阅读说明：本技术 彩色辐射制冷材料及其制备方法 (Color radiation refrigerating material and its preparation method ) 是由 李洪轲 黄金华 兰品军 于 2021-09-15 设计创作，主要内容包括：本发明公开了一种彩色辐射制冷材料,其包括：基底层、金属层、布拉格反射层和间隔层；其中,布拉格反射层至少包括层叠设置的第一介质层和第二介质层,第一介质层的折射率与第二介质层的折射率不同,且第一介质层的厚度与第二介质层的厚度不同；间隔层设置在金属层和布拉格反射层之间；金属层、间隔层以及布拉格反射层共同形成塔姆结构。本发明还提供了一种前述彩色辐射制冷材料的制备方法。本发明提供的彩色辐射制冷材料通过金属层、间隔层和布拉格反射层的设置,能够在金属层和间隔层界面间激发塔姆共振,实现高品质因子的可见光选择性吸收；而且通过间隔层的设置可以获得较高的吸收率和极窄的吸收峰宽,抑制对阳光的吸收而导致的热效应。(The invention discloses a colored radiation refrigerating material, which comprises: the array substrate comprises a substrate layer, a metal layer, a Bragg reflection layer and a spacing layer; the Bragg reflection layer at least comprises a first medium layer and a second medium layer which are arranged in a stacked mode, the refractive index of the first medium layer is different from that of the second medium layer, and the thickness of the first medium layer is different from that of the second medium layer; the spacing layer is arranged between the metal layer and the Bragg reflection layer; the metal layer, the spacing layer and the Bragg reflection layer form a Tam structure together. The invention also provides a preparation method of the colored radiation refrigeration material. The colored radiation refrigeration material provided by the invention can excite Tamm resonance between the interfaces of the metal layer and the spacing layer through the arrangement of the metal layer, the spacing layer and the Bragg reflection layer, thereby realizing the selective absorption of visible light with high quality factors; and a higher absorptivity and a very narrow absorption peak width can be obtained by arranging the spacing layer, and the heat effect caused by the absorption of sunlight is restrained.)

1. A colored radiation cooling material, comprising:

a base layer extending in a set direction;

a metal layer disposed on the base layer;

the Bragg reflection layer at least comprises a first medium layer and a second medium layer which are arranged in a stacked mode, the refractive index of the first medium layer is different from that of the second medium layer, and the thickness of the first medium layer is different from that of the second medium layer;

a spacer layer disposed between the metal layer and the Bragg reflection layer;

the metal layer, the spacing layer and the Bragg reflection layer together form a Tam structure.

2. A colored radiation refrigerating material as claimed in claim 1 wherein the substrate layer is of at least one of PET, PEN, PI, PC, PMMA and glass.

3. A colored radiation refrigerating material as recited in claim 1 wherein said metal layer has a visible light reflectance of greater than 80%.

4. A colored radiation refrigerating material as claimed in claim 3, characterized in that the material of said metal layer is one or more of silver, gold, copper and aluminium.

5. A colored radiation refrigerating material as claimed in claim 1, wherein the thickness of said spacer layer is between 20 and 500 nm.

6. The colored radiation cooling material of claim 1, wherein the bragg reflector layer further comprises a third dielectric layer having a refractive index different from the refractive index of both the first dielectric layer and the second dielectric layer.

7. The colored radiation refrigerating material as claimed in claim 6, wherein the refractive index of the first dielectric layer is 1.1 to 1.6, and the refractive index of the second dielectric layer is 1.6 to 3.5.

8. The colored radiation cooling material of claim 7, wherein the first dielectric layer is made of at least one of zinc oxide, titanium oxide, niobium oxide, zirconium oxide, hafnium oxide, aluminum oxide, yttrium oxide, tantalum oxide, silicon nitride, aluminum nitride, and silicon carbide, and the second dielectric layer is made of at least one of magnesium fluoride, silicon oxide, calcium fluoride, and PTFE.

9. The colored radiation cooling material of claim 1, wherein the bragg reflector layer is further provided with a surface functional layer, and the material of the surface functional layer comprises at least one of zinc oxide, titanium oxide, niobium oxide, zirconium oxide, hafnium oxide, aluminum oxide, yttrium oxide, tantalum oxide, silicon nitride, aluminum nitride, silicon carbide, magnesium fluoride, silicon oxide, calcium fluoride, PET, PEN, PI, PC, PMMA, PTFE, PDMS, TPU, and cellulose.

10. The colored radiation refrigeration material according to any one of claims 1 to 9, further comprising a protective layer formed on a side of the surface functional layer facing away from the bragg reflective layer.

11. A method for preparing a colored radiation refrigerating material is characterized by comprising the following steps:

providing a substrate layer extending along a set direction;

depositing a metal layer on one side of the substrate layer;

depositing a spacer layer on the metal layer;

sequentially laminating and depositing a first dielectric layer and a second dielectric layer on the spacing layer, wherein the refractive index of the first dielectric layer is different from that of the second dielectric layer, and the thickness of the first dielectric layer is different from that of the second dielectric layer;

the metal layer, the spacing layer, the first dielectric layer and the second dielectric layer form a Tam structure together.

Technical Field

The invention relates to the technical field of materials, in particular to a colored radiation refrigeration material and a preparation method thereof.

Background

Most of the existing radiation refrigerating materials are metallic or white in color, because the heat effect can be avoided only by reducing the absorption of sunlight as much as possible, and therefore the materials need to have a metallic or pure white surface to reflect sunlight as sufficiently as possible.

However, passive radiative cooling materials with metallic or pure white surfaces are not the best choice for practical applications and aesthetic appearance, and also create the possibility of light contamination due to reflection or scattering of sunlight. Therefore, a passive radiation refrigeration material with colors is urgently needed to be developed, and the passive radiation refrigeration material is very important for expanding the application scale of the passive radiation refrigeration material in various practical scenes so as to improve the effect of the technology on energy conservation and emission reduction.

Patent CN202010898293.5 discloses a color radiation refrigeration flexible composite film and a preparation method thereof, the composite film comprises a high molecular polymer substrate, and phase change microcapsules and pigments doped in the substrate, and the color composite film is obtained by utilizing an electrostatic spinning technology. This is a technical means of obtaining the desired colour with chemical pigments, the colour depending on the type of pigment, the incorporation of which brings about partial absorption of sunlight, leading to an increase in temperature. Although the phase-change microcapsule has the property of absorbing heat in phase change, the heat transfer is only one kind of heat transfer, and the problem of increasing heat load cannot be fundamentally solved. Meanwhile, the light absorption of the pigment depends on the basic material characteristics thereof, and is difficult to be precisely controlled.

Therefore, there is a need to provide a new colored radiation refrigeration material to solve the problems in the prior art.

Disclosure of Invention

The invention aims to provide a colored radiation refrigerating material which has the advantages of controllable color and low visible light absorptivity.

In order to achieve the purpose, the technical scheme provided by the invention is as follows:

a colored radiation refrigeration material, comprising: the array substrate comprises a substrate layer, a metal layer, a Bragg reflection layer and a spacing layer; wherein, the basal layer extends along the set direction; a metal layer disposed on the base layer; the Bragg reflection layer at least comprises a first medium layer and a second medium layer which are arranged in a stacked mode, the refractive index of the first medium layer is different from that of the second medium layer, and the thickness of the first medium layer is different from that of the second medium layer; a spacer layer disposed between the metal layer and the Bragg reflection layer; the metal layer, the spacing layer and the Bragg reflection layer together form a Tam structure.

In one or more embodiments of the present invention, the material of the substrate layer is at least one of PET, PEN, PI, PC, PMMA and glass.

In one or more embodiments of the present invention, the metal layer has a visible light reflectance of more than 80%.

In one or more embodiments of the present invention, the material of the metal layer is one or more of silver, gold, copper, and aluminum.

In one or more embodiments of the present invention, the thickness of the spacer layer is between 20nm and 500 nm.

In one or more embodiments of the present invention, the bragg reflector further includes a third dielectric layer having a refractive index different from both the first dielectric layer and the second dielectric layer.

In one or more embodiments of the present invention, the refractive index of the first dielectric layer is between 1.1 and 1.6, and the refractive index of the second dielectric layer is between 1.6 and 3.5.

In one or more embodiments of the present invention, a material of the first dielectric layer is at least one of zinc oxide, titanium oxide, niobium oxide, zirconium oxide, hafnium oxide, aluminum oxide, yttrium oxide, tantalum oxide, silicon nitride, aluminum nitride, and silicon carbide, and a material of the second dielectric layer is at least one of magnesium fluoride, silicon oxide, calcium fluoride, and PTFE.

In one or more embodiments of the present invention, a surface functional layer is further disposed on the bragg reflection layer, and a material of the surface functional layer includes at least one of zinc oxide, titanium oxide, niobium oxide, zirconium oxide, hafnium oxide, aluminum oxide, yttrium oxide, tantalum oxide, silicon nitride, aluminum nitride, silicon carbide, magnesium fluoride, silicon oxide, calcium fluoride, PET, PEN, PI, PC, PMMA, PTFE, PDMS, TPU, and cellulose.

In one or more embodiments of the present invention, the colored radiation refrigerating material further includes a protective layer formed on a side of the surface functional layer facing away from the bragg reflection layer.

The invention also provides a preparation method of the colored radiation refrigeration material, which specifically comprises the following steps: providing a substrate layer extending along a set direction; depositing a metal layer on one side of the substrate layer; depositing a spacer layer on the metal layer; sequentially laminating and depositing a first dielectric layer and a second dielectric layer on the spacing layer, wherein the refractive index of the first dielectric layer is different from that of the second dielectric layer, and the thickness of the first dielectric layer is different from that of the second dielectric layer; the metal layer, the spacing layer, the first dielectric layer and the second dielectric layer form a Tam structure together.

Compared with the prior art, the colorful radiation refrigeration material provided by the invention can form a Tamu structure through the arrangement of the metal layer, the spacing layer and the Bragg reflection layer so as to realize the color development function with controllable color; and a Tamm resonance is excited between the interfaces of the metal layer and the spacing layer, so that the selective absorption of visible light with high quality factors is realized; moreover, by arranging the spacing layer, higher absorptivity and extremely narrow absorption peak width can be obtained, and the heat effect caused by sunlight absorption cannot be obviously increased; meanwhile, the surface heat of the material is radiated to the low-temperature universe through the atmosphere transparent window by utilizing the medium-infrared high emissivity of the surface functional layer, so that radiation cooling is realized.

Drawings

FIG. 1 is a schematic structural view of a colored radiation refrigerating material according to an embodiment of the present invention;

FIG. 2 is a reflection spectrum of a colored radiation refrigerating material obtained in example 1 of the present invention;

FIG. 3 is the reflection spectrum of the colored radiation refrigerating material prepared in example 2 of the present invention;

FIG. 4 is a reflection spectrum of a colored radiation refrigerating material obtained in example 3 of the present invention;

FIG. 5 is a reflection spectrum of a colored radiation refrigerating material obtained in example 4 of the present invention;

FIG. 6 shows the reflection spectrum of the colored radiation refrigerating material prepared in example 5 of the present invention.

Description of the main reference numerals:

the structure comprises a substrate layer 1, a metal layer 2, a spacing layer 3, a Bragg reflection layer 4, a first dielectric layer 41, a second dielectric layer 42, a third dielectric layer 43, a surface functional layer 5 and a protective layer 6.

Detailed Description

The following detailed description of the present invention is provided in conjunction with the accompanying drawings, but it should be understood that the scope of the present invention is not limited to the specific embodiments.

In the following description, "%" and "part" representing amounts are based on weight unless otherwise specified. Unless otherwise indicated, all numbers expressing feature sizes, quantities, and physical characteristics used in the specification and claims are to be understood as being modified in all instances by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and attached claims are approximations that can be suitably varied by those skilled in the art in seeking to obtain the desired properties utilizing the teachings disclosed herein. The use of numerical ranges by endpoints includes all numbers within that range and any range within that range, for example, 1 to 5 includes 1, 1.2, 1.4, 1.55, 2, 2.75, 3, 3.80, 4, and 5, and the like.

It is also noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus; the term "preferred" refers to a preferred alternative, but is not limited to only the selected alternative.

As shown in fig. 1, the color radiation refrigeration material according to an embodiment of the present invention can be applied to various scenes such as building materials, landscape chairs, clothes, outdoor products, and the like, and includes: a substrate layer 1, a metal layer 2, a spacer layer 3 and a bragg reflector layer 4.

Wherein the substrate layer 1 extends in a set direction. The metal layer 2 is disposed on the base layer 1. The bragg reflection layer 4 at least includes a first dielectric layer 41 and a second dielectric layer 42 which are stacked, the refractive index of the first dielectric layer 41 is different from that of the second dielectric layer 42, and the thickness of the first dielectric layer 41 is different from that of the second dielectric layer 42. The spacing layer 3 is arranged between the metal layer 2 and the Bragg reflection layer 4; and the metal layer 3, the spacer layer 2 and the bragg reflector layer 4 together form a lambda structure.

A Tam structure is formed by the metal layer 2, the spacing layer 3 and the Bragg reflection layer 4, optical Tam resonance can be excited at the interface of the spacing layer 3 and the metal layer 2, so that reflection valleys/absorption peaks with high quality factors are obtained, the color development function is realized, and the color development functions with different colors can be realized through the thickness of the Bragg reflection layer 4. In addition, the width of the absorption peak can be controlled by adjusting the thickness of the spacing layer 3, and the position of the absorption peak is insensitive to the thickness change of the spacing layer 3, i.e. the width of the absorption peak can be adjusted by the nodal spacing layer 3 without affecting the position of the absorption peak (the position of the absorption peak corresponds to specific color development), so that the absorption peak with narrow peak shape and small full width at half maximum can be obtained, higher absorptivity and extremely narrow absorption peak width can be obtained, and the thermal effect caused by the absorption of sunlight can be inhibited.

In an exemplary embodiment, the material of the substrate layer 1 may be at least one of PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PI (polyimide), PC (polycarbonate), PMMA (polymethyl methacrylate), and glass (silica glass). The base layer 1 may be made of metal, fiber, fur, cloth, ceramic, building material, etc. The thickness of the base material layer is not particularly limited and may be selected as needed.

In an exemplary embodiment, the visible light reflectivity of the metal layer 2 is greater than 80%, and most of the visible light is reflected by the metal layer 2, i.e., the metal layer 2 has a very low visible light absorption rate, which does not significantly increase the thermal effect caused by the absorption of sunlight. The material of the metal layer 2 may be one or more of silver, gold, copper, and aluminum. The material of the metal layer 2 is preferably silver in consideration of high reflectivity.

In an exemplary embodiment, the thickness of the spacer layer 3 may be greater than or less than the thickness of the first dielectric layer or the second dielectric layer in the bragg reflector layer. Specifically, the thickness of the spacer layer 3 is between 20nm and 500 nm. The material of the spacer layer 3 may be at least one of zinc oxide, titanium oxide, niobium oxide, zirconium oxide, hafnium oxide, aluminum oxide, yttrium oxide, tantalum oxide, silicon nitride, aluminum nitride, and silicon carbide.

In an exemplary embodiment, the bragg reflector layer 4 further includes a third dielectric layer 43 having a refractive index different from the refractive index of each of the first and second dielectric layers 41 and 42. The number of dielectric layers in the bragg reflector may be set according to actual needs, as long as the bragg reflector 4 is an aperiodic bragg reflector 4. The non-periodic structure arranged on the Bragg reflection layer 4 can control the reflectivity of the Tamm structure to visible light; the distribution characteristic of the standing wave light field in the Tamm structure is improved.

In an exemplary embodiment, the refractive index of the first dielectric layer 41 is between 1.1 and 1.6, and the refractive index of the second dielectric layer 42 is between 1.6 and 3.5. The material of the first dielectric layer 41 may be one or more of magnesium fluoride, silicon dioxide, calcium fluoride and PTFE (polytetrafluoroethylene); the material of the second dielectric layer 42 may be one or more of zinc oxide, titanium oxide, niobium oxide, zirconium oxide, hafnium oxide, aluminum oxide, yttrium oxide, tantalum oxide, silicon nitride, aluminum nitride, and silicon carbide.

In an exemplary embodiment, a surface functional layer is further disposed on the bragg reflection layer. The material of the surface functional layer 5 includes at least one of zinc oxide, titanium oxide, niobium oxide, zirconium oxide, hafnium oxide, aluminum oxide, yttrium oxide, tantalum oxide, silicon nitride, aluminum nitride, silicon carbide, magnesium fluoride, silicon oxide, calcium fluoride, PET, PEN, PI, PC, PMMA, PTFE, PDMS (polydimethylsiloxane), TPU (thermoplastic polyurethane), and cellulose.

In an exemplary embodiment, the absorption rate of the surface functional layer 5 in the visible light band is less than 20%, and the absorption rate of the middle infrared band of 8-13 μm is greater than 80%. The middle infrared 8-13 mu m wave band high absorption rate of the surface functional layer 5 enables the surface functional layer to have a middle infrared wave band high emission rate, and the surface heat of an object can be transferred to a cold space in a heat radiation mode through an atmosphere transparent window of the middle infrared 8-13 mu m wave band, so that the radiation cooling function is realized.

In an exemplary embodiment, the colored radiation refrigerating material further comprises a protective layer 6, wherein the protective layer 6 is formed on a side of the surface functional layer 5 facing away from the bragg reflector layer 4. The protective layer 6 is used for protecting the color radiation refrigerating material outdoors, and can reduce the erosion to the material under the harsh natural condition. The material of the protective layer 6 may be the same as that of the surface functional layer 5, such as silicon nitride, aluminum nitride, PTFE, PMMA, PI, or may be different from that of the surface functional layer 5, such as a fluorosilane or fluorocarbon self-cleaning coating mainly providing a hydrophobic/oleophobic function.

The invention also provides a preparation method of the colored radiation refrigeration material, which specifically comprises the following steps: providing a substrate layer 1 extending along a set direction; depositing a metal layer 2 on one side of the substrate layer 1; depositing a spacer layer 3 on the metal layer 2; a first dielectric layer 41 and a second dielectric layer 42 are sequentially deposited on the spacer layer 3.

Wherein, the refractive index of the first dielectric layer 41 is different from that of the second dielectric layer 42, and the thickness of the first dielectric layer 41 is different from that of the second dielectric layer 42; and the metal layer 2, the spacer layer 3, the first dielectric layer 41 and the second dielectric layer 42 together form a pyramidal structure.

In the preparation process of the color radiation refrigerating material, the deposition and coating manner of each layer is not particularly limited. For example, the deposition mode can be magnetron sputtering deposition, electron beam evaporation deposition, thermal evaporation deposition, pulsed laser deposition and the like; the coating method may be drop coating, spin coating, roll coating, knife coating, slit coating, gravure coating, or the like.

The invention is further illustrated by the following specific examples:

example 1

Depositing a silver metal layer 2 with the thickness of 120nm on one surface of a PMMA substrate layer 1 with the thickness of 200 mu m; depositing a tantalum oxide spacing layer 3 with the thickness of 32nm on the silver metal layer 2; depositing a plurality of silicon dioxide first dielectric layers 41 and tantalum oxide second dielectric layers 42 on the spacing layer 3 in sequence and alternately to form a Bragg reflection layer 4, wherein the thickness of each layer in the Bragg reflection layer 4 is 47nm, 51nm, 50nm, 51nm, 70nm, 51nm and 15nm in sequence; finally, a PTFE surface functional layer 5 with the thickness of 15 mu m is deposited on the Bragg reflection layer 4; obtaining the goose-yellow radiation refrigerating material. The reflection spectrum of the material is shown in FIG. 2.

Example 2

Depositing an aluminum metal layer 2 with the thickness of 120nm on one surface of a PI substrate layer 1 with the thickness of 100 mu m; depositing a titanium oxide spacer layer 3 with a thickness of 40nm on the aluminum metal layer 2; depositing a plurality of silicon dioxide first dielectric layers 41 and titanium oxide second dielectric layers 42 on the spacing layer 3 in turn to form a Bragg reflection layer 4, wherein the thickness of each layer in the Bragg reflection layer 4 is 85nm, 60nm, 80nm, 52nm, 110nm, 49nm and 20nm in turn; finally, depositing a PDMS surface functional layer 5 with the thickness of 25 μm on the Bragg reflection layer 4; obtaining pink radiation refrigeration material. The reflection spectrum of this pink radiation refrigerant material is shown in fig. 3.

Example 3

Depositing an aluminum metal layer 2 with the thickness of 120nm on one surface of a PET substrate layer 1 with the thickness of 150 mu m; depositing a zinc oxide spacing layer 3 with the thickness of 55nm on the aluminum metal layer 2; a plurality of silicon dioxide first dielectric layers 41 and zinc oxide second dielectric layers 42 are sequentially and alternately deposited on the spacing layer 3 to form a Bragg reflection layer 4, wherein the thickness of each layer in the Bragg reflection layer 4 is 112nm, 80nm, 115nm, 79nm, 116nm, 79nm and 234 nm; finally, a PMMA surface functional layer 5 with the thickness of 25 mu m is deposited on the Bragg reflection layer 4; the cyan radiation refrigerating material is obtained. The reflection spectrum of this cyan radiation refrigerant material is shown in fig. 4.

Example 4

Depositing a copper metal layer 2 with the thickness of 150nm on one surface of a PEN substrate layer 1 with the thickness of 125 mu m; depositing a zinc oxide spacing layer 3 with the thickness of 150nm on the copper metal layer 2; depositing a plurality of magnesium fluoride first dielectric layers 41 and a plurality of zinc oxide second dielectric layers 42 on the spacing layer 3 in turn to form a Bragg reflection layer 4, wherein the thickness of each layer in the Bragg reflection layer 4 is 65nm, 265nm, 90nm, 170nm, 60nm, 160nm and 190nm in turn; finally, a TPU surface functional layer 5 with the thickness of 15 mu m is deposited on the Bragg reflection layer 4; a near pink radiation refrigeration material was obtained. The reflection spectrum of the radiant cooling material is shown in fig. 5.

Example 5

Depositing a silver metal layer 2 with the thickness of 120nm on one surface of a PMMA substrate layer 1 with the thickness of 200 mu m; depositing a tantalum oxide spacing layer 3 with the thickness of 120nm on the silver metal layer 2; depositing a plurality of silicon dioxide first dielectric layers 41 and tantalum oxide second dielectric layers 42 on the spacing layer 3 in sequence and alternately to form a Bragg reflection layer 4, wherein the thickness of each layer in the Bragg reflection layer 4 is 47nm, 51nm, 50nm, 51nm, 70nm, 51nm and 15nm in sequence; finally, a PTFE surface functional layer 5 with the thickness of 15 mu m is deposited on the Bragg reflection layer 4; the obtained goose yellow radiation refrigeration material has high quality factor and narrow absorption peak width. The reflection spectrum of the material is shown in FIG. 6.

In summary, the color radiation refrigeration material provided by the invention can form a tamer structure through the arrangement of the metal layer 2, the spacing layer 3 and the bragg reflection layer 4, so as to realize a color development function with controllable color; and Tamm resonance is excited between the interfaces of the metal layer 2 and the spacing layer 3, so that the selective absorption of visible light with high quality factors is realized; moreover, a higher absorption rate and a very narrow absorption peak width can be obtained through the arrangement of the spacing layer 3, and the heat effect caused by the absorption of sunlight cannot be obviously increased; meanwhile, the surface heat of the material is radiated to the low-temperature universe through the atmosphere transparent window by utilizing the medium-infrared high emissivity of the surface functional layer 5, so that radiation cooling is realized.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and its practical application to enable one skilled in the art to make and use various exemplary embodiments of the invention and various alternatives and modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims and their equivalents.