mg, 0.025 mmol) were weighed and dissolved in anhydrous THF (2.72 mL). The reaction system was transferred to a Schlenk tube. After three cycles of freezing-vacuuming-dissolving, the Schlenk tube was placed at 70°C. After reacting for 6 hours, the Schlenk tube was quickly placed in liquid nitrogen to quench the reaction. After diluting the reaction solution with THF, it was slowly added dropwise to a large amount of vigorously stirred n-hexane solution. The product was collected by filtration and the solid was dried in a vacuum oven overnight. A red solid (poly 2-(2-hydroxyethoxy)ethyl methacrylate (PHEO2MA) was obtained. 44 )1.2g, yield 69%.

[0108] Example 1

[0109] Preparation of block polymers

[0110] The product PHEO2MA of Synthesis Example 5 30 (109 mg, 0.2 mmol), TPMA (1.174 g, 60 mmol), and AIBN (0.78 mg, 0.04 mmol) were dissolved in methanol (8.5 ml). The solution was transferred to a Schlenk tube and subjected to three cycles of freeze-vacuum-thaw. The Schlenk tube was sealed and placed in a 70°C oil bath for 24 h to obtain the product PHEO2MA. 30 -PTPMA 300 The particle size was measured by dynamic light scattering (DLS). Figure 1 , TEM photos see Figure 2 According to the two results, the average particle size of the product was confirmed to be 207 nm. 100 mg (10 wt% solid content) of the polymer emulsion was centrifuged at 15000 rpm and the supernatant was removed to obtain 10 mg of solid polymer.

[0111] Example 2

[0112] Preparation of thiophene-containing nanoparticles

[0113] 10 mg of the polymer synthesized in Example 1 was mixed with 1000 μL of H2O to obtain a polymer emulsion. 102 mg of (NH4)2S2O8 and 1.58 mg of CuCl2 were added to a 2 ml Schlenk tube together with the polymer solution. A stirring magnet was added. After three cycles of freezing-vacuuming-dissolving, the Schlenk tube was sealed and placed in an oil bath at 50°C for 8 h. The particle size of the obtained product was measured by dynamic light scattering. Figure 3 , TEM photos see Figure 4According to the results of both tests, the average particle size of the product was confirmed to be 268 nm.

[0114] Example 3

[0115] Preparation of nanoemulsion

[0116] See the photo of alcohol phase emulsion of polymer in Example 1 Figure 5 , solid content is 10wt%. Take 2g and 5g of the polymer alcohol phase emulsion of Example 1 respectively, centrifuge at 15000rpm, remove the supernatant, add 2g of H2O respectively to mediate dispersion to obtain aqueous phase emulsion, as shown in the photo. Figure 6 The solid contents are 10 wt% and 25 wt% respectively. Figure 7 , solid content is 10wt%.

[0117] That is, by combining the PISA method with living free radical polymerization, a polymer with a nanoparticle size can be prepared in the first step, and in the second step, the conjugated monomers in the particles in the previous step are oxidatively crosslinked, so that the conjugated monomer content in the nanoparticles and the solid content of the nanoparticle emulsion can be significantly increased, thereby improving the optoelectronic and other properties of the product.

[0118] Comparative Example 1

[0119] A similar method as in Example 2 was used to prepare PHEO2MA from Synthesis Example 6. 44 PHEO2MA was prepared by changing the ratio of conjugated monomers and other conventional operations. 44 -PTPMA 250 It is then dissolved in THF to destroy the morphology of its nanoparticles and form long polymer chains. It is then slowly added dropwise to a large amount of vigorously stirred n-hexane solution, and the product is collected by filtration. Weigh 10 mg of the polymer and 30 mg of FeCl3 and add them together to a 5 ml Schlenk tube. Then add 2.4 g of chloroform and place a stirring magnet. After three cycles of freezing-vacuuming-dissolving, seal the Schlenk tube and place the Schlenk tube in an ice-water bath for 36 hours. After the reaction is complete, filter and collect the product. Dry the solid in a vacuum oven overnight to obtain a brown-black product. Take 10 mg of the product and assemble it in water. Only a small amount of it is assembled into nanoparticles. The solid content is less than 1 wt% and the concentration cannot be increased to disperse. Precipitation occurs when the concentration exceeds 1 wt%. The obtained nanoparticles have a solid content of less than 1 wt%. The UV absorption and fluorescence emission spectra are as follows: Figure 8 As shown, it can be seen that only part of the thiophene undergoes oxidative cross-linking reaction ( Figure 8 In the right figure, the peak appears red-shifted after the reaction), and the emulsion photo is shown in Figure 9 , DLS measured particle size see Figure 10 .

[0120] Test Example 1 Spectrum

[0121] Take 50uL of the mixed solution before reaction and the solution after reaction in Example 2 into a 5ml centrifuge tube, centrifuge for 3min, add 2ml MeOH to the precipitate, swirl and mix, and measure the UV absorption spectrum. The results are as follows: Figure 11 As shown, since the ultraviolet absorption of monomer thiophene after polymerization is mainly at 380nm, the fluorescence emission spectrum is measured at an excitation wavelength of 380nm. The results are as follows Figure 12 As shown in the figure, the UV absorption spectrum of the polymer before the reaction mainly absorbs at around 220nm, while after the reaction, the spectrum has red-shifted to mainly absorb at 260nm. The fluorescence emission spectrum mainly red-shifts from 440nm to 540nm. This proves that the conjugated monomers have been almost completely cross-linked to form a conjugated polymer.

[0122] Test Example 2 Electrical Performance

[0123] The electrical properties were measured using an electrochemical workstation and a three-electrode system (platinum wire electrode, glassy carbon electrode, saturated silver chloride electrode). First, 0.3μm and 0.05μm polishing powder (Al2O3) were used to polish the glassy carbon electrode several times, and the ferrocene electrolyte solution was measured to check the polishing condition. 10uL of the mixed solution before the reaction and the solution after the reaction in Example 2 were dropped onto the glassy carbon electrode to form a dense film, and then the cyclic voltammetry curve was measured by adding acetonitrile electrolyte solution. The results are shown in the figure. Figure 13 As shown, analysis of the cyclic voltammetry (CV) curve shows that there is no oxidation peak before the cross-linking reaction, which indicates that the redox rates of thiophene in the nanoparticles are different, the oxidation reaction rate is very slow, and the reversibility is very low; since the peak current is proportional to the polymer concentration and the concentration of reducing substances, the peak current after cross-linking is significantly higher than that before cross-linking, indicating that more thiophene is reduced. The polymer powder after the reaction in the comparative example was assembled into nanoparticles in water, and then the results were measured using the same method as shown below. Figure 14 As shown, analysis of the CV curve shows that the redox reaction of thiophene in the comparative example is a reversible reaction, and both the oxidation peak and the reduction peak current increase significantly after cross-linking. By comparison, it is found that the nanoparticles of the present invention have better cross-linking stability, a tighter structure, and better electrical properties.

[0124] In the above embodiments, all technical solutions that fall within the scope of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, several improvements and modifications that do not depart from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A nanoparticle containing a pendant conjugated structure, wherein the nanoparticle containing a pendant conjugated structure comprises an oxidative cross-linking product of a block copolymer containing the following polymeric segment a and polymeric segment b: (A) a polymeric segment a comprising a repeating unit of at least one conjugated monomer, wherein the repeating unit structure of the conjugated monomer is as shown in formula (I): (I); sum, (B) a polymeric segment b comprising a repeating unit of at least one hydrophilic monomer, wherein the repeating unit structure of the hydrophilic monomer is as shown in formula (II): (II); in: The R1 are the same or different and are each independently selected from H or methyl; The R2 are the same or different and are independently selected from 、 、 ,or At least one of; The R3 are the same or different and are each independently selected from -CH2-CH(CH3)-OH, -CH(CH3)-CH2-OH, -CH2-CH2-O-CH2-CH2-OH or -CH2-CH2-O-CH2-CH2-O-CH3; In the block copolymer, the content of the repeating unit of the conjugated monomer is 50-99.5 mol%; In the block copolymer, the content of the repeating unit of the hydrophilic monomer is 0.5-50 mol%; The weight average molecular weight of the block copolymer is 5-50 kg / mol; the particle size of the nanoparticles is 30-3000 nm; The preparation method of the nanoparticles containing the suspended conjugated structure comprises the following steps: (S1) polymerizing a hydrophilic monomer using a living free radical polymerization method to obtain a macroinitiator comprising segment b; (S2) polymerizing the macromolecular initiator and the conjugated monomer in step S1 by a polymerization-induced self-assembly method to obtain the block copolymer comprising segment a and segment b; and, (S3) Oxidatively crosslinking the block copolymer obtained in step S2 in the presence of an oxidative catalyst to obtain nanoparticles containing a pendant conjugated structure.

2. The nanoparticles containing a suspended conjugated structure according to claim 1, wherein the conjugated monomer is or At least one of; the hydrophilic monomer is .

3. The nanoparticles containing a pendant conjugated structure according to any one of claims 1 to 2, wherein in the block copolymer, the content of the repeating units of the conjugated monomer is 70-95 mol%, and the content of the repeating units of the hydrophilic monomer is 5-30 mol%. 4 . The nanoparticles containing a suspended conjugated structure according to claim 1 , wherein the particle size of the nanoparticles is 100-500 nm.

5. A method for preparing nanoparticles containing a pendant conjugated structure according to any one of claims 1 to 4, comprising the steps of: (S1) polymerizing a hydrophilic monomer using a living free radical polymerization method to obtain a macroinitiator comprising segment b; (S2) polymerizing the macromolecular initiator and the conjugated monomer in step S1 by a polymerization-induced self-assembly method to obtain the block copolymer comprising segment a and segment b; and, (S3) Oxidatively crosslinking the block copolymer obtained in step S2 in the presence of an oxidative catalyst to obtain nanoparticles containing a pendant conjugated structure.

6. The preparation method according to claim 5, wherein in step S2, the molar ratio of the macroinitiator to the conjugated monomer is 1:40-1:300; and in step S3, the molar ratio of the block copolymer to the oxidizing catalyst is 1:m-1:10m, where m is the average degree of polymerization of the conjugated monomer in segment a.

7. A nanoemulsion comprising: (1) The nanoparticles containing a pendant conjugated structure according to any one of claims 1 to 4; and, (2) aqueous solvents; The solid content of the nanoemulsion is 3wt%-30wt%.

8. The nanoemulsion according to claim 7, wherein the solid content of the nanoemulsion is 5wt-30wt%.

9. The nanoemulsion according to any one of claims 7-8, wherein the nanoparticles are obtained by the preparation method according to any one of claims 5-6.

10. The nanoemulsion according to any one of claims 7 to 8, which is obtained by dispersing the nanoparticles in the aqueous solvent.

11. The nanoemulsion according to any one of claims 7-8, wherein the nanoemulsion does not contain a dispersant or a surfactant.

12. The nanoemulsion according to claim 11, wherein the nanoemulsion does not contain an emulsifier.

13. Use of the nanoparticles containing a pendant conjugated structure according to any one of claims 1 to 4, the nanoparticles containing a pendant conjugated structure obtained by the method according to any one of claims 5 to 6, or the nanoemulsion according to any one of claims 7 to 12 in the preparation of biopharmaceutical products, electronic materials, or optoelectronic materials.

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