Preparation method and application of ring-crosslinked polyphosphazene-based dual-modal emission nanoparticle film

Abstract

The invention relates to the technical field of afterglow materials, and specifically discloses a preparation method and application of a cyclic cross-linked polyphosphazene-based dual-mode emission nanoparticle film. Acridine yellow is used as a chromophore, polyphenol flavonoid substance kaempferol is used as a polyphenol substance, and hexachlorocyclotriphosphazene is used as a basic skeleton of the cyclic cross-linked polyphosphazene. A plurality of methods for improving and stabilizing triplet excitons are synergistically integrated to realize the preparation of nanoparticles with dual-mode emission of thermally activated delayed fluorescence and room temperature phosphorescence under visible light excitation, and then the cyclic cross-linked polyphosphazene-based dual-mode emission nanoparticle film is prepared. The cyclic cross-linked polyphosphazene-based dual-mode emission nanoparticle film is applied to anti-counterfeiting technology. The invention utilizes the polymerization and cross-linking effects of the cyclic polyphosphazene and the rigidification effect of the hydrogen bond enhancement system of PVA to inhibit the non-radiative decay process of the triplet exciton, and utilizes heteroatoms and heavy atoms to enhance the ISC process, thereby enhancing the photophysical properties of the material such as the afterglow life, afterglow duration and quantum yield.

Description

Technical Field

[0001] The invention relates to the technical field of afterglow materials, and in particular to a preparation method and application of a ring-crosslinked polyphosphazene-based dual-mode emission nanoparticle film. Background Art

[0002] Afterglow materials can continue to emit light for a period of time after the excitation source is removed, showing unique advantages in the fields of anti-counterfeiting, display and bio-imaging. Compared with traditional inorganic afterglow materials, organic afterglow materials have the advantages of low cost, abundant sources, good flexibility, good processing performance and biocompatibility. Afterglow materials can be divided into two types according to the different principles of their afterglow generation: (1) in the lowest triplet excited state T 1 The excitons reach the lowest singlet excited state S through the reverse intersystem crossing (RISC) process. 1 , thus returning to the ground state S 0 Thermally activated delayed fluorescence (TADF) materials; (2) excitons directly from the lowest triplet excited state T 1 Room temperature phosphorescence (RTP) materials that return to the ground state. Both TADF and RTP afterglow emitters require stable and abundant triplet excitons. However, due to the energy gap DE between the singlet and triplet states of organic matter, ST They are usually large, so it is difficult to obtain rich and stable triplet excitons through the intersystem crossing process (ISC), which makes it challenging to construct long-lived organic afterglow emitters.

[0003] In order to obtain organic long-lived afterglow emitters with excellent performance, it is usually necessary to adopt some strategies to enrich and stabilize the triplet excitons of the system. At present, there are three main methods to enhance triplet excitons: (1) Introducing heteroatoms containing lone pairs of electrons, such as N, O, P, S, etc. to enhance the intersystem crossing (ISC) process; (2) Increasing the spin-orbit coupling constant (x) through heavy atom effects (Cl, Br, I), etc. to promote the spin-orbit coupling (SOC) process; (3) Using rigidification effects (such as polymerization, cross-linking, hydrogen bonding) to suppress non-radiative relaxation processes and quenching effects. In addition, polyphenols can also effectively increase triplet excitons. Based on the above strategies, researchers have constructed TADF-type or RTP-type single-emitting organic afterglow materials with different lifetimes and different colors. However, since the realization of the RISC process requires higher temperatures and smaller DE ST TADF is easy to achieve at higher temperatures; while triplet excitons can easily return to the ground state through other non-radiative relaxation pathways at higher temperatures, RTP is easy to achieve at low temperatures. Therefore, how to reasonably modulate T 1 The exciton returns to the ground state S 0 Produce RTP type afterglow; at the same time T 1 The excitons in the state reach S through the RISC process 1The development of afterglow materials with TADF and RTP dual-modal emission, especially afterglow materials with dual-modal emission excited by visible light, still faces challenges.

[0004] Cyclic cross-linked polyphosphazene is based on HCCP as the basic skeleton, and is 3 ) is a class of organic-inorganic hybrid polymer materials with stable covalently cross-linked network chemical structures prepared by ultrasonic-assisted precipitation polymerization of aromatic organic monomers. By changing the type of comonomers and regulating the polymerization reaction conditions, cyclic cross-linked polyphosphazenes with different morphologies such as spherical, core-shell, and tubular, as well as different functions such as flame retardancy, drug delivery, fluorescence, and adsorption can be prepared. By selecting specific emission centers and polyphenols as comonomers, cyclic cross-linked polyphosphazene afterglow materials can be prepared, which can effectively introduce heteroatoms such as N, P, O, and S, produce heavy atom effects through Cl atoms on the phosphazene ring, and introduce rigidification effects by using polymerization and cross-linking characteristics, which is expected to achieve multi-method synergistic enhancement of triplet excitons, thereby greatly improving various photophysical properties of the emission center (lifetime, intensity, quantum yield). In addition, through the integration of many effects, cyclic cross-linked polyphosphazene nanoparticles are expected to re-modulate triplet excitons so that triplet excitons reach equilibrium during the ISC and RISC processes, thereby achieving TADF and RTP dual-mode emission at room temperature.

[0005] Therefore, the present invention provides a preparation method and application of a ring-crosslinked polyphosphazene-based dual-modal emission nanoparticle film, and develops an organic afterglow material with dual-modal emission, which can be used not only in high-temperature places, but also in low-temperature places, further expanding the application places of the afterglow material. Summary of the invention

[0006] The purpose of the present invention is to provide a preparation method and application of a ring-crosslinked polyphosphazene-based dual-mode emission nanoparticle film, filling the gap in the current technology.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] The preparation method of the ring-crosslinked polyphosphazene-based dual-mode emission nanoparticle film comprises the following steps:

[0009] (1) Solution preparation: Deionized water and acetonitrile were used as solvents, with a volume percentage of 1-4:96-99. Chromophore, polyphenolic flavonoids, and HCCP were used as solutes, respectively. The Cl in HCCP and the functional groups OH and NH in the chromophore and polyphenolic flavonoids were controlled. 2and the ratio of chromophore to polyphenol flavonoids, a certain amount of chromophore is placed in deionized water and ultrasonically dissolved until it is completely dissolved to form solution 1, and polyphenol flavonoids and HCCP (hexachlorocyclotriphosphazene) are dissolved in acetonitrile and ultrasonically dissolved to form solution 2, and then solution 1 and solution 2 are transferred to the same container and mixed to obtain mixed solution 1 for use;

[0010] (2) Preparation of cyclic cross-linked polyphosphazene nanoparticles by ultrasound-assisted precipitation polymerization: the mixed solution 1 obtained in step (1) is placed in another container for ultrasound treatment for 10 to 12 minutes, and then triethylamine, an acid-binding agent, is slowly added thereto. After further ultrasound treatment, the precipitate is centrifuged to obtain the precipitate, which is washed with anhydrous ethanol and deionized water respectively, dried in a vacuum drying oven, and then ground into powder to synthesize cyclic cross-linked polyphosphazene nanoparticles HACK;

[0011] (3) Preparation of nanoparticle polyvinyl alcohol composite film: weigh the cyclic cross-linked polyphosphazene nanoparticles HACK synthesized in step (2) and disperse them in deionized water. After ultrasonic treatment, stir at room temperature to obtain solution 3 for use. At the same time, dissolve polyvinyl alcohol (PVA) in deionized water, heat and stir until PVA is completely dissolved, then reduce the temperature to room temperature to obtain solution 4 for use. Mix solution 4 with solution 3, stir and mix at room temperature to obtain mixed solution 2. Pipette mixed solution 2 and slowly add it dropwise onto a glass slide. Use a four-sided preparation device to scrape at a uniform speed and remove excess mixed solution 2. Place the glass slide coated with mixed solution 2 under an infrared lamp for 50 to 60 minutes, remove the formed composite film, and place the mixed solution 2 film with the solvent completely removed in a vacuum drying oven at 60 to 70°C for 12 to 16 hours to obtain a cyclic cross-linked polyphosphazene-based dual-modal emission nanoparticle film.

[0012] Preferably, in step (1), the chromophore is acriflavine (ACF) and the polyphenolic flavonoid is kaempferol (KAE).

[0013] Preferably, in step (1), the ratio of Cl in the HCCP to the chromophore and the functional group in the polyphenol flavonoids is 9:7-11.

[0014] Preferably, in step (1), the ratio of the chromophore to the polyphenol flavonoids is 1-3:1-8.

[0015] Preferably, in step (2), the time of the continued ultrasonic treatment is 1 to 6 hours; the power of the continued ultrasonic treatment is 60 to 150 W.

[0016] Further preferably, in step (2), the time of the continued ultrasonic treatment is 2 to 5 hours; the power of the continued ultrasonic treatment is 80 to 120 W.

[0017] Preferably, in step (2), the precipitate is first washed with anhydrous ethanol for 3 to 4 times, and then washed with deionized water for 3 to 4 times. After washing, the precipitate is placed in a vacuum drying oven at 60 to 70° C. and dried for 10 to 16 hours.

[0018] Preferably, in step (3), the temperature of the heating and stirring for preparing solution 4 is controlled to be 65-95°C, the time of the heating and stirring is controlled to be 4-6h, and the rate of the heating and stirring is 500-650r / min; the ultrasonic power of the ultrasonic treatment for preparing solution 3 is 100-150W, the time is controlled to be 30-50min, the rate of stirring at room temperature is 550-650r / min, and the time of stirring at room temperature is controlled to be 2-4h; the solution 4 is mixed with the solution 3, the rate of stirring at room temperature is 550-650r / min, and the stirring time is controlled to be 2-4h.

[0019] Preferably, in step (3), the four-sided preparation device has a side of 2000 mm, and the glass slide is a smooth glass slide for ordinary microscope.

[0020] The working mechanism of the present invention is: Acriflavine (ACF) is used as the chromophore, polyphenolic flavonoid substance kaempferol (KAE) is used as the polyphenolic substance, and HCCP is used as the basic skeleton of the ring-crosslinked polyphosphazene, and multiple agents are synergistically integrated to enhance and stabilize the triplet exciton (T 3 ) method to achieve visible light excited nanoparticles with dual-modal emissions of thermally activated delayed fluorescence (TADF) and room temperature phosphorescence (RTP).

[0021] Due to the application of the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0022] 1. The present invention utilizes cyclic polyphosphazene to conveniently introduce heteroatoms such as N, O, and P to further improve the stability of triplet excitons and enhance photophysical properties such as afterglow lifetime, duration, and quantum yield;

[0023] 2. The present invention utilizes cyclic polyphosphazene to conveniently introduce Cl heavy atoms, utilizes the heavy atom effect to enhance the SOC process, and then enhances the ISC process, increases the number of triplet excitons, and enhances the photophysical properties such as afterglow lifetime, duration and quantum yield;

[0024] 3. The present invention utilizes the polymerization and cross-linking effects of cyclic polyphosphazene and the hydrogen bonding effect of polyvinyl alcohol (PVA) to enhance the rigidification effect of the system, inhibit the non-radiative decay process of triplet excitons, and enhance the photophysical properties such as afterglow lifetime, duration and quantum yield;

[0025] 4. The present invention utilizes the spherical morphology of the ring-based polyphosphazene nanoparticles to greatly improve the various photophysical properties of the system;

[0026] 5. The present invention realizes visible light excitation based on acridinium yellow, and the preparation of a long-life emitter with an optimal excitation wavelength of 470nm;

[0027] 6. Based on the various advantages of acridinium yellow integrated with cyclic polyphosphazene nanoparticles, the present invention realizes the preparation of a dual-mode emitter with RTP and TADF at room temperature, and TADF emits at 500nm and RTP emits at 580nm;

[0028] 7. The mixed solution of nanoparticles and polyvinyl alcohol involved in the present invention can be conveniently used to write or make anti-counterfeiting patterns in various substrates;

[0029] 8. The mixed solution of nanoparticles and polyvinyl alcohol involved in the present invention is not only suitable for low-temperature occasions, but also suitable for room temperature and high-temperature occasions (about 80°C), and the afterglow color can change with temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, some of the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be made based on these drawings without paying any creative work.

[0031] Figure 1 is a SEM image of the ring-crosslinked polyphosphazene-based bimodal emitting nanoparticles of Example 1 of the present invention;

[0032] Figure 2 is a SEM image of the ring-crosslinked polyphosphazene-based bimodal emitting nanoparticles of Example 2 of the present invention;

[0033] Figure 3 is a SEM image of the ring-crosslinked polyphosphazene-based bimodal emitting nanoparticles of Example 3 of the present invention;

[0034] Figure 4 is a SEM image of the ring-crosslinked polyphosphazene-based bimodal emitting nanoparticles of Example 4 of the present invention;

[0035] Figure 5 is a SEM image of the ring-crosslinked polyphosphazene-based bimodal emitting nanoparticles of Example 5 of the present invention;

[0036] Figure 6 is a fluorescence spectrum of the ring-crosslinked polyphosphazene-based dual-modal emission nanoparticle film of Example 1 of the present invention;

[0037] Figure 7 This is a delayed spectrum diagram of the ring-crosslinked polyphosphazene-based dual-modal emission nanoparticle film according to Example 1 of the present invention. DETAILED DESCRIPTION

[0038] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, a specific implementation scheme is now described in detail.

[0039] The present invention is further described below in conjunction with the examples, but the present invention is not limited to the following examples. The implementation conditions used in the examples can be further adjusted according to the different requirements of specific use, and the implementation conditions not specified are conventional conditions in the industry. The technical features involved in each embodiment of the present invention can be combined with each other as long as they do not conflict with each other.

[0040] Example 1

[0041] See attached Figure 1 , Attachment Figure 6 And attached Figure 7 , this embodiment provides a preparation method and application of a ring-crosslinked polyphosphazene-based dual-modal emission nanoparticle film;

[0042] The preparation method of the ring-crosslinked polyphosphazene-based dual-mode emission nanoparticle film specifically comprises the following steps:

[0043] (1) Preparation of solutions: 32 mg of acriflavine was dissolved in 1 ml of deionized water and ultrasonically dissolved until completely dissolved to obtain solution 1; 52 mg of hexachlorocyclotriphosphazene and 35 mg of kaempferol were dissolved in 149 ml of acetonitrile and ultrasonically dissolved to obtain solution 2, wherein the volume percentage of deionized water and acetonitrile was 1:99, the ratio of Cl in HCCP to the functional groups in acriflavine and kaempferol was 9:10, and the ratio of acriflavine to kaempferol was 1:1. Then, solution 1 and solution 2 were transferred to the same conical flask and mixed to obtain mixed solution 1 for use;

[0044] (2) Preparation of cyclic cross-linked polyphosphazene nanoparticles by ultrasound-assisted precipitation polymerization: The mixed solution 1 obtained in step (1) was placed in a three-necked flask and subjected to ultrasound at 120W for 10 minutes, after which 6 ml of acid-binding agent triethylamine was slowly added. The mixture was subjected to ultrasound at 120W for 4 hours, after which the precipitate was separated by centrifugation. The precipitate was washed three times with anhydrous ethanol and deionized water respectively, dried in a vacuum drying oven, and then ground into powder to synthesize cyclic cross-linked polyphosphazene nanoparticles HACK.

[0045] (3) Preparation of nanoparticle polyvinyl alcohol composite membrane: 0.9 mg of the cyclic cross-linked polyphosphazene nanoparticles HACK synthesized in step (2) was weighed and dispersed in 2 ml of deionized water. After ultrasonic treatment at 120 W for 30 min, the solution was stirred at a stirring rate of 600 r / min for 4 h at room temperature to obtain solution 3 for use. At the same time, polyvinyl alcohol (PVA) No. 1799 was dissolved in deionized water, heated to 80 ° C and stirred at a stirring rate of 600 r / min for 4 h until the PVA was completely dissolved. The temperature was then lowered to room temperature to obtain a solution with a concentration of 10%. Solution 4 is set aside, 1 ml of solution 4 is mixed with solution 3, and the mixture is stirred at a stirring rate of 600 r / min for 4 h at room temperature to obtain a mixed solution 2, the mixed solution 2 is drawn and slowly dropped onto a glass slide, and the excess mixed solution 2 is removed after being scraped at a uniform speed with a four-sided preparation device, and the glass slide coated with the mixed solution 2 is placed under an infrared lamp for 50 min, the formed composite film is removed, and the mixed solution 2 film with most of the solvent removed is placed in a vacuum drying oven at 65°C and dried for 12 h to obtain a ring-crosslinked polyphosphazene-based dual-modal emission nanoparticle film.

[0046] Example 2

[0047] See attached Figure 2 , this embodiment provides a preparation method and application of a ring-crosslinked polyphosphazene-based dual-modal emission nanoparticle film;

[0048] The preparation method of the ring-crosslinked polyphosphazene-based dual-mode emission nanoparticle film specifically comprises the following steps:

[0049] (1) Preparation of solutions: Dissolve 21 mg of acriflavine in 1 ml of deionized water and ultrasonicate until completely dissolved to obtain solution 1; dissolve 52 mg of hexachlorocyclotriphosphazene and 47 mg of kaempferol in 149 ml of acetonitrile and ultrasonicate until completely dissolved to obtain solution 2; then transfer solution 1 and solution 2 to the same conical flask and mix well to obtain mixed solution 1 for later use;

[0050] (2) Preparation of cyclic cross-linked polyphosphazene nanoparticles by ultrasound-assisted precipitation polymerization: The mixed solution 1 obtained in step (1) was placed in a three-necked flask and subjected to ultrasound at 120W for 10 minutes, after which 6 ml of acid-binding agent triethylamine was slowly added. The mixture was subjected to ultrasound at 120W for 4 hours, after which the precipitate was separated by centrifugation. The precipitate was washed three times with anhydrous ethanol and deionized water respectively, dried in a vacuum drying oven, and then ground into powder to synthesize cyclic cross-linked polyphosphazene nanoparticles HACK.

[0051] (3) Preparation of nanoparticle polyvinyl alcohol composite membrane: 0.9 mg of the cyclic cross-linked polyphosphazene nanoparticles HACK synthesized in step (2) was weighed and dispersed in 2 ml of deionized water. After ultrasonic treatment at 120 W for 30 min, the solution was stirred at a stirring rate of 600 r / min for 4 h at room temperature to obtain solution 3 for use. At the same time, polyvinyl alcohol (PVA) No. 1799 was dissolved in deionized water, heated to 80 ° C and stirred at a stirring rate of 600 r / min for 4 h until the PVA was completely dissolved. The temperature was then lowered to room temperature to obtain a solution with a concentration of 10%. Solution 4 is set aside, 1 ml of solution 4 is mixed with solution 3, and the mixture is stirred at a stirring rate of 600 r / min for 4 h at room temperature to obtain a mixed solution 2, the mixed solution 2 is drawn and slowly dropped onto a glass slide, and the excess mixed solution 2 is removed after being scraped at a uniform speed with a four-sided preparation device, and the glass slide coated with the mixed solution 2 is placed under an infrared lamp for 50 min, the formed composite film is removed, and the mixed solution 2 film from which part of the solvent has been removed is placed in a vacuum drying oven and dried at 65°C for 12 h to obtain a ring-crosslinked polyphosphazene-based dual-modal emission nanoparticle film.

[0052] Example 3

[0053] See attached Figure 3 , this embodiment provides a preparation method and application of a ring-crosslinked polyphosphazene-based dual-modal emission nanoparticle film;

[0054] The preparation method of the ring-crosslinked polyphosphazene-based dual-mode emission nanoparticle film specifically comprises the following steps:

[0055] (1) Preparation of solutions: Dissolve 16 mg of acriflavine in 1 ml of deionized water and ultrasonicate until completely dissolved to obtain solution 1; dissolve 52 mg of hexachlorocyclotriphosphazene and 53 mg of kaempferol in 149 ml of acetonitrile and ultrasonicate until completely dissolved to obtain solution 2; then transfer solution 1 and solution 2 to the same conical flask and mix well to obtain mixed solution 1 for later use;

[0056] (2) Preparation of cyclic cross-linked polyphosphazene nanoparticles by ultrasound-assisted precipitation polymerization: The mixed solution 1 obtained in step (1) was placed in a three-necked flask and subjected to ultrasound at 120W for 10 minutes, after which 6 ml of acid-binding agent triethylamine was slowly added. The mixture was subjected to ultrasound at 120W for 4 hours, after which the precipitate was separated by centrifugation. The precipitate was washed three times with anhydrous ethanol and deionized water respectively, dried in a vacuum drying oven, and then ground into powder to synthesize cyclic cross-linked polyphosphazene nanoparticles HACK.

[0057] (3) Preparation of nanoparticle polyvinyl alcohol composite membrane: 0.9 mg of the cyclic cross-linked polyphosphazene nanoparticles HACK synthesized in step (2) was weighed and dispersed in 2 ml of deionized water. After ultrasonic treatment at 120 W for 30 min, the solution was stirred at a stirring rate of 600 r / min for 4 h at room temperature to obtain solution 3 for use. At the same time, polyvinyl alcohol (PVA) No. 1799 was dissolved in deionized water, heated to 80 ° C and stirred at a stirring rate of 600 r / min for 4 h until the PVA was completely dissolved. The temperature was then lowered to room temperature to obtain a solution with a concentration of 10%. Solution 4 is set aside, 1 ml of solution 4 is mixed with solution 3, and the mixture is stirred at a stirring rate of 600 r / min for 4 h at room temperature to obtain a mixed solution 2, the mixed solution 2 is drawn and slowly dropped onto a glass slide, and the excess mixed solution 2 is removed after being scraped at a uniform speed with a four-sided preparation device, and the glass slide coated with the mixed solution 2 is placed under an infrared lamp for 50 min, the formed composite film is removed, and the mixed solution 2 film from which part of the solvent has been removed is placed in a vacuum drying oven and dried at 65°C for 12 h to obtain a ring-crosslinked polyphosphazene-based dual-modal emission nanoparticle film.

[0058] Example 4

[0059] See attached Figure 4 , this embodiment provides a preparation method and application of a ring-crosslinked polyphosphazene-based dual-modal emission nanoparticle film;

[0060] The preparation method of the ring-crosslinked polyphosphazene-based dual-mode emission nanoparticle film specifically comprises the following steps:

[0061] (1) Preparation of solutions: Dissolve 12 mg of acriflavine in 1 ml of deionized water and ultrasonicate until completely dissolved to obtain solution 1; dissolve 52 mg of hexachlorocyclotriphosphazene and 57 mg of kaempferol in 149 ml of acetonitrile and ultrasonicate until completely dissolved to obtain solution 2; then transfer solution 1 and solution 2 to the same conical flask and mix well to obtain mixed solution 1 for later use;

[0062] (2) Preparation of cyclic cross-linked polyphosphazene nanoparticles by ultrasound-assisted precipitation polymerization: The mixed solution 1 obtained in step (1) was placed in a three-necked flask and subjected to ultrasound at 120W for 10 minutes, after which 6 ml of acid-binding agent triethylamine was slowly added. The mixture was subjected to ultrasound at 120W for 4 hours, after which the precipitate was separated by centrifugation. The precipitate was washed three times with anhydrous ethanol and deionized water respectively, dried in a vacuum drying oven, and then ground into powder to synthesize cyclic cross-linked polyphosphazene nanoparticles HACK.

[0063] (3) Preparation of nanoparticle polyvinyl alcohol composite membrane: 0.9 mg of the cyclic cross-linked polyphosphazene nanoparticles HACK synthesized in step (2) was weighed and dispersed in 2 ml of deionized water. After ultrasonic treatment at 120 W for 30 min, the solution was stirred at a stirring rate of 600 r / min for 4 h at room temperature to obtain solution 3 for use. At the same time, polyvinyl alcohol (PVA) No. 1799 was dissolved in deionized water, heated to 80 ° C and stirred at a stirring rate of 600 r / min for 4 h until the PVA was completely dissolved. The temperature was then lowered to room temperature to obtain a solution with a concentration of 10%. Solution 4 is set aside, 1 ml of solution 4 is mixed with solution 3, and the mixture is stirred at a stirring rate of 600 r / min for 4 h at room temperature to obtain a mixed solution 2, the mixed solution 2 is drawn and slowly dropped onto a glass slide, and the excess mixed solution 2 is removed after being scraped at a uniform speed with a four-sided preparation device, and the glass slide coated with the mixed solution 2 is placed under an infrared lamp for 50 min, the formed composite film is removed, and the mixed solution 2 film from which part of the solvent has been removed is placed in a vacuum drying oven and dried at 65°C for 12 h to obtain a ring-crosslinked polyphosphazene-based dual-modal emission nanoparticle film.

[0064] Example 5

[0065] See attached Figure 5 , this embodiment provides a preparation method and application of a ring-crosslinked polyphosphazene-based dual-modal emission nanoparticle film;

[0066] The preparation method of the ring-crosslinked polyphosphazene-based dual-mode emission nanoparticle film specifically comprises the following steps:

[0067] (1) Preparation of solutions: Dissolve 7 mg of acriflavine in 1 ml of deionized water and ultrasonicate until completely dissolved to obtain solution 1; dissolve 52 mg of hexachlorocyclotriphosphazene and 63 mg of kaempferol in 149 ml of acetonitrile and ultrasonicate until completely dissolved to obtain solution 2; then transfer solution 1 and solution 2 to the same conical flask and mix well to obtain mixed solution 1 for later use;

[0068] (2) Preparation of cyclic cross-linked polyphosphazene nanoparticles by ultrasound-assisted precipitation polymerization: The mixed solution 1 obtained in step (1) was placed in a three-necked flask and subjected to ultrasound at 120W for 10 minutes, after which 6 ml of acid-binding agent triethylamine was slowly added. The mixture was subjected to ultrasound at 120W for 4 hours, after which the precipitate was separated by centrifugation. The precipitate was washed three times with anhydrous ethanol and deionized water respectively, dried in a vacuum drying oven, and then ground into powder to synthesize cyclic cross-linked polyphosphazene nanoparticles HACK.

[0069] (3) Preparation of nanoparticle polyvinyl alcohol composite membrane: 0.9 mg of the cyclic cross-linked polyphosphazene nanoparticles HACK synthesized in step (2) was weighed and dispersed in 2 ml of deionized water. After ultrasonic treatment at 120 W for 30 min, the solution was stirred at a stirring rate of 600 r / min for 4 h at room temperature to obtain solution 3 for use. At the same time, polyvinyl alcohol (PVA) No. 1799 was dissolved in deionized water, heated to 80 ° C and stirred at a stirring rate of 600 r / min for 4 h until the PVA was completely dissolved. The temperature was then lowered to room temperature to obtain a solution with a concentration of 10%. Solution 4 is set aside, 1 ml of solution 4 is mixed with solution 3, and the mixture is stirred at a stirring rate of 600 r / min for 4 h at room temperature to obtain a mixed solution 2, the mixed solution 2 is drawn and slowly dropped onto a glass slide, and the excess mixed solution 2 is removed after being scraped at a uniform speed with a four-sided preparation device, and the glass slide coated with the mixed solution 2 is placed under an infrared lamp for 50 min, the formed composite film is removed, and the mixed solution 2 film from which part of the solvent has been removed is placed in a vacuum drying oven and dried at 65°C for 12 h to obtain a ring-crosslinked polyphosphazene-based dual-modal emission nanoparticle film.

[0070] Comparative Example 1

[0071] This comparative example provides a preparation method and application of a ring-crosslinked polyphosphazene-based dual-modal emission nanoparticle film.

[0072] The preparation method of the ring-crosslinked polyphosphazene-based dual-mode emission nanoparticle film specifically comprises the following steps:

[0073] (1) Preparation of solutions: Dissolve 32 mg of acriflavine in 1 ml of deionized water and ultrasonicate until completely dissolved to obtain solution 1; dissolve 52 mg of hexachlorocyclotriphosphazene and 35 mg of kaempferol in 149 ml of acetonitrile and ultrasonicate until completely dissolved to obtain solution 2; then transfer solution 1 and solution 2 to the same conical flask and mix well to obtain mixed solution 1 for later use;

[0074] (2) Preparation of cyclic cross-linked polyphosphazene nanoparticles by ultrasound-assisted precipitation polymerization: The mixed solution 1 obtained in step (1) was placed in a three-necked flask and subjected to ultrasound at 120W for 10 minutes, after which 6 ml of acid-binding agent triethylamine was slowly added. The mixture was subjected to ultrasound at 120W for 4 hours, after which the precipitate was separated by centrifugation. The precipitate was washed three times with anhydrous ethanol and deionized water respectively, dried in a vacuum drying oven, and then ground into powder to synthesize cyclic cross-linked polyphosphazene nanoparticles HACK.

[0075] (3) Preparation of nanoparticle polyvinyl alcohol composite membrane: 0.9 mg of the cyclic cross-linked polyphosphazene nanoparticles HACK synthesized in step (2) was weighed and dispersed in 2 ml of deionized water. After ultrasonic treatment at 120 W for 30 min, the solution was stirred at a stirring rate of 600 r / min for 4 h at room temperature to obtain solution 3 for use. At the same time, polyvinyl alcohol (PVA) No. 1788 was dissolved in deionized water, heated to 80 ° C and stirred at a stirring rate of 600 r / min for 4 h until the PVA was completely dissolved. The temperature was then lowered to room temperature to obtain a solution with a concentration of 10%. Solution 4 is set aside, 1 ml of solution 4 is mixed with solution 3, and the mixture is stirred at a stirring rate of 600 r / min for 4 h at room temperature to obtain a mixed solution 2, the mixed solution 2 is drawn and slowly dropped onto a glass slide, and the excess mixed solution 2 is removed after being scraped at a uniform speed with a four-sided preparation device, and the glass slide coated with the mixed solution 2 is placed under an infrared lamp for 50 min, the formed composite film is removed, and the mixed solution 2 film from which part of the solvent has been removed is placed in a vacuum drying oven and dried at 65°C for 12 h to obtain a ring-crosslinked polyphosphazene-based dual-modal emission nanoparticle film.

[0076] Comparative Example 2

[0077] This comparative example provides a preparation method and application of a ring-crosslinked polyphosphazene-based dual-modal emission nanoparticle film.

[0078] The preparation method of the ring-crosslinked polyphosphazene-based dual-mode emission nanoparticle film specifically comprises the following steps:

[0079] (1) Preparation of solutions: Dissolve 32 mg of acriflavine in 1 ml of deionized water and ultrasonicate until completely dissolved to obtain solution 1; dissolve 52 mg of hexachlorocyclotriphosphazene and 35 mg of kaempferol in 149 ml of acetonitrile and ultrasonicate until completely dissolved to obtain solution 2; then transfer solution 1 and solution 2 to the same conical flask and mix well to obtain mixed solution 1 for later use;

[0080] (2) Preparation of cyclic cross-linked polyphosphazene nanoparticles by ultrasound-assisted precipitation polymerization: The mixed solution 1 obtained in step (1) was placed in a three-necked flask and subjected to ultrasound at 120W for 10 minutes, after which 6 ml of acid-binding agent triethylamine was slowly added. The mixture was subjected to ultrasound at 120W for 4 hours, after which the precipitate was separated by centrifugation. The precipitate was washed three times with anhydrous ethanol and deionized water respectively, dried in a vacuum drying oven, and then ground into powder to synthesize cyclic cross-linked polyphosphazene nanoparticles HACK.

[0081] (3) Preparation of nanoparticle polyvinyl alcohol composite membrane: 0.9 mg of the cyclic cross-linked polyphosphazene nanoparticles HACK synthesized in step (2) was weighed and dispersed in 2 ml of deionized water. After ultrasonic treatment at 120 W for 30 min, the solution was stirred at a stirring rate of 600 r / min for 4 h at room temperature to obtain solution 3 for use. At the same time, polyvinyl alcohol (PVA) No. 1780 was dissolved in deionized water, heated to 80 ° C and stirred at a stirring rate of 600 r / min for 4 h until the PVA was completely dissolved. The temperature was then lowered to room temperature to obtain a solution with a concentration of 10%. Solution 4 is set aside, 1 ml of solution 4 is mixed with solution 3, and the mixture is stirred at a stirring rate of 600 r / min for 4 h at room temperature to obtain a mixed solution 2, the mixed solution 2 is drawn and slowly dropped onto a glass slide, and the excess mixed solution 2 is removed after being scraped at a uniform speed with a four-sided preparation device, and the glass slide coated with the mixed solution 2 is placed under an infrared lamp for 50 min, the formed composite film is removed, and the mixed solution 2 film from which part of the solvent has been removed is placed in a vacuum drying oven and dried at 65°C for 12 h to obtain a ring-crosslinked polyphosphazene-based dual-modal emission nanoparticle film.

[0082] Comparative Example 3

[0083] This comparative example provides a preparation method and application of a ring-crosslinked polyphosphazene-based dual-modal emission nanoparticle film.

[0084] The preparation method of the ring-crosslinked polyphosphazene-based dual-mode emission nanoparticle film specifically comprises the following steps:

[0085] (1) Preparation of solutions: Dissolve 32 mg of acriflavine in 1 ml of deionized water and ultrasonicate until completely dissolved to obtain solution 1; dissolve 52 mg of hexachlorocyclotriphosphazene and 35 mg of kaempferol in 149 ml of acetonitrile and ultrasonicate until completely dissolved to obtain solution 2; then transfer solution 1 and solution 2 to the same conical flask and mix well to obtain mixed solution 1 for later use;

[0086] (2) Preparation of cyclic cross-linked polyphosphazene nanoparticles by ultrasound-assisted precipitation polymerization: The mixed solution 1 obtained in step (1) was placed in a three-necked flask and subjected to ultrasound at 120W for 10 minutes, after which 6 ml of acid-binding agent triethylamine was slowly added. The mixture was subjected to ultrasound at 120W for 4 hours, after which the precipitate was separated by centrifugation. The precipitate was washed three times with anhydrous ethanol and deionized water respectively, dried in a vacuum drying oven, and then ground into powder to synthesize cyclic cross-linked polyphosphazene nanoparticles HACK.

[0087] (3) Preparation of nanoparticle polyvinyl alcohol composite membrane: 0.9 mg of the cyclic cross-linked polyphosphazene nanoparticles HACK synthesized in step (2) was weighed and dispersed in 2 ml of deionized water. After ultrasonic treatment at 120 W for 30 min, the solution was stirred at a stirring rate of 600 r / min for 4 h at room temperature to obtain solution 3 for use. At the same time, polyvinyl alcohol (PVA) No. 1773 was dissolved in deionized water, heated to 80 ° C and stirred at a stirring rate of 600 r / min for 4 h until the PVA was completely dissolved. The temperature was then lowered to room temperature to obtain a solution with a concentration of 10%. Solution 4 is set aside, 1 ml of solution 4 is mixed with solution 3, and the mixture is stirred at a stirring rate of 600 r / min for 4 h at room temperature to obtain a mixed solution 2, the mixed solution 2 is drawn and slowly dropped onto a glass slide, and the excess mixed solution 2 is removed after being scraped at a uniform speed with a four-sided preparation device, and the glass slide coated with the mixed solution 2 is placed under an infrared lamp for 50 min, the formed composite film is removed, and the mixed solution 2 film from which part of the solvent has been removed is placed in a vacuum drying oven and dried at 65°C for 12 h to obtain a ring-crosslinked polyphosphazene-based dual-modal emission nanoparticle film.

[0088] The optical and physical properties of the ring-crosslinked polyphosphazene-based dual-mode emission nanoparticle film of the present invention are tested by cutting the film into a rectangle of 2 cm by 3 cm in size, placing the film in an Edinburgh FS5 steady-state / transient fluorescence spectrometer, selecting an excitation wavelength of 470 nm, a detection wavelength of 500 nm, a scanning range of 475-700 nm, and using a commonly used delayed spectrum test method for testing.

[0089] The final test results are:

[0090] Example 1: The average particle size of the nanoparticles was measured to be 76 nm, and the intensity of the highest peak of the delayed spectrum was 4.3´10 4 , lifespan is 0.55 seconds;

[0091] Example 2: The average particle size of the nanoparticles was measured to be 87 nm, and the intensity of the highest peak of the delayed spectrum was 4.3´10 4 , lifespan is 0.55 seconds;

[0092] Example 3: The average particle size of the nanoparticles was measured to be 138 nm, and the intensity of the highest peak of the delayed spectrum was 4.3´10 4 , lifespan is 0.55 seconds;

[0093] Example 4: The average particle size of the nanoparticles was measured to be 145 nm, and the intensity of the highest peak of the delayed spectrum was 4.3´10 4 , lifespan is 0.55 seconds;

[0094] Example 5: The average particle size of the nanoparticles was measured to be 186 nm, and the intensity of the highest peak of the delayed spectrum was 4.3´10 4 , lifespan is 0.55 seconds;

[0095] Comparative Example 1: The average particle size of the nanoparticles was measured to be 76 nm, and the intensity of the highest peak of the delayed spectrum was 3.5´10 3 , lifespan is 0.42 seconds;

[0096] Comparative Example 2: The average particle size of the nanoparticles was measured to be 76 nm, and the intensity of the highest peak of the delayed spectrum was 2.3´10 3 , lifespan is 0.25 seconds;

[0097] Comparative Example 3: The average particle size of the nanoparticles was measured to be 76 nm, and the intensity of the highest peak of the delayed spectrum was 1.1´10 3 , with a lifetime of 0.12 seconds.

[0098] By comparing Example 1 with Comparative Examples 1 to 3, it can be seen that polyvinyl alcohol No. 1799 is better than polyvinyl alcohol No. 1788, better than polyvinyl alcohol No. 1780, and better than polyvinyl alcohol No. 1773, indicating that the higher the alcoholysis degree of polyvinyl alcohol, the better the performance.

[0099] In summary, the present invention utilizes the cyclic cross-linked polyphosphazene to conveniently introduce heteroatoms such as N, O, and P to further improve the stability of triplet excitons, and enhance the photophysical properties such as afterglow lifetime, duration, and quantum yield; the present invention utilizes the cyclic cross-linked polyphosphazene to conveniently introduce Cl heavy atoms, utilizes the heavy atom effect to enhance the SOC process, and then enhances the ISC process, increases the number of triplet excitons, and enhances the photophysical properties such as afterglow lifetime, duration, and quantum yield; the present invention utilizes the polymerization and cross-linking effects of the cyclic cross-linked polyphosphazene and the hydrogen bonding effect of PVA to enhance the rigidification effect of the system, inhibit the non-radiative decay process of triplet excitons, and enhance the photophysical properties such as afterglow lifetime, duration, and quantum yield; the present invention utilizes the spherical morphology of the cyclic cross-linked polyphosphazene nanoparticles , greatly improving the various photophysical properties of the system; the present invention realizes visible light excitation based on acridinium yellow, and prepares a long-life emitter with an optimal excitation wavelength of 470nm; based on the various advantages of acridinium yellow integrating ring-crosslinked polyphosphazene nanoparticles, the present invention realizes the preparation of a dual-modal emitter with RTP and TADF at room temperature, and TADF emits at 500nm and RTP emits at 580nm; the mixed solution of nanoparticles and polyvinyl alcohol involved in the present invention can be conveniently written or used to make anti-counterfeiting patterns in various matrices; the mixed solution of nanoparticles and polyvinyl alcohol involved in the present invention is not only suitable for low-temperature occasions, but also suitable for room temperature and high-temperature occasions (about 80°C), and the afterglow color can change with temperature.

[0100] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing a ring-crosslinked polyphosphazene-based dual-modal emission nanoparticle film, characterized in that: The following steps are involved: (1) Preparation of solution: deionized water and acetonitrile are used as solvents, respectively, with the volume percentage of the two being 1-4:96-99, and chromophore, polyphenolic flavonoids, and hexachlorocyclotriphosphazene are used as solutes, respectively, and the ratio of Cl in hexachlorocyclotriphosphazene to the functional groups OH and NH2 in the chromophore and polyphenolic flavonoids, and the ratio of the chromophore to the polyphenolic flavonoids are controlled, a certain amount of chromophore is placed in deionized water and ultrasonically dissolved until it is completely dissolved to obtain solution 1, and polyphenolic flavonoids and hexachlorocyclotriphosphazene are dissolved in acetonitrile and ultrasonically dissolved to obtain solution 2, and then solution 1 and solution 2 are transferred to the same container and mixed to obtain mixed solution 1 for standby use; (2) Preparation of cyclic cross-linked polyphosphazene nanoparticles by ultrasound-assisted precipitation polymerization: The mixed solution 1 obtained in step (1) is placed in another container for ultrasound treatment for 10 to 12 minutes, and then triethylamine, an acid-binding agent, is slowly added thereto. After further ultrasound treatment, the mixture is centrifuged to obtain a precipitate, which is washed with anhydrous ethanol and deionized water, respectively, and then dried in a vacuum drying oven. The precipitate is then ground into powder to synthesize cyclic cross-linked polyphosphazene nanoparticles HACK. (3) Preparation of nanoparticle polyvinyl alcohol composite film: weigh the cyclic cross-linked polyphosphazene nanoparticles HACK synthesized in step (2) and disperse them in deionized water. After ultrasonic treatment, stir at room temperature to obtain solution 3 for use. Meanwhile, dissolve polyvinyl alcohol in deionized water, heat and stir until the polyvinyl alcohol is completely dissolved, then cool to room temperature to obtain solution 4 for use. Mix solution 4 with solution 3, stir and mix at room temperature to obtain mixed solution 2. Pipette mixed solution 2 and slowly drip it onto a glass slide. Use a four-sided preparation device to scrape at a uniform speed and remove excess mixed solution 2. Place the glass slide coated with mixed solution 2 under an infrared lamp for 50 to 60 minutes. Remove the formed composite film and place it in a vacuum drying oven at 60 to 70°C to dry for 12 to 16 hours to obtain a cyclic cross-linked polyphosphazene-based dual-modal emission nanoparticle film. Wherein, in step (1), the chromophore is acriflavine and the polyphenol flavonoid is kaempferol.

2. The method for preparing the ring-crosslinked polyphosphazene-based dual-modal emission nanoparticle film according to claim 1, characterized in that: In step (1), the ratio of Cl in the hexachlorocyclotriphosphazene to the chromophore and the functional group in the polyphenol flavonoids is 9:7-11.

3. The method for preparing the ring-crosslinked polyphosphazene-based dual-mode emission nanoparticle film according to claim 1, characterized in that: In step (1), the ratio of the chromophore to the polyphenol flavonoids is 1-3:1-8.

4. The method for preparing the ring-crosslinked polyphosphazene-based dual-modal emission nanoparticle film according to claim 1, characterized in that: In step (2), the time of the continued ultrasonic treatment is 1 to 6 hours; the power of the continued ultrasonic treatment is 60 to 150 W.

5. The method for preparing the ring-crosslinked polyphosphazene-based dual-modal emission nanoparticle film according to claim 1, characterized in that: In step (2), the precipitate is first washed with anhydrous ethanol for 3 to 4 times, and then washed with deionized water for 3 to 4 times. After washing, it is placed in a vacuum drying oven at 60 to 70° C. and dried for 10 to 16 hours.

6. The method for preparing the ring-crosslinked polyphosphazene-based dual-modal emission nanoparticle film according to claim 1, characterized in that: In step (3), the temperature of the heating and stirring for preparing solution 4 is controlled to be 65-95°C, the time of the heating and stirring is controlled to be 4-6 hours, and the rate of the heating and stirring is 500-650 r / min; the ultrasonic power of the ultrasonic treatment for preparing solution 3 is 100-150 W, the time is controlled to be 30-50 min, the rate of stirring at room temperature is 550-650 r / min, and the time of stirring at room temperature is controlled to be 2-4 hours; the solution 4 is mixed with the solution 3, the rate of stirring at room temperature is 550-650 r / min, and the stirring time is controlled to be 2-4 hours.

7. The method for preparing the ring-crosslinked polyphosphazene-based dual-modal emission nanoparticle film according to claim 1, characterized in that: In step (3), the thickness of the prepared film is 0.1-0.2 mm, and the glass slide is a smooth glass slide for ordinary microscope.

8. Use of the ring-crosslinked polyphosphazene-based bimodal emitting nanoparticle film prepared by the method for preparing the ring-crosslinked polyphosphazene-based bimodal emitting nanoparticle film according to any one of claims 1 to 7 in anti-counterfeiting.

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