Method for preparing polyacrylonitrile-coated perovskite quantum dot luminous textile film through electrostatic spinning

Abstract

The invention discloses a method for preparing a polyacrylonitrile-coated perovskite quantum dot light-emitting textile film through electrostatic spinning, and belongs to the technical field of quantum dot light-emitting material preparation. The method comprises the following specific steps: co-dissolving a perovskite quantum dot precursor and polyacrylonitrile to obtain a spinning solution; performing electrostatic spinning on the spinning solution to obtain a primary luminous textile film; and finally, carrying out thermal crosslinking treatment on the primary luminous textile film to obtain the polyacrylonitrile-coated perovskite quantum dot luminous textile film. The method is easy and convenient to operate, a thermal injection method and an anti-solvent extraction method do not need to be adopted, large-area preparation of the non-lead light-emitting film can be achieved, and the obtained light-emitting textile film has excellent light-emitting performance (such as high fluorescence quantum efficiency) and environmental stability (such as moisture resistance and light attenuation resistance) and has good application prospects in the fields of display, LED illumination and the like.

Description

Technical Field

[0001] This invention belongs to the field of quantum dot luminescent material preparation technology, and particularly relates to a method for preparing polyacrylonitrile-coated perovskite quantum dot luminescent textile films by electrospinning. Background Technology

[0002] As a promising new type of semiconductor luminescent material, perovskite quantum dots, with their high carrier mobility, narrow spectral bandwidth, wide color gamut, high photoluminescence quantum yield, and low cost, have shown great commercial application potential in multiple fields such as display devices, LED lighting, solar cells, photodetectors, and laser technology, becoming one of the current research hotspots in materials science. However, due to their inherent defects of strong ion mobility and poor crystal structure stability, perovskite quantum dots are prone to decomposition in practical application environments such as humidity, high temperature, oxygen-rich environments, and light exposure. This not only leads to a sharp decline in their fluorescence efficiency but can even result in complete photoquenching in severe cases. This problem greatly restricts their large-scale application and industrialization in practical scenarios.

[0003] To address the aforementioned stability challenges, researchers have conducted extensive studies. One proven strategy for enhancing the environmental stability of perovskite quantum dots is the encapsulation of these dots with polymers followed by thermal cross-linking. The polymer encapsulation effectively encapsulates the perovskite quantum dots in a relatively stable microenvironment, significantly slowing down oxidation and hydrolysis reactions between the quantum dots and the external environment, thereby greatly improving the material's environmental stability. Simultaneously, the polymer also constructs a physical protective barrier for the perovskite quantum dots, effectively preventing damage to their structure and properties from ultraviolet radiation, moisture penetration, and oxygen corrosion. This ensures that the perovskite quantum dot-polymer composite material exhibits superior performance and a longer service life in practical applications.

[0004] Existing polymer coating methods commonly include solution mixing, in-situ polymerization, and emulsion polymerization. However, these methods generally require the initial preparation of perovskite quantum dots via hot injection—that is, dissolving the metal halide precursor in a high-temperature solvent and then rapidly injecting an alkali metal source solution to achieve precise quantum dot nucleation. Subsequent purification using antisolvent extraction (e.g., adding toluene, chloroform, etc.) is also necessary to remove residual impurities and excess ligands before subsequent coating operations can proceed. However, these coating methods combining hot injection and antisolvent extraction still have significant limitations: hot injection requires high temperature control precision, involves complex equipment, and is difficult to use for continuous production; antisolvent extraction requires multiple centrifugation and washing processes, which are cumbersome and prone to quantum dot loss. Furthermore, residual antisolvent may affect the coating effect, and the overall process is difficult to implement for large-area preparation, hindering industrial-scale application. Summary of the Invention

[0005] The purpose of this invention is to overcome the technical shortcomings of existing perovskite quantum dot coating technologies, which generally rely on thermal injection for quantum dot preparation and antisolvent extraction for purification. These shortcomings include complex operations, high equipment requirements, easy quantum dot loss, and difficulty in achieving large-area continuous preparation. This invention provides a method for preparing polyacrylonitrile-coated perovskite quantum dot luminescent textile films via electrospinning. This method eliminates the need for thermal injection and antisolvent extraction, significantly simplifying the operation process. Simultaneously, it enables large-area preparation of lead-free luminescent films, and the resulting polyacrylonitrile-coated perovskite quantum dot luminescent textile films possess both excellent fluorescence performance and environmental stability, effectively meeting the dual requirements of practical applications for material performance and large-scale production.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A method for preparing polyacrylonitrile-coated perovskite quantum dot luminescent textile films by electrospinning, the method specifically comprising the following steps: Step 1: Dissolve the precursor used to synthesize perovskite quantum dots and the polymer together in a solvent to obtain a mixture; Step 2: Place the mixture obtained in Step 1 on a stirrer and stir at room temperature until it becomes clear to obtain the spinning solution; Step 3: Electrospin the spinning solution obtained in Step 2 to obtain a preliminary luminescent textile film; Step 4: Transfer the preliminary textile film obtained in Step 3 to a high-temperature furnace for thermal cross-linking treatment to obtain a polyacrylonitrile-coated perovskite quantum dot luminescent textile film.

[0007] Furthermore, in step 1, the precursors used to synthesize perovskite quantum dots are tetraphenylphosphine bromide and manganese bromide tetrahydrate, and the total concentration of the two in the mixture is 0.06-0.18 mmol / mL, and the molar ratio of tetraphenylphosphine bromide and manganese bromide tetrahydrate is 1:1 to 2:1.

[0008] Furthermore, in step 1, the mass percentage of polyacrylonitrile in the mixture is 5%-10%.

[0009] Furthermore, in step 1, the solvent is N,N-dimethylformamide.

[0010] Furthermore, in step 2, the stirring time is 8-12 hours to ensure that the solid components (precursor and polyacrylonitrile) in the mixture are completely dissolved, forming a clear solution without precipitate or particles, which is the spinning solution required for electrospinning.

[0011] Furthermore, in step 3, the electrospinning voltage is 15-25kV, the distance between the injection pump nozzle and the receiving plate (used to receive the spun product) is controlled at 15-25cm, and the flow rate of the spinning solution is 4μL·min. -1 ~10μL·min -1 Under the influence of an electric field, the spinning solution forms fibers and deposits on the receiving plate, directly yielding a preliminary luminescent textile film.

[0012] Furthermore, in step 4, the process parameters for the thermal crosslinking treatment are: temperature of 160~200℃, heating rate of 5~10℃ / min, holding time of 4~8h, and cooling rate of 1~5℃ / min.

[0013] Compared with the prior art, the beneficial effects of the present invention are reflected in: 1. This invention uses polyacrylonitrile as the coating polymer and employs an electrospinning process to form a tight fibrous coating structure between polyacrylonitrile and perovskite quantum dots. Polyacrylonitrile not only efficiently encapsulates perovskite quantum dots in a closed microenvironment, significantly slowing down the oxidation and hydrolysis reaction rates between the quantum dots and the external environment, but also constructs a dense physical protective barrier. This effectively blocks adverse external factors such as ultraviolet radiation, moisture penetration, and oxygen corrosion from damaging the quantum dot crystal structure, preventing fluorescence decay or photoquenching due to environmental influences. Ultimately, this results in a longer service life and more stable performance of the luminescent textile film in practical applications, solving the problem of limited stability improvement caused by existing coating methods.

[0014] 2. This invention directly eliminates the need for the hot injection method and antisolvent extraction method commonly relied upon in the prior art through an integrated process of "precursor dissolution - stirring to prepare solution - electrospinning - thermal crosslinking". On the one hand, perovskite quantum dots can spontaneously nucleate during the spinning process as the solvent evaporates, without the need for a separate high-temperature preparation step. On the other hand, the spinning and thermal crosslinking processes can simultaneously achieve quantum dot purification and coating, avoiding complex post-processing, significantly reducing equipment complexity and operational difficulty, and more easily meeting the requirements of industrial production for process simplicity.

[0015] 3. This invention relies on the continuous and large-area deposition characteristics of electrospinning to achieve the mass production of lead-free perovskite quantum dot luminescent textile films, breaking through the bottleneck of existing technologies that are difficult to produce on a large scale. At the same time, by precisely controlling the precursor (molar ratio of tetraphenylphosphine bromide to manganese bromide tetrahydrate 1:1 to 2:1), spinning parameters (15-25kV voltage, 15-25cm nozzle distance), and thermal crosslinking conditions (160-200℃ for 4-8h), the obtained lead-free luminescent material not only has uniform fluorescence emission and high quantum yield (e.g., fluorescence quantum efficiency of 63% in Example 1), but also has excellent long-term stability (fluorescence intensity retention rate of 93% after 30 days of air exposure), taking into account both the needs of large-scale production and the core performance of the material. Attached Figure Description

[0016] Figure 1 The image shows the X-ray diffraction pattern of the luminescent textile film prepared in Example 1.

[0017] Figure 2 The flowchart shows the electrospinning process for preparing the luminescent textile film in Example 1.

[0018] Figure 3 The fluorescence spectrum of the luminescent textile film prepared in Example 1 is shown.

[0019] Figure 4 The image shows the air stability of the luminescent textile film prepared in Example 1.

[0020] Figure 5 The image shows the waterproof stability of the luminescent textile film prepared in Example 1. Detailed Implementation

[0021] To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0022] Example 1 In this embodiment, a polyacrylonitrile-coated perovskite quantum dot luminescent textile film was prepared according to the following steps: Step 1: Mix 0.252g of tetraphenylphosphine bromide, 0.086g of manganese bromide tetrahydrate and 0.5g of polyacrylonitrile and dissolve them in 5mL of N,N-dimethylformamide to obtain a mixture. The molar ratio of tetraphenylphosphine bromide to manganese bromide tetrahydrate is 2:1, the total amount of tetraphenylphosphine bromide and manganese bromide tetrahydrate is 0.9mmol, and the mass percentage of polyacrylonitrile in the mixture is 10%.

[0023] Step 2: Place the mixture obtained in Step 1 on a stirrer and stir at room temperature for 10 hours to clarify the solution and obtain the spinning solution.

[0024] Step 3: Electrospin the spinning solution obtained in Step 2: Load the clarified spinning solution into the electrospinning apparatus, and set the spinning parameters as follows: voltage 20kV, nozzle distance of injection pump 15cm from receiving plate, and spinning solution flow rate 5μL·min. -1 After spinning, a preliminary luminescent textile film is obtained.

[0025] Step 4: Transfer the preliminary luminescent textile film obtained in Step 3 to a high-temperature furnace for thermal crosslinking treatment: Set the furnace heating rate to 10℃ / min, and when the furnace temperature reaches 200℃, keep it at that temperature for 6 hours, and then cool it to room temperature at a rate of 5℃ / min to finally obtain a polyacrylonitrile-coated perovskite quantum dot luminescent textile film.

[0026] Figure 1 The image shows the XRD pattern of the luminescent textile film prepared in Example 1, where (C) 24 H 20 P)2MnBr4 is a perovskite quantum dot standard, PAN is a polyacrylonitrile standard, (C) 24 H 20 P)2MnBr4@PAN is the XRD pattern of the polyacrylonitrile-coated perovskite quantum dot luminescent textile film obtained in this embodiment. The peak positions accurately indicate that perovskite quantum dots were synthesized in PAN fibers. Figure 2 The flowchart illustrates the electrospinning process for preparing the luminescent textile film in Example 1. Direct electrospinning of the spinning solution yields the luminescent textile film, which emits bright green light under ultraviolet light. The polyacrylonitrile fibers are interlaced, forming a continuous yet irregular three-dimensional network, and quantum dots are successfully embedded within the polyacrylonitrile fibers. This dense encapsulation structure provides protection for the quantum dots, effectively blocking moisture and oxygen from the air, thereby significantly inhibiting the decomposition of the quantum dots. Figure 3 The image shows the fluorescence emission spectrum of the luminescent textile film prepared in Example 1. The fluorescence emission wavelength of the spun film is 525 nm, the half-width at half-maximum is 55 nm, and the fluorescence quantum efficiency is 63%. Figure 4 The room temperature air photostable stability test of the luminescent textile film prepared in Example 1 showed that the fluorescence intensity of the luminescent textile film was 93% after being placed in room temperature air for 30 days, indicating that the sample has good photostable stability. Figure 5 The light stability test of the luminescent textile film prepared in Example 1 showed that the fluorescence intensity of the luminescent textile film was 64% after being placed in water for 24 hours, indicating that the sample has good waterproof performance.

[0027] Example 2 In this embodiment, a polyacrylonitrile-coated perovskite quantum dot luminescent textile film was prepared according to the following steps: Step 1: Mix 0.168g tetraphenylphosphine bromide, 0.057g manganese bromide tetrahydrate and 0.25g polyacrylonitrile and dissolve them in 5mL N,N-dimethylformamide to obtain a mixture. The molar ratio of tetraphenylphosphine bromide to manganese bromide tetrahydrate is 2:1, the total amount of tetraphenylphosphine bromide and manganese bromide tetrahydrate is 0.6mmol, and the mass percentage of polyacrylonitrile in the mixture is 5%.

[0028] Step 2: Place the mixture obtained in Step 1 on a stirrer and stir at room temperature for 8 hours to clarify the solution and obtain the spinning solution.

[0029] Step 3: Electrospin the spinning solution obtained in Step 2: Load the clarified spinning solution into the electrospinning apparatus, and set the spinning parameters as follows: voltage 20kV, nozzle distance of injection pump 15cm from receiving plate, and spinning solution flow rate 5μL·min. -1 After spinning, a preliminary luminescent textile film is obtained.

[0030] Step 4: Transfer the preliminary luminescent textile film obtained in Step 3 to a high-temperature furnace for thermal crosslinking treatment: Set the furnace heating rate to 10℃ / min, and when the furnace temperature reaches 200℃, keep it at that temperature for 4 hours, and then cool it to room temperature at a rate of 5℃ / min to finally obtain a polyacrylonitrile-coated perovskite quantum dot luminescent textile film.

[0031] The luminescent textile film prepared in Example 2 has a fluorescence emission wavelength of 524 nm and a fluorescence quantum efficiency of 61%.

[0032] Example 3 In this embodiment, a polyacrylonitrile-coated perovskite quantum dot luminescent textile film was prepared according to the following steps: Step 1: Mix 0.084 g tetraphenylphosphine bromide, 0.029 g manganese bromide tetrahydrate and 0.25 g polyacrylonitrile and dissolve them in 5 mL of N,N-dimethylformamide to obtain a mixture. The molar ratio of tetraphenylphosphine bromide to manganese bromide tetrahydrate is 2:1, the total amount of tetraphenylphosphine bromide and manganese bromide tetrahydrate is 0.3 mmol, and the mass percentage of polyacrylonitrile in the mixture is 5%.

[0033] Step 2: Place the mixture obtained in Step 1 on a stirrer and stir at room temperature for 8 hours to clarify the solution and obtain the spinning solution.

[0034] Step 3: Electrospin the spinning solution obtained in Step 2: Load the clarified spinning solution into the electrospinning apparatus, and set the spinning parameters as follows: voltage 15kV, nozzle distance of injection pump 15cm from receiving plate, and spinning solution flow rate 6μL·min. -1 After spinning, a preliminary luminescent textile film is obtained.

[0035] Step 4: Transfer the preliminary luminescent textile film obtained in Step 3 to a high-temperature furnace for thermal crosslinking treatment: Set the furnace heating rate to 10℃ / min, and when the furnace temperature reaches 200℃, keep it at that temperature for 6 hours, and then cool it to room temperature at a rate of 5℃ / min to finally obtain a polyacrylonitrile-coated perovskite quantum dot luminescent textile film.

[0036] The luminescent textile film prepared in Example 3 has a fluorescence emission wavelength of 525 nm and a fluorescence quantum efficiency of 58%.

[0037] Example 4 In this comparative example, a polyacrylonitrile-coated perovskite quantum dot luminescent textile film was prepared according to the following steps: Step 1: Mix 0.084 g tetraphenylphosphine bromide, 0.086 g manganese bromide tetrahydrate and 0.5 g polyacrylonitrile and dissolve them in 5 mL of N,N-dimethylformamide to obtain a mixture. The molar ratio of tetraphenylphosphine bromide to manganese bromide tetrahydrate is 1:1, the total amount of tetraphenylphosphine bromide and manganese bromide tetrahydrate is 0.4 mmol, and the mass percentage of polyacrylonitrile in the mixture is 10%.

[0038] Step 2: Place the mixture obtained in Step 1 on a stirrer and stir at room temperature for 10 hours to clarify the solution and obtain the spinning solution.

[0039] Step 3: Electrospin the spinning solution obtained in Step 2: Load the clarified spinning solution into the electrospinning apparatus, and set the spinning parameters as follows: voltage 20kV, nozzle distance of injection pump 15cm from receiving plate, and spinning solution flow rate 5μL·min. -1 After spinning, a preliminary luminescent textile film is obtained.

[0040] Step 4: Transfer the preliminary luminescent textile film obtained in Step 3 to a high-temperature furnace for thermal crosslinking treatment: Set the furnace heating rate to 10℃ / min, and when the furnace temperature reaches 200℃, keep it at that temperature for 6 hours, and then cool it to room temperature at a rate of 5℃ / min to finally obtain a polyacrylonitrile-coated perovskite quantum dot luminescent textile film.

[0041] The luminescent textile film prepared in Example 4 has a fluorescence emission wavelength of 524 nm and a fluorescence quantum efficiency of 55%.

[0042] The present invention has been illustrated with the above embodiments to explain the detailed preparation method of the present invention. However, the present invention is not limited to the above detailed preparation method, that is, it does not mean that the present invention must rely on the above product and detailed preparation method to be implemented. Those skilled in the art should understand that any improvement to the present invention, or the combination or equivalent substitution of the raw materials of the present invention, falls within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing polyacrylonitrile-coated perovskite quantum dot luminescent textile films by electrospinning, characterized in that, Includes the following steps: Step 1: Dissolve the precursor used to synthesize perovskite quantum dots together with polyacrylonitrile in a solvent to obtain a mixture; Step 2: Place the mixture obtained in Step 1 on a stirrer and stir at room temperature until it becomes clear to obtain the spinning solution; Step 3: Electrospin the spinning solution obtained in Step 2 to obtain a preliminary luminescent textile film; Step 4: Transfer the preliminary textile film obtained in Step 3 to a high-temperature furnace for thermal cross-linking treatment to obtain a polyacrylonitrile-coated perovskite quantum dot luminescent textile film.

2. The method for preparing polyacrylonitrile-coated perovskite quantum dot luminescent textile films by electrospinning according to claim 1, characterized in that, In step 1, the precursors used to synthesize perovskite quantum dots are tetraphenylphosphine bromide and manganese bromide tetrahydrate, and the total concentration of the two in the mixture is 0.06-0.18 mmol / mL, and the molar ratio of tetraphenylphosphine bromide and manganese bromide tetrahydrate is 1:1 to 2:

1.

3. The method for preparing polyacrylonitrile-coated perovskite quantum dot luminescent textile films by electrospinning according to claim 1, characterized in that, In step 1, the mass percentage of polyacrylonitrile in the mixture is 5%-10%.

4. The method for preparing polyacrylonitrile-coated perovskite quantum dot luminescent textile films by electrospinning according to claim 1, characterized in that, In step 1, the solvent is N,N-dimethylformamide.

5. The method for preparing polyacrylonitrile-coated perovskite quantum dot luminescent textile films by electrospinning according to claim 1, characterized in that, In step 2, the stirring time is 8-12 hours.

6. The method for preparing polyacrylonitrile-coated perovskite quantum dot luminescent textile films by electrospinning according to claim 1, characterized in that, In step 3, the electrospinning voltage is 15-25 kV, the distance between the injection pump nozzle and the receiving plate is controlled at 15-25 cm, and the flow rate of the spinning solution is 4 μL·min. -1 ~10μL·min -1 .

7. The method for preparing polyacrylonitrile-coated perovskite quantum dot luminescent textile films by electrospinning according to claim 1, characterized in that, In step 4, the process parameters for thermal crosslinking treatment are: temperature 160~200℃, heating rate 5~10℃ / min, holding time 4~8h, and cooling rate 1~5℃ / min.

8. A polyacrylonitrile-coated perovskite quantum dot luminescent textile film prepared by the method of any one of claims 1 to 7.

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