A red light silver indium sulfide quantum dot light conversion film and preparation method thereof

Abstract

The present invention relates to the technical field of light conversion film preparation, and in particular to a red light silver indium sulfur quantum dot light conversion film and a preparation method thereof. The method comprises: preparing a silver indium sulfur quantum dot solution by a hot injection method: mixing a silver source, an indium source, n-octadecene, oleylamine and tri-n-octylphosphine, and then rapidly dropping n-dodecyl mercaptan to react; rapidly dropping a sulfur source after the reaction, heating the mixture to 80-100°C, and reacting for 5-15 minutes to obtain a silver indium sulfur quantum dot solution; coating the silver indium sulfur quantum dots with new shells; adding the coated silver indium sulfur quantum dot solution to ethanol, centrifuging, discarding the supernatant, and drying to obtain a solid silver indium sulfur quantum dot powder, mixing it with polyethylene powder and a flux, and blowing to obtain a red light silver indium sulfur quantum dot light conversion film. The advantage is that the light conversion film can convert ultraviolet light in sunlight into red light, thereby effectively enhancing the photosynthesis of plants.

Description

Technical Field

[0001] The invention relates to the technical field of light-converting film preparation, and in particular to a red light silver indium sulfur quantum dot light-converting film and a preparation method thereof. Background Art

[0002] The violet light with a wavelength of 280-400nm in sunlight is harmful to the growth of plants, inhibits the growth and development of plants, and accelerates the aging of plastic films. At the same time, the green light with a wavelength of 500-600nm is also harmful to the growth of plants to a certain extent. The light conversion film can convert the ultraviolet light in sunlight that is harmful to crops or the green light that is useless to crop growth into the red-orange light or blue-violet light required for plant growth, which plays an important role in the field of agricultural production.

[0003] The core of the light conversion film is the light conversion agent, which mainly includes organic dyes, inorganic salts or rare earth complexes. The disadvantages of organic dye light conversion agents are that organic dyes are easily decomposed by long-term light exposure, have a short service life, and have a low light conversion rate; the absorption of certain specific bands of ultraviolet light by rare earth complex light conversion agents is limited, making it difficult for the light conversion film to further enhance the absorption of ultraviolet light, and the preparation process is relatively complex and expensive; the biggest disadvantage of existing inorganic light conversion agents is poor dispersibility and easy aggregation in agricultural plastic films, which makes the emission of light conversion films uneven and is not conducive to crop growth. How to broaden the absorption range of current light conversion agents in the ultraviolet band, improve the matching degree between the emission spectrum of light conversion agents and the absorption spectrum of chlorophyll, and prepare low-cost, stable and long-lasting light conversion agents are the challenges faced by agricultural light conversion films in the current stage of research and development technology. There are still many deficiencies in light conversion agents in terms of efficiency, cost, compatibility with greenhouse films, light matching, and light transmittance, which greatly limits the application of multifunctional agricultural films. Therefore, studying agricultural films with polymers as carriers and their ideal additive components is a career worthy of scientific researchers' lifelong efforts.

[0004] The key to the preparation of light-converting agricultural film lies in the introduction of light-converting agents. There are already some methods for preparing light-converting films, such as the dyeing method, which is to soak the light-converting agent with white oil and then directly mix it with resin and other functional masterbatches, and then perform hot-melt mixing and blow molding. This method is particularly suitable for the preparation of a small amount of test film; the masterbatch method has become the main method for introducing light-converting agents into agricultural films, and it has a good application effect on inorganic or organic fluorescent light-converting agents; the three-layer co-extrusion method improves the compatibility of light-converting agents with additives such as anti-aging agents and anti-fogging agents, improves dispersibility and maintains light-converting durability.

[0005] Quantum dots have a wide and continuous absorption spectrum and a narrow and symmetrical emission spectrum. The emission spectrum can be adjusted by the size, composition and structure of the material itself, covering the range from visible light to near infrared, and are excellent light conversion agents. 2 )、Silver Indium Sulfide(AgInS2 The performance of I-III-VI group quantum dot materials represented by ) has gradually improved (where I=Cu, Ag; III=In, Ga; X=S, Se, Te), showing advantages such as high quantum yield, easy spectral control, and stable luminescence performance; in addition, this material does not contain heavy metal elements such as antimony, arsenic, chromium, and lead, and is non-toxic and environmentally friendly; its doping preparation and film-forming process is compatible with the preparation process of ordinary polymer films, and it is easy to prepare low-cost, large-area films. The above advantages have brought hope to scientists' exploration of new light-conversion materials, so research based on this system of materials has attracted much attention.

[0006] However, to date, there has been no literature report on practical I-III-VI group quantum dot light-converting agricultural films at home and abroad, which shows that there has been no breakthrough in the basic scientific issues and key preparation technologies involved in improving the quantum yield of silver indium sulfide quantum dot materials and their doping in polymer matrices. Summary of the invention

[0007] In order to solve the above problems, the present invention provides a red light silver indium sulfide quantum dot light conversion film and a preparation method thereof.

[0008] The first object of the present invention is to provide a method for preparing a red light silver indium sulfide quantum dot light conversion film, which specifically comprises the following steps:

[0009] S1. A silver indium sulfur quantum dot solution was prepared by a hot injection method: a silver source, an indium source, n-octadecene, oleylamine and tri-n-octylphosphine were mixed, and n-dodecyl mercaptan was quickly added dropwise to react; after the reaction, a sulfur source was quickly added dropwise, and the mixture was heated to 80-100° C. and reacted for 5-15 min to obtain a silver indium sulfur quantum dot solution;

[0010] S2. Silver indium sulfur quantum dots are coated with new shells: a sulfur source is slowly and uniformly added dropwise to the silver indium sulfur quantum dot solution, the reaction is continued for 3 to 10 minutes after the addition is completed, and the reaction is terminated in an ice bath to obtain a shelled silver indium sulfur quantum dot solution;

[0011] S3. Preparation of solid silver indium sulfur quantum dots: adding the shelled silver indium sulfur quantum dot solution to ethanol, centrifuging, discarding the supernatant, and drying to obtain solid silver indium sulfur quantum dot powder;

[0012] S4. Blow molding of silver indium sulfur quantum dot light-converting film: the solid silver indium sulfur quantum dot powder, polyethylene powder and flux are mixed, and blow molding is performed to obtain a red light silver indium sulfur quantum dot light-converting film.

[0013] Preferably, the silver source in step S1 is silver acetate; the indium source is indium acetate; and the sulfur source is prepared by dissolving sulfur powder in oleylamine.

[0014] Preferably, step S1 specifically includes the following steps:

[0015] S101. Mix silver acetate, indium acetate, n-octadecene and oleylamine and stir until completely dissolved to form a solution;

[0016] S102. The solution of step S101 is heated to 80-120 ° C, and n-dodecyl mercaptan is added dropwise rapidly for 5-15 min;

[0017] S103. After the reaction, a sulfur source is quickly added dropwise, the mixture is cooled to 80-100° C., and the reaction is carried out for 5-15 minutes to obtain a silver indium sulfur quantum dot solution.

[0018] Preferably, the sulfur source in step S2 is zinc sulfide.

[0019] Preferably, zinc sulfide is prepared by mixing 0.0064 g of sulfur powder, 0.0386 g of zinc acetate and oleylamine.

[0020] Preferably, the centrifugation in step S3 has a rotation speed of 4000-6000 rpm and a centrifugation time of 8-15 minutes.

[0021] Preferably, the blow molding in step S4 is performed by a film blowing machine, the die head temperature of the film blowing machine is 140-160°C, and the melting temperature is 160-180°C.

[0022] Preferably, in step S4, the mass ratio of the solid silver indium sulfide quantum dot powder, the polyethylene powder and the flux is 30:30:1.

[0023] Preferably, the flux is vinyl bisstearamide.

[0024] The second purpose of the present invention is to provide a red light silver indium sulfide quantum dot light conversion film, which is prepared by a method for preparing a red light silver indium sulfide quantum dot light conversion film.

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

[0026] The present invention uses a new process for preparing a light-conversion film, that is, a step-by-step hot injection method is used to prepare silver indium sulfur quantum dots that convert ultraviolet light into red light, zinc sulfide is coated, and a silver indium sulfur quantum dot-doped polyethylene light-conversion film is prepared by a film blowing machine; AIS quantum dots with red fluorescence emission are successfully prepared by the step-by-step hot injection method, and the red light AIS quantum dots have a high quantum yield. By doping the red light AIS quantum dots with PE, a red light AIS / PE light-conversion film is successfully prepared by a film blowing machine. The red light silver indium sulfur quantum dot light-conversion film (red light AIS / PE film) of the present invention can convert ultraviolet light (200~380nm) in sunlight into red light (610~800nm), effectively enhancing the photosynthesis of plants; the preparation process is simple, low-cost, non-toxic and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a physical picture of silver indium sulfide quantum dots provided according to an embodiment of the present invention.

[0028] Figure 2 This is a photoluminescence spectrum of silver indium sulfide quantum dots provided according to an embodiment of the present invention.

[0029] Figure 3 It is a UV-visible absorption spectrum of silver indium sulfide quantum dots provided according to an embodiment of the present invention.

[0030] Figure 4 is a diagram of the photoinduced quantum yield of silver indium sulfide quantum dots provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the same modules are represented by the same reference numerals. In the case of the same reference numerals, their names and functions are also the same. Therefore, the detailed description thereof will not be repeated.

[0032] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention.

[0033] Example 1

[0034] A method for preparing a red light silver indium sulfide quantum dot light conversion film specifically comprises the following steps:

[0035] S1. Preparation of silver indium sulfide quantum dot solution by hot injection method: CH 3 COOAg (0.0042g, 0.025mmol), CH 3 COOIn (0.0365 g, 0.025 mmol), n-octadecene (ODE) solution (6 mL), oleylamine (OLA) solution (0.08 mL), and tri-n-octylphosphine (TOP) solution (0.04 mL) were added to a 25 mL three-necked flask and stirred until completely dissolved; the temperature was raised to 80°C, and 0.25 mL of n-dodecyl mercaptan (DDT) was quickly added dropwise with a syringe and reacted for 10 min; then, a S source (0.0064 g of S powder was dissolved in 0.34 ml of OLA) was quickly added dropwise, the mixture was heated to 90°C, and reacted for 10 min to prepare a silver indium sulfur (AIS) quantum dot solution;

[0036] S2. Silver indium sulfur quantum dots coated with new shells: S powder (0.0064 g, 0.2 mmol), CH 3COOZn (0.0386 g, 0.2 mmol) was mixed with OLA to prepare zinc sulfide; the prepared zinc sulfide (ZnS) was slowly and evenly added to the silver indium sulfur (AIS) quantum dot solution in step S1 using a syringe needle for 30 min; after the addition was completed, the reaction was allowed to complete for 5 min, and the reaction mixture was cooled in an ice water bath to terminate the growth of quantum dots, thereby obtaining a shelled silver indium sulfur quantum dot solution;

[0037] S3. Preparation of solid silver indium sulfur quantum dots: After cooling, the shelled silver indium sulfur quantum dot solution was added to about 30 ml of ethanol (analytical grade), and centrifuged at 5000 rpm for 10 min, twice; after centrifugation, the supernatant was discarded and dried to obtain solid silver indium sulfur quantum dot powder;

[0038] S4. Blow molding of silver indium sulfur quantum dot light-converting film: Mix solid silver indium sulfur quantum dot powder, polyethylene (PE) powder and flux vinyl bisstearamide, put into the barrel of a film blowing machine, the die head temperature of the film blowing machine is 150°C, the melting temperature is 170°C, and the rotation speed is 100-400 r / min. After blow molding, a red light silver indium sulfur quantum dot light-converting film that converts ultraviolet light into red light is obtained, and the wavelength of the red light is 620.6nm.

[0039] Example 2

[0040] A method for preparing a red light silver indium sulfide quantum dot light conversion film specifically comprises the following steps:

[0041] S1. Preparation of silver indium sulfide quantum dot solution by hot injection method: CH 3 COOAg (0.0042g, 0.025mmol), CH 3 COOIn (0.0365 g, 0.025 mmol), n-octadecene (ODE) solution (6 mL), oleylamine (OLA) solution (0.08 mL), and tri-n-octylphosphine (TOP) solution (0.04 mL) were added to a 25 mL three-necked flask and stirred until completely dissolved; the temperature was raised to 90°C, and 0.25 mL of n-dodecyl mercaptan (DDT) was quickly added dropwise with a syringe and reacted for 10 min; then, a S source (0.0064 g of S powder was dissolved in 0.34 ml of OLA) was quickly added dropwise, the mixture was heated to 90°C, and reacted for 10 min to prepare a silver indium sulfur (AIS) quantum dot solution;

[0042] S2. Silver indium sulfur quantum dots coated with new shells: S powder (0.0064 g, 0.2 mmol), CH 3COOZn (0.0386 g, 0.2 mmol) was mixed with OLA to prepare zinc sulfide; the prepared zinc sulfide (ZnS) was slowly and evenly added to the silver indium sulfur (AIS) quantum dot solution in step S1 using a syringe needle for 30 min; after the addition was completed, the reaction was allowed to complete for 5 min, and the reaction mixture was cooled in an ice water bath to terminate the growth of quantum dots, thereby obtaining a shelled silver indium sulfur quantum dot solution;

[0043] S3. Preparation of solid silver indium sulfur quantum dots: After cooling, the shelled silver indium sulfur quantum dot solution was added to about 30 ml of ethanol (analytical grade), and centrifuged at 5000 rpm for 10 min, twice; after centrifugation, the supernatant was discarded and dried to obtain solid silver indium sulfur quantum dot powder;

[0044] S4. Blow molding of silver indium sulfur quantum dot light-converting film: Mix solid silver indium sulfur quantum dot powder, polyethylene (PE) powder and flux vinyl bisstearamide, put into the barrel of a film blowing machine, the die head temperature of the film blowing machine is 150°C, the melting temperature is 170°C, and the rotation speed is 100-400 r / min. After blow molding, a red light silver indium sulfur quantum dot light-converting film that converts ultraviolet light into red light is obtained, and the wavelength of the red light is 633.2nm.

[0045] Example 3

[0046] A method for preparing a red light silver indium sulfide quantum dot light conversion film specifically comprises the following steps:

[0047] S1. Preparation of silver indium sulfide quantum dot solution by hot injection method: CH 3 COOAg (0.0042g, 0.025mmol), CH 3 COOIn (0.0365 g, 0.025 mmol), n-octadecene (ODE) solution (6 mL), oleylamine (OLA) solution (0.08 mL), and tri-n-octylphosphine (TOP) solution (0.04 mL) were added to a 25 mL three-necked flask and stirred until completely dissolved; the temperature was raised to 100°C, and 0.25 mL of n-dodecyl mercaptan (DDT) was quickly added dropwise with a syringe, and the reaction lasted for 10 min; then, a S source (0.0064 g of S powder was dissolved in 0.34 ml of OLA) was quickly added dropwise, the temperature was lowered to 90°C, and the reaction lasted for 10 min to prepare a silver indium sulfur (AIS) quantum dot solution;

[0048] S2. Silver indium sulfur quantum dots coated with new shells: S powder (0.0064 g, 0.2 mmol), CH 3COOZn (0.0386 g, 0.2 mmol) was mixed with OLA to prepare zinc sulfide; the prepared zinc sulfide (ZnS) was slowly and evenly added to the silver indium sulfur (AIS) quantum dot solution in step S1 using a syringe needle for 30 min; after the addition was completed, the reaction was allowed to complete for 5 min, and the reaction mixture was cooled in an ice water bath to terminate the growth of quantum dots, thereby obtaining a shelled silver indium sulfur quantum dot solution;

[0049] S3. Preparation of solid silver indium sulfur quantum dots: After cooling, the shelled silver indium sulfur quantum dot solution was added to about 30 ml of ethanol (analytical grade), and centrifuged at 5000 rpm for 10 min, twice; after centrifugation, the supernatant was discarded and dried to obtain solid silver indium sulfur quantum dot powder;

[0050] S4. Blow molding of silver indium sulfur quantum dot light-converting film: Mix solid silver indium sulfur quantum dot powder, polyethylene (PE) powder and flux vinyl bisstearamide, put into the barrel of a film blowing machine, the die head temperature of the film blowing machine is 150°C, the melting temperature is 170°C, and the rotation speed is 100-400 r / min. After blow molding, a red light silver indium sulfur quantum dot light-converting film that converts ultraviolet light into red light is obtained, and the wavelength of the red light is 634.6nm.

[0051] Example 4

[0052] A method for preparing a red light silver indium sulfide quantum dot light conversion film specifically comprises the following steps:

[0053] S1. Preparation of silver indium sulfide quantum dot solution by hot injection method: CH 3 COOAg (0.0042g, 0.025mmol), CH 3 COOIn (0.0365 g, 0.025 mmol), n-octadecene (ODE) solution (6 mL), oleylamine (OLA) solution (0.08 mL), and tri-n-octylphosphine (TOP) solution (0.04 mL) were added to a 25 mL three-necked flask and stirred until completely dissolved; the temperature was raised to 120°C, and 0.25 mL of n-dodecyl mercaptan (DDT) was quickly added dropwise with a syringe, and the reaction lasted for 10 min; then, a S source (0.0064 g of S powder was dissolved in 0.34 ml of OLA) was quickly added dropwise, the temperature was lowered to 90°C, and the reaction lasted for 10 min to prepare a silver indium sulfur (AIS) quantum dot solution;

[0054] S2. Silver indium sulfur quantum dots coated with new shells: S powder (0.0064 g, 0.2 mmol), CH 3COOZn (0.0386 g, 0.2 mmol) was mixed with OLA to prepare zinc sulfide; the prepared zinc sulfide (ZnS) was slowly and evenly added to the silver indium sulfur (AIS) quantum dot solution in step S1 using a syringe needle for 30 min; after the addition was completed, the reaction was allowed to complete for 5 min, and the reaction mixture was cooled in an ice water bath to terminate the growth of quantum dots, thereby obtaining a shelled silver indium sulfur quantum dot solution;

[0055] S3. Preparation of solid silver indium sulfur quantum dots: After cooling, the shelled silver indium sulfur quantum dot solution was added to about 30 ml of ethanol (analytical grade), and centrifuged at 5000 rpm for 10 min, twice; after centrifugation, the supernatant was discarded and dried to obtain solid silver indium sulfur quantum dot powder;

[0056] S4. Blow molding of silver indium sulfur quantum dot light-converting film: Mix solid silver indium sulfur quantum dot powder, polyethylene (PE) powder and flux vinyl bisstearamide, put into the barrel of a film blowing machine, the die head temperature of the film blowing machine is 150°C, the melting temperature is 170°C, and the rotation speed is 100-400 r / min. After blow molding, a red light silver indium sulfur quantum dot light-converting film that converts ultraviolet light into red light is obtained, and the wavelength of the red light is 643nm.

[0057] Comparative Example 1

[0058] The method for preparing a light conversion film for converting ultraviolet light into red light in this comparative example comprises the following steps:

[0059] Polyethylene (PE) powder and flux are mixed, put into the barrel of a film blowing machine, and blow-molded to obtain a polyethylene film; the specific parameters of the blow-molding are the same as those in Example 1.

[0060] The performance of the light conversion films prepared in the above multiple embodiments and comparative examples was measured, and the results are as follows:

[0061] The specific luminescence peak position information and fluorescence quantum efficiency are shown in Table 1;

[0062] Table 1 Luminescence properties of red light silver indium sulfide quantum dot light conversion film

[0063]

[0064] It can be seen from Table 1 that the silver indium sulfur quantum dot light-conversion films prepared in Examples 1 to 4 of the present invention emit red light, the photoluminescence wavelength is between 620.6 and 643 nm, and the fluorescence quantum efficiency is between 67.1 and 74.8%, but the light-conversion film of the control example that is not doped with silver indium sulfur quantum dots does not emit red light.

[0065] Figure 1 This is a real picture of the luminescence of AIS quantum dots in Examples 1 to 4.

[0066] Figure 2 is the photoluminescence spectrum of the AIS quantum dots of Example 1 to Example 4; it can be seen from the figure that the photoluminescence peaks of the examples all show red emission, which is consistent with Figure 1 Match.

[0067] Figure 3 3 is the UV-visible absorption spectrum of Example 1 to Example 4; as can be seen from the figure, the absorption peaks of the examples are all located in the UV region, indicating that they absorb ultraviolet light.

[0068] Figure 4 3 is a graph of the photoluminescence quantum yield of the AIS quantum dots synthesized in Examples 1 to 4. It can be seen from the graph that with the increase of temperature (the temperature at which n-dodecanethiol is added dropwise in step S1 and the reaction is carried out), the photoluminescence yield of the AIS quantum dots is significantly improved.

[0069] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the disclosure of the present invention can be performed in parallel, sequentially or in different orders, as long as the desired results of the technical solution disclosed in the present invention can be achieved, and this document does not limit this.

[0070] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A red light silver indium sulfide quantum dot light conversion film, characterized in that: The preparation of the red light silver indium sulfide quantum dot light conversion film specifically includes the following steps: S1. Prepare silver indium sulfur quantum dot solution by hot injection method; specifically comprising the following sub-steps: S101. Mix silver acetate, indium acetate, n-octadecene, oleylamine and tri-n-octyl phosphine and stir until completely dissolved to form a solution; S102. The solution of step S101 is heated to 80-120 ° C, and n-dodecyl mercaptan is added dropwise rapidly for 5-15 min; S103. After the reaction, a sulfur source was quickly added dropwise, the mixture was cooled to 80 to 100 ° C, and the reaction was carried out for 5 to 15 min to prepare a silver indium sulfur quantum dot solution; S2. Silver indium sulfur quantum dots coated with zinc shell: zinc sulfide is slowly and uniformly added dropwise to the silver indium sulfur quantum dot solution, and the reaction is continued for 3 to 10 minutes after the addition is completed, and the reaction is terminated in an ice bath to obtain a shelled silver indium sulfur quantum dot solution; S3. Preparation of solid silver indium sulfur quantum dots: adding the shelled silver indium sulfur quantum dot solution to ethanol, centrifuging, discarding the supernatant, and drying to obtain solid silver indium sulfur quantum dot powder; S4. Blow molding of silver indium sulfur quantum dot light-converting film: the solid silver indium sulfur quantum dot powder, polyethylene powder and flux are mixed, and a red light silver indium sulfur quantum dot light-converting film is obtained by blow molding; the blow molding is carried out by a film blowing machine, and the die head temperature of the film blowing machine is 150°C and the melting temperature is 170°C.

2. The red light silver indium sulfide quantum dot light conversion film according to claim 1, characterized in that: The sulfur source in step S1 is prepared by dissolving sulfur powder into oleylamine.

3. The red light silver indium sulfide quantum dot light conversion film according to claim 2, characterized in that: The zinc sulfide is prepared by mixing 0.0064 g of sulfur powder, 0.0386 g of zinc acetate and oleylamine.

4. The red light silver indium sulfide quantum dot light conversion film according to claim 3, characterized in that: The centrifugation in step S3 has a rotation speed of 4000-6000 rpm and a centrifugation time of 8-15 minutes.

5. The red light silver indium sulfide quantum dot light conversion film according to claim 4, characterized in that: In step S4, the mass ratio of the solid silver indium sulfide quantum dot powder, the polyethylene powder and the flux is 30:30:

1.

6. The red light silver indium sulfide quantum dot light conversion film according to claim 5, characterized in that: The flux is vinyl bisstearamide.

Images