TPE (Thermoplastic Elastomer) nano particle with luminescence regulated by alkyl chain as well as preparation method and application of TPE nano particle

Abstract

The invention relates to the technical field of organic light-emitting materials, and provides TPE (Thermoplastic Elastomer) nano particles capable of regulating and controlling light emission by alkyl chains as well as a preparation method and application thereof. The preparation method of the TPE nanoparticles comprises the following steps: mixing tetra-(4-hydroxybenzene) ethylene, triethylamine, tetrahydrofuran and long-chain acyl chloride, and sequentially carrying out primary reaction and secondary reaction to obtain a reactant A; mixing the reactant A, triethylamine, tetrahydrofuran and methacryloyl chloride, and sequentially carrying out primary reaction and secondary reaction to obtain a reactant B; and mixing the reactant B, methyl methacrylate, azodiisobutyronitrile, 2-cyanopropyl-2-benzodisulfide and N, N-dimethylformamide, and then carrying out a polymerization reaction, so as to obtain the TPE nano particles capable of regulating and controlling luminescence by using the alkyl chain. The TPE nano-particles capable of regulating and controlling luminescence through the alkyl chain, disclosed by the invention, have relatively high luminous intensity and uniform particle size distribution.

Description

Technical Field

[0001] This invention belongs to the field of organic light-emitting materials technology, specifically relating to a TPE nanoparticle with alkyl chain-regulated luminescence, its preparation method, and its application. Background Technology

[0002] Aggregation-induced emission (AIE) materials, due to their strong light emission activated by intramolecular rotational restriction (RIR) in an aggregated state, have shown significant application value in fluorescence detection, bioimaging, and organic optoelectronic devices. Tetraphenylethylene (TPE), as a typical AIE molecule, exhibits highly sensitive luminescence properties to its molecular aggregation state: in benign solvents such as tetrahydrofuran (THF), free molecular rotation leads to fluorescence quenching; while in unfavorable solvents such as water, the luminescence intensity is significantly enhanced when nanoaggregates are formed. However, traditional methods for preparing TPE-based nanomaterials face two major challenges: first, nanoparticles obtained through physical blending or simple precipitation methods exhibit non-uniform size (particle size distribution PDI > 0.3) and poor dispersibility, leading to unstable luminescence properties; second, research on modifying TPE hydrophobicity through alkyl chain modification to optimize aggregation behavior has only focused on the improvement of solubility by short-chain alkyl groups, while the gradient regulation mechanism of molecular packing density and luminescence intensity by long-chain alkyl groups remains unclear, especially lacking comparative studies on the changes in luminescence intensity with water content in THF / water mixed solvents with alkyl groups of different chain lengths.

[0003] Methyl methacrylate (MMA) is often used as a comonomer due to its good film-forming properties and compatibility. However, traditional free radical polymerization makes it difficult to control the molecular weight distribution (PDI>1.5), resulting in excessive size differences in the polymers used to prepare nanoparticles and unstable luminescent properties. Although PMMA with a low dispersion index (PDI<1.5) achieves precise molecular weight control through RAFT polymerization, its molecular chains lack hydrophilic groups, preventing it from forming stable nanoparticles through self-assembly in water. Specifically, hydrophobic interactions between pure PMMA segments dominate, leading to intermolecular aggregation in aqueous phases, forming micron-sized aggregates with uneven dimensions rather than nanoscale dispersions. This phenomenon severely affects the application of AIE-type MMA-based polymers in pure water systems.

[0004] The existing technology has the following shortcomings: (1) There is a lack of systematic research on the gradient regulation of the luminescence intensity of TPE-based polymer nanostates by alkyl chain length; (2) The synergistic effect of RAFT controllable polymerization technology and alkyl chain modification has not been developed, and it is impossible to accurately design narrow-distribution TPE-based copolymers with high luminescence performance; (3) The balance mechanism between dispersibility and luminescence intensity in the amphiphilic polymer encapsulation process is missing, which restricts the practical application of the material in the aqueous system.

[0005] Therefore, it is of great significance to study TPE nanoparticles with high luminescence intensity and uniform particle size distribution in pure water environment, as well as their preparation method and application. Summary of the Invention

[0006] This invention provides TPE nanoparticles with alkyl chain-regulated luminescence, their preparation method, and applications. The purpose is to solve the problems of low luminescence intensity and uneven particle size distribution of TPE nanoparticles in pure water environment in the prior art.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0008] This invention provides TPE nanoparticles with alkyl chain-regulated luminescence, the structural formula of which is shown in Formula I:

[0009]

[0010] Where m and n are independent integers that are not zero;

[0011] X is:

[0012]

[0013] This invention also provides a method for preparing TPE nanoparticles with alkyl chain-regulated luminescence, comprising the following steps:

[0014] 1) Tetra-(4-hydroxyphenyl)ethylene, triethylamine, tetrahydrofuran and long-chain acyl chloride are mixed and subjected to a first reaction and a second reaction in sequence to obtain reactant A;

[0015] 2) Reactant A, triethylamine, tetrahydrofuran and methacrylamide chloride are mixed and subjected to a first reaction and a second reaction in sequence to obtain reactant B;

[0016] 3) Reactant B, methyl methacrylate, azobisisobutyronitrile, 2-cyanopropyl-2-ylbenzodisulfide and N,N-dimethylformamide were mixed and polymerized to obtain TPE nanoparticles with alkyl chain-regulated luminescence.

[0017] Preferably, in step 1), the ratio of tetra-(4-hydroxyphenyl)ethylene, triethylamine, tetrahydrofuran, and long-chain acyl chloride is 1 mmol: 3-4.8 mmol: 10-25 mL: 2.5-4 mmol;

[0018] The long-chain acyl chloride is dodecanoyl chloride or octadecanoyl chloride.

[0019] Preferably, in step 2), the ratio of reactant A, triethylamine, tetrahydrofuran and methacrylamide chloride is 1 mmol: 1.2–2.4 mmol: 10–25 mL: 1.2–2 mmol.

[0020] Preferably, in steps 1) and 2), the temperature of each reaction is independently 0–5°C, and the reaction time is independently 2–3 h.

[0021] The temperature of the secondary reaction is independently 20–30 °C, and the time of the secondary reaction is independently 20–24 h.

[0022] Preferably, in step 3), the ratio of reactant B, methyl methacrylate, azobisisobutyronitrile, 2-cyanopropyl-2-ylbenzodisulfide and N,N-dimethylformamide is 0.8–1.2 mmol: 145–165 mmol: 0.08–0.22 mmol: 0.8–1.2 mmol: 1 mL.

[0023] Preferably, in step 3), the polymerization reaction is a RAFT polymerization reaction;

[0024] The polymerization reaction is carried out under an inert atmosphere;

[0025] The polymerization reaction is carried out at a temperature of 75–80°C for 20–24 hours.

[0026] This invention also provides an application of alkyl chain-regulated luminescence TPE nanoparticles in the fields of bioimaging and optoelectronic devices.

[0027] Preferably, high-performance luminescent nanoparticles are prepared by using TPE nanoparticles with alkyl chain-regulated luminescence and then applied.

[0028] The preparation method of the high-performance luminescent nanoparticles is as follows:

[0029] a. Mix TPE nanoparticles with alkyl chain-modulated luminescence with tetrahydrofuran to obtain a mixture;

[0030] b. Mix the mixture, the amphiphilic block polymer, and water to obtain high-performance luminescent nanoparticles.

[0031] Preferably, in step a, the ratio of alkyl chain-regulated luminescence TPE nanoparticles to tetrahydrofuran is 4.5–5.5 mg: 1 mL.

[0032] In step b, the ratio of the mixture, the amphiphilic block polymer, and water is 30 μL: 0.3–0.35 mg: 0.8–1.2 mL. The mixing is performed by ultrasonic mixing at a temperature of 35–45 °C for 8–12 min.

[0033] As can be seen from the above technical solution, compared with the prior art, the present invention has the following beneficial effects:

[0034] This invention utilizes RAFT polymerization technology to achieve precise control of the molecular weight of TPE and MMA copolymers. Compared with traditional free radical polymerization, it significantly improves the uniformity and performance repeatability of polymers, providing technical support for the stable preparation of luminescent materials.

[0035] By encapsulating the nanoparticles with amphiphilic block polymers, the problem of dispersing hydrophobic polymers in water was successfully solved. The prepared nanoparticles have uniform size, excellent dispersibility, and a PDI of <0.15 as detected by DLS. They can also exist stably in pure water.

[0036] This invention combines alkyl chain modification, controlled polymerization, and amphiphilic encapsulation technology to achieve a synergistic improvement in the luminescence intensity and dispersion stability of nanoparticles. This not only enhances the molecular aggregation-induced luminescence effect but also avoids the performance degradation caused by particle aggregation, laying the foundation for the application of TPE-based materials in fields such as bioimaging and optoelectronic devices.

[0037] The synthesis and preparation methods involved in this invention are simple to operate, have mild conditions, use readily available raw materials, are easy to produce, and have good application prospects. Attached Figure Description

[0038] Figure 1 The 4-(1,2,2-triphenylvinyl)phenyl methacrylate obtained in Comparative Example 1 1 HNMR spectrum;

[0039] Figure 2 The tris(dodecanoate)-mono(methacrylate)-tetra-(4-phenyl)ethylene obtained in Example 1 1 HNMR spectrum;

[0040] Figure 3 The tri(octadecyl ester)-mono(methacrylate)-tetra-(4-phenyl)ethylene obtained in Example 2 1 HNMR spectrum;

[0041] Figure 4 For the P(MMA-co-TPE) obtained in Comparative Example 1 1 HNMR spectrum;

[0042] Figure 5 The P(MMA-co-TPE-C12) obtained in Example 1 1 HNMR spectrum;

[0043] Figure 6 The P(MMA-co-TPE-C18) obtained in Example 2 1 HNMR spectrum;

[0044] Figure 7 The gel permeation chromatogram of P(MMA-co-TPE-C12) obtained in Example 1;

[0045] Figure 8 The gel permeation chromatogram of P(MMA-co-TPE-C18) obtained in Example 2;

[0046] Figure 9 The AIE performance diagram of P(MMA-co-TPE) obtained in Comparative Example 1 is shown.

[0047] Figure 10 The diagram shows the AIE performance of P(MMA-co-TPE-C12) obtained in Example 1;

[0048] Figure 11 The AIE performance diagram of P(MMA-co-TPE-C18) obtained in Example 2 is shown.

[0049] Figure 12 A comparison chart of AIE performance for P(MMA-co-TPE), P(MMA-co-TPE-C12), and P(MMA-co-TPE-C18);

[0050] Figure 13 DLS data plots for P(MMA-co-TPE-C12) & P(MMA-b-PEGMA);

[0051] Figure 14 DLS data plots for P(MMA-co-TPE-C18) & P(MMA-b-PEGMA). Detailed Implementation

[0052] This invention provides TPE nanoparticles with alkyl chain-regulated luminescence, the structural formula of which is shown in Formula I:

[0053]

[0054] Where m and n are independent integers that are not zero;

[0055] X is:

[0056]

[0057] This invention also provides a method for preparing TPE nanoparticles with alkyl chain-regulated luminescence, comprising the following steps:

[0058] 1) Tetra-(4-hydroxyphenyl)ethylene, triethylamine, tetrahydrofuran and long-chain acyl chloride are mixed and subjected to a first reaction and a second reaction in sequence to obtain reactant A;

[0059] 2) Reactant A, triethylamine, tetrahydrofuran and methacrylamide chloride are mixed and subjected to a first reaction and a second reaction in sequence to obtain reactant B;

[0060] 3) Reactant B, methyl methacrylate, azobisisobutyronitrile, 2-cyanopropyl-2-ylbenzodisulfide and N,N-dimethylformamide were mixed and polymerized to obtain TPE nanoparticles with alkyl chain-regulated luminescence.

[0061] In this invention, in step 1), the preferred ratio of tetra-(4-hydroxyphenyl)ethylene, triethylamine, tetrahydrofuran, and long-chain acyl chloride is 1 mmol: 3-4.8 mmol: 10-25 mL: 2.5-4 mmol, more preferably 1 mmol: 3.6-4.6 mmol: 12-22 mL: 3-3.8 mmol, and even more preferably 1 mmol: 3.8-4.2 mmol: 15-18 mL: 3.2-3.5 mmol;

[0062] The long-chain acyl chloride is preferably dodecanoyl chloride or octadecanoyl chloride.

[0063] In this invention, the mixing in step 1) is preferably done by first mixing tetra-(4-hydroxyphenyl)ethylene, triethylamine and tetrahydrofuran and then adding a mixed solvent of long-chain acyl chloride and tetrahydrofuran dropwise to the mixed solution;

[0064] The dripping rate is preferably 5-10 mL / h, more preferably 6-9 mL / h, and even more preferably 7-8 mL / h.

[0065] In this invention, the structural formula of reactant A in step 1) is shown in Formula II.

[0066]

[0067] Wherein, X is preferably:

[0068]

[0069] In this invention, in step 2), the preferred ratio of reactant A, triethylamine, tetrahydrofuran, and methacrylamide chloride is 1 mmol: 1.2–2.4 mmol: 10–25 mL: 1.2–2 mmol, more preferably 1 mmol: 1.6–2 mmol: 12–20 mL: 1.4–1.8 mmol, and even more preferably 1 mmol: 1.8–1.9 mmol: 15–16 mL: 1.5–1.6 mmol.

[0070] In this invention, in steps 1) and 2), the temperature of each reaction is preferably 0-5°C, more preferably 1-4°C, and even more preferably 2-3°C; the reaction time is preferably 2-3 hours, and even more preferably 2.5 hours.

[0071] The temperature of the secondary reaction is preferably 20–30°C, more preferably 22–28°C, and even more preferably 24–26°C. The time of the secondary reaction is preferably 20–24 h, more preferably 21–23 h, and even more preferably 22 h.

[0072] In this invention, in step 2), the mixing is preferably performed by first mixing reactant A, triethylamine and tetrahydrofuran, and then adding a mixed solvent of methacryloyl chloride and tetrahydrofuran dropwise to the mixed solution.

[0073] The dripping rate is preferably 5-10 mL / h, more preferably 6-9 mL / h, and even more preferably 7-8 mL / h.

[0074] In this invention, in step 2), the structural formula of reactant B is shown in Formula III.

[0075]

[0076] Wherein, X1 is preferably:

[0077]

[0078] X is preferably:

[0079]

[0080] In this invention, in steps 1) and 2), the sample is stir-fried, column chromatography and drying are performed sequentially after the secondary reaction;

[0081] The preferred method for stir-frying the sample involves mixing the reacted solution with silica gel powder and then stir-frying the sample in a rotary evaporator. The preferred ratio of the reacted solution to silica gel powder is 10–20:1, more preferably 12–18:1, and even more preferably 14–16:1. The preferred temperature for stir-frying the sample is 40–45°C, more preferably 41–44°C, and even more preferably 42–43°C. The preferred time for stir-frying the sample is 8–12 min, more preferably 9–11 min, and even more preferably 10 min.

[0082] The preferred mobile phase for column chromatography is a mixture of petroleum ether and ethyl acetate, with a preferred mass ratio of petroleum ether to ethyl acetate of 20:1.

[0083] The drying process is preferably vacuum drying, with a vacuum degree of -1 to -0.8 bar, more preferably -0.98 to -0.92 bar, and even more preferably -0.97 to -0.95 bar. The vacuum drying temperature is preferably 35 to 45°C, more preferably 37 to 43°C, and even more preferably 40 to 42°C. The vacuum drying time is preferably 20 to 24 hours, more preferably 21 to 23 hours, and even more preferably 22 hours.

[0084] In this invention, in step 3), the preferred ratio of reactant B, methyl methacrylate, azobisisobutyronitrile, 2-cyanopropyl-2-ylbenzodisulfide, and N,N-dimethylformamide is 0.8–1.2 mmol: 145–165 mmol: 0.08–0.22 mmol: 0.8–1.2 mmol: 1 mL, more preferably 0.9–1.1 mmol: 150–160 mmol: 0.1–0.2 mmol: 0.9–1.1 mmol: 1 mL, and even more preferably 1 mmol: 155–158 mmol: 0.15–0.18 mmol: 1 mmol: 1 mL;

[0085] In this invention, in step 3), the polymerization reaction is preferably a RAFT polymerization reaction;

[0086] The polymerization reaction is preferably carried out under an inert atmosphere;

[0087] The polymerization reaction temperature is preferably 75-80°C, more preferably 76-79°C, and even more preferably 77-78°C. The polymerization reaction time is preferably 20-24 hours, more preferably 21-23 hours, and even more preferably 22 hours.

[0088] In this invention, step 3) is preferably carried out in a flask with a side arm;

[0089] Before carrying out the polymerization reaction, the side-mounted flask is deoxygenated.

[0090] The deoxygenation operation is performed as follows: the side-necked flask is frozen with liquid nitrogen, the vacuum pump is kept on to create a vacuum inside the side-necked flask, the flask is frozen and evacuated for 5 minutes, then placed at room temperature to thaw, the process is repeated three times, and then an inert gas is introduced.

[0091] In this invention, in step 3), purification is performed after the polymerization reaction;

[0092] The purification steps are as follows: the reaction solution is added dropwise to diethyl ether, and after standing, it is centrifuged to obtain a solid product. The solid product is then dried to obtain TPE nanoparticles with alkyl chain-regulated luminescence.

[0093] The ratio of the reacted solution to diethyl ether is 1 mL:6 mL. The preferred dripping rate is 5 mL / min. The preferred settling time is 5–10 min, more preferably 6–9 min, and even more preferably 7–8 min. The preferred centrifugation speed is 8000–10000 rpm, more preferably 8500–9500 rpm, and even more preferably 9000 rpm. The preferred centrifugation time is 3–7 min, more preferably 4–6 min, and even more preferably 5 min. The preferred drying method is vacuum drying. The preferred vacuum degree is -1 to -0.8 bar, more preferably -0.98 to -0.92 bar, and even more preferably -0.97 to -0.95 bar. The preferred vacuum drying temperature is 35–45°C, more preferably 37–43°C, and even more preferably 40–42°C. The preferred vacuum drying time is 20–24 h, more preferably 21–23 h, and even more preferably 22 h.

[0094] This invention also provides an application of alkyl chain-regulated luminescence TPE nanoparticles in the fields of bioimaging and optoelectronic devices.

[0095] In this invention, TPE nanoparticles with alkyl chain-regulated luminescence are used to prepare high-performance luminescent nanoparticles in water for application.

[0096] The preparation method of the high-performance luminescent nanoparticles is as follows:

[0097] a. Mix TPE nanoparticles with alkyl chain-modulated luminescence with tetrahydrofuran to obtain a mixture;

[0098] b. Mix the mixture, the amphiphilic block polymer, and water to obtain high-performance luminescent nanoparticles.

[0099] In this invention, in step a, the preferred ratio of alkyl chain-regulated luminescence TPE nanoparticles to tetrahydrofuran is 4.5–5.5 mg:1 mL, more preferably 4.6–5.2 mg:1 mL, and even more preferably 4.8–5 mg:1 mL.

[0100] In step b, the preferred ratio of the mixture, the amphiphilic block polymer, and water is 30 μL: 0.3–0.35 mg: 0.8–1.2 mL, more preferably 30 μL: 0.31–0.34 mg: 0.9–1.1 mL, and even more preferably 30 μL: 0.32–0.33 mg: 1 mL. The mixing is preferably ultrasonic mixing, the preferred ultrasonic mixing temperature is 35–45 °C, more preferably 36–42 °C, and even more preferably 38–40 °C, and the preferred ultrasonic mixing time is 8–12 min, more preferably 9–11 min, and even more preferably 10 min.

[0101] In this invention, the amphiphilic block polymer is preferably polymethyl methacrylate-block-poly(ethylene glycol) methacrylate (P(MMA-b-PEGMA)), wherein the molecular weight ratio of polymethyl methacrylate to poly(ethylene glycol) methacrylate is preferably 196-204:60-68, more preferably 198-202:62-66, and even more preferably 200:64-65.

[0102] In this invention, a narrowly distributed copolymer is prepared by combining long-chain acyl chloride-modified TPE monomers with RAFT polymerization, and an amphiphilic block polymer is used to achieve efficient encapsulation, providing a key technical solution for the controllable synthesis of TPE nanoparticles.

[0103] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0104] Example 1

[0105] The structural formula of the alkyl chain-regulated luminescence TPE nanoparticles prepared in this embodiment is as follows:

[0106]

[0107] m is 150, n is 1;

[0108] The preparation steps are as follows:

[0109] 1.2 mmol tetra-(4-hydroxyphenyl)ethylene, 3.6 mmol triethylamine, and 20 mL THF were mixed. Under stirring in an ice-water bath (0 °C), a mixed solvent of 3.6 mmol dodecanoyl chloride and 5 mL tetrahydrofuran was added dropwise at a rate of 5 mL / h. After the addition was complete, stirring was continued for 2 h in an ice-water bath (0 °C). Then, the temperature was raised to 25 °C, and the reaction was allowed to proceed for 22 h to obtain the reaction mixture. The reaction mixture was mixed with 1 g silica gel powder and poured into a 500 mL pear-shaped flask. The mixture was then placed in a rotary evaporator and evaporated at 43 °C for 10 min. The mixture was then purified by column chromatography using a mixed solvent of petroleum ether and ethyl acetate in a mass ratio of 20:1. Finally, the mixture was vacuum dried at 40 °C under a vacuum of -1 bar for 24 h to obtain tris(dodecanoyl)-tetra-(4-hydroxyphenyl)ethylene.

[0110] 1 mmol of tris(dodecanoyl)-tetra-(4-hydroxyphenyl)ethylene, 1.2 mmol of triethylamine, and 20 mL of THF were mixed. Under stirring in an ice-water bath (0 °C), a mixed solvent of 1.2 mmol of methacryloyl chloride and 5 mL of tetrahydrofuran was added dropwise at a rate of 5 mL / h. After the addition was complete, stirring was continued for 2 h in an ice-water bath (0 °C). Then, the temperature was raised to 25 °C, and the reaction was allowed to proceed for 21 h to obtain the reaction mixture. The reaction mixture was mixed with 1 g of silica gel powder and poured into a 500 mL pear-shaped flask. The mixture was then evaporated at 43 °C for 10 min in a rotary evaporator. Purification was then performed by column chromatography using a mixed solvent of petroleum ether and ethyl acetate in a mass ratio of 20:1. The mixture was then vacuum dried at 40 °C under a vacuum of -1 bar for 24 h to obtain tris(dodecanoate)-mono(methacrylate)-tetra-(4-phenyl)ethylene, with the following structural formula:

[0111]

[0112] 1 mmol of tris(dodecanoate)-mono(methacrylate)-tetra-(4-phenyl)ethylene, 160 mmol of methyl methacrylate, 0.2 mmol of azobisisobutyronitrile, 1 mmol of 2-cyanopropyl-2-ylbenzodisulfide, and 1 mL of N,N-dimethylformamide were placed in a 25 mL side-mounted flask. The side-mounted flask was frozen with liquid nitrogen, and the vacuum pump was kept on to maintain a vacuum environment inside the flask. After freezing and evacuation for 5 min, the flask was allowed to thaw at room temperature. This process was repeated three times. Nitrogen gas was then introduced, and a RAFT polymerization reaction was carried out at 78 °C for 24 h under a nitrogen atmosphere. After that, air was introduced, and the reaction solution was added dropwise to 30 mL of diethyl ether at a rate of 5 mL / min. After standing for 8 min, the solution was centrifuged at 10,000 rpm for 5 min. The solid product obtained by centrifugation was then dried at 40 °C for 22 h under a vacuum of -1 bar to obtain alkyl chain-regulated luminescence TPE nanoparticles, denoted as "P(MMA-co-TPE-C12)".

[0113] Example 2

[0114] The structural formula of the alkyl chain-regulated luminescence TPE nanoparticles prepared in this embodiment is as follows:

[0115]

[0116] m is 152, n is 1;

[0117] The preparation steps are as follows:

[0118] 1.4 mmol tetra-(4-hydroxyphenyl)ethylene, 4.2 mmol triethylamine, and 20 mL THF were mixed. Under stirring in an ice-water bath (0 °C), a mixed solvent of 4.2 mmol octadecanoyl chloride and 5 mL tetrahydrofuran was added dropwise at a rate of 5 mL / h. After the addition was complete, stirring was continued for 2 h in an ice-water bath (0 °C). Then, the temperature was raised to 25 °C, and the reaction was allowed to proceed for 21 h to obtain the reaction mixture. The reaction mixture was mixed with 1 g silica gel powder and poured into a 500 mL pear-shaped flask. The mixture was then placed in a rotary evaporator and evaporated at 43 °C for 12 min. The mixture was then purified by column chromatography using a mixed solvent of petroleum ether and ethyl acetate in a mass ratio of 20:1. Finally, the mixture was vacuum dried at 40 °C for 22 h under a vacuum of -0.8 bar to obtain tris(octadecanoyl)-tetra-(4-hydroxyphenyl)ethylene.

[0119] 1 mmol of tris(octadecyl)-tetra-(4-hydroxyphenyl)ethylene, 1.4 mmol of triethylamine, and 20 mL of THF were mixed. Under stirring in an ice-water bath (0 °C), a mixed solvent of 1.4 mmol of methacryloyl chloride and 5 mL of tetrahydrofuran was added dropwise at a rate of 5 mL / h. After the addition was complete, stirring was continued for 2 h in an ice-water bath (0 °C). Then, the temperature was raised to 25 °C, and the reaction was allowed to proceed for 21 h to obtain the reaction mixture. The reaction mixture was mixed with 1 g of silica gel powder and poured into a 500 mL pear-shaped flask. The mixture was then placed in a rotary evaporator and evaporated at 43 °C for 10 min. Purification was then performed by column chromatography using a mixed solvent of petroleum ether and ethyl acetate in a mass ratio of 20:1. The mixture was then vacuum dried at 40 °C for 24 h under a vacuum of -0.9 bar to obtain tris(octadecyl)-mono(methacrylate)-tetra-(4-phenyl)ethylene, with the following structural formula:

[0120]

[0121] 1 mmol of tris(octadecyl ester)-mono(methacrylate)-tetra-(4-phenyl)ethylene, 160 mmol of methyl methacrylate, 0.2 mmol of azobisisobutyronitrile, 1 mmol of 2-cyanopropyl-2-ylbenzodisulfide, and 1 mL of N,N-dimethylformamide were placed in a 25 mL side-mounted flask. The side-mounted flask was frozen with liquid nitrogen, and the vacuum pump was kept on to maintain a vacuum environment inside the flask. After freezing and evacuating for 5 min, the flask was allowed to thaw at room temperature. This process was repeated three times. Nitrogen gas was then introduced, and a RAFT polymerization reaction was carried out at 78 °C for 24 h under a nitrogen atmosphere. After that, air was introduced, and the reaction solution was added dropwise to 30 mL of diethyl ether at a rate of 5 mL / min. After standing for 10 min, the solution was centrifuged at 8000 rpm for 5 min. The solid product obtained by centrifugation was then dried at 40 °C for 22 h under a vacuum of -1 bar to obtain alkyl chain-regulated luminescence TPE nanoparticles, denoted as "P(MMA-co-TPE-C18)".

[0122] Comparative Example 1

[0123] The structural formula of the TPE nanoparticles prepared in this comparative example is as follows:

[0124]

[0125] m is 86, n is 1;

[0126] 2 mmol of 4-(1,2,2-triphenylvinyl)phenol, 2.4 mmol of triethylamine, and 50 mL of THF were mixed. Under stirring in an ice-water bath (0 °C), a mixed solvent of 2.4 mmol of methacryloyl chloride and 5 mL of tetrahydrofuran was added dropwise at a rate of 5 mL / h. After the addition was complete, stirring was continued for 2 h in an ice-water bath (0 °C). Then, the temperature was raised to 25 °C, and the reaction was allowed to proceed for 21 h to obtain the reaction mixture. The reaction mixture was mixed with 2 g of silica gel powder and poured into a 500 mL pear-shaped flask. The mixture was then placed in a rotary evaporator and evaporated at 43 °C for 11 min. Purification was then performed by column chromatography using a mixed solvent of petroleum ether and ethyl acetate in a mass ratio of 20:1. The mixture was then vacuum dried at 40 °C for 22 h under a vacuum of -0.9 bar to obtain 4-(1,2,2-triphenylvinyl)phenyl methacrylate, with the following structural formula:

[0127]

[0128] 1 mmol of 4-(1,2,2-triphenylvinyl)phenyl methacrylate, 100 mmol of methyl methacrylate, 0.2 mmol of azobisisobutyronitrile, 1 mmol of 2-cyanopropyl-2-ylbenzodisulfide, and 1 mL of N,N-dimethylformamide were placed in a 25 mL side-mounted flask. The flask was frozen with liquid nitrogen, and the vacuum pump was kept on to maintain a vacuum environment inside the flask. After freezing and evacuation for 5 min, the flask was allowed to thaw at room temperature. This process was repeated three times. Nitrogen gas was then introduced, and a RAFT polymerization reaction was carried out at 78 °C for 24 h under a nitrogen atmosphere. After that, air was introduced, and the reaction solution was added dropwise to 30 mL of diethyl ether at a rate of 5 mL / min. After standing for 8 min, the solution was centrifuged at 8500 rpm for 5 min. The solid product obtained by centrifugation was then dried at 40 °C for 22 h under a vacuum of -1 bar to obtain TPE nanoparticles, denoted as "P(MMA-co-TPE)".

[0129] The gel permeation chromatogram of P(MMA-co-TPE-C12) obtained in Example 1 is shown below. Figure 7 As shown, the gel permeation chromatogram of P(MMA-co-TPE-C18) obtained in Example 2 is as follows. Figure 8 As shown. By Figure 7 and Figure 8The data results shown in Table 1 can be obtained as follows:

[0130] Table 1. Gel permeation chromatography data of TPE nanoparticles obtained in Examples 1-2

[0131]

[0132]

[0133] The TPE nanoparticles obtained in Example 1, Example 2 and Comparative Example 1 were subjected to the following performance tests.

[0134] 1. Aggregation-induced emission performance test:

[0135] Weigh out 2.54 mg P(MMA-co-TPE), 4.92 mg P(MMA-co-TPE-C12), and 5.13 mg P(MMA-co-TPE-C18), and dissolve them in 1 mL of spectral grade THF to obtain mother liquors. The TPE content in each of the mother liquors is 3 × 10⁻⁶. -4 M;

[0136] Different concentrations of THF aqueous solutions were mixed with 30 μL of mother liquor to prepare TPE with a concentration of 9 × 10⁻⁶. -6 The solutions of M, wherein the water content of the THF aqueous solution is 0%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 95% respectively;

[0137] The fluorescence emission spectra of these solutions were measured using an F-7000 fluorescence spectrophotometer (trade name: Fluorescence Spectrophotometer) sold by Hitachi, Japan, under the conditions of excitation wavelength = 315 nm, slit width Ex / Em = 2.5 / 2.5 nm, scan speed = 2400 nm / min, and scan voltage = 700 V. The detection results are as follows: Figures 9-11 As shown.

[0138] The AIE performance graph of P(MMA-co-TPE) obtained in Comparative Example 1 is shown below. Figure 9 As shown; the AIE performance diagram of P(MMA-co-TPE-C12) obtained in Example 1 is shown in Figure 1. Figure 10 As shown; the AIE performance diagram of P(MMA-co-TPE-C18) obtained in Example 2 is shown in Figure 2. Figure 11 As shown. By Figures 9-11 It is evident that the fluorescence intensity of each polymer group increases with increasing water content.

[0139] The AIE performance comparison chart of P(MMA-co-TPE), P(MMA-co-TPE-C12), and P(MMA-co-TPE-C18) is shown below. Figure 12 As shown. By Figure 12 As can be seen, the trend of AIE intensity is: P(MMA-co-TPE-C18) > P(MMA-co-TPE-C12) > P(MMA-co-TPE). The TPE in P(MMA-co-TPE-C18) has the longest rigid alkyl chain, which can interact with the polymer backbone, generating greater steric hindrance and enhancing intramolecular rotational restriction, thus resulting in the strongest fluorescence performance. P(MMA-co-TPE-C12) has the second strongest fluorescence performance, while P(MMA-co-TPE) has the lowest fluorescence performance.

[0140] 2. Dynamic light scattering test:

[0141] Preparation of high-performance luminescent nanoparticles in water:

[0142] Take 4.92 mg P(MMA-co-TPE-C12) and 5.13 mg P(MMA-co-TPE-C18), and mix them separately with 1 mL of spectral grade THF to obtain mother liquors. The TPE content in both mother liquors is 3 × 10⁻⁶. -4 M;

[0143] Take 30 μL of mother liquor, 0.34 mg of P(MMA-b-PEGMA) (the molecular weight ratio of MMA to PEGMA is 200:66), and 1 mL of water and sonicate at 40 kHz for 10 min at 40 °C to obtain high-performance luminescent nanoparticles in water. The high-performance luminescent nanoparticles in water prepared by P(MMA-co-TPE-C12) are denoted as "P(MMA-co-TPE-C12)&P(MMA-b-PEGMA)", and the high-performance luminescent nanoparticles in water prepared by P(MMA-co-TPE-C18) are denoted as "P(MMA-co-TPE-C18)&P(MMA-b-PEGMA)".

[0144] Using a Litesizer 500 nanometer and Zeta potentiometer sold by Anton Paar in Europe under the trade name, the above-mentioned high-performance luminescent nanoparticles in water were subjected to nanoparticle size and dispersion at 25°C with polymethyl methacrylate as a template. The results are as follows: Figure 13 and Figure 14 As shown.

[0145] The DLS data graphs for P(MMA-co-TPE-C12) & P(MMA-b-PEGMA) are shown below. Figure 13 As shown; the DLS data graphs for P(MMA-co-TPE-C18) & P(MMA-b-PEGMA) are as follows. Figure 14 As shown. By Figure 13 and Figure 14As shown, the prepared luminescent nanoparticles have a narrow single peak, and the PDI is less than 0.15. They also have good dispersion, indicating that the preparation method of high-performance luminescent nanoparticles in this invention can produce high-performance luminescent nanoparticles with excellent technical effects in water.

[0146] In summary, the luminescence intensity of P(MMA-co-TPE-C18) obtained in Example 2 is increased by 100.1% compared with the unmodified system. RAFT polymerization enables precise control of molecular weight and nanoparticle size. The nanoparticles exist stably in pure water, laying the foundation for the application of TPE-based materials in the nano-micro field.

[0147] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A TPE nanoparticle with alkyl chain-regulated luminescence, characterized in that, The structural formula of the TPE nanoparticles is shown in Formula I: Where m and n are independent integers that are not zero; X is:

2. The method for preparing alkyl chain-regulated luminescence TPE nanoparticles according to claim 1, characterized in that, Includes the following steps: 1) Tetra-(4-hydroxyphenyl)ethylene, triethylamine, tetrahydrofuran and long-chain acyl chloride are mixed and subjected to a first reaction and a second reaction in sequence to obtain reactant A; 2) Reactant A, triethylamine, tetrahydrofuran and methacrylamide chloride are mixed and subjected to a first reaction and a second reaction in sequence to obtain reactant B; 3) Reactant B, methyl methacrylate, azobisisobutyronitrile, 2-cyanopropyl-2-ylbenzodisulfide and N,N-dimethylformamide were mixed and polymerized to obtain TPE nanoparticles with alkyl chain-regulated luminescence.

3. The method for preparing alkyl chain-regulated luminescence TPE nanoparticles according to claim 2, characterized in that, In step 1), the ratio of tetra-(4-hydroxyphenyl)ethylene, triethylamine, tetrahydrofuran, and long-chain acyl chloride is 1 mmol: 3-4.8 mmol: 10-25 mL: 2.5-4 mmol. The long-chain acyl chloride is dodecanoyl chloride or octadecanoyl chloride.

4. The method for preparing alkyl chain-regulated luminescence TPE nanoparticles according to claim 2, characterized in that, In step 2), the ratio of reactant A, triethylamine, tetrahydrofuran and methacrylamide chloride is 1 mmol: 1.2–2.4 mmol: 10–25 mL: 1.2–2 mmol.

5. The method for preparing alkyl chain-regulated luminescence TPE nanoparticles according to claim 2 or 4, characterized in that, In steps 1) and 2), the temperature of each reaction is independently 0–5°C, and the reaction time is independently 2–3 h. The temperature of the secondary reaction is independently 20–30 °C, and the time of the secondary reaction is independently 20–24 h.

6. The method for preparing alkyl chain-regulated luminescence TPE nanoparticles according to claim 5, characterized in that, In step 3), the ratio of reactant B, methyl methacrylate, azobisisobutyronitrile, 2-cyanopropyl-2-ylbenzodisulfide and N,N-dimethylformamide is 0.8–1.2 mmol: 145–165 mmol: 0.08–0.22 mmol: 0.8–1.2 mmol: 1 mL.

7. The method for preparing alkyl chain-regulated luminescence TPE nanoparticles according to claim 6, characterized in that, In step 3), the polymerization reaction is a RAFT polymerization reaction; The polymerization reaction is carried out under an inert atmosphere; The polymerization reaction is carried out at a temperature of 75–80°C for 20–24 hours.

8. The application of the alkyl chain-regulated luminescence TPE nanoparticles as described in claim 1 in the fields of bioimaging and optoelectronic devices.

9. The application of the alkyl chain-regulated luminescence TPE nanoparticles according to claim 8 in the fields of bioimaging and optoelectronic devices, characterized in that, High-performance luminescent nanoparticles were prepared by using TPE nanoparticles with alkyl chain-regulated luminescence and then applied. The preparation method of the high-performance luminescent nanoparticles is as follows: a. Mix TPE nanoparticles with alkyl chain-modulated luminescence with tetrahydrofuran to obtain a mixture; b. Mix the mixture, the amphiphilic block polymer, and water to obtain high-performance luminescent nanoparticles.

10. The application of the alkyl chain-regulated luminescence TPE nanoparticles according to claim 9 in the fields of bioimaging and optoelectronic devices, characterized in that, In step a, the ratio of alkyl chain-regulated luminescence TPE nanoparticles to tetrahydrofuran is 4.5–5.5 mg: 1 mL. In step b, the ratio of the mixture, the amphiphilic block polymer, and water is 30 μL: 0.3–0.35 mg: 0.8–1.2 mL. The mixing is performed by ultrasonic mixing at a temperature of 35–45 °C for 8–12 min.

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