Louver type photo-thermal regulation and control film and preparation method thereof

Abstract

The invention relates to the technical field of thin films, and particularly discloses a shutter type photo-thermal regulation and control film and a preparation method thereof. The shutter type photo-thermal regulation and control film comprises a base layer, a reflecting layer and a protective layer, the surface of the base layer is composed of a tooth-shaped structure; and the upward surface of the tooth-shaped structure is covered with a reflecting layer. According to the shutter type photo-thermal regulation and control film, the permeability of solar radiation is flexibly regulated according to different solar altitude angles, so that the photo-thermal regulation and control purpose is achieved, and the film has the self-adaptive regulation capability in different seasons and different time periods. Compared with an active temperature control system such as an air conditioner, no energy supply is needed for photo-thermal regulation and control. Compared with a common shutter, the shutter type photo-thermal regulation and control film is small in size, has certain ductility, can be folded, is easy to carry, can be attached to an outer wall, a glass window and other places, and is wide in application range.

Description

Technical Field

[0001] The present invention relates to the technical field of thin films, and in particular to a shutter-type light-heat regulating film and a preparation method thereof. Background Art

[0002] With the advancement of industrialization and urbanization, human demand for energy continues to grow. Although new energy sources such as wind energy, hydrogen energy and solar energy are gradually developed and utilized, fossil energy still dominates. Its large-scale use has aggravated the greenhouse effect and ecological pollution, and worsened the human living environment. Traditional vapor compression refrigeration technology cools down through the phase change of refrigerants, but this method not only consumes a lot of electricity, but the use and leakage of refrigerants also further damage the environment, leading to a vicious cycle of global warming. Under the dual pressure of energy depletion and climate change, the development of new green and low-carbon refrigeration technologies has become an urgent need.

[0003] Radiative cooling technology is a new type of passive cooling technology that does not require any energy input. It can cool objects by relying solely on the properties of the material itself. No exhaust gas or pollutants are discharged during cooling, and it has received widespread attention from researchers.

[0004] Venetian blinds are a commonly used energy-free, adjustable room temperature control structure. They affect the transfer of light and heat by adjusting the angle and position of the blades and using the characteristics of blocking, reflection, absorption and light transmission. The basic principle is to use the arrangement and material properties of the blades to control the solar radiation entering the room. When the blades are closed, they can completely block the light and prevent the sunlight from directly shining into the room, thereby reducing the input of solar heat; when the blades are partially opened or adjusted to a certain angle, they can reduce the heat entry by reflecting the light, while allowing a certain amount of natural light to enter the room, achieving a balance between shading and lighting. Venetian blinds are a good indoor temperature control structure, but their application scenarios are limited due to the large space they occupy. If the blinds can be miniaturized and made into films, it can not only reduce the space occupied, but also be used as a radiation cooling film to break through the scene restrictions and be applied to windows, building exterior walls, car surfaces and other areas.

[0005] Based on this, it is necessary to provide a louver-type photothermal regulation film and a preparation method thereof, which can flexibly adjust the transmittance of solar radiation according to different solar altitude angles, so as to achieve the purpose of photothermal regulation. Summary of the invention

[0006] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. To this end, the present invention proposes a louver-type photothermal regulation film and a preparation method thereof, which can flexibly adjust the transmittance of solar radiation according to different solar altitude angles, thereby achieving the purpose of photothermal regulation.

[0007] A first aspect of the present invention provides a louver-type light-heat regulating film.

[0008] Specifically, the shutter-type light-heat regulating film includes a base layer, a reflective layer, and a protective layer;

[0009] The surface of the base layer is composed of a tooth-like structure;

[0010] The upper surface of the toothed structure is covered with a reflective layer.

[0011] Preferably, the protective layer is located at the outermost layer of the louver-type light-heat regulating film.

[0012] Preferably, the angle formed by the upper side and the lower side of the tooth-shaped structure is the vertex angle;

[0013] The vertex angle is 60 to 90 degrees.

[0014] Further preferably, the vertex angle is 75 to 90 degrees.

[0015] More preferably, the vertex angle is 90 degrees.

[0016] Preferably, the upper end angle of the toothed structure is a reflection angle;

[0017] The reflection angle is 40 to 60 degrees.

[0018] More preferably, the reflection angle is 40 to 50 degrees.

[0019] More preferably, the reflection angle is 45 to 50 degrees.

[0020] Preferably, the raw material of the base layer includes any one of ultraviolet light curing adhesive and polydimethylsiloxane.

[0021] Preferably, the thickness of the base layer is 50-100 μm.

[0022] More preferably, the thickness of the base layer is 60-75 μm.

[0023] Preferably, the material of the reflective layer includes any one of aluminum and silver.

[0024] Preferably, the reflectivity of the reflective layer is 0.8-0.95.

[0025] Further preferably, the reflectivity of the reflective layer is 0.85-0.95.

[0026] More preferably, the reflectivity of the reflective layer is 0.9-0.95.

[0027] Preferably, the material of the protective layer includes any one of ultraviolet curing adhesive and polydimethylsiloxane.

[0028] Preferably, the louver-type light-heat regulating film has a thickness of 80 to 200 μm.

[0029] A second aspect of the present invention provides a method for preparing a louver-type light-heat regulating film.

[0030] Specifically, the following steps are included:

[0031] (1) Setting the size of the tooth structure to generate a grayscale image, then transferring the grayscale image to a laser direct writing system to obtain a substrate, and performing nanoimprinting to obtain a base layer;

[0032] (2) coating the upper surface of the toothed structure on the surface of the base layer to obtain a reflective layer;

[0033] (3) The coated base layer is subjected to nano-imprinting non-demolding treatment to obtain a protective layer, thereby producing a shutter-type light-heat regulating film.

[0034] Preferably, in step (2), the coating treatment method is magnetron sputtering. The upper side of the tooth-like structure on the surface of the base layer is not subjected to coating treatment.

[0035] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0036] The shutter-type light-heat regulating film of the present invention flexibly adjusts the permeability of solar radiation according to different solar altitude angles, thereby achieving the purpose of regulating light-heat. The film has the ability to self-adapt in different seasons and time periods. Compared with active temperature control systems such as air conditioners, the present invention does not require any energy supply to regulate light-heat. Compared with ordinary shutters, the shutter-type light-heat regulating film of the present invention is small in size and has a certain degree of ductility. It can be folded and easy to carry, and can be attached to exterior walls, glass windows, etc., and has a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a schematic diagram of the partial structure of the shutter-type light-heat regulating film prepared in Example 1 of the present invention;

[0038] Figure 2 This is a schematic diagram of the partial appearance of the shutter-type light-heat regulating film prepared in Example 1 of the present invention;

[0039] Figure 3 Schematic diagram of the working mode of the shutter-type light-heat regulating film prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0040] In order to make the technical scheme of the present invention more clearly understood by those skilled in the art, the following embodiments are listed for illustration. It should be pointed out that the following embodiments do not limit the protection scope of the present invention.

[0041] Unless otherwise specified, the raw materials, reagents or devices used in the following examples can be obtained from conventional commercial sources or by existing known methods.

[0042] Example 1

[0043] A shutter-type light-heat regulating film and a preparation method thereof.

[0044] Louver-type light and heat regulating film: including base layer, reflective layer and protective layer;

[0045] The raw material of the base layer is polydimethylsiloxane. The base layer plays the role of basic support and connection of each tooth-like structure. The surface of the base layer is composed of tooth-like structures; the upper side of the tooth-like structure is covered with a reflective layer. The surface of the reflective layer is aluminum-plated, and the reflectivity is 0.9. The lower side of the tooth-like structure is not coated and serves as a transmission surface. After coating, the tooth surface is nano-imprinted to form a protective layer to protect the tooth surface. The raw material of the protective layer is polydimethylsiloxane. The angle formed by the upper and lower sides of the tooth-like structure is the vertex angle, and the vertex angle is 90 degrees. The upper end angle of the tooth-like structure is the reflection angle, and the reflection angle is 45 degrees. The tooth-like structure is an isosceles triangle. The thickness of the base layer is 60μm, the thickness of the protective layer is 30μm, and the total thickness of the louver-type photothermal regulation film is 95μm. The schematic diagram of the local structure of the louver-type photothermal regulation film obtained in Example 1 of the present invention is shown as follows Figure 1 As shown, a partial schematic diagram of the appearance of the shutter-type light-heat regulating film prepared by the present invention is as shown Figure 2 shown.

[0046] Preparation method: using maskless grayscale lithography technology, magnetron sputtering coating technology, and nanoimprint technology.

[0047] (1) First, Matlab is used to set the tooth structure and size to generate a grayscale image. After the grayscale image is transferred to the laser direct writing system to write the substrate, a template is obtained by hot pressing nanoimprinting or ultraviolet nanoimprinting. After that, the template is nanoimprinted to obtain the cooling film base.

[0048] (2) The magnetron sputtering coating angle is adjusted according to the reflection angle of the structure to carry out coating treatment. The coating thickness should meet the principle of being opaque to obtain a reflective layer.

[0049] (3) Finally, the coated base layer is subjected to nanoimprinting without demoulding treatment to obtain a protective layer, thereby completing the production of the shutter-type light-heat regulating film of the present invention.

[0050] like Figure 3The figure shows the working mode of the shutter-type light-heat regulating film prepared in Example 1 of the present invention. The shutter-type light-heat regulating film prepared in Example 1 is attached to a vertical glass window. When the solar altitude angle is greater than 45 degrees, the sunlight cannot directly penetrate the shutter-type light-heat regulating film, but is reflected by the reflective layer, thereby achieving the effect of radiation cooling. When the solar altitude angle is less than 45 degrees, part of the sunlight can pass through the shutter-type light-heat regulating film through the transmission surface and enter the room, so as to achieve the purpose of regulating indoor light and indoor temperature.

[0051] Example 2

[0052] A shutter-type light-heat regulating film and a preparation method thereof.

[0053] The difference from Example 1 is that the reflection angle is 50 degrees. The preparation method is the same as that of Example 1.

[0054] Comparative Example 1

[0055] A shutter-type light-heat regulating film and a preparation method thereof.

[0056] The difference from Example 1 is that the reflection angle is 75 degrees. The preparation method is the same as that of Example 1.

[0057] Comparative Example 2

[0058] A shutter-type light-heat regulating film and a preparation method thereof.

[0059] The difference from Example 1 is that the reflection angle is 15 degrees. The preparation method is the same as that of Example 1.

[0060] Effect detection:

[0061] When the shutter-type light and heat regulating film of Example 1 is pasted on the glass window facing east, sunlight before about 10:30 can be allowed to enter the room in December of winter in Dongguan. At the same time, the solar altitude angle in summer is higher than that in winter, that is, the time period during which the shutter-type light and heat regulating film of Example 1 allows sunlight to enter the room is shorter than that in December of winter. When it is July in summer in Dongguan, the shutter-type light and heat regulating film faces east and allows sunlight before about 9:40 to enter the room. This also confirms the ability of the shutter-type light and heat regulating film to seasonally regulate light and heat.

[0062] When the shutter-type light and heat regulation film of Example 2 is affixed to the glass window facing east, the film allows sunlight to pass through the glass window before 9:40 on July 1st in summer in Dongguan. On January 1st in winter, the film allows sunlight to pass through the film before 11:20. On July 1st in summer in Beijing, the film allows sunlight to pass through the glass window before 9:37. On January 1st in winter, the film allows sunlight to pass through the entire morning time period. It can be seen from Example 2 that the film allows sunlight to pass through less time periods in summer than in winter, which plays a role of warming in winter and cooling in summer.

[0063] When the blind-type light and heat regulating film of Comparative Example 1 is affixed to the glass window facing east, on July 1st in summer in Dongguan, the film allows sunlight to pass through the glass window before 11:10. On January 1st in winter, the film allows sunlight to pass through the entire morning time period. On July 1st in summer in Beijing, the film allows sunlight to pass through the entire morning time period. On January 1st in winter, the film allows sunlight to pass through the entire morning time period. It can be seen from Comparative Example 1 that at a reflection angle of 75 degrees, in Dongguan summer, the film allows sunlight to pass through most of the time period, while in winter, the film allows sunlight to pass through the entire morning time period. In Beijing, the film allows sunlight to pass through in both summer and winter. From the results, at a reflection angle of 75 degrees, the film basically has no effect on regulating sunlight. This is because the larger the reflection angle, the smaller the proportion of the reflection surface with a metal layer will be, and the larger the proportion of the transmission surface will be, and the transmission surface is no different from a general film, which also means that the larger the reflection angle, the closer the regulating film is to a general transparent film.

[0064] When the blind-type light and heat regulating film of Comparative Example 2 is affixed to the glass window facing east, on July 1st in summer in Dongguan, the film allows sunlight to pass through the glass window before 6:52. On January 1st in winter, the film allows sunlight to pass through the glass window before 8:34. On July 1st in summer in Beijing, the film allows sunlight to pass through the glass window before 6:38. On January 1st in winter, the film allows sunlight to pass through the glass window before 9:21. Compared with the 75-degree reflection angle example in Comparative Example 1, the 15-degree reflection angle in Comparative Example 2 basically blocks the penetration of sunlight. In addition, the smaller the reflection angle, the closer the regulating film will be to a mirror. It can be seen from Comparative Examples 1 to 2 that the use of regulating films with the same reflection angle in different dimensional regions has differences in regulating the time period of sunlight, which is due to the different solar altitude angles in different dimensions. Therefore, the selection of a suitable reflection angle needs to be combined with the solar altitude angle in the current dimensional region.

[0065] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution obtained by any modification, equivalent replacement, improvement, etc. made by a person skilled in the art based on the concept of the present invention through logical analysis, reasoning or limited experiments on the basis of the prior art shall be within the scope of protection determined by the claims.

Claims

1. A shutter-type light-heat regulating film, characterized in that: The shutter-type light-heat regulating film comprises a base layer, a reflective layer, and a protective layer; The surface of the base layer is composed of a tooth-like structure; The upper surface of the toothed structure is covered with a reflective layer.

2. The shutter-type light-heat regulating film according to claim 1, characterized in that: The angle formed by the upper side and the lower side of the tooth-like structure is the vertex angle; The vertex angle is 60 to 90 degrees.

3. The shutter-type light-heat regulating film according to claim 1, characterized in that: The upper end angle of the toothed structure is the reflection angle; The reflection angle is 40 to 60 degrees.

4. The shutter-type light-heat regulating film according to claim 1, characterized in that: The raw material of the base layer includes any one of ultraviolet curing adhesive and polydimethylsiloxane.

5. The shutter-type light-heat regulating film according to claim 1, characterized in that: The thickness of the base layer is 50-100 μm.

6. The shutter-type light-heat regulating film according to claim 1, characterized in that: The material of the reflective layer includes any one of aluminum and silver.

7. The shutter-type light-heat regulating film according to claim 6, characterized in that: The reflectivity of the reflective layer is 0.8-0.

95.

8. The shutter-type light-heat regulating film according to claim 1, characterized in that: The material of the protective layer includes any one of ultraviolet curing adhesive and polydimethylsiloxane.

9. The shutter-type light-heat regulating film according to claim 1, characterized in that: The thickness of the shutter-type light-heat regulating film is 80 to 200 μm.

10. The method for preparing the shutter-type light-heat regulating film according to any one of claims 1 to 9, characterized in that: The following steps are involved: (1) Setting the size of the tooth structure to generate a grayscale image, then transferring the grayscale image to a laser direct writing system to obtain a substrate, and performing nanoimprinting to obtain a base layer; (2) coating the upper surface of the toothed structure on the surface of the base layer to obtain a reflective layer; (3) The coated base layer is subjected to nano-imprinting non-demolding treatment to obtain a protective layer, thereby producing a shutter-type light-heat regulating film.

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