A cyclically deformed multilayer polymer composite and applications and building envelopes

Abstract

The application belongs to the technical field of building enclosure, and discloses a multilayer polymer composite material with cyclic deformation, application and building enclosure. The multilayer polymer composite material comprises at least two layers of thermal expansion material arranged from top to bottom, and the layers of thermal expansion material are bonded and combined. The thermal expansion rate of the lower thermal expansion material layer is at least one order of magnitude larger than that of the upper thermal expansion material layer, so that the multilayer polymer composite material is subjected to cyclic deformation of curling and stretching under the response of sunlight conditions. The application utilizes the difference in interlayer thermal expansion rate of the multilayer structure composed of different materials, and the multilayer polymer composite structure responds to different light conditions, and the reversible deformation is generated by the temperature change of the material.

Description

Technical Field

[0001] This invention belongs to the field of building envelope technology, and more specifically, relates to a cyclically deformable multilayer polymer composite material and its application in building envelope. Background Technology

[0002] Buildings account for 30% of global energy consumption, with 48% of that used for heating and cooling. Building surface temperature is dominated by solar radiation, and the net heat flow P passing through the building interface into the interior... net It can be represented as: P net =P sun +P atm -P R -P E Among them, P sun For solar heat flow, P atm For atmospheric radiation, P R For building heat reflection, P E This refers to radiative heat flow in buildings. Currently, the main method for thermal management of buildings by regulating sunlight is through the use of building materials and envelopes. This involves controlling heat flow between the interior and exterior of the building through three methods: insulation and heat absorption, reflection, and near-infrared radiation, thereby regulating the building's internal temperature. When the building's internal temperature is low and heating is needed, the heat flow reflection and radiation from the building envelope are reduced; conversely, when cooling is required, the heat flow reflection and radiation from the envelope need to be increased to prevent heat from entering. Considering the complexity of building structures and the changes in sunlight caused by time and seasons, the flux of heat flowing through the building interface across different areas of the building surface is not constant, making thermal management requirements complex.

[0003] The main methods for existing building envelopes to respond in real time to building heating and cooling demands based on dynamic variables such as building shape and sunlight conditions include: 1. Adjusting lighting by driving the building envelope through electromechanical systems, such as patents "CN116201258A - A wall structure system with variable thermal performance and its adjustment method", "CN217129402U - An adjustable transparent low-emissivity roll-up shading device built into doors, windows and curtain walls", "CN217974958U - A building curtain wall with adjustable light transmittance" and "US20230020511A1 - Dual-mode heating and cooling device and related systems and methods", etc.

[0004] 2. Changing the light transmittance of building envelope through electrical signals, such as patents "CN115503307B - A photothermal dual-response smart window and its preparation method" and "CN116953961A - Smart window component and its manufacturing method".

[0005] 3. Regulating building heating and cooling needs through phase change energy storage, such as patents "CN114687466A - A new type of dynamic phase change material wall structure" and "CN115075377A - An enclosure structure combining double-glazed windows and phase change material walls", etc.

[0006] 4. Applying light and temperature responses to alter the light transmittance of building envelopes, such as the patent "CN113341597B - A silica aerogel whose light transmittance changes with ambient temperature and its preparation method and application", etc.

[0007] Current building envelope luminous flux regulation solutions either require complex mechanical structures to deform the building envelope and adjust luminous flux, consume electrical energy to change light transmittance, or require manual adjustment of the envelope's light transmittance. Therefore, a zero-energy building envelope with a simple structure that can actively respond to lighting conditions and automatically adjust luminous flux can save heating energy, improve energy efficiency, and reduce environmental pollution from buildings. Summary of the Invention

[0008] The purpose of this invention is to address the shortcomings of existing technologies by providing a cyclically deformable multilayer polymer composite material and its applications in building envelopes. This invention utilizes the difference in thermal expansion coefficients between the layers of a multilayer structure composed of different materials. The multilayer polymer composite structure responds to different lighting conditions, and the material temperature changes result in reversible deformation.

[0009] To achieve the above objectives, the first aspect of the present invention provides a cyclically deformable multilayer polymer composite material, the multilayer polymer composite material comprising at least two thermally expandable material layers arranged sequentially from top to bottom, and the thermally expandable material layers being bonded together. The thermal expansion coefficient of the lower thermal expansion material layer is at least an order of magnitude greater than that of the upper thermal expansion material layer, thereby causing the multilayer polymer composite material to undergo cyclic deformation of curling and stretching in response to sunlight conditions.

[0010] In this invention, "one order of magnitude" means that the thermal expansion rate of the lower thermal expansion material layer is 10 times that of the upper thermal expansion material layer. Similarly, if "the thermal expansion rate of the lower thermal expansion material layer is two orders of magnitude greater than that of the upper thermal expansion material layer," it means that the thermal expansion rate of the lower thermal expansion material layer is 10 times that of the upper thermal expansion material layer. 2 times.

[0011] In this invention, the thermal conductivity of the material also affects the curl-stretch cyclic deformation of the multilayer polymer composite material. The better the thermal conductivity, the more ideal the degree of curling. According to this invention, preferably, the anisotropic thermal conductivity ratio of the tangential to the normal of the uppermost thermal expansion material layer of the multilayer polymer composite material is (3-300):1.

[0012] According to the present invention, preferably, the overall thickness of the multilayer polymer composite material is 0.01mm-5mm; the thickness of the lower thermal expansion material layer is 10-500μm, and the thickness of the upper thermal expansion material layer is 10-100μm.

[0013] According to the present invention, preferably, the overall length of the multilayer polymer composite material is greater than or equal to 100 mm, more preferably 100-500 mm. The overall width of the multilayer polymer composite material is 10-300 mm.

[0014] According to the present invention, preferably, the width ratio of the lower thermal expansion material layer to the width ratio of the upper thermal expansion material layer is (1-10):1.

[0015] According to the present invention, preferably, such as Figure 1 , 2 As shown, when the width of the lower thermal expansion material layer is greater than the width of the upper thermal expansion material layer, a surface thermal expansion material layer is provided in the area where the lower thermal expansion material layer does not cover the upper thermal expansion material layer. The thermal expansion rate of the surface thermal expansion material layer is greater than or equal to that of the lower thermal expansion material layer, with the difference being less than one order of magnitude. The thermal expansion rate of the surface thermal expansion material layer is greater than that of the upper thermal expansion material layer, with the difference being not less than one order of magnitude. This ensures that when the multilayer polymer composite material undergoes curling deformation under solar radiation conditions, the surface thermal expansion material layer does not undergo curling deformation. Furthermore, when the surface thermal expansion material layer is provided, this invention does not limit the "anisotropic thermal conductivity ratio of the tangential and normal directions of the uppermost thermal expansion material layer of the multilayer polymer composite material," but only limits the anisotropic thermal conductivity ratio of the tangential and normal directions of the surface thermal expansion material layer to (3-300):1.

[0016] According to the present invention, preferably, each thermal expansion material layer is independently at least one of a reflective material layer, a light-shielding material layer, and a light-transmitting material layer. In the present invention: As a preferred embodiment, the upper thermal expansion material layer is a light-shielding material layer, and the lower thermal expansion material layer is a light-transmitting material layer; Alternatively, as a preferred embodiment, the upper thermal expansion material layer is a light-shielding material layer, and the lower thermal expansion material layer is a light-shielding material layer; Alternatively, as a preferred embodiment, the upper thermal expansion material layer is a light-transmitting material layer, and the lower thermal expansion material layer is a light-transmitting material layer; Alternatively, as a preferred embodiment, the upper thermal expansion material layer is a reflective material layer, and the lower thermal expansion material layer is a light-transmitting material layer; Alternatively, as a preferred embodiment, the upper thermal expansion material layer is a reflective material layer, and the lower thermal expansion material layer is a light-shielding material layer; Alternatively, as a preferred embodiment, the upper thermal expansion material layer is a light-shielding material layer, and the lower thermal expansion material layer is a reflective material layer.

[0017] According to the present invention, preferably, the reflective material layer is a blended and rolled layer of reflective powder and reflective layer resin, a coating obtained by mixing reflective powder with two-component acrylic resin and coating it on a base resin, aluminum foil, or a base resin layer with aluminum foil deposited on one side. More preferably, the mass ratio of reflective powder to reflective layer resin is (0.1-10):1; More preferably, the mass ratio of reflective powder to two-component acrylic resin is (0.1-10):1; More preferably, the reflective powder is at least one selected from alumina powder, silicon oxide powder, calcium carbonate powder, boron nitride powder, and titanium dioxide powder; More preferably, the reflective layer resin and the matrix resin are each independently at least one of polystyrene, polycarbonate, acrylonitrile-styrene-butadiene copolymer, polyamide, polyolefin, polyethylene terephthalate, polyphenylene ether, polyphenylene sulfide, polymethyl methacrylate, polyoxymethylene, polysulfone, polyimide, polytetrafluoroethylene, polychlorotrifluoroethylene, polybutylene terephthalate, chlorinated polyether, styrene-butadiene rubber, nitrile rubber, silicone rubber, cis-butadiene rubber, polyisoprene, ethylene propylene rubber, and chloroprene rubber. More preferably, the polyolefin is at least one of low-density polyethylene, polypropylene, a blend of low-density polyethylene and polypropylene, and high-density polyethylene.

[0018] According to the present invention, preferably, the light-shielding material layer is at least one of activated carbon, carbon black, graphite, graphene, MXene, iron oxide, chromium oxide and copper oxide, which is blended with the reflective layer resin and then rolled into an activated carbon layer, a carbon black layer, a graphite paper, a graphene paper, MXene, iron oxide layer, chromium oxide and copper oxide layer.

[0019] According to the present invention, preferably, the light-transmitting material layer is a transparent resin layer and / or a transparent resin layer with an indium tin oxide film deposited on one side; the transparent resin is at least one of polypropylene, low-density polyethylene, polycarbonate, polyethylene terephthalate, polymethyl methacrylate, polychlorotrifluoroethylene and transparent silicone rubber.

[0020] In this invention, the method used for "deposition" is a physical deposition method or a chemical deposition method known to those skilled in the art. The physical deposition method includes vacuum evaporation and magnetron sputtering, and the chemical deposition method includes chemical vapor deposition and electrochemical deposition.

[0021] According to the present invention, preferably, the adhesive used to bond the thermal expansion material layers is at least one of thermoplastic adhesive, thermosetting adhesive and rubber-based adhesive; the adhesive used to bond the thermal expansion material layers forms an adhesive layer with a thickness of 0.01-1 mm; More preferably, the thermoplastic adhesive is at least one selected from polyvinyl acetate, polyvinyl alcohol, polyvinyl acetal adhesives, polyvinyl alcohol, polyvinyl acid adhesives, polyacrylic acid adhesives, polyamide, cellulose adhesives, saturated polyester adhesives, polyurethane adhesives, and polyvinyl chloride adhesives; More preferably, the thermosetting adhesive is at least one selected from urea-formaldehyde resin, melamine resin, phenolic resin, resorcinol-formaldehyde resin, epoxy resin, unsaturated polyester, polyisocyanate, polyimide, and polybenzimidazole. More preferably, the rubber-type adhesive is at least one selected from chloroprene rubber, nitrile rubber, styrene-butadiene rubber, butyl rubber, polysulfide rubber, carboxyl rubber, silicone rubber, and thermoplastic rubber; More preferably, the composite adhesive is at least one selected from phenolic resin, polyvinyl acetal, phenolic-chloroprene rubber, phenolic-nitrile rubber, epoxy-nitrile rubber, epoxy-polyamide, epoxy-phenolic resin, and epoxy-polyurethane.

[0022] In this invention, the degree of deformation, deformation speed, and deformation direction of the multilayer polymer composite structure can also be controlled by the material and geometry of the 3D-printed line array. According to this invention, preferably, the lower surface of the lower thermal expansion material layer is provided with a 3D-printed line array; The material of the 3D printed line array is at least one of polyolefin, polylactic acid, polyurethane, acrylonitrile-styrene-butadiene copolymer and polyethylene terephthalate; more preferably, the polyolefin is low-density polyethylene or a blend of low-density polyethylene and polypropylene. The 3D printing operation parameters include: printhead temperature range of 150℃-240℃, substrate temperature of 30℃-100℃, printing speed of 1mm / s-50mm / s, printing line width of 0.1mm-5mm, line thickness of 0.1mm-5mm, and line spacing of 0.2mm-10mm. As shown in Figure 3, the angle between the 3D printed line array and the long side of the lower thermal expansion material layer is any angle between 0° and 90°.

[0023] The second aspect of the present invention provides the application of the above-described cyclically deformable multilayer polymer composite material as a building envelope or building envelope surface.

[0024] A third aspect of the present invention provides a building envelope in which a plurality of the described cyclically deformable multilayer polymer composite materials are arranged in an array on the surface of a building to obtain a building envelope, and the lowest thermal expansion material layer of each cyclically deformable multilayer polymer composite material is fixedly connected to the surface of the building by at least one of the following fixing methods: bonding, welding, bolting and clamping.

[0025] According to the present invention, preferably, the width of the fixed connection is not less than 10 mm.

[0026] According to the present invention, preferably, the building is a curtain wall or window glass.

[0027] A fourth aspect of the present invention provides a building envelope comprising a surface layer and a substrate layer disposed sequentially from top to bottom; optionally, an intermediate layer is disposed between the surface layer and the substrate layer; The surface layer is a multilayer polymer composite material that undergoes cyclic deformation; the substrate layer is fixedly connected to the building surface.

[0028] According to the present invention, preferably, there are multiple intermediate layers, which are arranged in an array and fixedly connected to the substrate layer, and the array spacing of each intermediate layer is not less than 10 mm; there are multiple surface layers, which are arranged in an array, and the size of the surface layer is larger than the size of the intermediate layer, such that the lowest thermal expansion material layer of each cyclically deformed multilayer polymer composite material is fixedly connected to the array gap surface of the intermediate layer by at least one of the following fixing methods: bonding, welding, bolting and clamping. More preferably, the width of the fixed connection is not less than 10 mm.

[0029] According to the present invention, preferably, there are multiple intermediate layers, which are arranged in an array and fixedly connected to the substrate layer, and the array spacing of each intermediate layer is 10 mm; there are multiple surface layers, which are arranged in an array, and the size of each surface layer is equal to the size of the intermediate layer, such that the lowest thermal expansion material layer of each cyclically deformed multilayer polymer composite material is fixedly connected to the intermediate layer by at least one of the following fixing methods: bonding, welding, bolting and clamping. More preferably, the width of the fixed connection is not less than 10 mm.

[0030] In this invention, "the size of the surface layer is greater than the size of the intermediate layer" means that the width of the surface layer is greater than the width of the intermediate layer, and / or that the length of the surface layer is greater than the length of the intermediate layer.

[0031] In this invention, all possible arrays or any shapes that can achieve deformation-controlled heat flow are within the scope of patent protection. In one embodiment of this invention, the surface layer and the intermediate layer are polygonal arrays of parallelograms (including rectangles and squares), trapezoids, or triangles.

[0032] In this invention, as a preferred embodiment, the connection between the intermediate layer and the substrate layer is achieved by roller coating.

[0033] According to the present invention, preferably, the intermediate layer is a cooling layer and / or a reflective layer.

[0034] According to the present invention, preferably, the cooling layer is a blended and rolled layer of radiation cooling filler and cooling layer resin or a blended coating of radiation cooling filler and two-component acrylic resin. According to the present invention, preferably, the radiation cooling filler is prepared by mixing titanium dioxide powder with a nitrogen-containing compound, followed by ball milling, drying, sieving, and heat treatment; more preferably, the mass ratio of titanium dioxide powder to nitrogen-containing compound is (1-100):1; more preferably, the nitrogen-containing compound is at least one of boron nitride, ammonium chloride, ammonium nitrate, ammonium carbonate, ammonium bicarbonate, and urea powder; more preferably, the ball milling time is 2-24 h; more preferably, the heat treatment conditions include a nitrogen atmosphere, a heat treatment temperature of 800-1400℃, a heat treatment time of 1-10 h, a heating rate of 1-10℃ / min, a cooling rate of 1-20℃ / min, and a nitrogen flow rate of 10-200 mL / min.

[0035] According to the present invention, preferably, the resin of the cooling layer is at least one selected from polyamide, polyolefin, polyethylene terephthalate, polyphenylene ether, polyphenylene sulfide, polytetrafluoroethylene, polychlorotrifluoroethylene, chlorinated polyether, styrene-butadiene rubber, nitrile rubber, silicone rubber, cis-butadiene rubber, polyisoprene, ethylene propylene rubber, and chloroprene rubber. More preferably, the polyolefin is polypropylene, polyethylene, or a blend of polyethylene and polypropylene.

[0036] According to the present invention, preferably, the mass ratio of the radiation cooling filler to the cooling layer resin is (0.1-10):1.

[0037] According to the present invention, preferably, the mass ratio of the radiation cooling filler to the two-component acrylic resin is (0.1-10):1.

[0038] According to the present invention, preferably, the reflective layer is a coating prepared by mixing reflective powder (at least one of alumina powder, silica powder, calcium carbonate powder, boron nitride powder and titanium dioxide powder) with a two-component acrylic resin and coating it onto a substrate; more preferably, the mass ratio of reflective powder to two-component acrylic resin is (0.1-10):1; more preferably, the substrate is at least one of cement concrete, wood, brick and stone and metal plate.

[0039] According to the present invention, preferably, the substrate layer is at least one of cement concrete, wood, brick, metal plate and polymer substrate; the polymer substrate is at least one of polystyrene, polycarbonate, acrylonitrile-styrene-butadiene copolymer, polyamide, polyolefin, polyethylene terephthalate, polyphenylene ether, polyphenylene sulfide, polymethyl methacrylate, polyoxymethylene, polysulfone, polyimide, polytetrafluoroethylene, polychlorotrifluoroethylene, polybutylene terephthalate, chlorinated polyether, styrene-butadiene rubber, nitrile rubber, silicone rubber, cis-butadiene rubber, polyisoprene, ethylene propylene rubber and chloroprene rubber, and the polyolefin is a blend of polyethylene and polypropylene or high-density polyethylene.

[0040] The beneficial effects of the technical solution of the present invention are as follows: Traditional building envelopes are either fixed structures, use electromechanical systems, or employ shape memory alloys or shape memory polymers as driving devices to change the shape of the envelope to regulate the amount of light passing through the building interface. This invention utilizes the difference in thermal expansion coefficients between layers of a multi-layered structure composed of different materials. The multi-layered polymer composite structure responds to different lighting conditions, and the material temperature changes produce reversible deformation, achieving intelligent regulation of the heat flow passing through the building surface, thereby realizing temperature control within the building.

[0041] The degree, speed, and direction of deformation of multilayer polymer composite structures can be controlled by the combination of interlayer materials (material composition, thickness of each layer, and preparation method), the color of the surface material, and the intensity of light.

[0042] Different interlayer combinations, through the deformation of multilayer composite structures, can alter shading, reflection, and transmission, as well as radiative cooling, thereby controlling luminous flux and adjusting the heat flow entering the building to achieve building thermal management. The reflection, shading, transmission, and radiation properties of the multilayer polymer composite material of this invention are determined by the combination of interlayer materials (material composition, thickness, and preparation method) and material shapes (such as area, thickness, and specific shape, including parallelograms (including rectangles and squares), trapezoids, triangles, or combinations thereof, or any specific shape)).

[0043] This invention utilizes the fundamental physical laws of thermal expansion and contraction of materials to drive deformation. Compared to electromechanical systems, the deformation process of this invention requires no additional energy consumption, is noiseless, and has higher reliability. Compared to shape memory alloy-driven deformation, this invention offers a wider range of material choices, lower material costs, and better compatibility with building materials. Compared to shape memory polymers, this invention features a simpler and more convenient material system, excellent deformation cycle performance, a wide deformation response temperature range, easily adjustable deformation direction, excellent weather resistance, and a long service life.

[0044] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0045] The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the invention.

[0046] Figure 1 A schematic diagram of a cyclically deformable multilayer polymer composite material and building envelope provided by the present invention is shown.

[0047] Figure 2 It shows Figure 1 A schematic diagram of the cyclic deformation of a multilayer polymer composite material undergoing curling deformation.

[0048] Figure 3 shows a schematic diagram of a 3D printed line array of a cyclically deformable multilayer polymer composite material provided by the present invention printed on a lower thermal expansion material layer. (Wherein: Figure 3(A) shows the printing direction along the length of the long side of the lower thermal expansion material layer with an angle of 0°; Figure 3(B) shows the printing direction with an angle of 90° to the length of the long side of the lower thermal expansion material layer; Figure 3(C) shows the situation described in Examples 6 and 7).

[0049] Figure 4 A schematic diagram of a building envelope provided in Embodiment 1 of the present invention is shown.

[0050] Figure 5 The results of the spherical integration of the outer emissivity of the intermediate layer in the infrared band are shown for Examples 1, 8, and 9, and Comparative Example 1.

[0051] The annotations in the attached figures are explained as follows: 1-Surface thermal expansion material layer; 2-Upper thermal expansion material layer; 3-Adhesive layer; 4-Lower thermal expansion material layer; 5-3D printed line array; 6-Angle between the 3D printed line array and the long side of the lower thermal expansion material layer; 7-Intermediate layer; 8-Substrate layer; 9-Surface layer. Detailed Implementation

[0052] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0053] In the following embodiments: Graphene paper: Guangzhou Weifu Technology Co., Ltd., model VF80035E series (Example 1), VF50045E series (Example 5).

[0054] Low-density polyethylene film: Nantong Jin Si Nan film material Co., Ltd. (Examples 1, 3, 4); Polyolefin (polyethylene-polypropylene blend): Beijing Oriental Yuhong Waterproof Technology Co., Ltd., thermoplastic polyolefin, model TPO-P (Examples 2, 5, 6, 7); Polyethylene terephthalate: Commercially available materials are acceptable (Example 3); Two-component acrylic resin: Evonik Industries, Component A 655 series, Component B 659 series; (Examples 1, 2, 4, 5, 7); High-density polyethylene film: Beijing Oriental Yuhong Waterproof Technology Co., Ltd., PMH-30 series (Examples 1, 4, 6); Graphite paper: Guangzhou Weifu Technology Co., Ltd., model VF03060E series (Example 6), VF02080E series (Example 2).

[0055] Polyacrylic adhesive: Shenzhen Goodlink Adhesive Co., Ltd., PP6603 type (Example 3); Polyurethane hot melt adhesive: Beijing Oriental Yuhong Waterproof Technology Co., Ltd.

[0056] Example 1 This embodiment provides a cyclically deformable multilayer polymer composite material, which includes two thermally expandable material layers arranged sequentially from top to bottom; The upper thermal expansion material layer 2 is a square piece of graphene paper, cut to a thickness of 35 μm, a width of 100 mm, and a length of 100 mm. Its thermal expansion coefficient is 2 × 10⁻⁶. -6 m / mK; In-plane (tangential) thermal conductivity is 1500 W / mK, perpendicular (normal) thermal conductivity is 5 W / mK, and the ratio of tangential to normal anisotropic thermal conductivity is 300:1; The lower thermal expansion material layer 4 is a rectangular low-density polyethylene film with a thickness of 20μm, a width of 100mm, and a length of 110mm, which has been cut to size; the thermal expansion coefficient is 2×10⁻⁶. -4 m / mK; Two layers of thermally expandable material are bonded together at room temperature with polyurethane hot melt adhesive aligned along the short side, and then placed in a vacuum drying oven to remove air bubbles from the adhesive layer 3.

[0057] Line array 5 was printed on the lower surface of a low-density polyethylene film using a 3D printer. The printing material was polyethylene terephthalate (PET), and the printing parameters were: substrate temperature 40℃, printing speed 10mm / s, nozzle temperature 200℃, line width 0.4mm, length 100mm, line thickness 0.4mm, and spacing 10mm. The printing direction was along the length of the low-density polyethylene film (angle 0°), as shown in Figure 3(A).

[0058] The cyclically deformable multilayer polymer composite material of this embodiment is obtained.

[0059] This embodiment also provides a building envelope, such as Figure 4 As shown, the building envelope includes a surface layer 9, an intermediate layer 7, and a base material layer 8 arranged sequentially from top to bottom; The surface layer 9 is a multilayer polymer composite material that undergoes cyclic deformation in this embodiment; the substrate layer 8 is fixedly connected to the building surface; The intermediate layers 7 are multiple, arranged in an array and fixedly connected to the substrate layer 8, with an array spacing of 10 mm between each intermediate layer 7; the surface layers 9 are multiple, arranged in an array, and the size of each surface layer 9 is larger than the size of each intermediate layer 7 (the intermediate layer 7 is a square with a width of 100 mm, a length of 100 mm, and a thickness of 0.02 mm), so that the short side of the lower thermal expansion material layer of each cyclically deformed multilayer polymer composite material is fixedly connected to the array gap surface of the intermediate layer 7 by thermal welding, with a fixed connection width of 10 mm; The intermediate layer 7 is a cooling layer, and its preparation method includes: (1) Preparation of radiation cooling filler: Titanium dioxide powder and boron nitride powder were directly mixed at a mass ratio of (5:1) and then placed in a drum-type ball mill jar. The mixture was ball-milled with zirconia balls for 12 hours using alcohol as the ball milling medium. After ball milling, the slurry was dried at 80℃ and then treated at 1200℃ for 5 hours in a nitrogen atmosphere. The heating rate was 5℃ / min, the cooling rate was 10℃ / min, and the nitrogen flow rate was 150mL / min, to obtain nitrogen-doped titanium dioxide powder. (2) Preparation of the cooling layer: Nitrogen-doped titanium dioxide powder and two-component acrylic resin are mixed at a mass ratio of 2:1 to prepare a cooling coating, and the cooling coating is rolled onto the surface of substrate layer 8 (high-density polyethylene film) to obtain the cooling layer.

[0060] Example 2 This embodiment provides a cyclically deformable multilayer polymer composite material, which includes two thermally expandable material layers arranged sequentially from top to bottom; The upper thermal expansion material layer is a rectangular piece of graphite paper, cut to a thickness of 80 μm, a width of 100 mm, and a length of 200 mm; its thermal expansion coefficient is 6 × 10⁻⁶. -6 m / mK; In-plane thermal conductivity is 200 W / mK, perpendicular thermal conductivity is 5 W / mK, and anisotropic thermal conductivity ratio is 40:1; The lower thermal expansion material layer is a rectangular polyolefin TPO-P film with a thickness of 180 μm, a width of 110 mm, and a length of 200 mm, which has been cut to size; the thermal expansion coefficient is 1.5 × 10⁻⁶. -4 m / mK; The two layers of thermal expansion material are bonded together along the long side at room temperature using polyurethane hot melt adhesive, and then placed in a vacuum drying oven to remove air bubbles from the adhesive layer.

[0061] A line array was printed on the lower surface of a polyolefin film using a 3D printer. The printing material was low-density polyethylene, and the printing parameters were: substrate temperature 40℃, printing speed 10mm / s, nozzle temperature 180℃, line width 0.6mm, length 200mm, line thickness 0.6mm, and spacing 10mm. The printing direction was along the length of the polyolefin film (angle 0°), as shown in Figure 3(A).

[0062] The cyclically deformable multilayer polymer composite material of this embodiment is obtained.

[0063] This embodiment also provides a building envelope, which differs from Embodiment 1 in that: The intermediate layer is a rectangle with a width of 100mm, a length of 200mm, and a thickness of 0.04mm; the long side of the lower thermal expansion material layer of each cyclically deformed multilayer polymer composite material is fixedly connected to the array gap surface of the intermediate layer 7 by thermal welding, and the width of the fixed connection is 10mm. The intermediate layer is a cooling layer, and its preparation method includes: (1) Preparation of radiation cooling filler: Titanium dioxide powder and ammonium chloride powder were directly mixed at a mass ratio of 2:1 and then placed in a drum-type ball mill jar. The mixture was ball-milled for 10 hours using zirconia balls with alcohol as the ball milling medium. After ball milling, the slurry was dried at 80℃ and then treated at 1000℃ for 4 hours in a nitrogen atmosphere. The heating rate was 5℃ / min, the cooling rate was 10℃ / min, and the nitrogen flow rate was 120mL / min, to obtain nitrogen-doped titanium dioxide powder. (2) Preparation of the cooling layer: Nitrogen-doped titanium dioxide powder and two-component acrylic resin are mixed at a mass ratio of 2:1 to prepare a cooling coating, and the cooling coating is rolled onto the surface of the substrate layer (TPO-P) to obtain the cooling layer.

[0064] Example 3 This embodiment provides a cyclically deformable multilayer polymer composite material, which includes two thermally expandable material layers arranged sequentially from top to bottom; The upper thermal expansion material layer is a rectangular low-density polyethylene film, cut to a thickness of 80μm, a width of 100mm, and a length of 150mm; its thermal expansion coefficient is 200×10⁻⁶. -6 m / mK; The lower thermal expansion material layer is a rectangular polyethylene terephthalate film, cut to a thickness of 125 μm, a width of 100 mm, and a length of 150 mm, deposited by single-sided electron beam evaporation of indium tin oxide film, with a resistivity of 150 Ω / m²; the thermal expansion coefficient is 6 × 10⁻⁶. -5 m / mK; The two thermal expansion material layers (the side of the low-density polyethylene film and the polyethylene terephthalate film without the indium tin oxide film) are aligned and bonded at room temperature using a polyacrylic adhesive, and then placed in a vacuum drying oven at 80°C for heat treatment to remove air bubbles from the adhesive layer.

[0065] The cyclically deformable multilayer polymer composite material of this embodiment is obtained.

[0066] This embodiment also provides a building envelope, wherein multiple cyclically deformable multilayer polymer composite materials of this embodiment are arranged in an array on the building surface to obtain a building envelope, and the short side of the lower thermal expansion material layer of each cyclically deformable multilayer polymer composite material is bonded and fixedly connected to the building surface by polyurethane hot melt adhesive, and the width of the fixed connection is not less than 5mm. The building is a curtain wall or window glass.

[0067] Example 4 This embodiment provides a cyclically deformable multilayer polymer composite material, which includes two thermally expandable material layers arranged sequentially from top to bottom; The upper thermal expansion material layer is a rectangular aluminum foil, cut to a thickness of 60 μm, a width of 100 mm, and a length of 200 mm; the aluminum foil has a thermal conductivity of 240 W / mK and a thermal expansion coefficient of 2.32 × 10⁻⁶. -5 m / mK; The lower thermal expansion material layer is a rectangular low-density polyethylene film, cut to a thickness of 80 μm, a width of 110 mm, and a length of 200 mm; its thermal expansion coefficient is 2 × 10⁻⁶. -4 m / mK; The two layers of thermal expansion material are bonded together along the long side at room temperature using polyurethane hot melt adhesive, and then placed in a vacuum drying oven to remove air bubbles from the adhesive layer.

[0068] A line array was printed on the lower surface of a low-density polyethylene (LDPE) film using a 3D printer. The printing material was LDPE film, and the printing parameters were: substrate temperature 40℃, printing speed 10mm / s, nozzle temperature 180℃, line width 0.4mm, length 200mm, line thickness 0.4mm, and spacing 10mm. The printing direction was along the length of the LDPE film (angle 0°), as shown in Figure 3(A).

[0069] The cyclically deformable multilayer polymer composite material of this embodiment is obtained.

[0070] This embodiment also provides a building envelope, which differs from Embodiment 1 in that: The intermediate layer is a cooling layer, and its preparation method includes: (1) Preparation of radiation cooling filler: Titanium dioxide powder and urea powder were directly mixed at a mass ratio of (4:1) and then placed in a drum-type ball mill jar. The mixture was ball-milled with zirconia balls for 10 hours using alcohol as the ball milling medium. After ball milling, the slurry was dried at 80℃ and then treated at 1000℃ for 2 hours in a nitrogen atmosphere. The heating rate was 5℃ / min, the cooling rate was 10℃ / min, and the nitrogen flow rate was 100mL / min, to obtain nitrogen-doped titanium dioxide powder. (2) Preparation of the cooling layer: Nitrogen-doped titanium dioxide powder and two-component acrylic resin are mixed at a mass ratio of 2:1 to prepare a cooling coating, and the cooling coating is rolled onto the surface of the substrate layer (high-density polyethylene film) to obtain the cooling layer.

[0071] Example 5 This embodiment provides a cyclically deformable multilayer polymer composite material, which includes two thermally expandable material layers arranged sequentially from top to bottom; The upper thermal expansion material layer is a rectangular graphene paper cut to a thickness of 45μm, a width of 100mm, and a length of 200mm; the thermal expansion coefficient is 2×10⁻⁶. -6 m / mK; In-plane thermal conductivity is 1200 W / mK, perpendicular thermal conductivity is 5 W / mK, and anisotropic thermal conductivity ratio is 240:1; The lower thermal expansion material layer is a blended roll-pressed film of reflective powder and reflective layer resin, cut to a rectangular shape with a thickness of 200 μm, a width of 110 mm, and a length of 200 mm. The blended roll-pressed film is obtained by mixing 90 parts of polyolefin (TPO-P) and 10 parts of boron nitride powder with an average particle size of 18 μm and an average thickness of 0.2 μm at 180°C and then rolling it. The thermal expansion coefficient is 1.5 × 10⁻⁶. -4 m / mK; The two layers of thermal expansion material are bonded together along the long side at room temperature using polyurethane hot melt adhesive, and then placed in a vacuum drying oven to remove air bubbles from the adhesive layer.

[0072] A line array was printed on the lower surface of the blended coating using a 3D printer. The printing material was polyethylene terephthalate (PET), and the printing parameters were: substrate temperature 40℃, printing speed 10mm / s, nozzle temperature 200℃, line width 0.4mm, length 200mm, line thickness 0.4mm, and spacing 10mm. The printing direction was along the long side of the two thermally expanding materials (angle 0°), as shown in Figure 3(A).

[0073] The cyclically deformable multilayer polymer composite material of this embodiment is obtained.

[0074] This embodiment also provides a building envelope, which differs from Embodiment 1 in that: The intermediate layer is a rectangle with a width of 100mm, a length of 200mm, and a thickness of 0.6mm; The intermediate layer is a cooling layer, and its preparation method includes: (1) Preparation of radiation cooling filler: Titanium dioxide powder and urea powder were directly mixed at a mass ratio of (4:1) and then placed in a drum-type ball mill jar. The mixture was ball-milled with zirconia balls for 10 hours using alcohol as the ball milling medium. After ball milling, the slurry was dried at 80℃ and then treated at 1000℃ for 2 hours in a nitrogen atmosphere. The heating rate was 5℃ / min, the cooling rate was 10℃ / min, and the nitrogen flow rate was 100mL / min, to obtain nitrogen-doped titanium dioxide powder. (2) Preparation of the cooling layer: Nitrogen-doped titanium dioxide powder and two-component acrylic resin were mixed at a mass ratio of 1:10 to prepare a cooling coating, and the cooling coating was rolled onto the surface of the substrate layer (TPO-P) to obtain the cooling layer.

[0075] Example 6 This embodiment provides a cyclically deformable multilayer polymer composite material, which includes two thermally expandable material layers arranged sequentially from top to bottom; The upper thermal expansion material layer is a rectangular piece of graphite paper, cut to a thickness of 60 μm, a width of 100 mm, and a length of 200 mm; its thermal expansion coefficient is 6 × 10⁻⁶. -6 m / mK; In-plane thermal conductivity is 300 W / mK, perpendicular thermal conductivity is 5 W / mK, and anisotropic thermal conductivity ratio is 60:1; The lower thermal expansion material layer is a square blend coating with a thickness of 200 μm and a side length of 200 mm, cut to size. This blend coating is obtained by mixing 80 parts of polyolefin (TPO-P) and 20 parts of TiO2 powder with an average particle size of 0.025 μm at 180°C and then rolling the mixture. The thermal expansion coefficient is 1.5 × 10⁻⁶. -4 m / mK; The two layers of thermal expansion material are bonded together with polyurethane hot melt adhesive at room temperature and then placed in a vacuum drying oven to remove air bubbles from the adhesive layer.

[0076] A line array was printed on the lower surface of the blended coating using a 3D printer. The printing material was low-density polyethylene, and the printing parameters were: substrate temperature 40℃, printing speed 10mm / s, nozzle temperature 180℃, line width 0.6mm, length 200mm, line thickness 0.6mm, and spacing 10mm. The printing area was the same as the area of ​​the graphite paper, and the angle between the printing direction and the length direction of the graphite paper was 0°, as shown in Figure 3(C).

[0077] The cyclically deformable multilayer polymer composite material of this embodiment is obtained.

[0078] This embodiment also provides a building envelope, which includes a surface layer and a base layer arranged sequentially from top to bottom; The surface layer is a multilayer polymer composite material that undergoes cyclic deformation according to this embodiment; the substrate layer is fixedly connected to the building surface. The surface layer consists of multiple layers arranged in an array on the surface of the substrate layer (high-density polyethylene film). The long side of the lower thermal expansion material layer of each cyclically deformed multilayer polymer composite material is fixedly connected to the surface of the substrate layer by thermal welding, and the width of the fixed connection is not less than 10 mm.

[0079] Example 7 This embodiment provides a cyclically deformable multilayer polymer composite material, which includes two thermally expandable material layers arranged sequentially from top to bottom; The upper thermal expansion material layer is a rectangular aluminum foil, cut to a thickness of 40 μm, a width of 100 mm, and a length of 200 mm; the aluminum foil has a thermal conductivity of 240 W / mK and a thermal expansion coefficient of 2.32 × 10⁻⁶. -5 m / mK; The lower thermal expansion material layer is a square blend coating with a thickness of 200 μm and a side length of 200 mm, cut to size. This blend coating is obtained by mixing 95 parts of polyolefin (TPO-P) and 5 parts of graphene powder with an average particle size of 0.4 μm and a thickness of 2 nm at 180°C and then rolling it. The thermal expansion coefficient is 1.5 × 10⁻⁶. -4 m / mK; The two layers of thermal expansion material are bonded together with polyurethane hot melt adhesive at room temperature and then placed in a vacuum drying oven to remove air bubbles from the adhesive layer.

[0080] A line array was printed on the lower surface of the blended coating using a 3D printer. The printing material was polyethylene terephthalate (PET), and the printing parameters were: substrate temperature 40℃, printing speed 10mm / s, nozzle temperature 200℃, line width 0.4mm, length 200mm, line thickness 0.4mm, and spacing 10mm. The printing area was the same as the area of ​​the aluminum foil, and the angle between the printing direction and the length direction of the aluminum foil was 0°, as shown in Figure 3(C).

[0081] The cyclically deformable multilayer polymer composite material of this embodiment is obtained.

[0082] This embodiment also provides a building envelope, such as Figure 4 As shown, the building envelope includes a surface layer, an intermediate layer, and a base layer arranged sequentially from top to bottom; The surface layer is a multilayer polymer composite material that undergoes cyclic deformation according to this embodiment; the substrate layer is fixedly connected to the building surface. The intermediate layers are multiple, arranged in an array and fixedly connected to the substrate layer, with a spacing of 10mm between each intermediate layer; the surface layers are multiple, arranged in an array, with the size of each surface layer equal to the size of the intermediate layers (the intermediate layers are squares with a side length of 200mm and a thickness of 0.6mm), such that the lower thermal expansion material layer of each cyclically deformable multilayer polymer composite material is fixedly connected to the intermediate layer by thermal welding, with a fixed connection width of 10mm; The intermediate layer is a cooling layer, and its preparation method includes: (1) Preparation of radiation-cooled filler: Titanium dioxide powder and ammonium bicarbonate powder were directly mixed at a mass ratio of 2:1 and then placed in a drum-type ball mill jar. The mixture was ball-milled for 10 hours using zirconia balls with alcohol as the milling medium. After ball milling, the slurry was dried at 80°C and then treated at 1000°C for 2 hours in a nitrogen atmosphere. The heating rate was 5°C / min, the cooling rate was 10°C / min, and the nitrogen flow rate was 150 mL / min, to obtain nitrogen-doped titanium dioxide powder. (2) Preparation of the cooling layer: Nitrogen-doped titanium dioxide powder and two-component acrylic resin are mixed at a mass ratio of 1:10 to prepare a cooling coating, and the cooling coating is rolled onto the surface of the substrate layer (TPO-P) to obtain the cooling layer.

[0083] Examples 8 and 9, Comparative Example 1 Examples 8 and 9 each provide a building envelope, and the only difference between Examples 8 and 9 and Example 1 is that: In the preparation of the radiation cooling filler in the intermediate layer of Example 8, the mass ratio of titanium dioxide powder to boron nitride powder is (3:1). In the preparation of the radiation cooling filler in the intermediate layer of Example 9, the mass ratio of titanium dioxide powder to boron nitride powder is (1:1). In the preparation of the radiation cooling filler in the intermediate layer of Comparative Example 1, the mass ratio of titanium dioxide powder to boron nitride powder was (0:1), i.e., pure boron nitride (pure BN). Using an integrating sphere Fourier transform infrared spectrometer, it can be seen that the emissivity of the outer intermediate layer in Examples 1, 8, and 9, and Comparative Example 1, shows the sphere integration results in the infrared band as follows: Figure 5 As shown, within the atmospheric window (8-13 μm), the infrared emissivity of the intermediate layer varies with the doping amount. When the mass ratio of titanium dioxide powder to boron nitride powder is 5:1, the infrared radiation of the intermediate layer is the strongest.

[0084] Test case This test case applies to Examples 1-7, and the test items include: Shape recovery rates of cyclically deformed multilayer polymer composites in Examples 1-7; Interlayer adhesion in shape-fixed regions of cyclically deformed multilayer polymer composites in Examples 1-7; The temperature rise per unit time of the enclosed region of the cyclically deformed multilayer polymer composite material of Examples 1-7 when it is moved from room temperature (23°C) to summer outdoor temperature (30-40°C). The decrease in temperature within the enclosed region of the cyclically deformed multilayer polymer composites of Examples 1-7 per unit time when placed from room temperature (23°C) into a winter outdoor temperature environment (0-10°C). Service life.

[0085] Test methods include GB / T328.1 and GB / T2790-1995.

[0086] The results are shown in Table 1.

[0087] Table 1 1 >92% 45* - 1 >300 2 >95% 95* - 1.5 >500 3 >90% 18** 1.5 - >300 4 >95% 42* 1 - >400 5 >98% 90* 1 - >600 6 >97% 92* 2 - >500 7 >98% 110* 1.2 - >500 (Among them, * GB / T328.1; ** GB / T2790-1995)

[0088] This invention essentially applies 4D printing technology (i.e., adding a time dimension by using light-responsive materials based on 3D printing technology) to manufacture deformable structures, achieving the overall structure through printing. Utilizing the reversible deformation of this structure under different environmental stimuli (light, temperature), the goal of automatically regulating and balancing the temperature inside a building is achieved.

[0089] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. The application of a cyclically deformable multilayer polymer composite material as a building envelope or building envelope surface layer, wherein the cyclically deformable multilayer polymer composite material comprises at least two thermally expandable material layers arranged sequentially from top to bottom, and the thermally expandable material layers are bonded together. The thermal expansion coefficient of the lower thermal expansion material layer is at least one order of magnitude greater than that of the upper thermal expansion material layer, thereby causing the multilayer polymer composite material to undergo cyclic deformation of curling and stretching under solar radiation conditions. Each thermal expansion material layer is independently at least one of the following: a reflective material layer, a light-shielding material layer, and a light-transmitting material layer; The reflective material layer is a blended and rolled layer of reflective powder and reflective resin, a coating made by mixing reflective powder with two-component acrylic resin and coating it onto a base resin, an aluminum foil, or a base resin layer with aluminum foil deposited on one side. The light-shielding material layer is at least one of activated carbon, carbon black, graphite, graphene, MXene, iron oxide, chromium oxide, and copper oxide, which is blended with the reflective layer resin and then rolled into an activated carbon layer, a carbon black layer, a graphite paper, a graphene paper, MXene, iron oxide layer, chromium oxide, and copper oxide layer. The light-transmitting material layer is a transparent resin layer with an indium tin oxide film deposited on one side; the transparent resin is at least one of polypropylene, low-density polyethylene, polycarbonate, polyethylene terephthalate, polymethyl methacrylate, polychlorotrifluoroethylene and transparent silicone rubber.

2. The application according to claim 1, wherein, The anisotropic thermal conductivity ratio between the tangential and normal directions of the uppermost thermal expansion material layer of the multilayer polymer composite material is (3-300):1; The overall thickness of the multilayer polymer composite material is 0.01mm-5mm; the thickness of the lower thermal expansion material layer is 10-500μm, and the thickness of the upper thermal expansion material layer is 10-100μm. The overall length of the multilayer polymer composite material is greater than or equal to 100 mm; The overall width of the multilayer polymer composite material is 10-300mm; the width ratio of the lower thermal expansion material layer to the upper thermal expansion material layer is (1-10):

1.

3. The application according to claim 1, wherein, When the width of the lower thermal expansion material layer is greater than the width of the upper thermal expansion material layer, a surface thermal expansion material layer is provided in the area where the lower thermal expansion material layer does not cover the upper thermal expansion material layer. The thermal expansion rate of the surface thermal expansion material layer is greater than that of the upper thermal expansion layer, but not less than that of the lower thermal expansion layer, so that when the multilayer polymer composite material undergoes curling deformation under solar radiation conditions, the surface thermal expansion material layer does not undergo curling deformation. The anisotropic thermal conductivity ratio of the tangential to the normal direction of the surface thermal expansion material layer is (3-300):

1.

4. The application according to claim 1, wherein, The mass ratio of reflective powder to reflective layer resin is (0.1-10):

1.

5. The application according to claim 1, wherein, The mass ratio of reflective powder to two-component acrylic resin is (0.1-10):

1.

6. The application according to claim 1, wherein, The reflective powder is at least one of alumina powder, silicon oxide powder, calcium carbonate powder, boron nitride powder, and titanium dioxide powder.

7. The application according to claim 1, wherein, The reflective layer resin and the matrix resin are each independently at least one of polystyrene, polycarbonate, acrylonitrile-styrene-butadiene copolymer, polyamide, polyolefin, polyethylene terephthalate, polyphenylene ether, polyphenylene sulfide, polymethyl methacrylate, polyoxymethylene, polysulfone, polyimide, polytetrafluoroethylene, polychlorotrifluoroethylene, polybutylene terephthalate, chlorinated polyether, styrene-butadiene rubber, nitrile rubber, silicone rubber, cis-butadiene rubber, polyisoprene, ethylene propylene rubber, and chloroprene rubber.

8. The application according to claim 7, wherein, The reflective layer resin and the matrix resin are each independently at least one of low-density polyethylene, polypropylene, a blend of low-density polyethylene and polypropylene, and high-density polyethylene.

9. The application according to claim 1, wherein, The adhesive used to bond the thermal expansion material layers is at least one of thermoplastic adhesives, thermosetting adhesives, and rubber-based adhesives; An adhesive is used to bond the layers of thermally expandable material to form an adhesive layer with a thickness of 0.01-1 mm.

10. The application according to claim 1, wherein, The lower surface of the lower thermal expansion material layer is provided with a 3D printed line array; The material of the 3D printed line array is at least one of polyolefin, polylactic acid, polyurethane, acrylonitrile styrene butadiene copolymer and polyethylene terephthalate; The 3D printing operation parameters include: printhead temperature range of 150℃-240℃, substrate temperature of 30℃-100℃, printing speed of 1mm / s-50mm / s, printing line width of 0.1mm-5mm, line thickness of 0.1mm-5mm, and line spacing of 0.2mm-10mm. The angle between the 3D printed line array and the long side of the lower thermal expansion material layer is 0° to 90°.

11. The application according to claim 10, wherein, The material of the 3D printed line array is low-density polyethylene or a blend of low-density polyethylene and polypropylene.

12. A building envelope, characterized in that, Cyclicly deformable multilayer polymer composites are arranged in an array on the building surface to form a building envelope, and the lowest thermal expansion material layer of each cyclically deformable multilayer polymer composite is fixedly connected to the building surface by at least one of the following methods: bonding, welding, bolting, and clamping. The cyclically deformable multilayer polymer composite material is the cyclically deformable multilayer polymer composite material as described in any one of claims 1-11 for use as a building envelope or building envelope surface.

13. The building envelope according to claim 12, wherein, The width of the lowest thermal expansion material layer of each cyclically deformed multilayer polymer composite material fixedly connected to the building surface is not less than 10 mm.

14. The building envelope according to claim 13, wherein, The building is a curtain wall or window glass.

15. A building envelope, characterized in that, The building envelope includes a surface layer and a base layer arranged sequentially from top to bottom; optionally, an intermediate layer is provided between the surface layer and the base layer. The surface layer is a cyclically deformable multilayer polymer composite material as described in any one of claims 1-11 as a building envelope or building envelope surface layer; the substrate layer is fixedly connected to the building surface.

16. The building envelope according to claim 15, wherein, The intermediate layer consists of multiple layers, which are arranged in an array and fixedly connected to the substrate layer, with the array spacing between each intermediate layer being no less than 10mm. The surface layer comprises multiple layers arranged in an array, and the size of each surface layer is greater than or equal to the size of the intermediate layer, such that the lowest thermal expansion material layer of each cyclically deformed multilayer polymer composite material is fixedly connected to the array gap surface of the intermediate layer or the intermediate layer by at least one of the following fixing methods: bonding, welding, bolting, and clamping.

17. The building envelope according to claim 16, wherein, The width of the array gap surface between the lowest thermal expansion material layer and the intermediate layer of each cyclically deformed multilayer polymer composite material, or the width of the intermediate layer fixed connection, shall not be less than 10 mm.

18. The building envelope according to claim 15, wherein, The intermediate layer is a cooling layer and / or a reflective layer; the cooling layer is a roller-pressed layer formed by blending radiation-cooling filler and cooling layer resin, or a blended coating of radiation-cooling filler and two-component acrylic resin; the radiation-cooling filler is obtained by mixing titanium dioxide powder with a nitrogen-containing compound, followed by ball milling, drying, sieving, and heat treatment; the cooling layer resin is at least one of polyamide, polyolefin, polyethylene terephthalate, polyphenylene ether, polyphenylene sulfide, polytetrafluoroethylene, polychlorotrifluoroethylene, chlorinated polyether, styrene-butadiene rubber, nitrile rubber, silicone rubber, cis-butadiene rubber, polyisoprene, ethylene propylene rubber, and chloroprene rubber; the reflective layer is a coating obtained by mixing reflective powder with two-component acrylic resin and coating it onto a substrate.

19. The building envelope according to claim 18, wherein, The resin of the cooling layer is polypropylene, polyethylene, or a blend of polyethylene and polypropylene.

20. The building envelope according to claim 15, wherein, The substrate layer is at least one of cement concrete, wood, brick, metal plate and polymer substrate.

21. The building envelope according to claim 18, wherein, The mass ratio of the titanium dioxide powder to the nitrogen-containing compound is (1-100):

1.

22. The building envelope according to claim 18, wherein, The nitrogen-containing compound is at least one of boron nitride, ammonium chloride, ammonium nitrate, ammonium carbonate, ammonium bicarbonate, and urea powder.

23. The building envelope according to claim 18, wherein, The ball milling time is 2-24 hours.

24. The building envelope according to claim 18, wherein, The heat treatment conditions include a nitrogen atmosphere, a heat treatment temperature of 800-1400℃, a heat treatment time of 1-10h, a heating rate of 1-10℃ / min, a cooling rate of 1-20℃ / min, and a nitrogen flow rate of 10-200mL / min.

25. The building envelope according to claim 18, wherein, The mass ratio of the radiation cooling filler to the cooling layer resin is (0.1-10):

1.

26. The building envelope according to claim 18, wherein, The mass ratio of the radiation cooling filler to the two-component acrylic resin is (0.1-10):

1.

27. The building envelope according to claim 18, wherein, In the reflective layer, the mass ratio of reflective powder to two-component acrylic resin is (0.1-10):

1.

28. The building envelope according to claim 18, wherein, In the reflective layer, the substrate is at least one of cement concrete, wood, brick and stone and metal plate.

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