Light modulating device

Abstract

The application provides a light-adjusting device, which comprises a first transparent base layer, a first transparent conductive layer, a light-adjusting layer, a second transparent conductive layer and a second transparent base layer, the light-adjusting layer comprises dichroic composite particles and a dispersion medium, the dichroic composite particles comprise an inner layer and an outer layer, the inner layer has a non-spherical symmetric shape, the outer layer is formed by epitaxial growth of a material with optical dichroism through a ligand modifying the surface of the inner layer, wherein the absolute value of the difference between the refractive index of the ligand and the refractive index of the dispersion medium is less than 0.19. For the light-adjusting device provided by the application, by controlling the refractive index of the ligand and the dispersion medium, the light-adjusting range of the light-adjusting device can be effectively adjusted. Meanwhile, by controlling the absolute value of the difference between the refractive index of the ligand and the refractive index of the dispersion medium, the optical matching of the outer layer material of the dichroic composite particles and the dispersion medium can be further controlled, so that the haze in the bright state is controlled to be within 5%.

Description

[0001] This application is a divisional application of the invention patent application filed on September 25, 2020, with application number 202011024773.5 and invention title "Dimming Device". Technical Field

[0002] This invention relates to a dimming device, specifically a dimming device having dichroic composite particles. Background Technology

[0003] With the development of technology, smart glass is being used more and more widely in the fields of architecture, transportation, and office, especially in the automotive, high-speed rail, and aircraft sectors. Currently, the more mature smart glass products on the market are PDLC smart glass and electrochromic smart glass. However, PDLC smart glass can only switch between transparency and haze, and cannot achieve light-blocking or heat insulation effects. Electrochromic smart glass, on the other hand, suffers from complex film processing and slow response time (8–20 seconds).

[0004] Another relatively mature technology is the SPD (Special Purpose Device) light valve technology. This involves suspending particles within a dimming layer. Without an applied electric field, the suspended particles undergo Brownian motion, absorbing, scattering, or reflecting incident light, resulting in a dark state for the SPD light valve. When an electric field is applied, the suspended particles are polarized, aligning in a straight line along the direction of the electric field, allowing most of the incident light to pass through the dimming layer, resulting in a bright state for the SPD light valve, as disclosed in US patent application US5650872A. In this technology, the shape and size of the suspended particles are crucial to the final effect. However, due to limitations in materials and manufacturing processes, precise control over both the shape and size of the suspended particles is impossible. Furthermore, this type of dimming device has a relatively limited dimming range and excessive haze in the bright state, failing to meet diverse needs.

[0005] Therefore, there is a need for a dimming device that can not only precisely control the size of suspended particles, but also adjust the dimming range, while reducing bright haze and improving clarity. Summary of the Invention

[0006] To address the aforementioned problems, the present invention provides a dimming device comprising a first transparent substrate, a first transparent conductive layer, a dimming layer, a second transparent conductive layer, and a second transparent substrate. The dimming layer comprises dichroic composite particles and a dispersion medium. The dichroic composite particles comprise an inner layer and an outer layer. The inner layer has a non-spherical symmetric shape, and the outer layer is formed by epitaxially growing an optically dichroic material onto a ligand modified on the surface of the inner layer. The absolute value of the difference between the refractive index of the ligand and the refractive index of the dispersion medium is less than 0.19.

[0007] In a preferred embodiment, the ligand is an organic carboxylic acid compound. In a more preferred embodiment, the organic carboxylic acid compound includes pyrrole carboxylic acids, thiazole carboxylic acids, imidazole carboxylic acids, pyrazole carboxylic acids, pyridine carboxylic acids, pyrimidine carboxylic acids, quinine carboxylic acids, pyrazine carboxylic acids, phenanthroline carboxylic acids, and purine carboxylic acids.

[0008] In a preferred embodiment, the dispersion medium is one or more of a polyester. In a more preferred embodiment, the polyester includes dioctyl adipate, trioctyl trimellitate, dibutyl phthalate, diethyl phthalate, butyl benzyl phthalate, dioctyl terephthalate, di(2-ethylhexyl) phthalate, di-n-octyl phthalate, diisodecyl phthalate, diisononyl phthalate, diisobutyl phthalate, dimethyl phthalate, dicyclohexyl phthalate, diisodecyl adipate, dioctyl azelate, dioctyl sebacate, diisooctyl sebacate, and triethylene glycol. Diisooctanoate, Trimethylbenzene Phosphate, Triphenyl Phosphate, 2-Ethylhexyl diphenyl phosphate, Toluene diphenyl phosphate, Epoxidized soybean oil, Epoxidized fatty acid butyl ester, Epoxidized fatty acid octyl ester, Tributyl trimellitate, Trihexyl trimellitate, Triallyl 1,2,4-benzenedric tricarboxylate, Tripropyl 1,3,4-benzenedric tricarboxylate, Trimethyl 1,2,4-benzenedric tricarboxylate, Tetraoctyl pyromellitic acid, 2-ethylhexyl phthalate, Monobenzene phthalate, Dibenzene phthalate, and diallyl phthalate.

[0009] In a preferred embodiment, the longest axis of the dichroic composite particle has a length of 100–1000 nm and the shortest axis has a length of 10–200 nm.

[0010] In a preferred embodiment, the inner layer is made of a metal or its compound, an inorganic non-metallic compound, or an organic compound. In a more preferred embodiment, the inner layer is hydroxyapatite nanorods.

[0011] In a preferred embodiment, the outer layer is a polyhalogenated material. In a more preferred embodiment, the outer layer is a polyiodine compound.

[0012] In a preferred embodiment, the mass ratio of dichroic composite particles to dispersion medium is 1:7 to 1:40.

[0013] In a preferred embodiment, the thickness of the dimming layer is 5 to 50 micrometers.

[0014] In some implementations, the dimming layer also includes a particle stabilizer.

[0015] This invention provides a dimming device comprising a first transparent substrate, a first transparent conductive layer, a dimming layer, a second transparent conductive layer, and a second transparent substrate. The dimming layer comprises dichroic composite particles, a particle stabilizer, and a dispersion medium. The dichroic composite particles comprise an inner layer and an outer layer. The inner layer has a non-spherical symmetric shape, and the outer layer is formed by epitaxially growing a material with optical dichroism onto a ligand modified on the surface of the inner layer. The absolute value of the difference between the refractive index of the ligand and the refractive index of the dispersion medium is less than 0.19.

[0016] This invention provides a dimming device comprising a dimming layer, wherein the dimming layer includes dichroic composite particles and a dispersion medium. The dichroic composite particles include an inner layer and an outer layer, wherein the inner layer has a non-spherical symmetric shape, and the outer layer is formed by epitaxially growing an optically dichroic material on a ligand modified with the surface of the inner layer. The absolute value of the difference between the refractive index of the ligand and the refractive index of the dispersion medium is less than 0.19. The dimming layer absorbs incident light to the maximum extent when no electric field is applied, and absorbs less incident light when an electric field is applied.

[0017] In some embodiments, the dimming device further includes a first transparent substrate, a first transparent conductive layer, a second transparent conductive layer, and a second transparent substrate.

[0018] The dimming device provided by this invention can effectively adjust its dimming range by controlling the refractive indices of the ligand and the dispersion medium. Furthermore, by controlling the absolute value of the difference between the refractive indices of the ligand and the dispersion medium, the optical matching between the outer layer material of the dichroic composite particles and the dispersion medium can be further controlled, thereby keeping the haze in the bright state below 5%. Attached Figure Description

[0019] The invention can be better understood by referring to the illustrated description of embodiments thereof, in which:

[0020] Figure 1 This is a schematic diagram of the structure and working principle of the dimming device provided by the present invention when no power is applied;

[0021] Figure 2 This is a schematic diagram of the structure of the composite particles provided by the present invention;

[0022] Figure 3 This is a schematic diagram of the structure and working principle of the dimming device provided by the present invention when powered on;

[0023] Figure 4 The image contains two images: image (a) is a TEM image of hydroxyapatite nanorods prepared according to a specific embodiment of the present invention, and image (b) is a SEM image of dichroic composite particles prepared according to a specific embodiment of the present invention.

[0024] Figure 5 This is a TEM image of the dichroic composite particles prepared according to a specific embodiment of the present invention. Detailed Implementation

[0025] In the following description, numerous specific details are set forth for the purpose of explanation and to provide a comprehensive understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be implemented without these specific details. The illustrative exemplary embodiments provided are for illustrative purposes only and do not constitute a limitation on the invention. Therefore, the scope of protection of the invention is not limited to the above specific embodiments, but is determined solely by the scope of the appended claims.

[0026] like Figure 1 As shown, this invention discloses a dimming device comprising a first transparent substrate 100, a first transparent conductive layer 200, a dimming layer 300, a second transparent conductive layer 400, and a second transparent substrate 500. The dimming layer 300 includes dichroic composite particles 301, a particle stabilizer (not shown), and a dispersion medium 302, wherein the dichroic composite particles 301 are suspended in the dispersion medium 302. The particle stabilizer is used to prevent the aggregation of the dichroic composite particles 301, allowing them to be dispersed and suspended in the dispersion medium 302. The particle stabilizer can be dispersed in the dispersion medium 302 or attached to the surface of the dichroic composite particles 301. The particle stabilizer and dispersion medium can use polymeric stabilizers and liquid suspension media disclosed in SPD, which will not be listed individually here. In this invention, the particle stabilizer is selected as nitrocellulose. The thickness of the dimming layer is 5–50 micrometers. Preferably, the thickness of the dimming layer is 5–30 micrometers.

[0027] The materials of the first transparent substrate 100 and the second transparent substrate 500 can be transparent glass or polymer materials, such as PET, PEN, PC, PP, PMMA, PBT, PVC, PI, cellulose, etc. The materials of the first transparent conductive layer 200 and the second transparent conductive layer 400 can be carbon-based conductive films, metal nanowire conductive films, metal oxide conductive films, etc. Carbon-based conductive films mainly include two categories: graphene oxide conductive films and carbon nanotube conductive films. Commonly used metal nanowire conductive films include silver nanowire conductive films and copper nanowire conductive films. Metal oxide conductive films include indium tin oxide conductive films, indium oxide conductive films, tin oxide conductive films, zinc oxide conductive films, and conductive films made from mixtures of other metal oxides. In the following embodiments, both the first transparent substrate 100 and the second transparent substrate 500 of the dimming device are made of transparent glass, and both the first transparent conductive layer 200 and the second transparent conductive layer 400 are indium tin oxide (ITO) layers.

[0028] like Figure 2 As shown, the dichroic composite particle 301 comprises an inner layer 310 and an outer layer 320. The inner layer 310 has a non-spherically symmetric shape (i.e., at least two optical axes of unequal length in its structure), such as rod-shaped, ribbon-shaped, sheet-shaped, needle-shaped, thread-shaped, or disc-shaped. However, the invention is not limited to these, and other suitable non-spherically symmetric shapes may also be used. For the inner layer 310 with a non-spherically symmetric shape, its shortest axis is generally nanometer-scale in size, while the size ratio of its longest axis to its shortest axis is greater than 1. The size of the shortest axis of the inner layer 310 is 0.5–100 nanometers, preferably 5–60 nanometers. The size ratio of the longest axis to the shortest axis of the inner layer 310 is 2:1–50:1, preferably 2:1–40:1. The material of the inner layer 310 may be a metal and its compounds, an inorganic non-metallic compound, or an organic compound. For example, the inner layer 310 can be gold nanowires, silver nanosheets, iron oxide nanorods, molybdenum disulfide nanosheets, hydroxyapatite nanorods, cellulose nanocrystals, etc. In the following embodiments of the present invention, the inner layer 310 is selected as hydroxyapatite nanorods.

[0029] The outer layer 320 can completely surround the inner layer 310 (e.g., Figure 2 As shown, the outer layer 320 may partially surround the inner layer 310. The outer layer 320 is made of a material different from that of the inner layer 310, which may exhibit optical dichroism under certain conditions, such as polyhalides. Preferably, the material of the outer layer 320 is a polyiodine compound. Such compounds have good optical dichroism, which can improve the optical properties of the final composite particles.

[0030] In this invention, the outer layer 320 is formed by epitaxial growth of an optically dichroic material onto a ligand modified on the surface of the inner layer 310, wherein the absolute value of the difference between the refractive index of the ligand and the refractive index of the dispersion medium 302 is less than 0.19. The ligand can be an organic carboxylic acid compound, such as pyrrole carboxylic acids, thiazole carboxylic acids, imidazole carboxylic acids, pyrazole carboxylic acids, pyridine carboxylic acids, pyrimidine carboxylic acids, quinine carboxylic acids, pyrazine carboxylic acids, phenanthroline carboxylic acids, or purine carboxylic acids. Such ligands can effectively and uniformly and stably modify carbonyl groups on the surface of the inner layer 310, providing a basis for the subsequent growth of the outer layer 320. The dispersion medium is one or more of the following polyesters: dioctyl adipate, trioctyl trimellitate, dibutyl phthalate, diethyl phthalate, butyl benzyl phthalate, dioctyl terephthalate, di(2-ethylhexyl) phthalate, di-n-octyl phthalate, diisodecyl phthalate, diisononyl phthalate, diisobutyl phthalate, dimethyl phthalate, dicyclohexyl phthalate, diisodecyl adipate, dioctyl azelate, dioctyl sebacate, diisooctyl sebacate, triethyl terephthalate, etc. Diol diisooctanoate, tricresyl phosphate, triphenyl phosphate, 2-ethylhexyl diphenyl phosphate, toluene diphenyl phosphate, epoxidized soybean oil, epoxidized fatty acid butyl ester, epoxidized fatty acid octyl ester, tri-n-butyl trimellitate, tri-n-hexyl trimellitate, triallyl 1,2,4-phenyltricarboxylate, tripropyl 1,3,4-phenyltricarboxylate, trimethyl 1,2,4-phenyltricarboxylic acid, tetraoctyl pyromellitic acid, benzyl phthalate 2-ethylhexyl ester, monobenzyl phthalate, dibenzyl phthalate, or diallyl phthalate. These compounds can effectively swell particle stabilizers, thereby stabilizing the dispersion of dichroic composite particles in the dispersion medium and preventing particle aggregation. Simultaneously, these compounds exhibit high chemical stability, improving the stability and weather resistance of dimming devices. Since the outer layer 320 is formed by epitaxially growing a material with optical dichroism through a ligand modified on the surface of the inner layer 310, the optical properties of the material in the outer layer 320 are greatly affected by the ligand. Therefore, the refractive index matching between the ligand and the dispersion medium affects the optical matching between the outer material of the dichroic composite particle and the dispersion medium, which further affects the optical properties of the dimming layer 300.

[0031] For dichroic composite particles, the material of the outer layer 320 is regularly distributed along the shape of the inner layer 310, giving the dichroic composite particle 301 optical dichroism and dielectric anisotropy. Simultaneously, the dichroic composite particle 301 retains the asymmetric characteristics of its inner layer 310 structure, and the final size and aspect ratio of the dichroic composite particle 301 can be controlled by controlling the size and aspect ratio of the inner layer 310. Preferably, the longest axis of the dichroic composite particle 301 is 100–1000 nanometers, and the shortest axis is 10–200 nanometers.

[0032] like Figure 1 As shown, in the absence of an applied electric field, the dichroic composite particles 301 undergo Brownian motion in the dispersion medium 302 and are randomly arranged in any direction within the dimming layer 300. At this point, their scattering and reflection of incident light are maximized. Simultaneously, since the dichroic material absorbs incident light differently in different directions, and this absorption varies with the angle between the optical axis of the dichroic material and the electric vector of the incident light, and the optical axis of the dichroic composite particles is arbitrary, their absorption of incident light is also maximized. At this point, the transmittance of incident light is minimized, and the dimming device appears dark. Furthermore, due to the optical dichroism of the dichroic composite particles, the entire dimming device can display a certain color. For example... Figure 3 As shown, when an electric field is applied, due to the structural and dielectric anisotropy of the dichroic composite particles, their long axes tend to align parallel to the electric field. The angle between the optical axis of the dichroic composite particles and the electric vector of the incident light decreases, resulting in less absorption of the incident light and further reduction in scattering or reflection. This leads to an increase in the transmittance of the incident light, causing the dimming device to appear bright. By adjusting the magnitude of the applied electric field, the transmittance of the dimming device can be continuously controlled. To ensure that the transmittance of the dimming device is sufficiently low in the dark state to achieve the desired dark state effect, the mass ratio of the dichroic composite particles 301 to the dispersion medium 302 is 1:7 to 1:40, preferably 1:7 to 1:25. In this invention, the refractive index difference between the dichroic composite particles and the dispersion medium is altered by controlling the absolute value of the difference between the refractive index of the ligand and the refractive index of the dispersion medium. This allows for the regulation of the highest transmittance in the bright state of the dimming device, while maintaining the lowest transmittance in the dark state essentially unchanged, thereby altering the overall dimming range of the device. Simultaneously, by controlling the optical matching between the dichroic composite particle material and the dispersion medium (i.e., the absolute value of the difference between the refractive indices of the ligand and the dispersion medium is less than 0.19), the haze in the bright state can be controlled within 5%, thus maintaining the clarity of the bright state.

[0033] In the following embodiments, unless otherwise specified, all concentrations are mass concentrations. The sizes of the inner layer and dichroic composite particles were obtained statistically from TEM or SEM images. The transmittance and haze of the dimming device were measured using a WGT-S haze meter, while the refractive index of the dispersion medium was measured using an Abbe refractometer.

[0034] Comparative Example 1

[0035] 2.80 g of nitrocellulose, 37.20 g of dioctyl sebacate, 0.10 g of hydroxyapatite nanorods (average length: 100 nm, average width: 10 nm), 1.13 g of iodine, 0.5 g of methanol, 0.84 g of CaI₂·4H₂O, and 0.75 g of 2,5-pyrazine dicarboxylic acid (refractive index of ligand: 1.638) were placed in a 100 mL container. The morphology of the hydroxyapatite nanorods is as follows: Figure 4 As shown in image (a). After stirring for 16 hours, the mixture was centrifuged, washed, and centrifuged again to obtain blue nanorods (average length: approximately 800 nm, average width: approximately 100 nm), with an appearance as shown in the image. Figure 4 As shown in picture (b).

[0036] The nanorods, nitrocellulose, and dioctyl adipate (refractive index of the dispersion medium: 1.447) prepared above were mixed at a mass ratio of 1:0.25:19 to form a dimming layer material. This dimming layer material was then used in conjunction with a first transparent substrate, a first transparent conductive layer, a second transparent conductive layer, and a second transparent substrate to form a 4×4 cm dimming device, wherein the thickness of the dimming layer was 20 micrometers. According to the test results, the transmittance in the dark state was 2.87%, the highest transmittance in the bright state was 39.4%, and the haze in the bright state was 5.1%. Due to the significant difference in refractive indices between the ligand 2,5-pyrazine dicarboxylic acid and the dispersion medium dioctyl adipate, the dimming device exhibited a relatively high haze in the bright state.

[0037] Example 1

[0038] 2.80 g of nitrocellulose, 37.20 g of dioctyl sebacate, 0.10 g of hydroxyapatite nanorods (average length: 100 nm, average width: 10 nm), 1.13 g of iodine, 0.5 g of methanol, 0.84 g of CaI₂·4H₂O, and 0.75 g of 2,5-pyrazine dicarboxylic acid (refractive index of ligand: 1.638) were placed in a 100 mL container. After stirring and reacting for 16 hours, the mixture was centrifuged, washed, and centrifuged again to obtain blue nanorods (average length: approximately 800 nm, average width: approximately 100 nm).

[0039] The nanorods, nitrocellulose, and trioctyl trimellitate (refractive index of the dispersion medium: 1.485) prepared above were mixed at a mass ratio of 1:0.25:19 to form a dimming layer material. This dimming layer material was then used in conjunction with a first transparent substrate, a first transparent conductive layer, a second transparent conductive layer, and a second transparent substrate to form a 4×4 cm dimming device, wherein the thickness of the dimming layer was 20 micrometers. The transmittance in the dark state was tested to be 2.45%, the highest transmittance in the bright state was 56.5%, and the haze in the bright state was 3.4%. The dimming range was 2.45%–56.5%.

[0040] Example 2

[0041] 2.80 g of nitrocellulose, 37.20 g of dioctyl sebacate, 0.10 g of hydroxyapatite nanorods (average length: 100 nm, average width: 10 nm), 1.13 g of iodine, 0.5 g of methanol, 0.84 g of CaI₂·4H₂O, and 0.75 g of 2,5-pyrazine dicarboxylic acid (refractive index of ligand: 1.638) were placed in a 100 mL container. After stirring and reacting for 16 hours, the mixture was centrifuged, washed, and centrifuged again to obtain blue nanorods (average length: approximately 800 nm, average width: approximately 100 nm).

[0042] The nanorods, nitrocellulose, and diethyl phthalate (refractive index of the dispersion medium: 1.502) prepared above were mixed at a mass ratio of 1:0.25:19 to form a dimming layer material. This dimming layer material was then used in conjunction with a first transparent substrate, a first transparent conductive layer, a second transparent conductive layer, and a second transparent substrate to form a 4×4 cm dimming device, wherein the thickness of the dimming layer was 20 micrometers. According to the test results, the transmittance in the dark state was 2.90%, the highest transmittance in the bright state was 66.2%, and the haze in the bright state was 1.9%. The dimming range was 2.90%–66.2%.

[0043] Example 3

[0044] 2.80 g of nitrocellulose, 37.20 g of dioctyl sebacate, 0.10 g of hydroxyapatite nanorods (average length: 100 nm, average width: 10 nm), 1.13 g of iodine, 0.5 g of methanol, 0.84 g of CaI₂·4H₂O, and 0.75 g of 2,5-pyrazine dicarboxylic acid (refractive index of ligand: 1.638) were placed in a 100 mL container. After stirring and reacting for 16 hours, the mixture was centrifuged, washed, and centrifuged again to obtain blue nanorods (average length: approximately 800 nm, average width: approximately 100 nm).

[0045] The nanorods, nitrocellulose, dioctyl adipate, and trioctyl trimellitate (refractive index of the dispersion medium: 1.454) prepared above were mixed in a mass ratio of 1:0.25:9.5:9.5 to form a dimming layer material. This dimming layer material was then used in conjunction with a first transparent substrate, a first transparent conductive layer, a second transparent conductive layer, and a second transparent substrate to form a 4×4 cm dimming device, wherein the thickness of the dimming layer was 20 micrometers. According to the test results, the transmittance in the dark state was 2.38%, the highest transmittance in the bright state was 45.1%, and the haze in the bright state was 3.8%. The dimming range was 2.38%–45.1%.

[0046] Example 4

[0047] 2.80 g of nitrocellulose, 37.20 g of dioctyl sebacate, 0.10 g of hydroxyapatite nanorods (average length: 100 nm, average width: 10 nm), 1.13 g of iodine, 0.5 g of methanol, 0.84 g of CaI₂·4H₂O, and 0.75 g of 2,5-pyrazine dicarboxylic acid (refractive index of ligand: 1.638) were placed in a 100 mL container. After stirring and reacting for 16 hours, the mixture was centrifuged, washed, and centrifuged again to obtain blue nanorods (average length: approximately 800 nm, average width: approximately 100 nm).

[0048] The nanorods, nitrocellulose, dibutyl phthalate, and butyl benzyl phthalate (refractive index of the dispersion medium: 1.530) prepared above were mixed in a mass ratio of 1:0.25:6.3:12.7 to form a dimming layer material. This dimming layer material was then used in conjunction with a first transparent substrate, a first transparent conductive layer, a second transparent conductive layer, and a second transparent substrate to form a 4×4 cm dimming device, wherein the thickness of the dimming layer was 20 micrometers. According to the test results, the transmittance in the dark state was 2.64%, the highest transmittance in the bright state was 71.0%, and the haze in the bright state was 1.2%. The dimming range was 2.64%–71.0%.

[0049] Example 5

[0050] 2.80 g of nitrocellulose, 37.20 g of dioctyl sebacate, 0.10 g of hydroxyapatite nanorods (average length: 100 nm, average width: 10 nm), 1.13 g of iodine, 0.5 g of methanol, 0.84 g of CaI₂·4H₂O, and 0.75 g of 2,5-pyrazine dicarboxylic acid (refractive index of ligand: 1.638) were placed in a 100 mL container. After stirring and reacting for 16 hours, the mixture was centrifuged, washed, and centrifuged again to obtain blue nanorods (average length: approximately 800 nm, average width: approximately 100 nm).

[0051] The nanorods, nitrocellulose, dioctyl adipate, trioctyl trimellitate, and butyl benzyl phthalate (refractive index of the dispersion medium: 1.507) prepared above were mixed in a mass ratio of 1:0.25:4.75:4.75:9.5 to form a dimming layer material. This dimming layer material was then used in conjunction with a first transparent substrate, a first transparent conductive layer, a second transparent conductive layer, and a second transparent substrate to form a 4×4 cm dimming device, wherein the thickness of the dimming layer was 20 micrometers. According to the test results, the transmittance in the dark state was 2.15%, the highest transmittance in the bright state was 68.1%, and the haze in the bright state was 1.3%. The dimming range was 2.15%–68.1%.

[0052] Example 6

[0053] 2.80 g of nitrocellulose, 37.20 g of dioctyl sebacate, 0.10 g of hydroxyapatite nanorods (average length: 100 nm, average width: 10 nm), 1.13 g of iodine, 0.5 g of methanol, 0.84 g of CaI₂·4H₂O, and 0.65 g of 5-methylpyrazine-2-carboxylic acid (refractive index of ligand: 1.510) were placed in a 100 mL container. After stirring and reacting for 16 hours, the mixture was centrifuged, washed, and centrifuged again to obtain blue nanorods (average length: approximately 800 nm, average width: approximately 100 nm).

[0054] The nanorods, nitrocellulose, dibutyl phthalate, and butyl benzyl phthalate (refractive index of the dispersion medium: 1.518) prepared above were mixed in a mass ratio of 1:0.25:9.5:9.5 to form a dimming layer material. This dimming layer material was then used in conjunction with a first transparent substrate, a first transparent conductive layer, a second transparent conductive layer, and a second transparent substrate to form a 4×4 cm dimming device, wherein the thickness of the dimming layer was 20 micrometers. According to the test results, the transmittance in the dark state was 2.66%, the highest transmittance in the bright state was 61.0%, and the haze in the bright state was 3.2%. The dimming range was 2.66%–61.0%.

[0055] Example 7

[0056] 2.80 g of nitrocellulose, 37.20 g of dioctyl sebacate, 0.10 g of hydroxyapatite nanorods (average length: 100 nm, average width: 10 nm), 1.13 g of iodine, 0.5 g of methanol, 0.84 g of CaI₂·4H₂O, and 0.65 g of pyrazine 2-carboxylate (refractive index of ligand: 1.480) were placed in a 100 mL container. After stirring and reacting for 16 hours, the mixture was centrifuged, washed, and centrifuged again to obtain blue nanorods (average length: approximately 800 nm, average width: approximately 100 nm).

[0057] The nanorods, nitrocellulose, and butyl benzyl phthalate (refractive index of the dispersion medium: 1.540) prepared above were mixed at a mass ratio of 1:0.25:10 to form a dimming layer material. This dimming layer material was then used in conjunction with a first transparent substrate, a first transparent conductive layer, a second transparent conductive layer, and a second transparent substrate to form a 4×4 cm dimming device, wherein the thickness of the dimming layer was 20 micrometers. According to the test results, the transmittance in the dark state was 1.22%, the highest transmittance in the bright state was 54.8%, and the haze in the bright state was 0.5%. The dimming range was 1.22%–54.8%.

[0058] Example 8

[0059] 2.80 g of nitrocellulose, 37.20 g of dioctyl sebacate, 0.10 g of hydroxyapatite nanorods (average length: 100 nm, average width: 10 nm), 1.13 g of iodine, 0.5 g of methanol, 0.84 g of CaI₂·4H₂O, and 0.65 g of pyrazine 2-carboxylate (refractive index of ligand: 1.480) were placed in a 100 mL container. After stirring and reacting for 16 hours, the mixture was centrifuged, washed, and centrifuged again to obtain blue nanorods (average length: approximately 800 nm, average width: approximately 100 nm).

[0060] The nanorods, nitrocellulose, and butyl benzyl phthalate (refractive index of the dispersion medium: 1.540) prepared above were mixed at a mass ratio of 1:0.25:30 to form a dimming layer material. This dimming layer material was then used in conjunction with a first transparent substrate, a first transparent conductive layer, a second transparent conductive layer, and a second transparent substrate to form a 4×4 cm dimming device, wherein the thickness of the dimming layer was 20 micrometers. According to the test results, the transmittance in the dark state was 7.35%, the highest transmittance in the bright state was 78.2%, and the haze in the bright state was 4.6%. The dimming range was 7.35%–78.2%.

[0061] Example 9

[0062] 2.80 g of nitrocellulose, 37.20 g of dioctyl sebacate, 0.10 g of hydroxyapatite nanorods (average length: 100 nm, average width: 10 nm), 0.113 g of iodine, 0.05 g of methanol, 0.084 g of CaI₂·4H₂O, and 0.065 g of pyrazine 2-carboxylic acid (refractive index of ligand: 1.480) were placed in a 100 mL container. After stirring and reacting for 16 hours, the mixture was centrifuged, washed, and centrifuged again to obtain blue nanorods (average length: approximately 200 nm, average width: approximately 20 nm), with an morphology as shown in the figure. Figure 5 As shown.

[0063] The nanorods, nitrocellulose, and butyl benzyl phthalate (refractive index of the dispersion medium: 1.540) prepared above were mixed at a mass ratio of 1:0.25:19 to form a dimming layer material. This dimming layer material was then used in conjunction with a first transparent substrate, a first transparent conductive layer, a second transparent conductive layer, and a second transparent substrate to form a 4×4 cm dimming device, wherein the thickness of the dimming layer was 7 micrometers. According to the test results, the transmittance in the dark state was 4.90%, the highest transmittance in the bright state was 75.1%, and the haze in the bright state was 2.2%. The dimming range was 4.90%–75.1%.

[0064] Example 10

[0065] 2.80 g of nitrocellulose, 37.20 g of dioctyl sebacate, 0.10 g of hydroxyapatite nanorods (average length: 100 nm, average width: 10 nm), 1.13 g of iodine, 0.5 g of methanol, 0.84 g of CaI₂·4H₂O, and 0.78 g of 2,5-pyridinedicarboxylic acid (refractive index of ligand: 1.628) were placed in a 100 mL container. After stirring and reacting for 16 hours, the mixture was centrifuged, washed, and centrifuged again to obtain blue nanorods (average length: approximately 800 nm, average width: approximately 100 nm).

[0066] The nanorods, nitrocellulose, and trioctyl trimellitate (refractive index of the dispersion medium: 1.485) prepared above were mixed at a mass ratio of 1:0.25:19 to form a dimming layer material. This dimming layer material was then used in conjunction with a first transparent substrate, a first transparent conductive layer, a dimming layer, a second transparent conductive layer, and a second transparent substrate to form a 4×4 cm dimming device, wherein the thickness of the dimming layer was 20 micrometers. According to test results, the transmittance in the dark state was 2.70%, the highest transmittance in the bright state was 51.5%, and the haze in the bright state was 3.7%. The dimming range was 2.70%–51.5%.

[0067] As can be seen from the above embodiments, the dimming range of the dimming device can be effectively adjusted by controlling the refractive index of the ligand and the dispersion medium. Simultaneously, by controlling the refractive index of the ligand and the dispersion medium (with the absolute value of the difference in refractive index less than 0.19), the optical matching between the outer layer material of the dichroic composite particles and the dispersion medium can be further controlled, thereby keeping the haze in the bright state below 5%.

[0068] Although several exemplary embodiments have been described in detail above, the disclosed embodiments are exemplary and not restrictive, and those skilled in the art will readily recognize that many other modifications, alterations, and / or substitutions are possible in the exemplary embodiments without materially departing from the novelty teachings and advantages of this disclosure. Therefore, all such modifications, alterations, and / or substitutions are intended to be included within the scope of this disclosure as defined by the appended claims.

Claims

1. A dimming device, the dimming device comprising a first transparent substrate, a first transparent conductive layer, a dimming layer, a second transparent conductive layer, and a second transparent substrate, wherein, The dimming layer includes dichroic composite particles and a dispersion medium. The dichroic composite particles include an inner layer and an outer layer. The inner layer has a non-spherical symmetric shape. The outer layer is formed by epitaxially growing an optically dichroic material on a ligand modified with the surface of the inner layer. The absolute value of the difference between the refractive index of the ligand and the refractive index of the dispersion medium is less than 0.

19.

2. The dimming device according to claim 1, wherein the ligand is an organic carboxylic acid compound.

3. The dimming device according to claim 2, wherein the organic carboxylic acid compound includes pyrrole carboxylic acid compounds, thiazole carboxylic acid compounds, imidazole carboxylic acid compounds, pyrazole carboxylic acid compounds, pyridine carboxylic acid compounds, pyrimidine carboxylic acid compounds, quinine carboxylic acid compounds, pyrazine carboxylic acid compounds, phenanthroline carboxylic acid compounds, and purine carboxylic acid compounds.

4. The dimming device of claim 1, wherein the dispersion medium is one or more of a polyester.

5. The dimming device of claim 4, wherein the polyester comprises dioctyl adipate, trioctyl trimellitate, dibutyl phthalate, diethyl phthalate, butyl benzyl phthalate, dioctyl terephthalate, di(2-ethylhexyl) phthalate, di-n-octyl phthalate, diisodecyl phthalate, diisononyl phthalate, diisobutyl phthalate, dimethyl phthalate, dicyclohexyl phthalate, diisodecyl adipate, dioctyl azelate, dioctyl sebacate, and diisooctyl sebacate. Triethylene glycol diisooctanoate, tricresyl phosphate, triphenyl phosphate, 2-ethylhexyl diphenyl phosphate, toluene diphenyl phosphate, epoxidized soybean oil, epoxidized fatty acid butyl ester, epoxidized fatty acid octyl ester, tributyl trimellitate, trihexyl trimellitate, triallyl 1,2,4-benzenedric tricarboxylate, tripropyl 1,3,4-benzenedric tricarboxylate, trimethyl 1,2,4-benzenedric tricarboxylate, tetraoctyl pyromellitic acid, benzyl phthalate 2-ethylhexyl ester, monobenzene phthalate, dibenzene phthalate, and diallyl phthalate.

6. The dimming device of claim 1, wherein the longest axis of the dichroic composite particle has a length of 100-1000 nm and the shortest axis has a length of 10-200 nm.

7. The dimming device of claim 1, wherein the material of the inner layer is a metal and its compounds, an inorganic non-metallic compound, or an organic compound.

8. The dimming device of claim 7, wherein the inner layer is a hydroxyapatite nanorod.

9. The dimming device of claim 2, wherein the material of the outer layer is a polyhalide.

10. The dimming device of claim 1, wherein the mass ratio of the dichroic composite particles to the dispersion medium is 1:7 to 1:

40.

11. The dimming device of claim 1, wherein the thickness of the dimming layer is 5 to 50 micrometers.

12. The dimming device of claim 1, wherein the dimming layer further comprises a particle stabilizer.

13. A dimming device, the dimming device comprising a dimming layer, wherein, The dimming layer comprises dichroic composite particles and a dispersion medium. The dichroic composite particles comprise an inner layer and an outer layer, wherein the inner layer has a non-spherical symmetric shape, and the outer layer is formed by epitaxially growing an optically dichroic material onto a ligand modified with the surface of the inner layer. The absolute value of the difference between the refractive index of the ligand and the refractive index of the dispersion medium is less than 0.

19. The dimming layer absorbs the incident light most effectively when no electric field is applied. When an electric field is applied, the dimming layer absorbs less incident light.

14. The dimming device of claim 13, wherein the ligand is an organic carboxylic acid compound.

15. The dimming device of claim 14, wherein the organic carboxylic acid compound includes pyrrole carboxylic acid compounds, thiazole carboxylic acid compounds, imidazole carboxylic acid compounds, pyrazole carboxylic acid compounds, pyridine carboxylic acid compounds, pyrimidine carboxylic acid compounds, quinine carboxylic acid compounds, pyrazine carboxylic acid compounds, phenanthroline carboxylic acid compounds, and purine carboxylic acid compounds.

16. The dimming device of claim 13, wherein the dispersion medium is one or more of a polyester.

17. The dimming device of claim 16, wherein the polyester comprises dioctyl adipate, trioctyl trimellitate, dibutyl phthalate, diethyl phthalate, butyl benzyl phthalate, dioctyl terephthalate, di(2-ethylhexyl) phthalate, di-n-octyl phthalate, diisodecyl phthalate, diisononyl phthalate, diisobutyl phthalate, dimethyl phthalate, dicyclohexyl phthalate, diisodecyl adipate, dioctyl azelate, dioctyl sebacate, and diisooctyl sebacate. Esters, triethylene glycol diisooctanoate, tricresyl phosphate, triphenyl phosphate, 2-ethylhexyl diphenyl phosphate, toluene diphenyl phosphate, epoxidized soybean oil, epoxidized fatty acid butyl ester, epoxidized fatty acid octyl ester, tributyl trimellitate, trihexyl trimellitate, triallyl 1,2,4-benzenedric tricarboxylate, tripropyl 1,3,4-benzenedric tricarboxylate, trimethyl 1,2,4-benzenedric tricarboxylate, tetraoctyl pyromellitic acid, benzyl phthalate 2-ethylhexyl ester, monobenzene phthalate, dibenzene phthalate, and diallyl phthalate.

18. The dimming device of claim 13, wherein the longest axis of the dichroic composite particle has a dimension of 100-1000 nm and the shortest axis has a dimension of 10-200 nm.

19. The dimming device of claim 13, wherein the material of the inner layer is a metal and its compounds, an inorganic non-metallic compound, or an organic compound.

20. The dimming device of claim 19, wherein the inner layer is a hydroxyapatite nanorod.

21. The dimming device of claim 14, wherein the material of the outer layer is a polyhalide.

22. The dimming device of claim 13, wherein the mass ratio of the dichroic composite particles to the dispersion medium is 1:7 to 1:

40.

23. The dimming device of claim 13, wherein the thickness of the dimming layer is 5 to 50 micrometers.

24. The dimming device of claim 13, wherein the dimming layer further comprises a particle stabilizer.

25. The dimming device of claim 13, wherein the dimming device further comprises a first transparent substrate, a first transparent conductive layer, a second transparent conductive layer, and a second transparent substrate.

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