Light conversion film and preparation method and application thereof

Abstract

The invention provides a light conversion film as well as a preparation method and application thereof. The light conversion film comprises an organic silicon polymer and an aggregation-induced emission material dispersed in the organic silicon polymer, the aggregation-induced emission material has a structure as shown in a formula I. Through the design and mutual compounding of the organosilicon polymer and the AIE material with the structure shown in the formula I, the fluorescence intensity is high, ultraviolet light and near-infrared light can be absorbed and converted into blue light and red light, and light useless for plants / crops is converted into useful light for promoting the growth of the plants / crops. The light conversion film has excellent light conversion effect, stability and weather resistance, can effectively improve the light quality, increase the utilization rate of sunlight and improve the efficiency of photosynthesis of plants, and has wide application prospects in the aspects of increasing the biomass and yield of bioactive compounds and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer films, and in particular relates to a light conversion film and a preparation method and application thereof. Background Art

[0002] Sunlight is the basic condition for plant growth. When sunlight shines on the surface of plant leaves, it will be absorbed by chlorophyll and other pigments in the plant body, and photosynthesis will be used to convert light energy into chemical energy and store it in organic matter. Plant photosynthesis is mainly completed by chlorophyll, but chlorophyll has different absorption capabilities for light of different wavelengths. Since chlorophyll has a strong absorption capacity for blue-violet light of 400-500nm and red-orange light of 600-700nm, blue-violet light and red-orange light are beneficial to promote plant photosynthesis, while ultraviolet light of 200-400nm promotes plant aging and pathogen reproduction; moreover, when the light intensity is high, plants have a higher photosynthesis rate. It is precisely because of the long days and short nights and sufficient light in summer that plants grow faster in summer than in winter. Therefore, the use of light energy conversion technology to effectively enhance the red light in light and weaken the ultraviolet light has broad application prospects in biology in terms of increasing the biomass and yield of bioactive compounds.

[0003] The typical product that uses light energy conversion technology to increase the photosynthesis rate of plants is light conversion film. Its basic principle is to provide light energy conversion function by adding light conversion agents (light conversion agents) on the basis of polymer films to promote the photosynthesis of crops. In the development of light conversion films, the key technology is to find suitable light conversion agents to add to the film matrix. The current light conversion agents mainly include organic and inorganic categories.

[0004] Commonly used organic light conversion agents are organic dyes, which have good fluorescence emission performance and good compatibility with the film matrix based on their organic characteristics. The concentration of light conversion agents in the prepared light conversion film is controllable and evenly dispersed. However, organic dyes are usually less stable and are easily oxidized and decomposed under long-term light exposure, resulting in obvious light attenuation, a short service life, and a relatively low light conversion intensity, so their application range is limited.

[0005] Compared with organic dye-based photoconverters, inorganic photoconverters are cheap, easy to prepare, and have good storage stability and high temperature resistance. Inorganic photoconverters are mostly inorganic compounds doped with rare earth ions or heavy metal ions, including metal alkaline earth aluminates, oxides, sulfides, tungstates and silicates, etc. They mainly emit light by the interaction between the doped rare earth or metal ions and the inorganic compound lattice. Inorganic photoconverters have high light conversion intensity, such as CaS:Eu emitting 655nm red light. 2+Photoconverters have been widely used at home and abroad, but inorganic photoconverters usually have problems such as environmental pollution caused by heavy metal ions or sulfides. In addition, inorganic substances have high crystallinity and poor compatibility with film matrix resins, which makes them poorly dispersed in polymer films, resulting in poor film uniformity, which not only affects the appearance and finish of the product, but also causes rare earth agglomeration to cause fluorescence quenching, resulting in reduced film transmittance and light conversion efficiency, and poor processing performance.

[0006] Another type of organic light conversion agent is an organometallic complex. Its luminescence is similar to that of rare earth inorganic light conversion agents. It uses rare earth metal ions to convert light. It has the characteristics of high luminescence brightness, good photothermal stability, and not easy to age. In addition, because it contains organic ligands, it is easy to disperse in organic polymer materials. It has the strong luminescence performance of inorganic ions and the high compatibility of organic ligands, overcoming the shortcomings of using organic dyes or inorganic light conversion agents alone. The commonly known organometallic complex light conversion agents are mostly europium ions (Eu 3+ ) is the central luminescent ion, β-diketone compounds are the first ligands, and pyridine-2,6-dicarboxylic acid and its derivatives are neutral ligands, such as β-DKs, etc. CN114516885A discloses a light conversion agent containing a new ligand, and its general structure is Eu2(TTA)xPA(4-x)BDPA4 or Eu2(TTA)xPA(4-x)BDPA6, wherein TTA is 2-thenoyltrifluoroacetone, PA is pyridine-2,6-dicarboxylic acid, BDPA4 is 4,4'-(butane-1,4-di(oxy))bis(pyridine-2,6-dicarboxylic acid), and BDPA6 is 4,4'-(butane-1,6-di(oxy))bis(pyridine-2,6-dicarboxylic acid). The general formula of the rare earth organic complex light conversion agent disclosed in CN101020820A is Re1Re2(X)3Y, wherein the rare earth element Re1 is europium Eu(III) or samarium Sm(III); the rare earth element Re2 is gadolinium Gd(III) or lanthanum La(III); the first ligand X is acetylsalicylic acid or benzoyl acetone; and the second ligand Y is o-phenanthroline or triphenylphosphine oxide.

[0007] Although the performance of organometallic complexes is improved compared to organic dye photoconverters and inorganic photoconverters, rare earth metal ions have abundant d or f empty orbitals, high coordination numbers (usually 6-12), and are prone to form ion clusters when the metal content is high, which often leads to fluorescence quenching. Therefore, it is difficult for light-converting films containing organometallic complexes to obtain high fluorescence intensity, and there is still a lot of room for improvement in light conversion performance. Therefore, the development of light-converting materials with excellent light conversion functions is an urgent problem to be solved in this field. Summary of the invention

[0008] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a light conversion film and a preparation method and application thereof. Through the design and mutual compounding of an organosilicon polymer and a specific aggregation-induced emission material, the light conversion film has an excellent light conversion effect, can effectively improve the light quality, and improve the photosynthesis efficiency.

[0009] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0010] In a first aspect, the present invention provides a light conversion film, the light conversion film comprising an organic silicon polymer and an aggregation-induced emission material dispersed in the organic silicon polymer; the aggregation-induced emission material has a structure as shown in Formula I:

[0011]

[0012] In the light conversion film of the present invention, the organic silicon polymer is used as the carrier material, which has excellent thermal oxidation stability and heat resistance far superior to general organic resins. It can be used for a long time at 200-250°C without decomposition or discoloration, and can withstand 300°C for a short time; at the same time, the organic silicon polymer can withstand low temperatures, and its chemical and physical properties change little with temperature. The excellent performance of the organic silicon polymer is related to the fact that its molecules are easily twisted spiral structures. When the temperature rises, on the one hand, the average distance between molecules is increased, and on the other hand, the spiral expansion reduces the distance between molecules. The extension and contraction of the spiral can alleviate the influence of temperature, thereby having excellent temperature resistance; moreover, the Si-O bond in the organic silicon polymer is very stable, and it is difficult to produce free radical reactions caused by ultraviolet rays, and it is not easy to have oxidation reactions, and it is not sensitive to sunlight; it is known that the wavelength of the sunlight spectrum distribution is mostly above 300nm, and most organic resins are sensitive to light in this wavelength range, while the organic silicon polymer hardly absorbs ultraviolet rays, so the sunlight has little effect on it, so that the organic silicon polymer has excellent weather resistance and high and low temperature stability.

[0013] In the light conversion film of the present invention, the aggregation-induced emission material of the structure shown in Formula I is used as a light conversion agent. On the one hand, the aggregation-induced emission (AIE) material has a photophysical phenomenon that the molecular aggregate exhibits a stronger emission than a single molecule. The mechanism of AIE is called intramolecular motion restriction (RIM). Specifically, in a solution or monodisperse state, the active motion (including vibration and rotation) within the molecule promotes non-radiative decay channels, such as dark or cone crossover decay processes, quenching emission, and in an aggregated state, due to the restriction of intramolecular motion, the non-radiative decay channel is blocked, resulting in enhanced emission. Therefore, the AIE material has high emissivity in the aggregate state, provides aggregate formation and high concentration, and has higher light conversion performance and light stability. On the other hand, the AIE material of the structure shown in Formula I has a specific fluorescence emission spectrum, has strong luminescence characteristics in the solid state / aggregate state, can effectively absorb ultraviolet light and near-infrared light, etc., and converts it into blue light and red light, thereby improving light quality and photosynthesis efficiency, and can be used as a sustainable lighting material to provide excellent light conversion performance.

[0014] Therefore, the present invention, through the design and mutual compounding of the organosilicon polymer and the AIE material of the structure shown in Formula I, makes the fluorescence intensity of the light conversion film high, can absorb ultraviolet light and near-infrared light and convert them into blue light and red light, converts light that is useless to plants / crops into useful light that promotes the growth of plants / crops, achieves excellent light conversion effect, improves light quality, and thus improves the utilization rate of sunlight and promotes the efficiency of plant photosynthesis. At the same time, the light conversion film has excellent stability and weather resistance, can continuously and stably exert excellent fluorescence intensity and light conversion effect, and will not be photobleached.

[0015] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved and realized.

[0016] Preferably, the raw material for preparing the organosilicon polymer includes a combination of a first polysiloxane component and a second polysiloxane component.

[0017] Preferably, the first polysiloxane component comprises vinyl polysiloxane and the second polysiloxane component comprises hydrogen-containing polysiloxane.

[0018] Preferably, the first polysiloxane component further comprises a platinum catalyst.

[0019] As a preferred technical solution of the present invention, the organosilicon polymer may be a commercially available product, for example, it may be platinum-catalyzed two-component organosilicon SORTA-Clear 12.

[0020] Preferably, the mass ratio of the first polysiloxane component to the second polysiloxane component is (0.8-1.2):1, for example, it can be 0.85:1, 0.9:1, 0.95:1, 1:1, 1.05:1, 1.1:1 or 1.15:1, etc.

[0021] Preferably, the mass percentage of the aggregation-induced emission material in the light conversion film is 0.1-4%, for example, it can be 0.2%, 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.2%, 2.5%, 2.8%, 3%, 3.2%, 3.5% or 3.8%, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, and 1-3% is further preferred.

[0022] Preferably, the light conversion film further comprises an antioxidant and / or a light stabilizer.

[0023] Preferably, the antioxidant comprises any one of phosphite antioxidants, hindered phenol antioxidants, hindered amine antioxidants, or a combination of at least two thereof.

[0024] Preferably, the thickness of the light conversion film is 0.1-10 mm, for example, it can be 0.2 mm, 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm, 2.2 mm, 2.5 mm, 2.8 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 6 mm, 7 mm, 8 mm or 9 mm, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, and 1-5 mm is further preferred.

[0025] In a second aspect, the present invention provides a method for preparing the light conversion film according to the first aspect, the preparation method comprising:

[0026] uniformly mixing the precursor of the organosilicon polymer and the aggregation-induced emission material to obtain a mixture;

[0027] The mixture is coated into a film and cured to obtain the light conversion film.

[0028] The light conversion film provided by the present invention uses an organic silicon polymer as a carrier material, and its precursor is mixed with an aggregation-induced luminescence material, film-formed and cured to complete the preparation. The preparation method can avoid a relatively complex and tedious preparation process, and has the advantages of simple operation method, controllable reaction conditions, short time, good reproducibility, etc.

[0029] Preferably, the precursor of the organosilicon polymer comprises a combination of a first polysiloxane component and a second polysiloxane component.

[0030] Preferably, the first polysiloxane component comprises vinyl polysiloxane and the second polysiloxane component comprises hydrogen-containing polysiloxane.

[0031] Preferably, the first polysiloxane component further comprises a platinum catalyst.

[0032] Preferably, the mass ratio of the first polysiloxane component to the second polysiloxane component is (0.8-1.2):1, for example, it can be 0.85:1, 0.9:1, 0.95:1, 1:1, 1.05:1, 1.1:1 or 1.15:1, etc.

[0033] Preferably, the mass percentage of the aggregation-induced emission material in the mixture is 0.1-4%, for example, it can be 0.2%, 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.2%, 2.5%, 2.8%, 3%, 3.2%, 3.5% or 3.8%, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively enumerates the specific point values ​​included in the range, and 1-3% is further preferred.

[0034] Preferably, the coating film forming method comprises: laying the mixture on a magnetic display sticker, removing bubbles, and obtaining a wet film.

[0035] Preferably, the curing temperature is 30-80°C, for example, it can be 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C or 75°C, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, and 40-65°C is further preferred.

[0036] Preferably, the curing time is 10-60 min, for example, it can be 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min or 55 min, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0037] In a third aspect, the present invention provides a use of the light conversion film as described in the first aspect in a bioreactor, an agricultural light conversion film, or a light conversion film for algae cultivation.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] (1) In the light conversion film provided by the present invention, the design and mutual compounding of the organosilicon polymer and the AIE material of the structure shown in Formula I make it have high fluorescence intensity, can absorb ultraviolet light and near-infrared light and convert them into blue light and red light, and convert light that is useless to plants / crops into useful light that promotes the growth of plants / crops. The light conversion film has excellent light conversion effect, stability and weather resistance, can effectively improve light quality, increase the utilization rate of sunlight, and enhance the efficiency of plant photosynthesis, and has broad application prospects in increasing the biomass and yield of bioactive compounds.

[0040] (2) The preparation method of the light conversion film provided by the present invention is simple, time-saving, and the reaction conditions are controllable, which is easy to operate and promote, laying a foundation for subsequent research. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 A schematic diagram of the preparation process of the light conversion film provided in Example 1;

[0042] Figure 2 An optical image of the light conversion film provided in Example 1;

[0043] Figure 3 This is a characterization diagram of the absorbance of the light conversion film provided in Example 1;

[0044] Figure 4 This is a luminance characterization diagram of the light conversion film provided in Example 1. DETAILED DESCRIPTION

[0045] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0046] As used herein, the terms "comprises," "including," "having," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0047] "Optionally" or "either" means that the subsequently described matter or event can or cannot occur, and that the description includes instances where the event occurs and instances where it does not.

[0048] In the following specific embodiments of the present invention, the materials used can be purchased from the market.

[0049] Example 1

[0050] A light conversion film and a preparation method thereof, wherein the light conversion film comprises an organosilicon polymer (SORTA-Clear 12) and an AIE material (structure shown in formula I, Astrazon Brilliant Red) dispersed in the organosilicon polymer.

[0051] The schematic diagram of the preparation process of the light conversion film is as follows Figure 1 As shown, the specific preparation method is as follows:

[0052] Weigh 40 g of component A of SORTA-Clear 12 and 40 g of component B of SORTA-Clear 12, mix them evenly in a ratio of 1:1 to obtain a precursor of an organic silicon polymer; weigh 1.4 g of AIE material (Astrazon Brilliant Red), mix it evenly with the precursor of the organic silicon polymer to obtain a mixture; spread the mixture on a magnetic display sticker, place it in an oven after removing bubbles, and cure it at 55°C for 30 minutes to obtain a light conversion film with a thickness of 5 mm.

[0053] The optical picture of the light conversion film provided in this embodiment is as follows: Figure 2 As shown, it appears red under natural light (sunlight).

[0054] The luminescent properties of the light conversion film provided in this embodiment were characterized by using an ultraviolet-visible spectrophotometer (model UV-8000, Shanghai Yuanxi) and a fluorescence spectrophotometer (FL970, Tianmei). The absorbance characterization graph obtained is as follows: Figure 3 As shown, the luminosity characterization diagram is as follows Figure 4 shown; combined Figure 3 and Figure 4 It can be seen that the conversion film can absorb 300-600nm ultraviolet / visible light and convert it into 550-800nm ​​fluorescence (which is a good match with the absorption of 550nm-700nm of chloroplasts). Therefore, the light conversion film can absorb ultraviolet light and near-infrared light and convert them into blue light and red light, achieving excellent light conversion effect.

[0055] Example 2

[0056] A light conversion film and a preparation method thereof, wherein the light conversion film comprises an organosilicon polymer (SORTA-Clear 12) and an AIE material (structure shown in Formula I, Astrazon Brilliant Red) dispersed in the organosilicon polymer; the preparation method is specifically as follows:

[0057] Weigh 40 g of component A of SORTA-Clear 12 and 40 g of component B of SORTA-Clear 12, mix them evenly in a ratio of 1:1 to obtain a precursor of an organic silicon polymer; weigh 2 g of AIE material (Astrazon Brilliant Red), mix it evenly with the precursor of the organic silicon polymer to obtain a mixture; spread the mixture on a magnetic display sticker, place it in an oven after removing bubbles, and cure it at 55°C for 30 minutes to obtain a light conversion film with a thickness of 3 mm.

[0058] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the light conversion film and its preparation method and application, but the present invention is not limited to the above-mentioned process steps, that is, it does not mean that the present invention must rely on the above-mentioned process steps to be implemented. Those skilled in the art should understand that any improvement to the present invention, equivalent replacement of the raw materials selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A light conversion film, characterized in that: The light conversion film includes an organic silicon polymer and an aggregation-induced luminescence material dispersed in the organic silicon polymer; the aggregation-induced luminescence material has a structure as shown in Formula I:

2. The light conversion film according to claim 1, characterized in that: The raw material for preparing the organosilicon polymer includes a combination of a first polysiloxane component and a second polysiloxane component; Preferably, the first polysiloxane component comprises vinyl polysiloxane and the second polysiloxane component comprises hydrogen-containing polysiloxane; Preferably, the first polysiloxane component further comprises a platinum catalyst; Preferably, the mass ratio of the first polysiloxane component to the second polysiloxane component is (0.8-1.2):

1.

3. The light conversion film according to claim 1 or 2, characterized in that: The mass percentage of the aggregation-induced emission material in the light conversion film is 0.1-4%, preferably 1-3%.

4. The light conversion film according to any one of claims 1 to 3, characterized in that: The light conversion film further includes an antioxidant and / or a light stabilizer.

5. The light conversion film according to any one of claims 1 to 4, characterized in that: The thickness of the light conversion film is 0.1-10 mm, preferably 1-5 mm.

6. A method for preparing a light conversion film according to any one of claims 1 to 5, characterized in that: The preparation method comprises: Mixing the precursor of the organosilicon polymer and the aggregation-induced emission material uniformly to obtain a mixture; The mixture is coated into a film and cured to obtain the light conversion film.

7. The preparation method according to claim 6, characterized in that: The precursor of the organosilicon polymer comprises a combination of a first polysiloxane component and a second polysiloxane component; Preferably, the first polysiloxane component comprises vinyl polysiloxane and the second polysiloxane component comprises hydrogen-containing polysiloxane; Preferably, the first polysiloxane component further comprises a platinum catalyst; Preferably, the mass percentage of the aggregation-induced emission material in the mixture is 0.1-4%, more preferably 1-3%.

8. The preparation method according to claim 6 or 7, characterized in that: The coating film forming method comprises: laying the mixture on a magnetic display sticker, removing bubbles, and obtaining a wet film.

9. The preparation method according to any one of claims 6 to 8, characterized in that: The curing temperature is 30-80°C, preferably 40-65°C; Preferably, the curing time is 10-60 minutes.

10. Use of the light conversion film according to any one of claims 1 to 5 in a bioreactor, an agricultural light conversion film or a light conversion film for algae cultivation.

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