Intelligent window with spectrum regulation and control and phase change energy storage functions and preparation method of intelligent window

Abstract

The invention provides an intelligent window with spectrum regulation and control and phase change energy storage functions and a preparation method of the intelligent window, and belongs to the field of door and window equipment. The intelligent window comprises a first high-light-transmittance film, temperature-sensitive gel, a second high-light-transmittance film and a phase change composite material which are sequentially stacked. According to the invention, the temperature-sensitive gel plays a role in spectrum adjustment, before and after phase change, the temperature-sensitive gel is converted from transparent to opaque, the sunlight transmittance is significantly reduced, the light transmittance is significantly reduced when the temperature rises to be close to the phase change temperature of the temperature-sensitive gel, and the entry of solar heat is reduced; the phase-change composite material can absorb heat on the surface of the window, increase thermal inertia of the window, slow down temperature rise of the surface of the window, reduce indoor thermal radiation and convection of the window, release heat at night, delay temperature drop of the window, change from opaque to transparent before and after phase change, and remarkably improve sunlight transmittance. The temperature is continuously reduced at night, high haze is presented, and the privacy protection effect is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of door and window equipment, and in particular to an intelligent window with both spectrum regulation and phase change energy storage and a preparation method thereof. Background Art

[0002] With the development of industry and the growth of population, global energy consumption continues to increase, and energy conservation and emission reduction have attracted much attention. It is expected that the energy consumption of building HVAC will continue to increase in the future. As a bridge connecting indoor and outdoor, windows are considered to be the part of the building envelope with the largest heat loss, accounting for 30% to 40% of the total energy consumption of the building. Therefore, the preparation of new smart windows is one of the effective ways to achieve building energy conservation.

[0003] Filling the inner cavity of hollow glass with phase change materials can greatly improve the indoor temperature. Windows filled with phase change materials can store some heat during the day and slowly release it in the form of latent heat at night. Compared with conventional glass windows, windows filled with phase change materials effectively alleviate the temperature fluctuations on the window surface, thereby maintaining the stability of the indoor ambient temperature. In addition, at low temperatures, phase change materials present high haze at low temperatures, which is conducive to privacy protection. However, there are also certain defects. The molten phase change material is highly transparent. In the hot summer, a large amount of solar radiation enters the room, greatly increasing the cooling load, which is not conducive to reducing building energy consumption. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide a smart window with both spectrum regulation and phase change energy storage and a preparation method thereof. The smart window of the present invention has the functions of thermal energy storage, privacy protection and spectrum regulation. By utilizing the spectrum regulation of the thermosensitive gel and the latent heat release of the phase change material, it can reduce indoor cold / heat loads and building energy consumption.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions: The present invention provides a smart window with both spectral regulation and phase change energy storage, comprising a first high-transmittance film, a temperature-sensitive gel, a second high-transmittance film and a phase-change composite material stacked in sequence, wherein the transmittances of the first high-transmittance film and the second high-transmittance film are independently 80-92%.

[0006] Preferably, the thickness of the thermosensitive gel is 1-5 mm.

[0007] Preferably, the phase transition temperature of the thermosensitive gel is 25-45°C.

[0008] Preferably, the thermosensitive polymer in the thermosensitive gel is an organic high molecular polymer with thermosensitive properties.

[0009] Preferably, the organic high molecular polymer having temperature-sensitive properties includes one or more of hydroxypropyl cellulose (HPC), poly (N-isopropylacrylamide), polyacrylamide, polyacrylic acid and polyethyleneimine.

[0010] Preferably, the thickness of the phase change composite material is 1-5 mm.

[0011] Preferably, the phase change composite material includes a phase change material and a polymer, the polymer includes one or more of styrene-ethylene-butylene-styrene block copolymer (SEBS block polymer), thermoplastic polyurethane and polymethyl methacrylate, and the phase change material includes one or more of paraffin, polyethylene glycol, eicosane, octadecane and polyol.

[0012] Preferably, the content of the phase change material in the phase change composite material is 40-70wt%.

[0013] Preferably, the phase change temperature of the phase change material is 25-38°C.

[0014] The present invention also provides a method for preparing the smart window with both spectral regulation and phase change energy storage as described in the above technical solution, comprising the following steps: The thermosensitive polymer and water are mixed and the phase transition temperature is adjusted to obtain a thermosensitive gel; Filling the thermosensitive gel into the cavity of the hollow high-transmittance film to obtain a thermochromic high-transmittance film window; The phase-change composite material is laminated to the surface of the thermochromic high-transmittance film window to obtain the smart window with both spectral regulation and phase-change energy storage.

[0015] The present invention provides a smart window with both spectral regulation and phase change energy storage, comprising a first high-transmittance film, a temperature-sensitive gel, a second high-transmittance film and a phase-change composite material stacked in sequence, wherein the transmittances of the first high-transmittance film and the second high-transmittance film are independently 80-92%.

[0016] Compared with the prior art, the present invention has the following beneficial effects: In the present invention, the thermosensitive gel plays a role in spectrum regulation. Before and after the phase change, the thermosensitive gel changes from transparent to opaque, and the sunlight transmittance decreases significantly. When the temperature rises to near the phase change temperature of the thermosensitive gel, the light transmittance decreases significantly, thereby reducing the entry of solar heat. The phase change composite material utilizes its high latent heat storage capacity to absorb heat from the window surface, increase the thermal inertia of the window, slow down the increase in the window surface temperature, and reduce the window's thermal radiation and convection to the room. At night, when the temperature drops, the phase change composite material releases heat to delay the drop in window temperature. Before and after the phase change, the phase change composite material changes from opaque to transparent, and the sunlight transmittance increases significantly. At night, the temperature continues to drop, presenting a high haze, thereby playing a role in privacy protection.

[0017] The smart window of the present invention effectively solves the defect of large temperature fluctuation of traditional high-transmittance film windows, reduces the heat radiation of windows to the room during the day in summer, and prevents overheating of the room in summer; at night, it reduces the loss of indoor heat through the windows; it presents high haze at night, and plays a good privacy protection function; it has a thermochromic function, and at high temperature, the molten phase change material presents high transmittance; the temperature-sensitive gel becomes opaque at high temperature, blocking solar radiation from entering the room and reducing the indoor cooling load.

[0018] The present invention also provides a method for preparing the smart window described in the above technical solution. The preparation process of the present invention is simple, the raw materials are easily available, and it is suitable for large-scale promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure of the smart window with both spectral regulation and phase change energy storage according to Example 1 of the present invention. DETAILED DESCRIPTION

[0020] The present invention provides a smart window with both spectral regulation and phase change energy storage, comprising a first high-transmittance film, a temperature-sensitive gel, a second high-transmittance film and a phase-change composite material stacked in sequence, wherein the transmittances of the first high-transmittance film and the second high-transmittance film are independently 80-92%.

[0021] In the present invention, unless otherwise specified, the raw materials used are all commercially available products in the art.

[0022] In the present invention, the thickness of the first high light transmittance film and the second high light transmittance film are independently preferably ≤10 mm, and specifically can be 0.05, 0.5, 1, 3, 6, 8 or 10 mm.

[0023] In the present invention, the first high light transmittance film and the second high light transmittance film are independently preferably glass, polypropylene (PP), polyethylene terephthalate (PET) or polyethylene (PE).

[0024] In the present invention, the light transmittance of the glass is preferably 90.9%.

[0025] In the present invention, the light transmittance of the PET is preferably 92%.

[0026] In the present invention, the thickness of the thermosensitive gel is preferably 1-5 mm, specifically 1, 2, 3, 4 or 5 mm; the thermosensitive gel plays a spectral regulation role. Before and after the phase change, the thermosensitive gel changes from transparent to opaque, and the sunlight transmittance decreases significantly. When the temperature rises to near the phase change temperature of the thermosensitive gel, the light transmittance decreases significantly, reducing the penetration of solar heat.

[0027] In the present invention, the phase transition temperature of the thermosensitive gel is preferably 25-45°C, specifically 25, 30, 35, 35.5, 40, 42, 43 or 45°C.

[0028] In the present invention, the thermosensitive polymer in the thermosensitive gel is preferably an organic high molecular polymer with thermosensitive properties.

[0029] In the present invention, the organic high molecular polymer with temperature-sensitive properties preferably includes one or more of hydroxypropyl cellulose, poly (N-isopropylacrylamide), polyacrylamide, polyacrylic acid and polyethyleneimine, and more preferably includes a mixture of hydroxypropyl cellulose and polyacrylic acid, and the mass ratio of hydroxypropyl cellulose to polyacrylic acid in the mixture is preferably 4:1.

[0030] In the present invention, the thickness of the phase change composite material is preferably 1-5 mm, specifically 1, 2, 3, 4 or 5 mm; the phase change composite material utilizes high latent heat storage capacity to absorb heat from the window surface, improve the thermal inertia of the window, slow down the increase in window surface temperature, and reduce the window's heat radiation to the room. At night, the temperature drops, the phase change composite material releases heat, and delays the drop in window temperature. In addition, before and after the phase change, the phase change composite material changes from opaque to transparent, and the sunlight transmittance is significantly improved. At night, the temperature is low and the fog is high, which plays a role in privacy protection.

[0031] In the present invention, the phase change composite material preferably includes a phase change material and a high molecular polymer, the high molecular polymer preferably includes one or more of styrene-ethylene-butylene-styrene block copolymer, thermoplastic polyurethane and polymethyl methacrylate, and the phase change material preferably includes one or more of paraffin, polyethylene glycol, eicosane, octadecane and polyol.

[0032] In the present invention, the polyethylene glycol is preferably polyethylene glycol-1000 (PEG1000).

[0033] In the present invention, the content of the phase change material in the phase change composite material is preferably 40-70wt%, specifically 40wt%, 45wt%, 50wt%, 55wt%, 60wt%, 65wt% or 70wt%.

[0034] In the present invention, the phase change temperature of the phase change material is preferably 25-38°C, specifically 25, 30, 35, 37 or 38°C.

[0035] The present invention also provides a method for preparing the smart window with both spectral regulation and phase change energy storage as described in the above technical solution, comprising the following steps: The thermosensitive polymer and water are mixed and the phase transition temperature is adjusted to obtain a thermosensitive gel; Filling the thermosensitive gel into the cavity of the hollow high-transmittance film to obtain a thermochromic high-transmittance film window; The phase-change composite material is laminated to the surface of the thermochromic high-transmittance film window to obtain the smart window with both spectral regulation and phase-change energy storage.

[0036] The invention mixes a thermosensitive polymer with water and adjusts the phase transition temperature to obtain a thermosensitive gel.

[0037] In the present invention, the concentration of the temperature-sensitive polymer in the system obtained after mixing is preferably 1-6 wt %, specifically 1 wt %, 2 wt %, 3 wt %, 4 wt %, 5 wt % or 6 wt %.

[0038] The present invention preferably uses dilute hydrochloric acid to adjust the pH value of the thermosensitive gel so that the phase transition temperature of the thermosensitive gel is 25-45° C. The present invention has no particular limitation on the concentration and amount of the dilute hydrochloric acid.

[0039] After obtaining the thermosensitive gel, the present invention injects the thermosensitive gel into the cavity of a hollow high-transmittance film to obtain a thermochromic high-transmittance film window.

[0040] After obtaining the thermochromic high-transmittance film window, the present invention laminates the phase-change composite material to the surface of the thermochromic high-transmittance film window to obtain the smart window with both spectral regulation and phase-change energy storage.

[0041] In the present invention, the phase change composite material is preferably prepared by a method comprising the following steps: The phase change material, high molecular polymer and solvent are sequentially mixed, dried and hot-pressed to obtain the phase change composite material.

[0042] In the present invention, the solvent is preferably a solvent that can dissolve the phase change material and the high molecular polymer. The present invention has no particular limitation on the amount of the solvent, as long as the solvent can completely dissolve the phase change material and the high molecular polymer.

[0043] In the present invention, the drying temperature is preferably 50-80° C., specifically 50, 60, 70 or 80° C., and the drying time is preferably 6-12 h, specifically 6, 8, 10 or 12 h.

[0044] In the present invention, the hot pressing temperature is preferably 150-180°C, specifically 150, 160, 170 or 180°C, the pressure is preferably 6-12MPa, specifically 6, 8, 10 or 12MPa, and the time is preferably 5-15min, specifically 5, 10 or 15min.

[0045] In the present invention, the hot pressing is preferably performed in a mold.

[0046] The present invention preferably cuts the phase change composite material into an area consistent with the high transmittance film, and then adheres it to the surface of the thermochromic high transmittance film window to obtain the smart window with both spectral regulation and phase change energy storage.

[0047] The present invention preferably heats the phase change composite material to make it transparent or adheres a transparent thermally conductive double-sided adhesive at room temperature, and then adheres it to the surface of the thermochromic high-transmittance film window.

[0048] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] In the examples and comparative examples of the present invention, hydroxypropyl cellulose (HPC, MW=100000) and polyacrylic acid (PAA, MW=3000) are from Aladdin Reagents (Shanghai) Co., Ltd., and SEBS block polymer (G1650) is from Kraton Polymers, Inc., USA.

[0050] Example 1 Figure 1 This is a schematic diagram of the structure of the smart window with both spectral regulation and phase change energy storage according to Example 1 of the present invention.

[0051] A smart window with both spectrum regulation and phase change energy storage, the preparation method of which comprises the following steps: S1: Weigh 2 g of hydroxypropyl cellulose and 0.5 g of polyacrylic acid, dissolve in 50 mL of deionized water to obtain a thermosensitive gel; S2: Do not change the pH value and maintain the original phase transition temperature; S3: pouring the thermosensitive gel into the hollow glass cavity (glass thickness 1 mm, cavity thickness 2 mm, glass transmittance is 90.9%) to obtain a thermochromic glass window; S4: Pour 12 g of eicosane and 8 g of SEBS block polymer into 40 g of toluene, stir until dissolved, and dry at 60° C. for 8 h to obtain a phase change composite material; S5: The phase change composite material of S4 was filled into a square mold with a thickness of 4 mm and hot pressed at 160 °C and a pressure of 8 MPa for 10 min; S6: Cut the phase change composite material of S5 (4mm thick) into an area consistent with the glass, heat it, and stick it on the surface of the thermochromic glass window to obtain a smart window with both spectral regulation and phase change energy storage.

[0052] In this embodiment, the phase change temperature of the thermosensitive gel is 43° C., the phase change temperature of the phase change composite material is 35.5° C., and the phase change enthalpy is 145 J / g.

[0053] The smart window with both spectral regulation and phase change energy storage achieves two phase change processes as the temperature rises, and the smart window achieves the change from opaque to transparent to opaque. The solar transmittance increases from 31% (25°C) to 66% (36°C), and then decreases to 28% (46°C); the visible light transmittance increases from 39% (25°C) to 78% (36°C), and then decreases to 36% (46°C). It can be seen that at low temperatures, it has high haze and plays a role in privacy protection. As the temperature rises, the solar transmittance increases, achieving lighting. When the temperature is too high, the solar transmittance is less than 30%, which hinders solar radiation.

[0054] Example 2 A smart window with both spectrum regulation and phase change energy storage, the preparation method of which comprises the following steps: S1: Weigh 2 g of hydroxypropyl cellulose and 0.5 g of polyacrylic acid, dissolve in 50 mL of deionized water to obtain a thermosensitive gel; S2: Do not change the pH value and maintain the original phase transition temperature; S3: pouring the thermosensitive gel into the hollow glass cavity (glass thickness 1 mm, cavity thickness 5 mm, glass transmittance is 90.9%) to obtain a thermochromic glass window; S4: Pour 12 g of octadecane and 8 g of SEBS block polymer into 40 g of toluene, stir until dissolved, and dry at 60° C. for 8 h to obtain a phase change composite material; S5: The phase change composite material of S4 was filled into a square mold with a thickness of 4 mm and hot pressed at 160 °C and a pressure of 8 MPa for 10 min; S6: Cut the phase change composite material of S5 (4mm thick) into an area consistent with the glass, heat it, and stick it on the surface of the thermochromic glass window to obtain a smart window with both spectral regulation and phase change energy storage.

[0055] In this embodiment, the phase change temperature of the thermosensitive gel is 43° C., the phase change temperature of the phase change composite material is 30° C., and the phase change enthalpy is 130 J / g.

[0056] The prepared smart window with both spectral regulation and phase change energy storage realizes two phase change processes as the temperature rises, and the smart window realizes the change from opaque to transparent to opaque. Compared with Example 1, the intermediate transparent temperature range is larger, and the spectrum regulation ability of the thermosensitive gel is stronger. The sunlight transmittance of the smart window with both spectral regulation and phase change energy storage in this embodiment increases from 30% (25°C) to 63% (32°C), and then decreases to 15% (45°C); the visible light transmittance increases from 40% (25°C) to 78% (32°C), and then decreases to 20% (45°C).

[0057] Example 3 A smart window with both spectrum regulation and phase change energy storage, the preparation method of which comprises the following steps: S1: Weigh 2 g of hydroxypropyl cellulose and 0.5 g of polyacrylic acid, dissolve in 50 mL of deionized water to obtain a thermosensitive gel; S2: Use dilute hydrochloric acid to adjust the pH value of the product of S1 to 3 to change the phase transition temperature of the thermosensitive gel; S3: pouring the thermosensitive gel into the hollow glass cavity (glass thickness 1 mm, cavity thickness 2 mm, glass transmittance is 90.9%) to obtain a thermochromic glass window; S4: Pour 12 g of polyethylene glycol-1000 and 8 g of thermoplastic polyurethane into 50 g of chloroform, stir until dissolved, and dry at 60° C. for 8 h to obtain a phase change composite material; S5: The phase change composite material of S4 was filled into a square mold with a thickness of 4 mm and hot pressed at 160 °C and a pressure of 8 MPa for 10 min; S6: Cut the phase change composite material of S5 (4 mm thick) into an area consistent with the glass, heat it, and stick it on the surface of the thermochromic glass window to obtain a smart window with both spectral regulation and phase change energy storage.

[0058] In this embodiment, the phase change temperature of the thermosensitive gel is 32° C., the phase change temperature of the phase change composite material is 37° C., and the phase change enthalpy value is 98 J / g.

[0059] The obtained smart window with both spectrum regulation and phase change energy storage has a visible light transmittance of 40% (25°C) to 18% (34°C) and then to 36% (39°C) as the temperature rises, always maintaining a high haze state, opaque, suitable for skylights, and anti-dizziness. The sunlight transmittance increases from 30% (25°C) to 14% (34°C) and then to 31% (39°C), ensuring low solar radiation transmission.

[0060] Example 4 A smart window with both spectrum regulation and phase change energy storage, the preparation method of which comprises the following steps: S1: Weigh 7.91 g of N-isopropylacrylamine and 215.6 mg of N,N'-methylenebisacrylamide and dissolve them in 100 mL of 70°C deionized water, stir thoroughly for 0.5 h to obtain a uniform transparent aqueous solution; S2: Take 5 mL of the aqueous solution prepared in S1, add 80 μL of tetramethylethylenediamine and 60 μL of ammonium persulfate solution (5 mg / mL) in sequence, and ultrasonically vibrate for 5 seconds to obtain a thermosensitive gel poly (N-isopropylacrylamide); S3: pouring the thermosensitive gel into the hollow glass cavity (glass thickness 1 mm, cavity thickness 2 mm, glass transmittance is 90.9%) to obtain a thermochromic glass window; S4: Pour 12 g of polyethylene glycol-1000 and 8 g of thermoplastic polyurethane into 50 g of chloroform, stir until dissolved, and dry at 60° C. for 8 h to obtain a phase change composite material; S5: The phase change composite material of S4 was filled into a square mold with a thickness of 4 mm and hot pressed at 160 °C and a pressure of 8 MPa for 10 min; S6: Cut the phase change composite material of S5 (4 mm thick) into an area consistent with the glass, heat it, and stick it on the surface of the thermochromic glass window to obtain a smart window with both spectral regulation and phase change energy storage.

[0061] In this embodiment, the phase change temperature of the thermosensitive gel is 32° C., the phase change temperature of the phase change composite material is 37° C., and the phase change enthalpy value is 98 J / g.

[0062] The smart window with both spectrum regulation and phase change energy storage has a visible light transmittance of 40% (25°C) to 14% (35°C) and then to 26% (39°C) as the temperature rises. The solar light transmittance increases from 31% (25°C) to 11% (34°C) and then to 18% (39°C).

[0063] Example 5 A smart window with both spectrum regulation and phase change energy storage, the preparation method of which comprises the following steps: S1: Weigh 2 g of hydroxypropyl cellulose and 0.5 g of polyacrylic acid, dissolve in 50 mL of deionized water to obtain a thermosensitive gel; S2: Do not change the pH value and maintain the original phase transition temperature; S3: pouring the thermosensitive gel into a hollow polyethylene terephthalate (PET) cavity (PET thickness is 0.05 mm, cavity thickness is 2 mm, and PET transmittance is 92%) to obtain a thermochromic glass window; S4: Pour 12 g of octadecane and 8 g of SEBS block polymer into 40 g of toluene, stir until dissolved, and dry at 60° C. for 8 h to obtain a phase change composite material; S5: The phase change composite material of S4 was filled into a square mold with a thickness of 4 mm and hot pressed at 160 °C and a pressure of 8 MPa for 10 min; S6: Cut the phase change composite material of S5 (4mm thick) into an area consistent with the glass, heat it, and stick it on the surface of the thermochromic glass window to obtain a smart window with both spectral regulation and phase change energy storage.

[0064] In this embodiment, the phase change temperature of the thermosensitive gel is 43° C., the phase change temperature of the phase change composite material is 30° C., and the phase change enthalpy is 130 J / g.

[0065] The smart window with both spectral regulation and phase change energy storage achieves two phase change processes as the temperature rises, and the smart window achieves the change from opaque to transparent to opaque. The solar transmittance increases from 32.2% (25°C) to 67.4% (36°C), and then decreases to 29.3% (46°C); the visible light transmittance increases from 39.6% (25°C) to 79.3% (36°C), and then decreases to 36.9% (46°C). It can be seen that at low temperatures, it has high haze and plays a role in privacy protection. When the temperature rises, the solar transmittance increases to achieve lighting. When the temperature is too high, the solar transmittance is less than 30%, which hinders solar radiation.

[0066] Comparative Example 1 S1: Weigh 2 g of hydroxypropyl cellulose and 0.5 g of polyacrylic acid, dissolve in 50 mL of deionized water to obtain a thermosensitive gel; S2: Do not change the pH value and maintain the original phase transition temperature; S3: Pour the thermosensitive gel into the hollow glass cavity (glass thickness 1 mm, cavity thickness 2 mm, glass transmittance is 90.9%) to obtain a thermochromic glass window.

[0067] In this comparative example, the phase transition temperature of the thermosensitive gel is 43°C, and before and after the phase transition, the thermosensitive gel changes from transparent to opaque. The solar transmittance increases from 78% (25°C) to 33.5% (50°C), and the visible light transmittance increases from 90% (25°C) to 40.4% (50°C).

[0068] Comparative Example 2 S1: Weigh 2 g of hydroxypropyl cellulose and 0.5 g of polyacrylic acid, dissolve in 50 mL of deionized water to obtain a thermosensitive gel; S2: Do not change the pH value and maintain the original phase transition temperature; S3: Pour the thermosensitive gel into the hollow glass cavity (glass thickness 1 mm, cavity thickness 5 mm, glass transmittance is 90.9%) to obtain a thermochromic glass window.

[0069] In this comparative example, the phase transition temperature of the thermosensitive gel is 43°C, and before and after the phase transition, the thermosensitive gel changes from transparent to opaque. The solar transmittance increases from 73.9% (25°C) to 17.6% (50°C), and the visible light transmittance increases from 89.2% (25°C) to 23.3% (50°C).

[0070] Comparative Example 3 S1: Pour 12 g of eicosane and 8 g of SEBS block polymer into 40 g of toluene, stir until dissolved, and dry at 60° C. for 8 h to obtain a phase change composite material; S2: The phase change composite material of S1 was filled into a square mold with a thickness of 4 mm, and hot-pressed at 160° C. and a pressure of 8 MPa for 10 min to obtain a phase change composite material.

[0071] The phase change temperature of the phase change composite material is 35.5℃, and the phase change enthalpy is 145J / g. Before and after the phase change, the phase change composite material changes from opaque to transparent. The sunlight transmittance is adjusted from 39% (25℃) to 84.1% (50℃), and the visible light transmittance increases from 43.8% (25℃) to 89.4% (50℃). At 25℃, the haze reaches 92%.

[0072] In summary: 1) The smart window of the present invention effectively solves the defect of large temperature fluctuation of traditional high-transmittance film windows, reduces the heat radiation from windows to the room during the day in summer, prevents indoor overheating in summer; and reduces the loss of indoor heat through windows at night.

[0073] 2) The smart window of the present invention presents high fog at night, which plays a good role in privacy protection.

[0074] 3) The smart window of the present invention is endowed with a thermochromic function. At high temperatures, the molten phase change material exhibits high transmittance; the thermosensitive gel becomes opaque at high temperatures, thereby blocking solar radiation from entering the room and reducing the indoor cooling load.

[0075] 4) The preparation process of the smart window of the present invention is simple, the raw materials are easily available, and it is suitable for large-scale promotion and application.

[0076] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A smart window with both spectrum regulation and phase change energy storage, characterized in that: The invention comprises a first high light transmittance film, a thermosensitive gel, a second high light transmittance film and a phase change composite material which are stacked in sequence, wherein the transmittances of the first high light transmittance film and the second high light transmittance film are independently 80-92%.

2. The smart window according to claim 1, characterized in that: The thickness of the thermosensitive gel is 1-5 mm.

3. The smart window according to claim 1, characterized in that: The phase transition temperature of the thermosensitive gel is 25-45°C.

4. The smart window according to claim 1 or 3, characterized in that: The thermosensitive polymer in the thermosensitive gel is an organic high molecular polymer with thermosensitive properties.

5. The smart window according to claim 4, characterized in that: The organic high molecular polymer with temperature-sensitive properties includes one or more of hydroxypropyl cellulose, poly-N-isopropylacrylamide, polyacrylamide, polyacrylic acid and polyethyleneimine.

6. The smart window according to claim 1, characterized in that: The thickness of the phase change composite material is 1-5 mm.

7. The smart window according to claim 1 or 6, characterized in that: The phase change composite material includes a phase change material and a high molecular polymer, wherein the high molecular polymer includes one or more of styrene-ethylene-butylene-styrene block copolymer, thermoplastic polyurethane and polymethyl methacrylate, and the phase change material includes one or more of paraffin, polyethylene glycol, eicosane, octadecane and polyol.

8. The smart window according to claim 7, characterized in that: The content of the phase change material in the phase change composite material is 40-70wt%.

9. The smart window according to claim 7, characterized in that: The phase change temperature of the phase change material is 25-38°C.

10. The method for preparing the smart window with both spectrum regulation and phase change energy storage according to any one of claims 1 to 9, characterized in that: The following steps are involved: The thermosensitive polymer and water are mixed and the phase transition temperature is adjusted to obtain a thermosensitive gel; Filling the thermosensitive gel into the cavity of the hollow high-transmittance film to obtain a thermochromic high-transmittance film window; The phase-change composite material is laminated to the surface of the thermochromic high-transmittance film window to obtain the smart window with both spectral regulation and phase-change energy storage.

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