A room temperature phosphorescent material based on rhodamine dye and its application

Abstract

The invention discloses a room temperature phosphorescent material based on rhodamine dye and its application. The phosphorescent material is an afterglow system composed of rhodamine dye and polyphosphonate polymer; the material is obtained by the following preparation method: firstly, the polyphosphonate polymer is dissolved in dimethyl sulfoxide; then the rhodamine dye is added, stirred evenly, and the obtained solution is dripped on a quartz substrate and dried to form a film to obtain a room temperature phosphorescent material. The obtained room temperature phosphorescent material is used in the fields of information encryption and anti-counterfeiting technology. The rigid network environment of the polyphosphonate polymer of the invention inhibits the molecular motion of the dye, reduces the non-radiative deactivation of triplet excitons, and realizes room temperature phosphorescent emission based on rhodamine dye. The invention has low cost and good universality, provides a simple strategy for the room temperature phosphorescent emission of fluorescent dyes, and has good application prospects in the field of information anti-counterfeiting.

Description

Technical Field

[0001] The invention belongs to the technical field of phosphorescent materials, and in particular relates to a long-life polymer room-temperature phosphorescent material based on rhodamine derivatives and a preparation method and application thereof. Background Art

[0002] Due to their unique luminescence properties, room temperature phosphorescent materials have broad application prospects in anti-counterfeiting, bioimaging, organic light-emitting diodes (OLEDs) and information encryption. Traditional phosphorescent materials are mainly concentrated on inorganic materials containing rare earths, but progress has been slow due to the complex preparation methods and high costs. Compared with inorganic phosphorescent materials, pure organic room temperature phosphorescent materials have low biotoxicity, good processing performance and strong plasticity. Therefore, the development of pure organic room temperature phosphorescent materials is crucial. It is well known that the intersystem crossing (ISC) process from singlet to triplet state is spin-forbidden, and triplet excitons are affected by free movement and oxygen quenching, resulting in non-radiative deactivation. Therefore, achieving room temperature phosphorescent emission remains a huge challenge. In recent years, many outstanding strategies have been designed to promote the ISC process and suppress the non-radiative decay rate, including heavy atom effects, crystal engineering, host-guest interactions, carbon dots and polymer matrix doping.

[0003] There are many methods dedicated to achieving room temperature phosphorescent materials with high quantum yield and long emission lifetime. The main method reported is the crystal form, because crystals can compress the vibration of molecules and protect molecules from oxygen. However, crystal engineering has disadvantages such as low flexibility and difficulty in processing. In addition, since crystals are easily affected by temperature and solvent, they are not easy to apply on a large scale. Copolymerization and host-guest interactions often involve complex molecular design, which is not conducive to the construction of the system. These difficulties have prevented researchers from using a large library of fluorescent dyes to develop phosphorescent materials. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a room temperature phosphorescent material based on rhodamine dye with strong universality and low cost, so as to solve the problems that the existing room temperature phosphorescent materials have complex components, low universality, great processing difficulty and are not conducive to large-scale applications.

[0005] Furthermore, the present invention also provides the application of the room temperature phosphorescent material in realizing information anti-counterfeiting.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A room temperature phosphorescent material based on rhodamine dye, characterized in that the afterglow system is composed of a polyphosphonate polymer and a rhodamine dye; the polyphosphonate polymer has the following structure:

[0008]

[0009] The room temperature phosphorescent material based on rhodamine dye is prepared by the following method:

[0010] 1) dissolving a polyphosphonate polymer in dimethyl sulfoxide to prepare a solution with a concentration of 20-22 g / L, then adding rhodamine dye to the solution and stirring evenly; the mass ratio of the polyphosphonate polymer to the rhodamine dye is 98-102:1;

[0011] 2) The obtained solution is drop-coated on a quartz substrate and dried to form a film to obtain a room temperature phosphorescent material.

[0012] Wherein, the step 2) is carried out in a vacuum oven at a temperature of 58-62° C. and a drying time of 22-24 hours.

[0013] Further, the rhodamine dye is any one of rhodamine (RhB), sulforhodamine B (SRB), rhodamine 6G (Rh6G) or rhodamine 110 (Rh110):

[0014]

[0015] Furthermore, the preparation method of the polyphosphonate polymer comprises:

[0016] S11. Preparation of polyphosphonate polymer intermediates

[0017]

[0018] (1) adding 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, p-benzoquinone and ethylene glycol ethyl ether into a three-necked flask equipped with a magnet and an argon inlet and outlet; reacting at 140-145° C. for 4-4.2 hours, and filtering and washing the resulting product after cooling to room temperature to obtain a crude product of a polyphosphonate polymer intermediate; wherein the molar ratio of the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and p-benzoquinone is the same;

[0019] (2) recrystallizing the crude product of the polyphosphonate polymer intermediate, cooling and filtering, and drying in a vacuum oven to obtain a white powdery solid, which is the polyphosphonate polymer intermediate;

[0020] S12, preparing polyphosphonate polymers:

[0021]

[0022] (1) adding the polyphosphonate polymer intermediate obtained in step S11, phenylphosphonyl dichloride and zinc chloride into a four-necked flask equipped with a mechanical stirring device and an argon inlet and outlet, heating and reacting at a temperature of 160-165° C. for a period of time until the system becomes viscous and a climbing phenomenon occurs; then heating to 230-235° C. and continuing the reaction for 5-5.5 hours, vacuuming to remove the hydrogen chloride gas, and cooling the obtained product to obtain a crude polyphosphonate polymer product; the molar ratio of the polyphosphonate polymer intermediate and phenylphosphonyl dichloride is the same;

[0023] (2) The crude polyphosphonate polymer obtained in step (1) is dissolved in chloroform and then precipitated with anhydrous ether; finally, acetone is used as the solvent of a Soxhlet extractor and refluxed at 85-95° C. for 8-9 hours, and dried to obtain a polyphosphonate polymer.

[0024] The present invention also provides an application of a room temperature phosphorescent material based on a rhodamine dye, which is applied to the technical fields of information encryption and anti-counterfeiting.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The present invention creatively adopts rhodamine dye and polyphosphonate polymer to form an afterglow system, and the luminescence time is more than 2s; and the luminescent color of the phosphorescent material of the present invention is red, which enriches the luminescent color of the phosphorescent material and solves the problem that the luminescent colors of current room temperature phosphorescent materials are mostly blue and green, while the red phosphorescent emission is relatively small.

[0027] 2. The present invention uses common small molecules as raw materials to prepare polyphosphonate polymers, which have simple ingredients and are easy to prepare. In addition, the prepared polyphosphonate polymers have a good rigid structure, and their rigid network environment inhibits the molecular motion of the dye, reduces the non-radiative deactivation of triplet excitons, and realizes room temperature phosphorescence emission based on rhodamine dye.

[0028] 3. The present invention provides a new research direction and technical support for the preparation of simple and efficient fluorescent dye-type room temperature phosphorescent materials, and also enriches the application of dyes as phosphorescent emission materials; not only is the preparation method simple and the cost is low; and commercial rhodamine dyes are selected, and various types of rhodamine dyes are applicable, which has strong universality, low production cost, and is conducive to large-scale application.

[0029] 4. The preparation method of the dye-based room temperature phosphorescent material of the present invention has strong universality and is applicable to various types of rhodamine dyes. After the 365nm ultraviolet light source is turned off, a room temperature phosphorescent material with an afterglow color of orange-red, orange and orange-yellow can be obtained, which can be used in application fields such as information encryption and anti-counterfeiting.

[0030] 5. The room temperature phosphorescent material of the polymer of the present invention has better biocompatibility than small molecule systems, has advantages such as greater flexibility and can be prepared on a large area. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a phosphorescence emission diagram of the room temperature phosphorescent film prepared in Example 1 of the present invention under a 365nm ultraviolet lamp;

[0032] Figure 2 The relevant photophysical property spectrum of the room temperature phosphorescent film prepared in Example 1 of the present invention is measured when excited at 365nm in an atmospheric environment;

[0033] Figure 3 The phosphorescence emission phenomenon of the room temperature phosphorescent film prepared in Example 2-4 of the present invention under a 365nm ultraviolet lamp;

[0034] Figure 4 The fluorescence emission spectrum of the room temperature phosphorescent film prepared in Example 2-4 of the present invention when excited at 365 nm;

[0035] Figure 5 The phosphorescence emission spectrum of the room temperature phosphorescent film prepared in Example 2-4 of the present invention after being excited at 365 nm;

[0036] Figure 6 The phosphorescence lifetime spectra of the room temperature phosphorescent films prepared in Examples 2-4 of the present invention at different emission wavelengths when excited at 365 nm. DETAILED DESCRIPTION

[0037] The present invention is further described in detail below in conjunction with embodiments.

[0038] 1. A room temperature phosphorescent material based on rhodamine dye

[0039] The afterglow system is composed of polyphosphonate polymer and rhodamine dye;

[0040] Wherein, the polyphosphonate polymer has the following structure:

[0041]

[0042] Further, the rhodamine dye is rhodamine (RhB), sulforhodamine B (SRB), rhodamine 6G (Rh6G) or rhodamine 110 (Rh110), and the specific structure is as follows:

[0043]

[0044] 2. Preparation of the polyphosphonate polymer

[0045] (1) Preparation of polyphosphonate polymer intermediates

[0046]

[0047] 17g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 7g of p-benzoquinone and 34ml of ethylene glycol ethyl ether were added to a three-necked flask equipped with a magnet and an argon inlet and outlet. The reaction was carried out at 140°C for 4h, and the obtained product was cooled to room temperature and filtered, and then washed with ethylene glycol ethyl ether and methanol. The obtained crude product was recrystallized with ethylene glycol ethyl ether, filtered after cooling, and dried in a vacuum oven at 60°C for 24h to obtain a white powdery solid product.

[0048] (2) Preparation of polyphosphonate polymers

[0049]

[0050] Weigh 3.4125g of the solid powder obtained in step (1), 2.05g of phenylphosphonyl dichloride and 0.014g of zinc chloride in a 100ml four-necked flask equipped with a mechanical stirring device and an argon inlet and outlet. At a temperature of 160°C, in an argon protective environment, the reactants in the heating flask are in a liquid state. Maintain this temperature for a period of time until the system becomes viscous and a climbing phenomenon occurs. Then raise the temperature to 230°C and continue the reaction for 5h. Later, vacuumize to remove the residual hydrogen chloride gas in the system. After the reactants are cooled, they are the crude product of the polyphosphonate polymer. The obtained crude product is dissolved with chloroform, then precipitated with anhydrous ether, and then refluxed at 90°C for 8h with acetone as the solvent of the Soxhlet extractor, and dried to obtain the polyphosphonate polymer.

[0051] According to infrared spectroscopy and nuclear magnetic resonance hydrogen spectrum detection, the polyphosphonate polymer has the following structure:

[0052]

[0053] 3. Preparation of room temperature phosphorescent materials based on rhodamine dyes

[0054] Example 1

[0055] Weigh 20 mg of the obtained polyphosphonate polymer and dissolve it in 1 ml of dimethyl sulfoxide solution to prepare a 20 g / L solution. Then, weigh 0.2 mg of rhodamine B (RhB) and add it to the above solution. Apply the prepared solution dropwise on a quartz plate and dry it at 95°C to form a film, thereby obtaining a room temperature phosphorescent material based on rhodamine dye.

[0056] Embodiment 2-4

[0057] The methods of Examples 2-4 are the same as those of Example 1, except that Rhodamine B is replaced with sulforhodamine B (SRB), Rhodamine 6G (Rh6G) or Rhodamine 110 (Rh110). It can be seen that this method is universal for rhodamine dyes.

[0058] In the present invention, the structural formulas of rhodamine (RhB), sulforhodamine B (SRB), rhodamine 6G (Rh6G) or rhodamine 110 (Rh110) and polyphosphonate polymers are as follows:

[0059]

[0060] The structural formula of the solvent (dimethyl sulfoxide) used is as follows:

[0061]

[0062] 4. Verify the luminescence characteristics of phosphorescent materials

[0063] Verification method:

[0064] By exciting the obtained film with a 365nm, 30W ultraviolet lamp in an atmospheric environment, the room temperature phosphorescence phenomenon of different dye polymer systems can be observed.

[0065] like Figure 1 As shown, when the film obtained in Example 1 is excited by a 365nm ultraviolet lamp in an atmospheric environment, it can be clearly observed that the phosphorescence changes from strong to weak and finally disappears (in order from left to right and from top to bottom).

[0066] like Figure 2 As shown, Figure 2 is the spectrum of relevant photophysical properties of the film obtained in Example 1, Figure 2 (a, b, c) It can be seen that the film has a strong fluorescence intensity at 596nm under 365nm excitation ( Figure 2 a) and phosphorescence intensity ( Figure 2 b) and 285.14 ms ( Figure 2 c) Phosphorescence lifetime.

[0067] like Figure 3 As shown, when the film obtained in Example 2-4 is excited by a 365nm ultraviolet lamp in an atmospheric environment, the emission of different colors of phosphorescence can be clearly observed. The phosphorescence emission time is 2s, which has the advantage of a long luminescence time. When applied to the fields of information encryption and anti-counterfeiting technology, it is more conducive to user observation.

[0068] Figure 4 is the fluorescence emission spectrum of the room temperature phosphorescent film prepared in Example 2-4 of the present invention when excited at 365nm; Figure 4 (a, b, c) show that it has strong fluorescence emission, and its colors are orange-red, orange and orange-yellow respectively.

[0069] Figure 5 The phosphorescence emission spectrum of the room temperature phosphorescent film prepared in Example 2-4 of the present invention after being excited at 365nm; Figure 5 It can be seen that the phosphorescence emission is strong, and the optimal emission is located at around 602nm, 582nm and 568nm respectively.

[0070] Figure 6 The phosphorescence lifetime spectra of the room temperature phosphorescent film prepared in Example 2-4 of the present invention at different emission wavelengths when excited at 365nm. Figure 6 It can be seen that the phosphorescence lifetimes of the three films under the optimal emission are 247.62ms, 101.60ms, and 94.16ms, respectively, which have a long phosphorescence lifetime.

[0071] It can be seen that the present invention provides a room temperature phosphorescent material based on rhodamine dye with strong universality and low cost, which solves the problems of complex components, low universality, great processing difficulty, and being unfavorable for large-scale application of existing room temperature phosphorescent materials. The afterglow system is creatively composed of rhodamine dye and polyphosphonate polymer, and the luminescence time is more than 2s; and the luminescent color of the phosphorescent material of the present invention is red, which enriches the luminescent color of the phosphorescent material and solves the problem that the luminescent colors of the current room temperature phosphorescent materials are mostly blue and green, and the red phosphorescent emission is relatively small.

[0072] The present invention provides a new research direction and technical support for the preparation of simple and efficient fluorescent dye type room temperature phosphorescent materials, and also enriches the application of dyes as phosphorescent emission materials. It is particularly suitable for application fields such as information encryption and anti-counterfeiting.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the technical solution. Those skilled in the art should understand that those modifications or equivalent substitutions of the technical solution of the present invention that do not depart from the purpose and scope of the technical solution should be included in the scope of the claims of the present invention.

Claims

1. A room temperature phosphorescent material based on rhodamine dye, characterized in that: The afterglow system is composed of a polyphosphonate polymer and a rhodamine dye; the mass ratio of the polyphosphonate polymer to the rhodamine dye is 98-102:1; and the polyphosphonate polymer has the following structure:

2. The room temperature phosphorescent material based on rhodamine dye according to claim 1, characterized in that: The rhodamine dye is any one of rhodamine, sulfonyl rhodamine B, rhodamine 6G or rhodamine 110, and the structural formula of rhodamine, sulfonyl rhodamine B, rhodamine 6G or rhodamine 110 is as follows:

3. The room temperature phosphorescent material based on rhodamine dye according to claim 1 or 2, characterized in that: The polyphosphonate polymer is prepared by the following method: S11. Preparation of polyphosphonate polymer intermediates S12, preparation of polyphosphonate polymers 4. The room temperature phosphorescent material based on rhodamine dye according to claim 3, characterized in that: The method for preparing a polyphosphonate polymer intermediate in S11 comprises: (1) adding 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, p-benzoquinone and ethylene glycol ethyl ether into a three-necked flask equipped with a magnet and an argon inlet and outlet; reacting at 140-145° C. for 4-4.2 hours, and filtering and washing the resulting product after cooling to room temperature to obtain a crude product of a polyphosphonate polymer intermediate; wherein the molar ratio of the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and p-benzoquinone is the same; (2) recrystallizing the crude product of the polyphosphonate polymer intermediate, cooling and filtering, and drying in a vacuum oven to obtain a white powdery solid, which is the polyphosphonate polymer intermediate; The method for preparing polyphosphonate polymers in S12 comprises: (1) adding the polyphosphonate polymer intermediate obtained in step S11, phenylphosphonyl dichloride and zinc chloride into a four-necked flask equipped with a mechanical stirring device and an argon inlet and outlet, heating and reacting at a temperature of 160-165° C. for a period of time until the system becomes viscous and a climbing phenomenon occurs; then heating to 230-235° C. and continuing the reaction for 5-5.5 hours, vacuuming to remove the hydrogen chloride gas, and cooling the obtained product to obtain a crude polyphosphonate polymer product; the molar ratio of the polyphosphonate polymer intermediate and phenylphosphonyl dichloride is the same; (2) The crude polyphosphonate polymer obtained in step (1) is dissolved in chloroform and then precipitated with anhydrous ether; finally, acetone is used as the solvent of a Soxhlet extractor and refluxed at 85-95° C. for 8-9 hours, and dried to obtain a polyphosphonate polymer.

5. The room temperature phosphorescent material based on rhodamine dye according to claim 1 or 2, characterized in that: The preparation method thereof comprises: S21, dissolving a polyphosphonate polymer in dimethyl sulfoxide to prepare a solution with a concentration of 20-22 g / L, then adding rhodamine dye to the solution and stirring evenly; the mass ratio of the polyphosphonate polymer to the rhodamine dye is 98-102:1; S22, drop-coat the solution obtained in S21 on a quartz substrate, dry it and form a film to obtain a room temperature phosphorescent material.

6. The room temperature phosphorescent material based on rhodamine dye according to claim 5, characterized in that: The step S22 is carried out in a vacuum oven at a temperature of 58-62° C. and a drying time of 22-24 hours.

7. An application of a room temperature phosphorescent material based on rhodamine dye, characterized in that: The room temperature phosphorescent material described in any one of claims 1 to 6 is applied in the field of information encryption and anti-counterfeiting technology.

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