A single-component room-temperature phosphorescence / fluorescence dual-emission polymer thin film and a preparation method and application thereof
By synthesizing and applying a single-component phosphorescent/fluorescent dual-emission polymer thin film, the problems of poor stability and signal anti-interference ability of existing materials have been solved, enabling quantitative detection and visual sensing applications of humidity.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NINGBO INST OF MATERIALS TECH & ENG CHINESE ACAD OF SCI
- Filing Date
- 2023-04-11
- Publication Date
- 2026-06-30
AI Technical Summary
Existing stimulus-responsive phosphorescent/fluorescent materials are mostly prepared from noble metal complexes, which have problems such as uncontrollable luminescence behavior, high cost, difficult synthesis, and single emission wavelength, resulting in poor material stability and signal anti-interference ability, making it difficult to achieve quantitative detection of humidity.
A single-component organic light-emitting small molecule with phosphorescence/fluorescence dual emission function was synthesized by reacting terminal amino-substituted alkanes with halogen heavy atom groups-modified naphthalene dicarboxylic anhydride. This molecule was then incorporated into a dynamically cross-linked supramolecular polymer network. The aggregation state structure of the light-emitting small molecule was controlled by the dynamic changes of hydrogen bonds to prepare a phosphorescence/fluorescence dual emission polymer film.
It achieves stable emission of phosphorescent/fluorescent dual emission ratio light signals at room temperature, can sense changes in ambient humidity, has self-correction capabilities, avoids interference from external factors, and is suitable for fields such as sensing, anti-counterfeiting, and bioimaging.
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Figure CN116554514B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the technical fields of organic light-emitting materials and intelligent polymer materials, specifically relating to a single-component room-temperature phosphorescent / fluorescent dual-emission polymer film, its preparation method, and its application. Background Technology
[0002] Stimulus-responsive phosphorescent / fluorescent materials are a class of smart materials that can sense changes in external environmental stimuli (such as heat, electricity, light, magnetism, pH, and chemical substances) and dynamically change their color, emission peak intensity, and lifetime accordingly. Due to their reversible and controllable phosphorescence / fluorescence emission characteristics, they show broad application prospects in fields such as intelligent sensing, information anti-counterfeiting, and bioimaging. However, existing stimulus-responsive phosphorescent / fluorescent materials are mostly prepared from inorganic compounds such as noble metal complexes. These materials have long suffered from problems such as uncontrollable luminescence behavior, high cost, and difficulty in synthesis. Therefore, the development of purely organic room-temperature phosphorescent / fluorescent materials has significant scientific and social value for the development of smart luminescent materials.
[0003] Currently, research on organic fluorescent and room temperature phosphorescent materials has a certain foundation. In the traditional preparation methods of organic fluorescent and room temperature phosphorescent materials, researchers obtain such luminescent materials through chemical modification, covalent polymerization, physical blending and other methods.
[0004] Patent CN 106188391 B discloses a method for preparing a humidity-responsive, room-temperature-temperature phosphorescent and fluorescent dual-emission polymer material. This method is applicable to most phosphorescent-fluorescent mixed systems. It utilizes the phenomenon of humidity disrupting hydrogen bonds in the polymer, thereby quenching the phosphorescence of the phosphorescent compound and controlling the luminescence changes of the mixed system. Simultaneously, by copolymerizing the phosphorescent monomer, the fluorescent monomer, and acrylamide, a humidity-responsive, two-component, room-temperature-temperature phosphorescent and fluorescent dual-emission pure organic polymer material can be obtained. The prepared polymer material emits phosphorescence through the heavy atom effect and exhibits strong luminescence intensity at room temperature.
[0005] Patent application CN 114716600 A discloses the synthesis and application of a fluorescent polymer. The method involves first synthesizing fluorescent monomers, and then copolymerizing these monomers, carboxyl monomers, and sulfonic acid monomers in specific proportions under specific process conditions to obtain the fluorescent polymer. The modified fluorescent monomers are introduced into the polymer via covalent polymerization, resulting in a polymer that stably emits fluorescence.
[0006] Although current smart luminescent materials have achieved effective control over luminescence intensity and wavelength, their emission wavelength is still a single peak. In humidity sensing applications, qualitative or semi-quantitative humidity sensing can only be achieved by enhancing or weakening the luminescence intensity of their single emission peak. Furthermore, they are highly susceptible to interference from external factors such as instruments, concentration, and environment, resulting in problems such as poor material stability, poor signal anti-interference ability, and low accuracy.
[0007] Therefore, there is an urgent need to develop new luminescent polymer thin film materials with dual emission peaks of fluorescence and phosphorescence, and to utilize the ratio of luminescence intensity at different wavelengths to realize their application in quantitative humidity detection. This is of great significance for the application of stimulus-responsive luminescent materials in the field of sensing and detection. Summary of the Invention
[0008] To address the aforementioned technical problems, this invention provides a method for preparing a single-component room-temperature phosphorescent / fluorescent dual-emission polymer film. This method involves reacting terminal amino-substituted alkanes with halogen-modified naphthalenecarboxylic anhydride to synthesize organic light-emitting small molecules with single-component phosphorescent / fluorescent dual-emission functionality in a one-step process. These organic light-emitting small molecules are then incorporated into a dynamically cross-linked supramolecular polymer network to prepare the phosphorescent / fluorescent dual-emission polymer film. This invention offers a wide range of linear polymer choices, a simple preparation method, an environmentally friendly and pollution-free stimulation mechanism, and low cost.
[0009] A method for preparing a single-component room-temperature phosphorescent / fluorescent dual-emission polymer thin film includes the following steps:
[0010] (1) React terminal amino-substituted alkanes with halogen heavy atom groups-modified naphthalic anhydride to synthesize organic light-emitting small molecules with single-component phosphorescence / fluorescence dual emission functions.
[0011] (2) The organic light-emitting small molecules prepared in step (1) are blended with the dynamically cross-linked supramolecular polymer to obtain a single-component room temperature phosphorescent / fluorescent dual-emission polymer film.
[0012] Since 1,8-naphthalic anhydride emits only weak fluorescence, reacting it with a primary amine can enhance its fluorescence intensity. The presence of halogen heavy atoms can effectively promote intersystem crossing, improve spin-orbit coupling, and endow the material with phosphorescent properties. Therefore, this invention selects terminal amino-substituted alkanes and halogen heavy atom-modified naphthalic anhydride as raw materials. The partially positively charged carbon atoms on the two carbonyl groups in the naphthalic anhydride molecule perform electrophilic attacks on the lone electron pairs on the nitrogen atoms of the primary amine, forming naphthalimide after dehydration, thereby preparing an organic light-emitting small molecule with both phosphorescence and fluorescence emission functions.
[0013] The single-component room-temperature phosphorescent / fluorescent dual-emission polymer film prepared by this invention is a humidity-responsive smart color-changing film. It utilizes the dynamic changes of hydrogen bonds in the supramolecular polymer network to regulate the aggregation state structure of organic light-emitting small molecules. Specifically, the spatial arrangement and intermolecular interactions of the light-emitting small molecules are changed by the entry of water molecules, which causes a conformational change in the macromolecular chain. As a result, the film can dynamically and reversibly change its emission color in response to changes in the humidity of the external environment.
[0014] In step (1), the alkyl chain length of the terminal amino-substituted alkane is not limited. Preferably, the halogen heavy atom group includes bromine, chlorine, or iodine atoms, and the single-component phosphorescent / fluorescent dual-emission organic light-emitting small molecule includes, but is not limited to, the following structures:
[0015]
[0016] Preferably, in step (1), the preparation method of the single-component phosphorescent / fluorescent dual-emission organic light-emitting small molecule is as follows:
[0017] (1-1) Compound 1 and compound 2 were mixed in an organic solvent and reacted at 65–95 °C for 4–12 h to obtain an intermediate product.
[0018] Compound 1 is naphthalic anhydride modified with bromine, chlorine, or iodine atoms; Compound 2 is an aliphatic primary amine; The organic solvent is methanol, ethanol, N,N-dimethylformamide, or dimethyl sulfoxide.
[0019] (1-2) The intermediate product obtained in step (1-1) was washed with saturated sodium carbonate solution for 24-48 h to obtain an organic light-emitting small molecule with single-component phosphorescence / fluorescence dual emission function.
[0020] Preferably, in step (1-1), the molar ratio of compound 1 to compound 2 is 1:2 to 2.5.
[0021] Preferably, in step (1-2), the molar ratio of the intermediate product to the saturated sodium carbonate solution is 1:1 to 10.
[0022] Preferably, in step (2), the dynamically cross-linked supramolecular polymer is polyacrylamide, polyacrylic acid, or polypyrrolidone containing side chains, and the side chains are amino, hydroxyl, or carboxyl groups.
[0023] The dynamically cross-linked supramolecular polymer is formed through non-covalent interactions, where the non-covalent bonds can respond to external stimuli. Under different humidity conditions, the non-covalent bonds can undergo reversible breakage and formation. This invention selects the above-mentioned humidity-sensitive dynamically cross-linked supramolecular polymer as a matrix and uses the dynamic changes of hydrogen bonds in the supramolecular polymer network to regulate the aggregation state structure of organic light-emitting small molecules, thereby regulating the change of the light emission color of the film.
[0024] Preferably, in step (2), the method for preparing the single-component room-temperature phosphorescent / fluorescent dual-emission polymer film is as follows:
[0025] (2-1) Dissolve the organic light-emitting small molecule with single-component phosphorescence / fluorescence dual emission function prepared in step (1) in methanol to prepare a solution, add the dynamically cross-linked supramolecular polymer, and obtain a mixed solution after the polymer is completely dissolved.
[0026] (2-2) Pour the mixed solution into the mold and wait for the solvent to evaporate completely to obtain a single-component room temperature phosphorescent / fluorescent dual-emission polymer film.
[0027] Preferably, in step (2-1), the molar ratio of the single-component phosphorescent / fluorescent dual-emission organic light-emitting small molecule to methanol is 1:10. 6 ~10 8 The blending ratio of the single-component phosphorescent / fluorescent dual-emission organic light-emitting small molecule to the supramolecular polymer is 1:10. 4 ~10 6 .
[0028] Preferably, in step (2-2), the volume ratio of the mixed solution to the polystyrene mold is 1:1 to 5. This volume ratio is chosen to prevent the mixed solution from overflowing if the mold is too small, and to avoid waste if the mold is too large.
[0029] Preferably, in step (2-2), the solvent evaporation is carried out by standing, blowing air or heating, and the ambient temperature for solvent evaporation is 20-100℃, and the time is 1-12h.
[0030] This invention also provides a single-component room-temperature phosphorescent / fluorescent dual-emission polymer film prepared by the above-described method. This film can generate phosphorescent / fluorescent dual-emission ratio light signals with only a single component, exhibits stable emission, and can sense ambient humidity in the range of 1–100%, showing broad application prospects in fields such as sensing, anti-counterfeiting, and bioimaging.
[0031] This invention also provides the application of the single-component room-temperature phosphorescent / fluorescent dual-emission thin film in visual humidity sensing. The single-component room-temperature phosphorescent / fluorescent dual-emission thin film of this invention exhibits two distinct emission peaks under ultraviolet light, and the ratio of the emission intensities of the two peaks changes with variations in ambient humidity, thereby causing a change in the color of the polymer film, thus enabling visual humidity sensing applications.
[0032] Preferably, the single-component room-temperature phosphorescent / fluorescent dual-emission film is used in a ratiometric fluorescent probe. This invention constructs a ratiometric fluorescent probe with self-calibration capability based on the ratio of the luminescence intensity of the single-component room-temperature phosphorescent / fluorescent dual-emission film at different wavelengths. The change in this ratio value is independent of the light source intensity and probe concentration, depending only on the concentration of the analyte, thus offering unique advantages in quantitative humidity detection.
[0033] Compared with the prior art, the present invention has at least the following beneficial effects:
[0034] (1) The linear polymers used in this invention have a wide range of choices, the preparation method is simple, and there is no need for expensive chemical reagents or instruments and equipment, resulting in low cost.
[0035] (2) In this invention, organic light-emitting small molecules are physically blended into a polymer network. The entry of water molecules causes a change in the conformation of the macromolecular chain, thereby changing the spatial arrangement and intermolecular interactions of the light-emitting small molecules to regulate the change of the light-emitting color. The stimulation method is environmentally friendly and pollution-free, and the operation is convenient.
[0036] (3) The present invention can generate phosphorescent / fluorescent dual emission ratio light signals with only a single component. The emission is stable, overcoming the shortcomings of the previous dual chromophore energy transfer process and the poor stability of different chromophores. Furthermore, the ratio type luminescence signal can determine the content of the target analyte based on the ratio of its emission peak intensities, avoiding interference from external factors such as concentration and test conditions on a single emission peak.
[0037] (4) The polymer film prepared by the present invention can emit strong phosphorescence / fluorescence signals at room temperature without the need for traditional organic dyes and semiconductor quantum dots containing heavy metal elements. It has the advantages of low biotoxicity, low cost and diverse molecular design. Attached Figure Description
[0038] Figure 1 A schematic diagram illustrating the process of preparing the single-component room-temperature phosphorescent / fluorescent dual-emission polymer film for this example;
[0039] Figure 2 The phosphorescence spectrum of the single-component room-temperature phosphorescent / fluorescent dual-emission polymer film prepared in Example 1 is shown.
[0040] Figure 3The humidity-responsive emission spectrum of the single-component room-temperature phosphorescent / fluorescent dual-emission polymer film prepared in Example 1;
[0041] Figure 4 A photograph of the single-component room-temperature phosphorescent / fluorescent dual-emission polymer film prepared in Example 1 under typical humidity conditions;
[0042] Figure 5 The diagram illustrates the mechanism of humidity response of the single-component room-temperature phosphorescent / fluorescent dual-emission polymer film prepared in the example. Detailed Implementation
[0043] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described and illustrated below with reference to examples. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0044] Figure 1 A schematic diagram of the process for preparing a single-component room-temperature phosphorescent / fluorescent dual-emission polymer film in the examples is shown. Figure 1 As shown, the prepared phosphorescent / fluorescent monomer (an organic light-emitting small molecule with single-component phosphorescent / fluorescent dual emission function) was dissolved in methanol to prepare a solution. The polymer was then dissolved in the solution containing the phosphorescent / fluorescent monomer until the polymer was completely dissolved to obtain a mixed solution. The mixed solution was poured into a polystyrene mold, and after the methanol was completely evaporated, a single-component room temperature phosphorescent / fluorescent dual emission polymer film was obtained.
[0045] Example 1
[0046] (1) Preparation of phosphorescent / fluorescent monomer: 3.048 g of naphthenic anhydride and 0.441 g of ethylenediamine were dissolved in 120 ml of methanol and refluxed at 65 °C for 10 h to obtain an intermediate product. The obtained intermediate product was washed with saturated sodium carbonate solution for 36 h and dried to obtain a relatively pure phosphorescent / fluorescent monomer.
[0047] (2) Preparation of a single-component room-temperature phosphorescent / fluorescent dual-emission polymer film: 0.1017 g of phosphorescent / fluorescent monomer was weighed and dissolved in 250 ml of methanol, and refluxed at 40 °C for 12 h to prepare a mixed solution. 0.5 g of poly(hydroxyethyl methacrylate) was weighed and dissolved in 5 ml of methanol solution containing phosphorescent / fluorescent monomer until the supramolecular polymer was completely dissolved to obtain a mixed solution. The mixed solution was poured into a polystyrene mold and allowed to stand at 45 °C for 6 h. After the solvent had completely evaporated, a humidity-responsive single-component room-temperature phosphorescent / fluorescent dual-emission polymer film was obtained.
[0048] The optical properties of the single-component room-temperature phosphorescent / fluorescent dual-emission polymer film prepared in this embodiment were characterized, and the phosphorescence spectrum of the single-component room-temperature phosphorescent / fluorescent dual-emission polymer film (e.g., Figure 2 ),Depend on Figure 2 It is known that the single-component room-temperature phosphorescent / fluorescent dual-emission polymer film prepared in this embodiment has a significant phosphorescence emission peak in the 550-650 nm range. The humidity-responsive emission spectrum of the single-component room-temperature phosphorescent / fluorescent dual-emission polymer film (e.g.) Figure 3 Under 365nm ultraviolet light, the humidity-responsive emission spectrum of the obtained polymer film has two distinct emission peaks, around 430nm and 570nm, respectively. As the water molecule content in the environment increases, the intensity ratio of the emission peak at the longer wavelength (570nm) to the emission peak at the shorter wavelength (430nm) decreases sequentially.
[0049] Figure 4 This is a photograph of the polymer film prepared in this embodiment under typical humidity conditions. Figure 3 Images of the film under 365nm and 254nm ultraviolet light are shown. In the color images, under 365nm ultraviolet light, the film color changes from a distinct purplish-red to blue with increasing humidity; under 254nm ultraviolet light, the film color changes from a distinct yellow to blue with increasing humidity.
[0050] The dual-emission thin film prepared in this embodiment can sense ambient humidity in the range of 1 to 100%, and can generate phosphorescent / fluorescent dual-emission ratio light signals with only a single component. The emission is stable, thus enabling ratio-type humidity sensing applications.
[0051] Example 2
[0052] (1) Preparation of phosphorescent / fluorescent monomer: 3.324 g of naphthic anhydride and 0.529 g of propylenediamine were dissolved in 240 ml of ethanol and refluxed at 95 °C for 4 h to obtain an intermediate product. The obtained intermediate product was washed with saturated sodium carbonate solution for 24 h and dried to obtain a relatively pure phosphorescent / fluorescent monomer.
[0053] (2) Preparation of a single-component room-temperature phosphorescent / fluorescent dual-emission polymer film: 0.01 g of phosphorescent / fluorescent monomer was dissolved in 50 ml of methanol and refluxed at 30 °C for 12 h to prepare a mixed solution. 0.1 g of poly(hydroxyethyl methacrylate) was dissolved in 3 ml of methanol solution containing phosphorescent / fluorescent monomer until the supramolecular polymer was completely dissolved to obtain a mixed solution. The mixed solution was poured into a polystyrene mold and allowed to stand at 60 °C for 2 h. After the solvent evaporated, a humidity-responsive single-component room-temperature phosphorescent / fluorescent dual-emission polymer film was obtained.
[0054] The optical properties of the single-component room-temperature phosphorescent / fluorescent dual-emission polymer film prepared in this embodiment were characterized, and the phosphorescence spectrum and humidity-responsive emission spectrum of the single-component room-temperature phosphorescent / fluorescent dual-emission polymer film were obtained. In the phosphorescence spectrum, the single-component room-temperature phosphorescent / fluorescent dual-emission polymer film prepared in this embodiment has a distinct phosphorescence emission peak in the 550-650 nm range. Under 365 nm ultraviolet light, the humidity-responsive emission spectrum of the obtained single-component room-temperature phosphorescent / fluorescent dual-emission polymer film shows two distinct emission peaks, and the intensity ratio of the emission peak at longer wavelengths to that at shorter wavelengths decreases sequentially with the increase of water molecule content in the environment.
[0055] Photographs of the polymer film prepared in this embodiment under typical humidity were obtained under 365nm and 254nm ultraviolet light. In the color images, under 365nm ultraviolet light, the film color changed from a distinct purplish-red to blue with increasing humidity; under 254nm ultraviolet light, the film color changed from a distinct yellow to blue with increasing humidity.
[0056] The dual-emission thin film prepared in this embodiment can sense ambient humidity in the range of 1 to 100%, and can generate phosphorescent / fluorescent dual-emission ratio light signals with only a single component. The emission is stable, thus enabling ratio-type humidity sensing applications.
[0057] Example 3
[0058] (1) Preparation of phosphorescent / fluorescent monomer: 5.54 g of naphthenic anhydride and 0.882 g of butanediamine were dissolved in 240 ml of methanol and refluxed at 80 °C for 6 h to obtain an intermediate product. The obtained intermediate product was washed with saturated sodium carbonate solution for 48 h and dried to obtain a relatively pure phosphorescent / fluorescent monomer.
[0059] (2) Preparation of a single-component room-temperature phosphorescent / fluorescent dual-emission polymer film: 0.05 g of phosphorescent / fluorescent monomer was dissolved in 180 ml of methanol and refluxed at 30 °C for 12 h to prepare a mixed solution. 0.3 g of poly(hydroxyethyl methacrylate) was dissolved in 5 ml of methanol solution containing phosphorescent / fluorescent monomer until the supramolecular polymer was completely dissolved to obtain a mixed solution. The mixed solution was poured into a polystyrene mold and allowed to stand at 30 °C for 12 h. After the solvent evaporated, a room-temperature phosphorescent / fluorescent ratio dual-emission polymer film with humidity responsiveness was obtained.
[0060] The optical properties of the single-component room-temperature phosphorescent / fluorescent dual-emission polymer film prepared in this embodiment were characterized, and the phosphorescence spectrum and humidity-responsive emission spectrum of the single-component room-temperature phosphorescent / fluorescent dual-emission polymer film were obtained. In the phosphorescence spectrum, the single-component room-temperature phosphorescent / fluorescent dual-emission polymer film prepared in this embodiment has a distinct phosphorescence emission peak in the 550-650 nm range. Under 365 nm ultraviolet light, the humidity-responsive emission spectrum of the obtained single-component room-temperature phosphorescent / fluorescent dual-emission polymer film shows two distinct emission peaks, and the intensity ratio of the emission peak at longer wavelengths to that at shorter wavelengths decreases sequentially with the increase of water molecule content in the environment.
[0061] Photographs of the polymer film prepared in this embodiment under typical humidity were obtained under 365nm and 254nm ultraviolet light. In the color images, under 365nm ultraviolet light, the film color changed from a distinct purplish-red to blue with increasing humidity; under 254nm ultraviolet light, the film color changed from a distinct yellow to blue with increasing humidity.
[0062] The dual-emission thin film prepared in this embodiment can sense ambient humidity in the range of 1 to 100%, and can generate phosphorescent / fluorescent dual-emission ratio light signals with only a single component. The emission is stable, thus enabling ratio-type humidity sensing applications.
[0063] Example 4
[0064] (1) Preparation of phosphorescent / fluorescent monomer: 3.878 g of naphthic anhydride and 0.62 g of pentanediamine were dissolved in 200 ml of ethanol and refluxed at 75 °C for 10 h to obtain an intermediate product. The obtained intermediate product was washed with saturated sodium carbonate solution for 36 h and dried to obtain a relatively pure phosphorescent / fluorescent monomer.
[0065] (2) Preparation of a single-component room-temperature phosphorescent / fluorescent dual-emission polymer film: 0.08 g of phosphorescent / fluorescent monomer was dissolved in 200 ml of methanol and refluxed at 50 °C for 10 h to prepare a mixed solution. 0.5 g of poly(hydroxyethyl methacrylate) was dissolved in 5 ml of methanol solution containing phosphorescent / fluorescent monomer until the supramolecular polymer was completely dissolved to obtain a mixed solution. The mixed solution was poured into a polystyrene mold and allowed to stand at 30 °C for 12 h. After the solvent evaporated, a humidity-responsive single-component room-temperature phosphorescent / fluorescent dual-emission polymer film was obtained.
[0066] The optical properties of the single-component room-temperature phosphorescent / fluorescent dual-emission polymer film prepared in this embodiment were characterized, and the phosphorescence spectrum and humidity-responsive emission spectrum of the single-component room-temperature phosphorescent / fluorescent dual-emission polymer film were obtained. In the phosphorescence spectrum, the single-component room-temperature phosphorescent / fluorescent dual-emission polymer film prepared in this embodiment has a distinct phosphorescence emission peak in the 550-650 nm range. Under 365 nm ultraviolet light, the humidity-responsive emission spectrum of the obtained single-component room-temperature phosphorescent / fluorescent dual-emission polymer film shows two distinct emission peaks, and the intensity ratio of the emission peak at longer wavelengths to that at shorter wavelengths decreases sequentially with the increase of water molecule content in the environment.
[0067] Photographs of the polymer film prepared in this embodiment under typical humidity were obtained under 365nm and 254nm ultraviolet light. In the color images, under 365nm ultraviolet light, the film color changed from a distinct purplish-red to blue with increasing humidity; under 254nm ultraviolet light, the film color changed from a distinct yellow to blue with increasing humidity.
[0068] The dual-emission thin film prepared in this embodiment can sense ambient humidity in the range of 1 to 100%, and can generate phosphorescent / fluorescent dual-emission ratio light signals with only a single component. The emission is stable, thus enabling ratio-type humidity sensing applications.
[0069] Example 5
[0070] (1) Preparation of phosphorescent / fluorescent monomer: 2.77 g of naphthenic anhydride and 0.441 g of hexamethylenediamine were dissolved in 100 ml of methanol and refluxed at 65 °C for 8 h to obtain an intermediate product. The obtained intermediate product was washed with saturated sodium carbonate solution for 36 h and dried to obtain a relatively pure phosphorescent / fluorescent monomer.
[0071] (2) Preparation of a single-component room-temperature phosphorescent / fluorescent dual-emission polymer film: 0.06 g of phosphorescent / fluorescent monomer was dissolved in 180 ml of methanol and refluxed at 50 °C for 6 h to prepare a mixed solution. 0.8 g of poly(hydroxyethyl methacrylate) was dissolved in 8 ml of methanol solution containing phosphorescent / fluorescent monomer until the supramolecular polymer was completely dissolved to obtain a mixed solution. The mixed solution was poured into a polystyrene mold and allowed to stand at 40 °C for 12 h. After the solvent evaporated, a humidity-responsive single-component room-temperature phosphorescent / fluorescent dual-emission polymer film was obtained.
[0072] The optical properties of the single-component room-temperature phosphorescent / fluorescent dual-emission polymer film prepared in this embodiment were characterized, and the phosphorescence spectrum and humidity-responsive emission spectrum of the single-component room-temperature phosphorescent / fluorescent dual-emission polymer film were obtained. In the phosphorescence spectrum, the single-component room-temperature phosphorescent / fluorescent dual-emission polymer film prepared in this embodiment has a distinct phosphorescence emission peak in the 550-650 nm range. Under 365 nm ultraviolet light, the humidity-responsive emission spectrum of the obtained single-component room-temperature phosphorescent / fluorescent dual-emission polymer film shows two distinct emission peaks, and the intensity ratio of the emission peak at longer wavelengths to that at shorter wavelengths decreases sequentially with the increase of water molecule content in the environment.
[0073] Photographs of the polymer film prepared in this embodiment under typical humidity were obtained under 365nm and 254nm ultraviolet light. In the color images, under 365nm ultraviolet light, the film color changed from a distinct purplish-red to blue with increasing humidity; under 254nm ultraviolet light, the film color changed from a distinct yellow to blue with increasing humidity.
[0074] The dual-emission thin film prepared in this embodiment can sense ambient humidity in the range of 1 to 100%, and can generate phosphorescent / fluorescent dual-emission ratio light signals with only a single component. The emission is stable, thus enabling ratio-type humidity sensing applications.
[0075] Example 6
[0076] (1) Preparation of phosphorescent / fluorescent monomers: 4.986 g of naphthic anhydride and 0.793 g of heptanediamine were dissolved in 280 ml of ethanol and refluxed at 95 °C for 8 h to obtain an intermediate product. The obtained intermediate product was washed with saturated sodium carbonate solution for 36 h and dried to obtain a relatively pure phosphorescent / fluorescent monomer.
[0077] (2) Preparation of a single-molecule room-temperature phosphorescent / fluorescent dual-emission polymer film: 0.08 g of phosphorescent / fluorescent monomer was dissolved in 220 ml of methanol and refluxed at 60 °C for 10 h to prepare a mixed solution. 0.7 g of poly(hydroxyethyl methacrylate) was dissolved in 7 ml of methanol solution containing phosphorescent / fluorescent monomer until the supramolecular polymer was completely dissolved to obtain a mixed solution. The mixed solution was poured into a polystyrene mold and allowed to stand at 30 °C for 12 h. After the solvent evaporated, a humidity-responsive single-component room-temperature phosphorescent / fluorescent dual-emission polymer film was obtained.
[0078] The optical properties of the single-component room-temperature phosphorescent / fluorescent dual-emission polymer film prepared in this embodiment were characterized, and the phosphorescence spectrum and humidity-responsive emission spectrum of the single-component room-temperature phosphorescent / fluorescent dual-emission polymer film were obtained. In the phosphorescence spectrum, the single-component room-temperature phosphorescent / fluorescent dual-emission polymer film prepared in this embodiment has a distinct phosphorescence emission peak in the 550-650 nm range. Under 365 nm ultraviolet light, the humidity-responsive emission spectrum of the obtained single-component room-temperature phosphorescent / fluorescent dual-emission polymer film shows two distinct emission peaks, and the intensity ratio of the emission peak at longer wavelengths to that at shorter wavelengths decreases sequentially with the increase of water molecule content in the environment.
[0079] Photographs of the polymer film prepared in this embodiment under typical humidity were obtained under 365nm and 254nm ultraviolet light. In the color images, under 365nm ultraviolet light, the film color changed from a distinct purplish-red to blue with increasing humidity; under 254nm ultraviolet light, the film color changed from a distinct yellow to blue with increasing humidity.
[0080] The dual-emission thin film prepared in this embodiment can sense ambient humidity in the range of 1 to 100%, and can generate phosphorescent / fluorescent dual-emission ratio light signals with only a single component. The emission is stable, thus enabling ratio-type humidity sensing applications.
[0081] Figure 5 This diagram illustrates the mechanism of humidity response in the single-component room-temperature phosphorescent / fluorescent dual-emission polymer film prepared in this example. Organic light-emitting small molecules and supramolecular polymers were dissolved in methanol. After the methanol evaporated, non-covalent interactions formed between the polymer chains. As humidity decreased, these non-covalent interactions strengthened, restricting the movement of the organic light-emitting small molecules, resulting in the film emitting both fluorescence and phosphorescence. Conversely, as humidity increased, these non-covalent interactions weakened, the movement of the organic light-emitting small molecules became unrestricted, and the phosphorescence intensity decreased. Thus, the emission color of the film dynamically and reversibly changed with variations in ambient humidity.
Claims
1. A method for preparing a single-component room-temperature phosphorescent / fluorescent dual-emission polymer thin film, characterized in that, Includes the following steps: (1) React terminal amino-substituted alkanes with halogen heavy atom groups-modified naphthalic anhydride to synthesize organic light-emitting small molecules with single-component phosphorescence / fluorescence dual emission functions; The halogen heavy atom group includes bromine, chlorine, or iodine atoms, and the single-component phosphorescent / fluorescent dual-emission organic light-emitting small molecule includes the following structure: ； (2) The organic light-emitting small molecules prepared in step (1) are blended with the dynamically cross-linked supramolecular polymer to obtain a single-component room temperature phosphorescent / fluorescent dual-emission polymer film; The dynamically cross-linked supramolecular polymer is poly(hydroxyethyl methacrylate).
2. The preparation method according to claim 1, characterized in that, The preparation method of the single-component phosphorescent / fluorescent dual-emission organic light-emitting small molecule is as follows: (1-1) Compound 1 and compound 2 were mixed in an organic solvent and reacted at 65–95 °C for 4–12 h to obtain an intermediate product. Compound 1 is naphthalene carboxylic anhydride modified with bromine, chlorine, or iodine atoms; Compound 2 is an amine organic compound; The organic solvent is methanol, ethanol, N,N-dimethylformamide, or dimethyl sulfoxide; (1-2) The intermediate product obtained in step (1-1) was washed with saturated sodium carbonate solution for 24-48 h to obtain an organic light-emitting small molecule with single-component phosphorescence / fluorescence dual emission function.
3. The preparation method according to claim 1, characterized in that, In step (2), the preparation method of the single-component room temperature phosphorescent / fluorescent dual-emission polymer film is as follows: (2-1) Dissolve the organic light-emitting small molecule with single-component phosphorescence / fluorescence dual emission function prepared in step (1) in methanol to prepare a solution, add the dynamically cross-linked supramolecular polymer, and obtain a mixed solution after the polymer is completely dissolved. (2-2) Pour the mixed solution into the mold and wait for the solvent to evaporate completely to obtain a single-component room temperature phosphorescent / fluorescent dual-emission polymer film.
4. A single-component room-temperature phosphorescent / fluorescent dual-emission polymer film prepared by the preparation method according to any one of claims 1-3.
5. The application of the single-component room-temperature phosphorescent / fluorescent dual-emission polymer film according to claim 4 in visual humidity sensing.
6. The application of the single-component room-temperature phosphorescent / fluorescent dual-emission polymer film according to claim 5 in visual humidity sensing, characterized in that, The application of the single-component room-temperature phosphorescent / fluorescent dual-emission thin film in ratiometric fluorescent probes.