CN113495370A

CN113495370A - Light modulation device and manufacturing method

Info

Publication number: CN113495370A
Application number: CN202010203358.XA
Authority: CN
Inventors: 刘俊玲; 高翾; 谢欢欢; 崔可建; 刘忠范
Original assignee: Beijing Graphene Institute BGI
Current assignee: Beijing Graphene Institute BGI
Priority date: 2020-03-20
Filing date: 2020-03-20
Publication date: 2021-10-12

Abstract

The invention provides a dimming device and a manufacturing method thereof. The thermochromic dimming device can achieve temperature control of the phase-change material in the color-change layer by electrifying and heating the conductive layer, so that the transparency of the device changes along with the temperature, and further the effect of active dimming is achieved.

Description

Light modulation device and manufacturing method

Technical Field

The invention belongs to the field of intelligent color-changing dimming, and particularly relates to a color-changing dimming device and a manufacturing method thereof.

Background

The intelligent color-changing glass is a light-adjusting functional device composed of base materials such as glass or transparent plastics and color-changing/light-adjusting materials, and can meet partial requirements of energy conservation or privacy protection by adjusting the transmittance of visible light and infrared light. The color-changing glass mainly has photochromism, thermochromism, electrochromism and the like.

Photochromic refers to a compound that, by chemical reaction at a specific wavelength, produces another compound with different structural and spectral properties that reversibly produces the former compound upon irradiation with another wavelength. However, no matter which compound is made of photochromic glass, different positions generate different light intensities under the influence of the environment, and color differences of different colors occur, so that the consistency of the curtain wall glass is damaged.

Thermochromic discoloration refers to a phenomenon in which the transmission or absorption characteristics of incident light are changed by a change in ambient temperature. Thermochromic glass is generally formed by coating a layer of reversible thermochromic material on common toughened glass. There are many thermochromic materials, and among them, a thin film coating based on Vanadium Oxide (VO) is a hot spot of current research. The VO film has high low-temperature transmittance and low high-temperature transmittance. The main problems existing at the present stage are two points: (1) the phase transition temperature of VO is 68 ℃, and the phase transition temperature of the VO film must be reduced to be near room temperature by doping or changing a preparation method and the like. (2) The prior research shows that the visible light transmittance of the VO film is lower no matter before and after phase change, and most of the VO film is less than 40 percent. Therefore, it is necessary to improve the visible light transmittance of VO to ensure indoor lighting. In addition, the conventional thermochromic device is a phenomenon that the transmission or absorption characteristics of incident light are changed through ambient temperature, and the color change of the thermochromic device cannot be opened or closed at will, so that the thermochromic device is relatively passive.

The active dimming glass for realizing mass production in the market at present is mainly PDLC type electro-dimming glass based on liquid crystal molecule inversion in an electric field, but the price of the dimming glass is relatively high all the time due to high material cost.

Disclosure of Invention

In view of the above problems, an object of the present invention is to provide a light modulation device and a method for manufacturing the same.

The invention provides a dimming device which comprises a substrate layer, a conductive layer and a color-changing layer, wherein the conductive layer is provided with a pair of electrodes, and the color-changing layer comprises a thermochromic material.

According to an embodiment of the invention, the light transmittance of the conductive layer is not less than 70%, the surface resistance is 60-2000 Ω/sq, preferably the light transmittance is more than 80%, and the surface resistance is 100-1200 Ω/sq; preferably, the conductive layer comprises one or more selected from metal oxide, graphene, nano silver wire, polyaniline and polythiophene, and more preferably, the conductive layer is a graphene film; preferably, the metal oxide is selected from SnO₂、InO₂One or more of ITO, AZO and IZO; the thickness of the conductive layer is preferably 0.3nm to 120nm, and more preferably 0.8 to 2.0 nm.

According to another embodiment of the present invention, the electrode of the conductive layer is electrically connected to a lead-out wire.

According to another embodiment of the invention, the color-changing layer comprises a substrate layer, a high polymer material matrix with a cross-linked structure, a color-changing material layer composed of the thermochromic material and a buffer protective layer which are sequentially laminated; preferably, the thermochromic material is a color-changing material with a phase transition temperature lower than 60 ℃; more preferably, the thermochromic material is selected from one or more of paraffin, vanadium dioxide, polymer mixture thermochromic materials, hydrogel thermochromic materials of polymers and aqueous solutions, triphenylmethane compounds, fluorane compounds, Schiff base compounds, spiro compounds, biomacromolecule compounds, dianthrone compounds and the like.

According to another embodiment of the present invention, the polymer material matrix contains a thermochromic dye, and preferably the polymer material matrix is selected from one or more of olefin block copolymers, organosiloxane polymers, and epoxy resins.

The invention also provides a manufacturing method of the light modulation device, which comprises the following steps: s1, providing a substrate; s2, forming a conductive layer on one surface of the substrate, and providing a pair of electrodes on the conductive layer; s3, forming a color changing layer, and laminating the color changing layer on the surface of the conductive layer or the other surface of the substrate, wherein the color changing layer comprises a thermochromic material.

According to an embodiment of the present invention, the forming of the color-changing layer includes: s31, providing a substrate layer; s32, coating a crosslinkable liquid polymer material on the surface of the substrate, and crosslinking and curing to obtain a polymer material matrix with a crosslinking structure; and S33, pouring the melted thermochromic material into the matrix to form a color-changing material layer.

According to another embodiment of the present invention, the polymer material matrix is selected from one or more of olefin block copolymer, organic siloxane polymer and epoxy resin.

According to another embodiment of the present invention, in the step S32, the liquid polymer material further includes a thermochromic dye.

According to another embodiment of the present invention, the method for manufacturing the dimming device further comprises: and S34, coating a buffer protective layer on the surface of the color-changing material layer.

The thermochromic dimming device can achieve temperature control of the phase-change material in the color-change layer by electrifying and heating the conductive layer, so that the transparency of the device changes along with the temperature, and further the effect of active dimming is achieved. Furthermore, the phase change temperature of the selected color change material is adjustable, and color change devices with different temperatures can be manufactured. Furthermore, the selected phase-change material has high phase-change latent heat, low steam pressure during melting, difficult chemical reaction, good chemical stability, small change of phase-change temperature and phase-change latent heat after multiple heat absorption and heat release, self-nucleation, no phase separation and corrosivity, application in the field of energy storage and building energy saving. Furthermore, the preferable conductive layer, especially the graphene conductive material, has the characteristics of good electrothermal conversion efficiency, high transparency, stable resistance under the condition of thermal oxygen and the like, and is long in service life. Furthermore, the dimming device of the invention can change the transparency and can also realize the change of color. The technical scheme of the invention overcomes the problems of high price, complex manufacturing process or passive color change and the like of the existing dimming product.

Drawings

The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings.

Fig. 1 is a schematic diagram of a structure of a dimming device of the present invention.

Fig. 2 is a schematic structural diagram of a color changing layer of the dimming device of the present invention.

Fig. 3 is a schematic diagram of the conductive layer of the dimming device of the present invention.

Fig. 4 is a top view of the conductive layer shown in fig. 3.

Wherein the reference numerals are as follows:

1-a glass layer; 2-a conductive layer; 3-a color-changing layer; 4, 5-electrode lead-out wires; 6-a substrate layer; 7-a layer of colour-changing material; 8-buffer protective layer; 9, 10-electrode

Detailed Description

For a better understanding of the present invention and the method of making the same, reference is made to the following detailed description of the invention taken in conjunction with the accompanying drawings.

The dimming device comprises a substrate layer, a conductive layer and a color changing layer, wherein the conductive layer is provided with a pair of electrodes, and the color changing layer comprises a thermochromic material. The base material layer, the conductive layer, and the color changing layer of the light control device of the present invention may be laminated in any manner, that is, may include a base material 1, a conductive layer 2, and a color changing layer 3 laminated in this order as shown in fig. 1, and the conductive layer 2 is provided with a pair of electrodes. Another lamination method may be adopted, and referring to fig. 1, the conductive layer 2, the substrate 1, and the color-changing layer 3 may be sequentially laminated. When the conductive layer 2 is at the outermost side, a protective layer may be provided on the outermost surface of the conductive layer 2 to protect the conductive layer 2 from being damaged during use.

The substrate 1 in the device plays a supporting role, and meanwhile, the substrate 1 should reach a certain transmittance to meet the light transmission effect. In general, the substrate 1 is preferably glass, a hard temperature-resistant transparent resin sheet, or the like.

The conducting layer 2 in the device is used for heating the color changing layer 3, so that the transparency of the color changing layer 3 is changed, and the active dimming function is realized. At the same time, the conductive layer 2 should have good light transmission to ensure the color change of the color change layer 3The light transmittance of the front and rear devices is not affected by the conductive layer 2. Preferably, the light transmittance of the conductive layer 2 is not less than 70%, and the surface resistance is 60-2000 Ω/sq, and the light transmittance and the surface resistance in the above ranges can ensure good light transmittance of the device and enable the conductive layer 2 to have a high electrothermal conversion effect. More preferably, the light transmittance is more than 80%, and the area resistance is 100-. The conductive layer 2 may include one or more selected from metal oxide, graphene, nano silver wire, polyaniline, and polythiophene. More preferably, the conductive layer 2 is a graphene conductive film, and the graphene conductive film can maintain stable photoelectric properties under long-term high-temperature application. The metal oxide is selected from SnO₂、InO₂One or more of ITO, AZO, IZO and the like. The thickness of the conductive layer 2 is 0.3nm to 120nm, and preferably the thickness of the conductive layer 2 is 0.8 to 2.0nm, so that high light transmittance and good resistivity are ensured. A pair of

electrodes

9 and 10 of the conductive layer 2 may be led out through the electrode lead-out

wires

4 and 5 to facilitate connection with a power supply.

The color changing layer 3 in the device changes the transmittance along with the temperature change, thereby realizing the dimming effect. Further, as shown in fig. 2, the discoloring layer 3 may include a substrate layer 6, a discoloring material layer 7, and a buffer shield layer 8, which are sequentially stacked. The substrate layer 6 may be transparent glass or temperature-resistant transparent resin or the like. The color-changing material layer 7 may be composed of a high molecular material matrix having a cross-linked structure and a thermochromic material impregnated therein. Thermochromic materials, preferably, but not limited to, low temperature type color change materials. When the thermochromic material is a low-temperature type thermochromic material, the phase transition temperature can be reached without consuming too much heat due to a low phase transition temperature point; meanwhile, the phase transition temperature is low, so that the device can be used in daily environment, and people nearby cannot be burnt due to overhigh temperature of the device. Of course, the medium-temperature and high-temperature type color-changing materials can also achieve the purpose of the invention. The phase transition temperature point of the color-changing material is more preferably below 60 ℃. The thermochromic material is selected from one or more of paraffin, vanadium dioxide, polymer mixture thermochromic material, hydrogel thermochromic material of polymer and aqueous solution, triphenylmethane, fluorane, Schiff base, spiro ring, biological macromolecule (such as Polydiacetylene (PDA) derivative), and dianthracene ketone. The appropriate material can be selected according to actual needs, the appropriate layer thickness, for example, the transmittance change range before and after the phase transition of 1mm paraffin is 6% -86%, the vanadium dioxide phase transition transmittance is lower than 10% -40%, and the polymer mixture is, for example: oxidized polypropylene-methylol methacrylate blends, polymer hydrogels such as: the transformation temperature of the hydrogel system of the poly isopropyl acrylamide is 30-40 ℃, the low temperature is more than 70% of transparent state, the high temperature is less than 1% of opaque state, and the like. The polymer material matrix can also contain a thermochromic dye. The thermochromic dye changes color along with temperature change, so that the thermochromic dye and the thermochromic material jointly act to adjust the color of the device. The high molecular material matrix can be one or more of olefin block copolymer material, organic siloxane polymer material, epoxy resin and the like. The thermochromic dye preferably has a color change temperature point of less than 60 ℃, although those skilled in the art will appreciate that any thermochromic dye having a color change temperature can achieve the objects of the present invention.

The dimming device can be manufactured as follows: s1, providing a substrate; s2, forming a conductive layer on the surface of the substrate, and providing a pair of electrodes on the conductive layer; s3, forming a color changing layer, wherein the color changing layer comprises a thermochromic dye material. S1, S2, S3 and S31, S32, S33, S34 described herein below are only used to distinguish different steps, and are not intended to limit the order of the steps.

The entire fabrication process is described in detail below in conjunction with fig. 3 and 4.

In step S1, a substrate 1 is provided for supporting the conductive layer 2 and the color-changing layer 3. A conductive layer 2 is formed on one surface of the substrate 1 in step S2. The conductive layer 2 may be formed by selecting an appropriate method according to the material of the conductive layer 2, such as, but not limited to, vapor deposition, screen printing, and the like. The material forming the conductive layer 2 is as described above and will not be described in detail. The discoloration layer 3 is formed in the S3 step, and the discoloration layer 3 may include a substrate layer 6, a discoloration material layer 7, and a buffer protection layer 8. The method of forming the discoloring layer 3 includes: s31, providing a substrate layer 6; s32, coating the crosslinkable liquid polymer material on the surface of the substrate layer 6, and crosslinking and curing to obtain a polymer material matrix with a crosslinking structure; and S33, pouring the molten thermochromic material into the matrix to form the thermochromic material layer 7. The method may further include step S34 of applying a buffer protective layer 8 on the surface of the discoloring material layer 7. The materials used for the above layers are as described above. In step S32, the liquid polymer material further contains a thermochromic dye. The liquid polymer material is crosslinked and cured, and the polymer material matrix contains the thermochromic dye. Specific thermochromic dyes are as described above.

The inventive concept of the present invention will be explained in detail below with reference to the accompanying figures 1-4 in conjunction with specific embodiments, but it will be understood by those skilled in the art that the above embodiments are not intended to limit the invention.

Example 1

1) Quartz glass with a thickness of 1.1mm was selected as the substrate 1 and subjected to cleaning treatment.

2) A graphene conductive film is grown directly on glass as the conductive layer 2 by Chemical Vapor Deposition (CVD). The resistance of the graphene conductive film (conductive layer 2) is about 1000 Ω/sq. The visible light transmittance of the graphene conductive glass (formed by directly growing the graphene conductive film on the glass) is 88%.

3) Coating two nano silver layers with the width of 3mm at two ends of the graphene conductive film prepared in the step 2) in a screen printing mode to be used as

electrodes

9 and 10, placing the graphene conductive film on a curing box or a heating plate at the temperature of 120 ℃ for heating for 20min for curing to prepare a pair of transparent nano

silver wire electrodes

9 and 10, and welding leading-

out wires

4 and 5.

4) Polydimethylsiloxane (PDMS) and a crosslinker were mixed as 10: 1, and performing vacuum defoaming to obtain a crosslinkable liquid PDMS polymer, spin-coating the crosslinkable liquid PDMS polymer on a clean glass substrate 6 at a spin-coating speed of 300 rpm, and heating the substrate coated with the crosslinkable polymer/glass on a hot plate or an oven at 80-100 ℃ for 60min for curing to obtain the solid PDMS/glass substrate with a crosslinked structure.

5) Melting white 58# section paraffin into a liquid state, soaking the solid PDMS/glass substrate prepared in the step 4) in liquid paraffin, placing the liquid paraffin in an environment of 100-120 ℃, taking out the solid PDMS/glass substrate after 4h, and sucking and removing the redundant paraffin on the surface, wherein the paraffin is poured into the solid PDMS with a cross-linking structure to form the color-changing material layer 7.

6) And spin-coating a layer of cross-linkable liquid PDMS polymer on the color-changing material layer 7 at the spin-coating speed of 350 r/min to form a buffer protection layer 8, meanwhile, stacking the conductive glass prepared in the step 3) on the buffer protection layer 8, and then putting the conductive glass on a hot plate or an oven at the temperature of 80-100 ℃ for heating for 60min for curing.

The light control device manufactured through the above steps includes a glass layer 1, a conductive layer 2, a color change material layer 3, and a pair of

electrode lead wires

4 and 5, as shown in fig. 1. The color-changing material layer 3 comprises a substrate layer 6, a color-changing material layer 7 and a buffer protection layer 8. Wherein the substrate layer 6 is glass with a thickness of 1.1 mm.

And detecting the dimming device, wherein the direct-current power supply supplies power to the dimming device, and the voltage is 12V. The change of the light transmittance of the light adjusting device is detected by a desk type transmittance tester. Meanwhile, the thermal infrared imager monitors the temperature of the light adjusting device. At room temperature, the transmittance of the light modulation device is only 7%, and through heating, when the temperature of the light modulation device reaches 65 ℃, the transmittance reaches 85%.

Example 2

A thermochromic dimmer device, which is different from embodiment 1 in that: the conducting layer 2 is an ITO conducting layer manufactured by a magnetron sputtering method, the resistance is 100 omega/sq, and the visible light transmittance is 80%; a pair of

electrodes

9,10 with the width of 3mm and made of conductive silver paste are arranged on the conductive layer 2, and lead-out

wires

4,5 are used; the color-changing material adopts 58# blue section paraffin. The other steps are the same as in example 1.

The above-described dimming device was tested in the same manner as in embodiment 1. At room temperature, the transmittance of the light modulation device is only 6%, and through heating, when the temperature of the light modulation device reaches 65 ℃, the transmittance reaches 78%.

Example 3

A thermochromic dimmer device, which is different from embodiment 1 in that: the base material with a cross-linked structure of the color-changing layer contains a temperature-sensitive red color-changing dye. Specifically, the step of forming the color-changing layer is that Polydimethylsiloxane (PDMS), a cross-linking agent (aminosilane coupling agent) and a temperature-sensitive red dye (the color-changing interval is 30-35 ℃) are mixed according to the weight ratio of 10: 1: 0.5, and performing vacuum defoaming to obtain a crosslinkable temperature-sensitive red liquid PDMS polymer, spin-coating the crosslinkable temperature-sensitive red liquid PDMS polymer on a clean glass substrate 6 at a spin-coating speed of 300 r/min, and heating the temperature-sensitive red polymer/glass substrate coated with the crosslinkable temperature-sensitive red polymer/glass substrate on a hot plate or in an oven at 100 ℃ for 60min for curing to obtain the red temperature-sensitive solid PDMS/glass substrate with a crosslinked structure. The other steps are the same as in example 1.

The above-described dimming device was tested in the same manner as in embodiment 1. At room temperature, the transmittance of the light adjusting device is only 5%, the color of the light adjusting device is red, through heating, when the temperature of the light adjusting device reaches 32 ℃, the transmittance reaches 15%, the light adjusting device is in a light pink translucent state, when the temperature of the light adjusting device reaches 60 ℃, the transmittance reaches 75%, and the light adjusting device becomes colorless and transparent.

The embodiment can show that the dimming device of the invention utilizes the conductive layer to heat the color changing layer, so that the transmittance of the color changing layer changes along with the change of temperature, thereby realizing the purpose of active dimming.

The preferred embodiments of the invention disclosed above are intended to be illustrative only. The preferred embodiments are not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. The dimming device is characterized by comprising a substrate layer, a conductive layer and a color-changing layer, wherein the conductive layer is provided with a pair of electrodes, and the color-changing layer comprises a thermochromic material.

2. A dimmer device as claimed in claim 1, wherein the conductive layer has a light transmittance of 70% or more and an area resistance of 60-2000 Ω/sq, preferablyThe light transmittance is more than 80 percent, and the surface resistance is 100-; preferably, the conductive layer comprises one or more selected from metal oxide, graphene, nano silver wire, polyaniline and polythiophene, and more preferably, the conductive layer is a graphene film; preferably, the metal oxide is selected from SnO₂、InO₂One or more of ITO, AZO and IZO; the thickness of the conductive layer is preferably 0.3nm to 120nm, and more preferably 0.8 to 2.0 nm.

3. The dimming device of claim 1, wherein the electrode of the conductive layer is electrically connected to a lead out wire.

4. The dimming device according to claim 1, wherein the color changing layer comprises a substrate layer, a polymer material matrix with a cross-linked structure, and a color changing material layer composed of the thermochromic material impregnated therein, and a buffer protective layer, which are sequentially stacked; preferably, the thermochromic material is a color-changing material with a phase transition temperature lower than 60 ℃; more preferably, the thermochromic material is selected from one or more of paraffin, vanadium dioxide, polymer mixture thermochromic materials, hydrogel thermochromic materials of polymers and aqueous solutions, triphenylmethane compounds, fluorane compounds, Schiff base compounds, spiro compounds, biomacromolecule compounds, dianthrone compounds and the like.

5. The light modulation device according to claim 4, wherein the polymer material matrix contains a thermochromic dye, and preferably the polymer material matrix is selected from one or more of olefin block copolymers, organic siloxane polymers and epoxy resins.

6. A method for fabricating a light modulator device, comprising:

s1, providing a substrate;

s2, forming a conductive layer on one surface of the substrate, and providing a pair of electrodes on the conductive layer;

s3, forming a color changing layer, and laminating the color changing layer on the surface of the conductive layer or the other surface of the substrate, wherein the color changing layer comprises a thermochromic material.

7. The method of claim 6, wherein the forming a color shifting layer comprises:

s31, providing a substrate layer;

s32, coating a crosslinkable liquid polymer material on the surface of the substrate, and crosslinking and curing to obtain a polymer material matrix with a crosslinking structure;

and S33, pouring the melted thermochromic material into the matrix to form a color-changing material layer.

8. The cross-linked matrix and the manufacturing method thereof according to claim 7, wherein the polymer material matrix is selected from one or more of olefin block copolymer, organic siloxane polymer and epoxy resin.

9. A method for manufacturing a light modulating device as defined in claim 7, wherein in the step S32, the liquid polymer material further contains a thermochromic dye.

10. A method for manufacturing a dimming device as claimed in claim 7, further comprising:

and S34, coating a buffer protective layer on the surface of the color-changing material layer.