Nano-composite with dimming function as well as preparation method and application of nano-composite

Abstract

The invention discloses a nanocomposite with a dimming function and a preparation method and application thereof. The nanocomposite comprises a resin organic polymer material and inorganic nanoparticles coordinated with the resin organic polymer material, and the inorganic nanoparticles comprise transition metal simple substances and / or metal compounds. According to the nano-composite disclosed by the invention, the use of organic dye is avoided while the stability of the core dimming color-changing material is ensured, the dispersion stability of the material in the whole system can be remarkably improved, the material is easier to polarize in an electric field, and the driving voltage is effectively reduced, so that the nano-composite has a wide application prospect in dimming products.

Description

Technical Field

[0001] The present invention belongs to the technical field of dimming devices, and in particular relates to a nanocomposite with a dimming function and a preparation method and application thereof. Background Art

[0002] At present, dimming products are widely used in various fields. For example, with the rising market penetration rate of new energy vehicles, on the one hand, users hope to have a comfortable experience when driving or riding in a car, including visual experience, auditory experience, physical experience, ambient temperature experience, etc. On the other hand, while ensuring the cockpit experience, factors such as energy conservation and emission reduction and safe driving need to be considered. In particular, the popularity of smart cockpits will inevitably bring about the demand for large-size skylights (panoramic skylights). However, only full-size skylight glass cannot well meet the user's needs for heat insulation and sun protection. Therefore, in order to achieve a balance between high-efficiency energy saving and user experience, a new color-changing dimming technology is inevitably needed, which can not only make the automotive glass lightweight, reduce wind resistance, leave enough head space for users, but also meet the user's needs for heat insulation and sun protection. In the past, smart dimming technologies mainly included polymer dispersed liquid crystal (PDLC) technology, electrochromic (EC) technology, and suspended particle (SPD) technology. Among them, suspended particle devices have attracted widespread attention in the industry due to their advantages such as large dimming dynamic range, continuously adjustable light transmittance, and fast response speed. An SPD dimming device generally consists of two layers of transparent conductive electrodes and a dimming layer sandwiched between the two layers of transparent conductive electrodes.

[0003] However, the suspended nanoparticles currently used in SPD light valves are mainly iodine-based organic composite nanorods, but the development of products based on iodine-based nanoparticles is greatly restricted. Although many domestic companies have joined the development of this technology, they are still unable to break away from the limitations of iodine-based materials. In addition, since this type of iodine-based particles are mainly organic metal complexes formed by iodine, metal ions, pyrazine dicarboxylic acid, etc., due to the color of iodine, this type of nanoparticles has only a single blue tone, and its thermal stability is poor, acid and alkali resistance is weak, and the nanoparticle size is large, which not only makes it difficult to make suspended particle media in SPDs, but also easily produces sublimation of iodine in actual use, causing the material to decompose and turn yellow, which greatly restricts the environmental tolerance of SPDs and pushes up the driving voltage.

[0004] Therefore, it is very important to develop a new type of suspended particles with excellent weather resistance and then develop a dimming product with more stable performance and richer colors. Summary of the invention

[0005] In order to solve at least some of the technical problems in the prior art, the present invention coordinates organic polymer materials and inorganic nanoparticles to obtain a nanocomposite with more stable performance, richer colors and dimming function. Specifically, the present invention includes the following contents.

[0006] In a first aspect, the present invention provides a nanocomposite with dimming function, which comprises an organic polymer material and inorganic nanoparticles coordinated therewith, wherein the inorganic nanoparticles comprise transition metal elements and / or metal compounds, and the organic polymer material comprises a resin organic polymer material.

[0007] In certain embodiments, according to the nanocomposite with dimming function of the present invention, the mass ratio of the inorganic nanoparticles to the organic polymer material is 1:(1-20).

[0008] In certain embodiments, according to the nanocomposite with dimming function described in the present invention, the raw materials for synthesizing the nanocomposite include a coordination enhancer, and the coordination enhancer includes at least one of polyimide, poly(3,4-ethylenedioxythiophene), polyaniline, nitrocellulose, imidazoles, pyrazines, pyridines, pyrrolidones and o-phenanthroline.

[0009] In certain embodiments, according to the nanocomposite with dimming function described in the present invention, the transition metal element includes at least one of Cu, Au, Ag, Pt and Pd; the metal compound includes at least one of CuO, CuS, CuSe, CuTe, Fe3O4, Bi2S3, Bi2Se3, Bi2Te3, CuBiS, CuInS, CuInSe2, SbCu3S4, CdS, Bi2Se3, MnO2, ZnO, ZrS2, TiS2, PbS, CdSe, PbSe, CdTe, ZnS, ZnSe, ZnTe, InP, InAs, BiSCl, BiSBr, BiSI, BiSeCl, BiSeBr, BiSeI, CoO, CoS, NiO and NiS; the resin organic polymer material includes at least one of polyurethane modified acrylic resin, phosphate modified acrylic resin, thiol modified polyester resin and amino resin.

[0010] In certain embodiments, according to the nanocomposite with light-modulating function of the present invention, the diameter of the nanocomposite is 20-100 nm and the length is 300-1000 nm.

[0011] In a second aspect of the present invention, a method for preparing the nanocomposite with dimming function according to the present invention is provided, which comprises the following steps:

[0012] (1) adding inorganic nanoparticles into an organic solvent of an organic polymer material and mixing them to obtain a nanoparticle dispersion;

[0013] (2) reacting the nanoparticle dispersion at 30-70° C. for 5-60 min, adding an organic solution containing a coordination enhancer, and continuing the reaction for 5-20 h to obtain the nanocomposite.

[0014] The third aspect of the present invention provides a dimming product, which includes the nanocomposite with dimming function described in the present invention.

[0015] In certain embodiments, according to the dimming product of the present invention, the dimming product further comprises a polymer matrix and a dispersing solvent.

[0016] In certain embodiments, according to the dimming product of the present invention, the polymer matrix includes a curable resin; and the dispersing solvent includes at least one of epoxy soybean oil, hydroxyl-terminated silicone oil, lauryl azone, pyrrolidones, pyridines, imidazoles, trioctyl trimellitate, acetyl tributyl citrate and triethylene glycol diisooctanoate.

[0017] In certain embodiments, according to the dimming product of the present invention, the curable resin includes at least one of an ultraviolet light curable resin, a room temperature curable resin, a heat curable resin, and an electron beam curable resin.

[0018] A fourth aspect of the present invention provides application of the nanocomposite with dimming function in a dimming product.

[0019] The present invention obtains a composite nanostructure with rich colors and stable chemical properties by coordinating inorganic nanoparticles with organic polymer materials. It is the core color-changing material of the dimming device, has a variety of color options, avoids the use of organic dyes, and can also ensure the various stabilities of the core color-changing material (such as thermal stability, light stability, water and oxygen resistance, etc.). In addition, compared with pure inorganic nanomaterials, the nanocomposite of the present invention can significantly improve the dispersion stability of the material in the entire system, avoiding the situation where the pure inorganic material cannot be effectively suspended and dispersed for a long time due to excessive density, thereby producing natural gravity sedimentation and causing the entire dimming device to fail. In addition, the nanocomposite of the present invention is easier to polarize under an electric field, effectively reducing the driving voltage. For example, the driving voltage of the material of the present invention can be reduced to 15-60V. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Shown is the TEM image of CuS+Bi2S3 composite nanorods.

[0021] Figure 2 TEM images of composite nanorods formed by CdS are shown.

[0022] Figure 3 TEM images of Ag+Pt composite nanorods are shown.

[0023] Figure 4 TEM images of BiSeI composite nanorods are shown. DETAILED DESCRIPTION

[0024] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0025] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that the upper and lower limits of the scope and each intermediate value therebetween are specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0026] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which the invention belongs. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0027] Nanocomposite

[0028] One aspect of the present invention provides a nanocomposite with dimming function, which includes an organic polymer material and inorganic nanoparticles coordinated therewith, wherein the inorganic nanoparticles include transition metal elements and / or metal compounds, and the organic polymer material includes a resin organic polymer material.

[0029] In the present invention, "dimming function" means that when the external electric field is not connected, the nano-composite performs irregular Brownian motion and is in a low transmittance state as a whole. At this time, the device containing the nano-composite is in a dark state; when the external electric field is connected, the nano-composite is oriented along the direction of the electric field and gradually rotates with the increase of the electric field intensity until it reaches a state completely parallel to the direction of the electric field, so that the incident light can partially or almost completely pass through the device, realizing the transparent state of the device, thereby achieving the purpose of dimming and heat insulation.

[0030] In the present invention, "coordination" refers to the process in which transition metal elements and / or metal compounds (preferably transition metal compounds) in inorganic nanoparticles and resin-based organic polymer materials combine through coordination bonds to form coordination compounds or complexes, wherein the functional groups in the resin-based organic polymer materials that can coordinate with the transition metal include but are not limited to: carboxyl, carbonyl, hydroxyl, thiol, phosphate, amino, catechol, etc.

[0031] In a preferred embodiment, the diameter of the inorganic nanoparticles is 1-50 nm, preferably 1-45 nm, also preferably 1-40 nm, further preferably 1-30 nm, more preferably 1-20 nm, for example 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 nm.

[0032] In order to obtain a nanocomposite with excellent properties, especially with significantly improved thermal stability, light stability, and water and oxygen resistance, the ratio of inorganic nanoparticles to organic polymer materials should not be too high or too low. In a preferred embodiment, the mass ratio of the inorganic nanoparticles to the organic polymer material is 1: (1-20), preferably 1: (1-15), and also preferably 1: (4-15), for example 1: 4, 1: 5, 1: 6, 1: 7, 1: 8, 1: 9, 1: 10, 1: 11, 1: 12, 1: 13, 1: 14, 1: 15. In a preferred embodiment, the mass ratio of the inorganic nanoparticles to the organic polymer material is 1: 12. In another preferred embodiment, the mass ratio of the inorganic nanoparticles to the organic polymer material is 1: 14. In another preferred embodiment, the mass ratio of the inorganic nanoparticles to the organic polymer material is 1: 4.

[0033] In certain embodiments, the raw materials for synthesizing the nanocomposite include a coordination enhancer. The inventors have found that when the coordination enhancer is not used, a rod-shaped complex cannot be formed, and it cannot be suspended and dispersed, so it cannot be used for dimming devices. When the coordination enhancer is added to the reaction system, not only a rod-shaped complex with excellent thermal stability, light stability, and water and oxygen resistance can be formed, but the rod-shaped complex can be effectively suspended and dispersed, and the dispersion stability in the entire system is improved, so that it can be used for dimming devices. The coordination enhancer of the present invention includes but is not limited to at least one of polyimide, poly (3,4-ethylenedioxythiophene), polyaniline, nitrocellulose, imidazoles, pyrazines, pyridines, pyrrolidones and o-phenanthroline. In a preferred embodiment, the coordination enhancer is o-phenanthroline. In another preferred embodiment, the coordination enhancer is 2-pyrrolidone. In another preferred embodiment, the coordination enhancer is pyrazine (e.g., 2,3-pyrazinedicarboxylic acid). In another preferred embodiment, the coordination enhancer is pyridine (e.g., benzylpyridine).

[0034] In the present invention, the amount of the coordination enhancer added should not be too high or too low. In order to prepare a rod-shaped composite with excellent thermal stability, light stability, and water and oxygen resistance, the mass ratio of the coordination enhancer to the inorganic nanoparticles is 1: (10-100), preferably 1: (20-95), for example 1: 20, 1: 22, 1: 24, 1: 26, 1: 28, 1: 30, 1: 32, 1: 34, 1: 36, 1: 38, 1: 39, 1: 40, 1: 41, 1: 42, 1: 43, 1: 44, 1: 45, 1: 46, 1: 47, 1: 48, 1: 49, 1: 50, 1: 51, 1: 52, 1 :40, 1:42, 1:44, 1:46, 1:48, 1:50, 1:52, 1:54, 1:56, 1:58, 1:60, 1:62, 1:64, 1:66, 1:68, 1:70, 1:72, 1:74, 1:76, 1:78, 1:80, 1:82, 1:84, 1:86, 1:88, 1:90, 1:92, 1:94, 1:95. In a preferred embodiment, the mass ratio of the coordination enhancer to the inorganic nanoparticles is 1:33. In another preferred embodiment, the mass ratio of the coordination enhancer to the inorganic nanoparticles is 1:39. In another preferred embodiment, the mass ratio of the coordination enhancer to the inorganic nanoparticles is 1:24. In another preferred embodiment, the mass ratio of the coordination enhancer to the inorganic nanoparticles is 1:95.

[0035] In the present invention, the transition metal element includes but is not limited to at least one of Cu, Au, Ag, Pt and Pd; the metal compound includes but is not limited to at least one of CuO, CuS, CuSe, CuTe, Fe3O4, Bi2S3, Bi2Se3, Bi2Te3, CuBiS, CuInS, CuInSe2, SbCu3S4, CdS, Bi2Se3, MnO2, ZnO, ZrS2, TiS2, PbS, CdSe, PbSe, CdTe, ZnS, ZnSe, ZnTe, InP, InAs, BiSCl, BiSBr, BiSI, BiSeCl, BiSeBr, BiSeI, CoO, CoS, NiO and NiS; the resin organic polymer material includes at least one of polyurethane modified acrylic resin, phosphate modified acrylic resin, mercapto modified polyester resin and amino resin.

[0036] In the present invention, the diameter of the dimming nanocomposite is 20-100nm, preferably 20-80nm, also preferably 20-60nm, more preferably 20-40nm, for example 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40; the length is 300-1000nm, preferably 300-800nm, also preferably 300-600nm, for example 300, 320, 340, 360, 380, 400, 420, 440, 460, 480, 500, 520, 540, 560, 580, 600nm.

[0037] Preparation method

[0038] In one aspect of the present invention, a method for preparing the nanocomposite with light-adjusting function is provided, which comprises steps (1) and (2). Steps (1) and (2) are described in detail below.

[0039] Step (1) of the present invention is to add inorganic nanoparticles to an organic solvent of an organic polymer material and mix them to obtain a nanoparticle dispersion, wherein after mixing, uniform dispersion can be achieved by, for example, mechanical stirring, ultrasonic dispersion, etc. The organic solvent is not particularly limited, and examples thereof include, but are not limited to, methanol, ethanol, propanol, isopropanol, n-butanol, isobutanol, amyl alcohol, isopentanol, or a combination of the above organic solvents. In a preferred embodiment, the organic solvent is ethanol. In another preferred embodiment, the organic solvent is n-butanol.

[0040] Step (2) of the present invention is to react the nanoparticle dispersion at 30-70° C. for 5-60 minutes, add an organic solution containing a coordination enhancer, and continue the reaction for 5-20 hours to obtain the nanocomposite.

[0041] In a preferred embodiment of step (2), the nanoparticle dispersion is at 30-70°C, preferably 31-69°C, also preferably 32-68°C, further preferably 33-67°C, more preferably 34-66°C, more preferably 35-65°C, for example 35°C, 36°C, 37°C, 38°C, 39°C, 40°C, 41°C, 42°C, 43°C, 44°C, 45°C, 46°C, 47°C, 48°C, 49°C, 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C, 60°C, 61°C, 62°C, 63°C, 64°C The mixture is reacted at 4°C or 65°C for 5-60 min, preferably 6-50 min, also preferably 8-40 min, more preferably 10-30 min, for example 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 min, and an organic solution containing a coordination enhancer is added, and the reaction is continued for 5-20 h, preferably 6-19 h, also preferably 7-18 h, for example 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 h to obtain the nanocomposite.

[0042] Dimming products

[0043] One aspect of the present invention provides a dimming product, wherein the dimming product comprises the nanocomposite with dimming function described in the present invention.

[0044] In a preferred embodiment, the dimming product further comprises a polymer matrix and a dispersing solvent. In the present invention, the polymer matrix comprises a curable resin, examples of which include but are not limited to ultraviolet curable resins, room temperature curable resins, heat curable resins, electron beam curable resins, etc. In a preferred embodiment, the curable resin comprises at least one of a silicone resin, an epoxy resin, an acrylate resin, a polyurethane resin, and a polyester resin.

[0045] In the present invention, the dispersing solvent is not particularly limited, as long as the nanocomposite can be uniformly dispersed and stably present in the dimming product. Examples thereof include but are not limited to epoxy soybean oil, hydroxyl-terminated silicone oil, laurocapron, NOP, pyrrolidones, pyridines, imidazoles, trioctyl trimellitate, acetyl tributyl citrate, triethylene glycol diisooctanoate, etc.

[0046] The dimming product of the present invention can be applied to, including but not limited to, car sunroofs, rearview mirrors, front and rear windshields, car windows, sun visors, building curtain wall glass, privacy partitions, dimming products for airport control towers, eyeglass lenses, mobile phone screens, and mobile phone films.

[0047] In a preferred embodiment, the dimming product is a dimming light valve, which includes: a first transparent base layer, a first transparent conductive layer attached to the first transparent base layer, a second transparent base layer, a second transparent conductive layer attached to the second transparent base layer, and a nanocomposite dimming functional layer sandwiched between the first and second transparent conductive layers, wherein the nanocomposite dimming functional layer includes a polymer matrix and droplets dispersed in the polymer matrix, and the droplets contain a suspended dispersed solvent and a nanocomposite.

[0048] In application, when the dimming light valve is powered on, as the power-on voltage gradually increases, the nanocomposites suspended in the dispersed solvent are successively deflected in a directional manner, thereby realizing a continuous change process of the light flux from a dark state to a transparent state or from a transparent state to a dark state.

[0049] In a preferred embodiment of the dimming light valve, the thickness of the nanocomposite dimming functional layer is 10-100 μm, preferably 20-90 μm, for example 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90 μm.

[0050] In a preferred embodiment of the dimming light valve, the size of the microdroplets is 1-50 μm, preferably 5-45 μm, and further preferably 10-40 μm, for example 10, 15, 20, 25, 30, 35, 40 μm.

[0051] In a preferred embodiment of the dimming light valve, the first and second transparent base layers include transparent glass, transparent films (for example but not limited to PET, PC, PE, PP, PI, CPI, COP, TPU or a combination thereof), etc., and the first and second transparent conductive layers include but are not limited to ITO, FTO, FZO, IZO, GZO, AZO, nano-Ag wires, conductive graphene, nano-Cu wires, etc.

[0052] The present invention also provides a method for preparing a dimming product (especially a light valve device), which comprises the following steps:

[0053] (a) mixing the nanocomposite and a dispersion solvent to obtain a nanocomposite dispersion;

[0054] (b) mixing the nanocomposite dispersion with a polymer matrix to obtain a coating solution;

[0055] (c) applying the coating solution between transparent conductive layers.

[0056] In a preferred embodiment for the preparation of light valve devices, the mass ratio of the nanocomposite to the dispersed solvent is 0.1-10%, preferably 0.5-10%, and further preferably 1-10%, for example 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, and 10%.

[0057] In a preferred embodiment of the preparation of the light valve device, the mass ratio of the nanocomposite dispersion to the polymer matrix is ​​(2-10):1, for example 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1.

[0058] In a preferred embodiment of the preparation of the light valve device, the thickness of the coating liquid is 10-100 μm, preferably 10-90 μm, also preferably 10-80 μm, further preferably 10-70 μm, more preferably 20-60 μm, more preferably 20-50 μm, more preferably 20-40 μm, for example 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40 μm.

[0059] The present invention further provides application of the nanocomposite with dimming function in dimming products.

[0060] Example 1

[0061] The following is an exemplary illustration of the preparation method of the nanocomposite of the present invention and an example of a dimming valve to illustrate the preparation method of a dimming product.

[0062] 1. Synthesis of composite nanorods

[0063] (1) adding the synthesized CuS and Bi2S3 spherical nanoparticles (diameter ≤ 5 nm) to an ethanol solution containing polyurethane-modified acrylic resin, and performing ultrasonic dispersion until the two nanoparticles are completely and evenly dispersed in the solution (the solution is gray-black), to obtain a nanoparticle dispersion; wherein the amount of CuS is 1 g, the amount of Bi2S3 is 0.8 g, the amount of polyurethane-modified acrylic resin is 22 g, and the amount of ethanol is 100 g;

[0064] (2) transferring the nanoparticle dispersion into a round-bottom flask, placing it in a 40° C. oil bath and stirring for 20 minutes, then adding 5.5 g of an ethanol solution containing 1% o-phenanthroline into the round-bottom flask, stirring for 12 hours, then stopping stirring and cooling to room temperature;

[0065] (3) The reaction solution in (2) is centrifuged to obtain a centrifuge, and the centrifuge is ultrasonically cleaned and redispersed with ethanol, and then centrifuged again to obtain composite nanorods.

[0066] 2. Preparation method of dimming valve

[0067] (1) ultrasonically dispersing the composite nanorods in a mixed solvent of trioctyl trimellitate and tributyl acetyl citrate (containing 0.1% polyurethane-modified acrylic resin), wherein the mass ratio of the nanorods to the mixed solvent is 2%, and the dispersion is gray-black as a whole, thereby obtaining a nanorod dispersion;

[0068] (2) adding the nanorod dispersion to UV-curable polyurethane-modified acrylate resin and stirring the mixture to obtain a gray-black coating solution, wherein the mass ratio of the dispersion to the resin is 5:1;

[0069] (3) The coating liquid is coated between two transparent conductive layers to a thickness of 30 μm, and UV light is cured to obtain a gray-black dimming valve device. The transmittance before power-on is measured to be 1%, and the transmittance after power-on is 35%.

[0070] In this embodiment, the dimming valve further comprises a first and a second transparent base layer prepared from a transparent PET film. In addition, the first and the second transparent conductive layers are ITO layers, the polymer matrix in the nanocomposite dimming functional layer is a UV curable polyurethane modified acrylic resin, the suspension and dispersion solvent is a mixed solvent of trioctyl trimellitate and tributyl acetyl citrate, and the nanocomposite is a nanorod formed by the complexation of CuS and Bi2S3 with polyurethane modified acrylic resin and o-phenanthroline, and the diameter is 30nm and the length is 500nm (such as Figure 1 As shown), the driving voltage is 40V.

[0071] Example 2

[0072] The following is an exemplary illustration of the preparation method of the nanocomposite of the present invention and an example of a dimming valve to illustrate the preparation method of a dimming product.

[0073] 1. Synthesis of composite nanorods

[0074] (1) adding pre-synthesized CdS spherical nanoparticles (with a diameter of less than 3 nm) to a n-butanol solution containing a polyurethane-modified acrylic resin, and performing ultrasonic dispersion until the nanoparticles are completely and evenly dispersed in the solution (the solution is bright yellow), thereby obtaining a nanoparticle dispersion; wherein the amount of CdS used is 2.1 g, the amount of mercapto-modified polyester resin used is 25 g, and the amount of n-butanol used is 120 g;

[0075] (2) the nanoparticle dispersion was transferred to a round-bottom flask, placed in a 60° C. oil bath and stirred for 20 minutes, and then 3.6 g of a 1.5% 2-pyrrolidone solution of n-butanol was added to the round-bottom flask, and the mixture was stirred for 10 hours before being stopped and cooled to room temperature;

[0076] (3) The reaction solution in (2) is centrifuged to obtain a centrifuge, and the centrifuge is ultrasonically cleaned and redispersed with ethanol, and then centrifuged again to obtain composite nanorods.

[0077] 2. Preparation method of dimming valve

[0078] (1) ultrasonically dispersing the composite nanorods in a mixed solvent of acetyl tributyl citrate and triethylene glycol diisooctanoate (containing 0.5% polyurethane-modified acrylic resin), wherein the mass ratio of the nanorods to the mixed solvent is 1.5%, and the dispersion is bright yellow as a whole, thereby obtaining a nanorod dispersion;

[0079] (2) adding the nanorod dispersion into a thermosetting epoxy-modified polyester resin and stirring the mixture thoroughly, wherein the mass ratio of the dispersion to the resin is 2:1, to obtain a bright yellow coating liquid;

[0080] (3) The coating liquid is coated between two transparent conductive layers to a thickness of 25 μm, and thermally cured to obtain a bright yellow dimming valve device. The transmittance before power-on is 6%, and the transmittance after power-on is 55%.

[0081] In this embodiment, the dimming valve further comprises a first and a second transparent base layer made of transparent glass. In addition, the first and the second transparent conductive layers are nano Ag wire layers, the polymer matrix in the nanocomposite dimming function layer is a thermosetting epoxy modified polyester resin, the suspension and dispersion solvent is a mixed solvent of acetyl tributyl citrate and triethylene glycol diisooctanoate, and the nanocomposite is a nanorod formed by CdS, polyurethane modified acrylic resin and 2-pyrrolidone, and the diameter is 20nm and the length is 300nm (such as Figure 2 ), the driving voltage is 60V.

[0082] Example 3

[0083] The following is an exemplary illustration of the preparation method of the nanocomposite of the present invention and an example of a dimming valve to illustrate the preparation method of a dimming product.

[0084] 1. Synthesis of composite nanorods

[0085] (1) adding the synthesized Ag and Pt spherical nanoparticles (with a diameter of less than 3 nm) to an isopropanol solution of a phosphate-modified acrylic resin, and performing ultrasonic dispersion until the two nanoparticles are completely and evenly dispersed in the solution (the solution is gray), to obtain a nanoparticle dispersion; wherein the amount of the Ag spherical nanoparticles is 1.2 g, the amount of the Pt spherical nanoparticles is 0.4 g, the amount of the phosphate-modified acrylic resin is 22 g, and the amount of isopropanol is 120 g;

[0086] (2) transferring the nanoparticle dispersion into a round-bottom flask, placing it in an oil bath at 60° C. and stirring for 20 minutes, then adding 4.0 g of an isopropanol solution containing 1.5% pyrazine (e.g., 2,3-pyrazinedicarboxylic acid) into the round-bottom flask, stirring for 10 hours, then stopping stirring and cooling to room temperature;

[0087] (3) The reaction solution in (2) is centrifuged to obtain a centrifuge, and the centrifuge is ultrasonically cleaned and redispersed with ethanol, and then centrifuged again to obtain composite nanorods.

[0088] 2. Preparation method of dimming valve

[0089] (1) ultrasonically dispersing the composite nanorods in a trioctyl trimellitate solvent (containing 0.5% polyurethane-modified acrylic resin), wherein the mass ratio of the nanorods to the mixed solvent is 2.5%, and the dispersion liquid is bright gray as a whole, thereby obtaining a nanorod dispersion liquid;

[0090] (2) adding the nanorod dispersion into a thermosetting epoxy-modified polyester resin and stirring the mixture thoroughly, wherein the mass ratio of the dispersion to the resin is 2:1, to obtain a gray coating solution;

[0091] (3) The coating liquid is coated between two transparent conductive layers to a thickness of 35 μm, and thermally cured to obtain a gray dimming valve device. The transmittance before power-on is measured to be 2.5%, and the transmittance after power-on is 45%.

[0092] In this embodiment, the dimming valve further comprises a first and a second transparent base layer made of transparent glass. In addition, the first and the second transparent conductive layers are nano Ag wire layers, the polymer matrix in the nanocomposite dimming function layer is a thermosetting epoxy modified polyester resin, the suspension dispersion solvent is a trioctyl trimellitate solvent, and the nanocomposite is a nanorod formed by Ag, Pt, phosphate modified acrylic resin and 2,3-pyrazine dicarboxylic acid, and the diameter is 100nm and the length is 1000nm (such as Figure 3 ), the driving voltage of the dimming device in this embodiment is 55V.

[0093] Example 4

[0094] The following is an exemplary illustration of the preparation method of the nanocomposite of the present invention and an example of a dimming valve to illustrate the preparation method of a dimming product.

[0095] 1. Synthesis of composite nanorods

[0096] (1) adding the synthesized BiSeI spherical nanoparticles (with a diameter of less than 4 nm) to an isopropanol solution containing an amino resin, and performing ultrasonic dispersion until the nanoparticles are completely and evenly dispersed in the solution (the solution is brown), to obtain a nanoparticle dispersion; wherein the amount of BiSeI spherical nanoparticles is 2.5 g; the amount of amino resin is 10 g; and the amount of isopropanol is 90 g;

[0097] (2) the nanoparticle dispersion was transferred to a round-bottom flask, placed in a 60° C. oil bath and stirred for 20 minutes, and then 2.2 g of an isopropanol solution containing 1.2% pyridine (benzylpyridine) was added to the round-bottom flask, and the stirring was stopped after continuous stirring for 10 hours, and the temperature was cooled to room temperature;

[0098] (3) The reaction solution in (2) is centrifuged to obtain a centrifuge, and the centrifuge is ultrasonically cleaned and redispersed with ethanol, and then centrifuged again to obtain composite nanorods.

[0099] 2. Preparation method of dimming valve

[0100] (1) ultrasonically dispersing the composite nanorods in hydroxyl-terminated silicone oil (containing 0.5% polyurethane-modified acrylic resin), wherein the mass ratio of the nanorods to the mixed solvent is 1.8%, and the dispersion is brown as a whole, thereby obtaining a nanorod dispersion;

[0101] (2) adding the nanorod dispersion into UV-curable aliphatic modified acrylate resin and stirring the mixture evenly, wherein the mass ratio of the dispersion to the resin is 2:1, to obtain a brown coating liquid;

[0102] (3) The coating liquid was coated between two transparent conductive layers to a thickness of 35 microns, and thermally cured to obtain a brown dimming valve device, the transmittance of which was 3.4% before power on and 52% after power on. The driving voltage here was 65V.

[0103] In this embodiment, the dimming valve further comprises a first and a second transparent base layer made of transparent glass. In addition, the first and the second transparent conductive layers are nano-Ag wire layers, the polymer matrix in the nano-composite dimming functional layer is a thermosetting epoxy modified polyester resin, the suspension and dispersion solvent is a trioctyl trimellitate solvent, and the nano-composite is a nano-rod formed by BiSeI, an amino resin and benzylpyridine, and the diameter is 20nm and the length is 300nm (such as Figure 4 ).

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some of the technical features therein by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A nanocomposite with dimming function, characterized in that: It comprises an organic polymer material and inorganic nanoparticles coordinated therewith, wherein the inorganic nanoparticles comprise transition metal simple substance and / or metal compound, and the organic polymer material comprises a resin organic polymer material.

2. The nanocomposite with dimming function according to claim 1, characterized in that: The mass ratio of the inorganic nanoparticles to the organic polymer material is 1:(1-20).

3. The nanocomposite with dimming function according to claim 1, characterized in that: The raw materials for synthesizing the nanocomposite include a coordination enhancer, and the coordination enhancer includes at least one of polyimide, poly(3,4-ethylenedioxythiophene), polyaniline, nitrocellulose, imidazoles, pyrazines, pyridines, pyrrolidones and o-phenanthroline.

4. The nanocomposite with dimming function according to claim 1, characterized in that: The transition metal element includes at least one of Cu, Au, Ag, Pt and Pd; the metal compound includes at least one of CuO, CuS, CuSe, CuTe, Fe3O4, Bi2S3, Bi2Se3, Bi2Te3, CuBiS, CuInS, CuInSe2, SbCu3S4, CdS, Bi2Se3, MnO2, ZnO, ZrS2, TiS2, PbS, CdSe, PbSe, CdTe, ZnS, ZnSe, ZnTe, InP, InAs, BiSCl, BiSBr, BiSI, BiSeCl, BiSeBr, BiSeI, CoO, CoS, NiO and NiS; the resin organic polymer material includes at least one of polyurethane modified acrylic resin, phosphate modified acrylic resin, mercapto modified polyester resin and amino resin.

5. The nanocomposite with dimming function according to claim 1, characterized in that: The diameter of the nanocomposite is 20-100 nm and the length is 300-1000 nm.

6. The method for preparing a nanocomposite with dimming function according to any one of claims 1 to 5, characterized in that: The following steps are involved: (1) adding inorganic nanoparticles into an organic solvent of an organic polymer material and mixing them to obtain a nanoparticle dispersion; (2) reacting the nanoparticle dispersion at 30-70° C. for 5-60 min, adding an organic solution containing a coordination enhancer, and continuing the reaction for 5-20 h to obtain the nanocomposite.

7. Dimming product, characterized in that, The dimming product comprises the nanocomposite with dimming function according to any one of claims 1 to 5.

8. The dimming product according to claim 7, characterized in that: The dimming product further includes a polymer matrix and a dispersing solvent.

9. The dimming product according to claim 8, characterized in that: The polymer matrix includes a curable resin; the dispersing solvent includes at least one of epoxy soybean oil, hydroxyl-terminated silicone oil, laurocapron, pyrrolidones, pyridines, imidazoles, trioctyl trimellitate, tributyl acetyl citrate and triethylene glycol diisooctanoate; Preferably, the curable resin includes at least one of an ultraviolet light curable resin, a room temperature curable resin, a heat curable resin and an electron beam curable resin.

10. Use of the nanocomposite with dimming function according to any one of claims 1 to 5 in dimming products.

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