Gadolinium, lanthanum, tin, barium and rare earth co-doped nanometer heat insulation material, preparation method and application thereof in glass curtain wall

Abstract

The invention provides a gadolinium-lanthanum-tin-barium-rare earth co-doped nano thermal insulation material, a preparation method and application of the gadolinium-lanthanum-tin-barium-rare earth co-doped nano thermal insulation material in a glass curtain wall, and the gadolinium-lanthanum-tin-barium-rare earth co-doped nano thermal insulation material is prepared from the following components in parts by weight: a barium source, a tin source, a lanthanum source, a gadolinium source, weak acid, an oxidizing agent, a hydrolysis inhibitor and a precipitating agent. The nano thermal insulation material disclosed by the invention avoids the influence of light pollution hazard on the environment and human beings, and meanwhile, the absorption effect is remarkably enhanced by utilizing the specific LSPR effect of the rare earth nano material. Therefore, compared with single doping, co-doping can enable lanthanum and gadolinium to be complementary, and controllable absorption of a full infrared band is realized by adjusting different proportions of lanthanum and gadolinium.

Description

Technical Field

[0001] The invention belongs to the technical field of building exterior wall decoration materials, and in particular relates to a gadolinium, lanthanum, tin, barium and rare earth co-doped nano thermal insulation material and a preparation method thereof, and application thereof in glass curtain walls. Background Art

[0002] Glass curtain wall refers to the building's external protective structure or decorative structure that has a certain displacement capacity relative to the main structure and does not share the effects on the main structure. The wall has two types of single-layer and double-layer glass. However, the double-layer glass layer must reach at least a certain depth to achieve natural ventilation between the outer glass layer and the double-layer insulating glass layer. This will reduce the usable area within the building area. The outer glass surface also needs to be coated with an anti-sun protection coating to reduce the heat load to an acceptable level. But at the same time, this coating will reduce the entry of natural light, thereby increasing the cost of artificial lighting. In addition, the single-layer facade structure has poor sound insulation, which also affects the comfort of the office environment. Therefore, the invention of a highly efficient ultraviolet and infrared blocking glass coating material that does not affect light transmission and air permeability has become a focus issue.

[0003] Existing nano thermal insulation materials are usually nanoporous materials, aerogels, carbon black, alumina nanotubes, etc. Studies have shown that its working principle is to use low thermal conductivity materials and pore structures to reduce the efficiency of three main heat transfers, heat conduction, heat radiation and heat convection, so as to achieve the purpose of slowing down heat transfer. However, most of these materials are reflective materials, which will cause harm to the environment. Therefore, researchers have begun to work on the development of new absorption materials.

[0004] In the past few decades, a major challenge in the field of oxide electronics has been to find materials with high room temperature carrier mobility. In 2017, researchers have proposed lanthanum-doped barium stannate to provide materials with higher carrier mobility. Barium stannate has a typical cubic perovskite structure and is a wide bandgap semiconductor with high electron mobility, high conductivity, good gas sensitivity and photoelectric properties. As a dielectric material, it has been used in thermally stable capacitors, high electrolyte ceramics, and later as a semiconductor humidity and gas sensing material. In recent years, as the research on perovskite solar cells has become popular, barium stannate has begun to be used as an electron transport layer material for in-depth research due to its excellent photoelectric properties, high electron mobility, no need for phase change and low photocatalytic activity. Nanopowder materials have the characteristics of small size effect, surface and interface effect and quantum size effect. They have excellent properties in adsorption and catalysis that are unmatched by conventional-sized materials. Therefore, compared with conventional-sized barium stannate, nanoscale barium stannate obviously has a broader application prospect.

[0005] It has been reported that the electron mobility of barium stannate single crystals and their epitaxial films doped with rare earth element lanthanum is as high as 320 cm 2 V -1 S -1 and 70cm 2 V -1 S -1 However, compared to LaSnBa, Gd has similar orbitals, but with a larger radius and a higher degree of lattice distortion.

[0006] Therefore, rare earth lanthanum and gadolinium co-doped barium stannate can be used to make the material have better thermoelectric properties and thermal radiation properties, and transparent nano-scale rare earth lanthanum and gadolinium co-doped barium stannate can enable the material to produce efficient infrared absorption performance in the 800-2500nm band without affecting the visible light transmittance of the glass. Coating it on the glass curtain wall can effectively block the energy radiation of the infrared light source. Summary of the invention

[0007] In view of this, the present invention aims to overcome the defects in the prior art and proposes a gadolinium lanthanum tin barium rare earth co-doped nano thermal insulation material and a preparation method and its application in the direction of glass curtain walls.

[0008] To achieve the above object, the technical solution of the present invention is achieved as follows: In the first aspect, the present invention provides a gadolinium, lanthanum, tin, barium and rare earth co-doped nano thermal insulation material, which comprises the following components in parts by weight: 12-18 parts of barium source; Tin source 25-28 parts; 0.5-3 parts of lanthanum source; Gadolinium source 0.5-4 parts; Weak acid 5-8 parts; 15-20 parts of oxidant; 5-10 parts of hydrolysis inhibitor; 20-30 parts of precipitant.

[0009] In some embodiments of the present invention, the barium source is selected from one or more of barium chloride dihydrate, barium nitrate, barium sulfate, and barium carbonate.

[0010] In some embodiments of the present invention, the tin source is selected from one or more of tin tetrachloride pentahydrate, stannous sulfide, tin sulfate, and dimethyltin dichloride.

[0011] In some embodiments of the present invention, the lanthanum source is selected from one or more of lanthanum chloride, lanthanum oxide, lanthanum sulfide, and lanthanum bromide.

[0012] In some embodiments of the present invention, the gadolinium source is selected from one or more of gadolinium chloride, gadolinium oxide, gadolinium sulfide, and gadolinium bromide.

[0013] In some embodiments of the present invention, the weak acid is selected from one or more of citric acid, malic acid, tartaric acid, and ascorbic acid.

[0014] In some embodiments of the present invention, the oxidant is selected from one or more of hydrogen peroxide, sodium peroxide, potassium peroxide, and calcium peroxide.

[0015] In some embodiments of the present invention, the hydrolysis inhibitor is selected from one or more of hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid.

[0016] In some embodiments of the present invention, the precipitant is selected from one or more of ammonia water, sodium hydroxide, ammonium sulfate, and ammonium chloride.

[0017] Second, the present invention also provides a method for preparing the above-mentioned gadolinium-lanthanum-tin-barium rare earth co-doped nano thermal insulation material, which includes the following steps: S1: Dissolve the barium source, tin source, lanthanum source, gadolinium source, and weak acid in the oxidant solution, and add a hydrolysis inhibitor to obtain a mixed solution; S2: React the precipitant in the mixed solution at a water bath temperature of 50-60 °C to obtain a suspension; S3: Filter the suspension by suction, wash it with water, rinse it, and dry it to obtain a solid precursor; S4: Put the solid precursor into a muffle furnace and anneal it at 200-300 °C for 1.5-2 hours. After cooling to room temperature, put it into the muffle furnace again and calcine it at 800-900 °C for 2-3 hours to obtain the gadolinium-lanthanum-tin-barium rare earth co-doped nano powder; S5: Mix the gadolinium-lanthanum-tin-barium rare earth co-doped nano powder, solvent, and dispersant, and then perform sanding to obtain the gadolinium-lanthanum-tin-barium rare earth co-doped nano thermal insulation material.

[0018] Third, the present invention also provides the application of the above-mentioned gadolinium-lanthanum-tin-barium rare earth co-doped nano thermal insulation material in the preparation of glass curtain walls.

[0019] In some embodiments of the present invention, the glass curtain wall includes a glass panel and an intermediate layer, a nano thermal insulation coating, and a protective layer sequentially coated on the outer surface of the glass panel.

[0020] In some embodiments of the present invention, the thickness of the nano thermal insulation coating is 0.2-50 nm.

[0021] Compared with the prior art, the present invention has the following advantages: (1) Compared with the single doped lanthanum, tin and barium, the newly added rare earth element gadolinium in the nano thermal insulation material of the present invention has a similar orbit, a larger radius and a higher degree of lattice distortion. Therefore, compared with single doping, co-doping will introduce more electron holes, thereby improving the absorption performance. Experiments show that lanthanum doping has good barrier performance in the far-infrared band and has certain defects in the near-infrared band, while gadolinium doping just makes up for the absorption defects in the near-infrared band. Therefore, the absorption band in the infrared region can be controlled by changing the doping amount in different proportions.

[0022] (2) The sintering temperature and calcination time in the present invention are significantly lower than those in the traditional preparation method, thus reducing energy consumption. The traditional method for preparing lanthanum tin barium generally requires extremely high sintering temperature and a relatively long calcination time (sintering temperature exceeds 1200°C and calcination time exceeds 24h). This preparation method consumes relatively large amounts of energy and results in a high preparation cost.

[0023] (3) The present invention grinds the co-doped powder of gadolinium, lanthanum, tin and barium into nanomaterials and uses them in the field of thermal insulation for the first time. Since the nanomaterials in the present invention have a unique LSPR effect, the nanomaterials will be transparent in a solution of a certain particle size and have excellent absorption properties. The significant advantage of color allows the material of the present invention to be directly coated on glass to achieve a thermal insulation effect. At the same time, the market requires that the color of glass is mostly blue or green, and the material of the present invention meets this requirement. The good absorption characteristics are reflected in the strong barrier performance in the entire infrared band.

[0024] (4) Compared with reflective materials, the present invention first avoids the impact of light pollution on the environment and humans. At the same time, the nano thermal insulation material of the present invention utilizes the LSPR effect unique to rare earth nanomaterials to achieve a significant enhancement in absorption effect. Lanthanum doping shows good absorption performance mainly in the far infrared, while gadolinium doping has good absorption characteristics in the near infrared band. It can be seen that single doping cannot achieve good absorption in the full infrared band. Therefore, compared with single doping, co-doping can make the two complement each other, and by adjusting the different ratios of lanthanum and gadolinium, controllable absorption in the full infrared band can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The following are powder photos of the solid precursor, the solid precursor after annealing, and the solid precursor after high-temperature calcination; Figure 2 is the XRD diffraction pattern of the gadolinium, lanthanum, tin, barium and rare earth co-doped powder prepared in Example 1; Figure 3 It is a transmittance curve diagram of Example 2 and Comparative Examples 1 to Comparative Examples 5; Figure 4This is a structural diagram of a glass curtain wall. In the figure: 1 is a glass panel, 2 is an intermediate layer, 3 is a nano heat insulation coating, and 4 is a protective layer. Specific Embodiments

[0026] The embodiments of the present invention will be described in detail below. The following described embodiments are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0027] In this article, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs.

[0028] In this article, when a value is described as a range, it should be understood that such disclosure includes the disclosure of all possible sub-ranges within that range, as well as specific numerical values falling within that range, regardless of whether specific numerical values or specific sub-ranges are explicitly indicated.

[0029] In this article, when referring to "multiple", etc., unless otherwise specified, it means greater than 2 or equal to 2 in quantity. For example, "one or more" means one or greater than or equal to two.

[0030] In this article, when referring to "preferred", "more preferred", it is only for describing embodiments or examples with better effects. It should be understood that it does not constitute a limitation to the protection scope of the present invention.

[0031] In this article, when referring to "further", etc., it is used for descriptive purposes and indicates differences in content, but should not be construed as a limitation to the protection scope of the present invention.

[0032] In this article, the term "and / or" is a description of the associated relationship of an object, indicating that there can be three relationships. For example, A and / or B means: A or B, or the three relationships of A and B.

[0033] In this article, the term "about" means + / - 10% of the specified value, preferably + / - 5%, more preferably + / - 1%.

[0034] In this article, the terms "comprising", "including", "having", "containing", etc. are all open-ended terms, that is, they are meant to include but not be limited to.

[0035] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of the present invention.

[0036] The present invention will be described in detail below in conjunction with embodiments.

[0037] Embodiment 1

[0038] Preparation method of gadolinium, lanthanum, tin, barium rare earth co-doped nano thermal insulation material, comprising the following steps: 1) Dissolve barium chloride dihydrate (390 g), tin tetrachloride pentahydrate (702 g), lanthanum chloride (24.5 g), gadolinium chloride (79.1 g) in 30% H2O2 (300 mL) solution in the presence of citric acid (192 g), and make the solution clear and transparent by adding hydrochloric acid (200 mL). At this time, the pH value is about 0.2.

[0039] 2) Then place the round-bottom flask containing the solution in a preheated water bath at 60 °C and let it stand for 15 minutes to reach the set temperature.

[0040] 3) Subsequently, quickly add 25% ammonia water (700 mL) under strong stirring. Immediately, white precipitates appear. At this time, the pH value of the suspension is about 9.

[0041] 4) After reacting for one hour, filter the suspension by suction, wash it with water for several times until the pH = 7, and rinse it once with ethanol to obtain a solid precursor. Put it in a drying oven to dry completely, then put it in a muffle furnace and anneal it at 200 °C for 2 hours. After cooling to room temperature, put it in the muffle furnace again and calcine it at 850 °C for 2 hours to obtain gadolinium, lanthanum, tin, barium rare earth co-doped nano powder.

[0042] 5) Configure the powder (50 g), PMA solvent (453 mL) and dispersant (15 g) in proportion and then perform sand grinding until the particle size is less than 90 nm to obtain gadolinium, lanthanum, tin, barium rare earth co-doped nano thermal insulation material.

[0043] Example 2

[0044] Preparation method of gadolinium, lanthanum, tin, barium rare earth co-doped nano thermal insulation material, comprising the following steps: 1) Dissolve barium chloride dihydrate (390 g), tin tetrachloride pentahydrate (702 g), lanthanum chloride (49.1 g), gadolinium chloride (52.7 g) in 30% H2O2 (300 mL) solution in the presence of citric acid (192 g), and make the solution clear and transparent by adding hydrochloric acid (200 mL). At this time, the pH value is about 0.2.

[0045] 2) Then place the round-bottom flask containing the solution in a preheated water bath at 60 °C and let it stand for 15 minutes to reach the set temperature.

[0046] 3) Subsequently, quickly add 25% ammonia water (700 mL) under strong stirring. Immediately, white precipitates appear. At this time, the pH value of the suspension is about 9.

[0047] 4) After reacting for one hour, the suspension was filtered by suction, washed with water multiple times until the pH reached 7, and rinsed once with ethanol to obtain a solid precursor. After being completely dried in a drying oven, it was annealed in a muffle furnace at 200 °C for 2 hours. After cooling to room temperature, it was calcined in the muffle furnace at 850 °C for 2 hours to obtain gadolinium, lanthanum, tin, and barium rare earth co-doped nano-powders.

[0048] 5) The powder (50 g), PMA solvent (453 mL), and dispersant (15 g) were configured in proportion and then milled until the particle size was less than 90 nm to obtain gadolinium, lanthanum, tin, and barium rare earth co-doped nano-thermal insulation materials.

[0049] Example 3

[0050] A preparation method of gadolinium, lanthanum, tin, and barium rare earth co-doped nano-thermal insulation materials includes the following steps: 1) Barium chloride dihydrate (390 g), tin tetrachloride pentahydrate (702 g), lanthanum chloride (73.6 g), gadolinium chloride (26.4 g) were dissolved in a 30% H2O2 (300 mL) solution in the presence of citric acid (192 g), and the solution was made clear and transparent by adding hydrochloric acid (200 mL). At this time, the pH value was about 0.2.

[0051] 2) Then, the round-bottom flask containing the solution was placed in a preheated water bath at 60 °C and left for 15 minutes to reach the set temperature.

[0052] 3) Subsequently, 25% ammonia water (700 mL) was quickly added under strong stirring, and white precipitates immediately appeared. At this time, the pH value of the suspension was about 9.

[0053] 4) After reacting for one hour, the suspension was filtered by suction, washed with water multiple times until the pH reached 7, and rinsed once with ethanol to obtain a solid precursor. After being completely dried in a drying oven, it was annealed in a muffle furnace at 200 °C for 2 hours. After cooling to room temperature, it was calcined in the muffle furnace at 850 °C for 2 hours to obtain gadolinium, lanthanum, tin, and barium rare earth co-doped nano-powders. 5) The powder (50 g), PMA solvent (453 mL), and dispersant (15 g) were configured in proportion and then milled until the particle size was less than 90 nm to obtain gadolinium, lanthanum, tin, and barium rare earth co-doped nano-thermal insulation materials.

[0054] Example 4

[0055] A preparation method of gadolinium, lanthanum, tin, and barium rare earth co-doped nano-thermal insulation materials includes the following steps: 1) Dissolve barium chloride dihydrate (120 g), tin tetrachloride pentahydrate (250 g), lanthanum chloride (5 g), gadolinium chloride (5 g) in 30% H2O2 (500 mL) solution in the presence of citric acid (50 g), and make the solution clear and transparent by adding hydrochloric acid (50 mL). At this time, the pH value is about 0.2.

[0056] 2) Then place the round-bottom flask containing the solution in a preheated water bath at 60 °C and let it stand for 15 minutes to reach the set temperature.

[0057] 3) Subsequently, quickly add 25% ammonia water (800 mL) under strong stirring. White precipitates immediately appear, and at this time, the pH value of the suspension is about 9.

[0058] 4) After reacting for one hour, filter the suspension by suction, wash it with water several times until pH = 7, and rinse it once with ethanol to obtain a solid precursor. After drying it completely in an oven, anneal it in a muffle furnace at 200 °C for 2 hours. After cooling to room temperature, calcine it in the muffle furnace at 850 °C for 2 hours to obtain gadolinium, lanthanum, tin, and barium rare-earth co-doped nano-powders.

[0059] 5) After configuring the powder (50 g), PMA solvent (453 mL), and dispersant (15 g) in proportion, carry out sand grinding until the particle size is less than 90 nm to obtain gadolinium, lanthanum, tin, and barium rare-earth co-doped nano-thermal insulation materials.

[0060] Example 5

[0061] A preparation method of gadolinium, lanthanum, tin, and barium rare-earth co-doped nano-thermal insulation materials, comprising the following steps: 1) Dissolve barium chloride dihydrate (180 g), tin tetrachloride pentahydrate (280 g), lanthanum chloride (30 g), gadolinium chloride (40 g) in 30% H2O2 (667 mL) solution in the presence of citric acid (80 g), and make the solution clear and transparent by adding hydrochloric acid (100 mL). At this time, the pH value is about 0.2.

[0062] 2) Then place the round-bottom flask containing the solution in a preheated water bath at 60 °C and let it stand for 15 minutes to reach the set temperature.

[0063] 3) Subsequently, quickly add 25% ammonia water (1200 mL) under strong stirring. White precipitates immediately appear, and at this time, the pH value of the suspension is about 9.

[0064] 4) After reacting for one hour, the suspension was filtered by suction, washed with water multiple times until the pH reached 7, and rinsed once with ethanol to obtain a solid precursor. After drying completely in a drying oven, it was annealed in a muffle furnace at 200 °C for 2 hours. After cooling to room temperature, it was calcined in the muffle furnace at 850 °C for 2 hours to obtain gadolinium, lanthanum, tin, and barium rare earth co-doped nano-powders. 5) The powder (50 g), PMA solvent (453 mL), and dispersant (15 g) were configured according to the ratio and then milled until the particle size was less than 90 nm to obtain gadolinium, lanthanum, tin, and barium rare earth co-doped nano-thermal insulation materials.

[0065] Comparative Example 1 A preparation method of lanthanum, tin, and barium rare earth single-doped nano-thermal insulation materials includes the following steps: 1) Barium chloride dihydrate (390 g), tin tetrachloride pentahydrate (702 g), lanthanum chloride (49.1 g) were dissolved in a 30% H2O2 (300 mL) solution in the presence of citric acid (192 g), and the solution was made clear and transparent by adding hydrochloric acid (200 mL). At this time, the pH value was about 0.2.

[0066] 2) Then the round-bottom flask containing the solution was placed in a preheated water bath at 60 °C and left for 15 minutes to reach the set temperature.

[0067] 3) Subsequently, 25% ammonia water (700 mL) was quickly added under strong stirring, and white precipitates immediately appeared. At this time, the pH value of the suspension was about 9.

[0068] 4) After reacting for one hour, the suspension was filtered by suction, washed with water multiple times until the pH reached 7, and rinsed once with ethanol to obtain a solid precursor. After drying completely in a drying oven, it was annealed in a muffle furnace at 200 °C for 2 hours. After cooling to room temperature, it was calcined in the muffle furnace at 850 °C for 2 hours to obtain lanthanum, tin, and barium rare earth single-doped nano-powders.

[0069] 5) The powder (50 g), PMA solvent (453 mL), and dispersant (15 g) were configured according to the ratio and then milled until the particle size was less than 90 nm to obtain lanthanum, tin, and barium rare earth single-doped nano-thermal insulation materials.

[0070] Comparative Example 2 A preparation method of gadolinium, tin, and barium rare earth single-doped nano-thermal insulation materials includes the following steps: 1) Barium chloride dihydrate (390 g), tin tetrachloride pentahydrate (702 g), gadolinium chloride (52.7 g) were dissolved in a 30% H2O2 (300 mL) solution in the presence of citric acid (192 g), and the solution was made clear and transparent by adding hydrochloric acid (200 mL). At this time, the pH value was about 0.2.

[0071] 2) Then place the round-bottom flask containing the solution in a preheated water bath at 60 °C and let it stand for 15 minutes to reach the set temperature.

[0072] 3) Subsequently, quickly add 25% ammonia water (700 mL) under strong stirring. White precipitates immediately appear, and the pH value of the suspension is approximately 9 at this time.

[0073] 4) After reacting for one hour, filter the suspension by suction, wash it with water multiple times until pH = 7, and rinse it once with ethanol to obtain a solid precursor. After drying it completely in an oven, place it in a muffle furnace and anneal it at 200 °C for 2 hours. After cooling to room temperature, place it in the muffle furnace again and calcine it at 850 °C for 2 hours to obtain the gadolinium-tin-barium rare earth single-doped nano powder.

[0074] 5) Configure the powder (50 g), PMA solvent (453 mL), and dispersant (15 g) in proportion and then perform sand grinding until the particle size is less than 90 nm to obtain the gadolinium-tin-barium rare earth single-doped nano thermal insulation material.

[0075] Comparative Example 3 Preparation method of gadolinium, lanthanum, tin, barium rare earth co-doped nano thermal insulation material, including the following steps: 1) Dissolve barium chloride dihydrate (390 g), tin tetrachloride pentahydrate (702 g), lanthanum chloride (100 g), gadolinium chloride (52.7 g) in a 30% H2O2 (300 mL) solution in the presence of citric acid (192 g), and make the solution clear and transparent by adding hydrochloric acid (200 mL). The pH value is approximately 0.2 at this time.

[0076] 2) Then place the round-bottom flask containing the solution in a preheated water bath at 60 °C and let it stand for 15 minutes to reach the set temperature.

[0077] 3) Subsequently, quickly add 25% ammonia water (700 mL) under strong stirring. White precipitates immediately appear, and the pH value of the suspension is approximately 9 at this time.

[0078] 4) After reacting for one hour, filter the suspension by suction, wash it with water multiple times until pH = 7, and rinse it once with ethanol to obtain a solid precursor. After drying it completely in an oven, place it in a muffle furnace and anneal it at 200 °C for 2 hours. After cooling to room temperature, place it in the muffle furnace again and calcine it at 850 °C for 2 hours to obtain the gadolinium, lanthanum, tin, barium rare earth co-doped nano powder.

[0079] 5) Configure the powder (50 g), PMA solvent (453 mL), and dispersant (15 g) in proportion and then perform sand grinding until the particle size is less than 90 nm to obtain the gadolinium, lanthanum, tin, barium rare earth co-doped nano thermal insulation material.

[0080] Comparative Example 4 Preparation method of gadolinium, lanthanum, tin, barium rare earth co-doped nano thermal insulation material, comprising the following steps: 1) Dissolve barium chloride dihydrate (390 g), tin tetrachloride pentahydrate (702 g), lanthanum chloride (49.1 g), gadolinium chloride (100 g) in 30% H2O2 (300 mL) solution in the presence of citric acid (192 g), and make the solution clear and transparent by adding hydrochloric acid (200 mL). At this time, the pH value is about 0.2.

[0081] 2) Then place the round-bottom flask containing the solution in a preheated water bath at 60 °C and let it stand for 15 minutes to reach the set temperature.

[0082] 3) Subsequently, quickly add 25% ammonia water (700 mL) under strong stirring. White precipitates immediately appear, and at this time, the pH value of the suspension is about 9.

[0083] 4) After reacting for one hour, filter the suspension by suction, wash it with water several times until pH = 7, and rinse it once with ethanol to obtain a solid precursor. After drying it completely in a drying oven, anneal it in a muffle furnace at 200 °C for 2 hours. After cooling to room temperature, calcine it in the muffle furnace at 850 °C for 2 hours to obtain gadolinium, lanthanum, tin, barium rare earth co-doped nano powder.

[0084] 5) Configure the powder (50 g), PMA solvent (453 mL) and dispersant (15 g) in proportion and then carry out sand grinding until the particle size is less than 90 nm to obtain gadolinium, lanthanum, tin, barium rare earth co-doped nano thermal insulation material.

[0085] Comparative Example 5 Preparation method of gadolinium, lanthanum, tin, barium rare earth co-doped non-nano material, comprising the following steps: 1) Dissolve barium chloride dihydrate (390 g), tin tetrachloride pentahydrate (702 g), lanthanum chloride (49.1 g), gadolinium chloride (52.7 g) in 30% H2O2 (300 mL) solution in the presence of citric acid (192 g), and make the solution clear and transparent by adding hydrochloric acid (200 mL). At this time, the pH value is about 0.2.

[0086] 2) Then place the round-bottom flask containing the solution in a preheated water bath at 60 °C and let it stand for 15 minutes to reach the set temperature.

[0087] 3) Subsequently, quickly add 25% ammonia water (700 mL) under strong stirring. White precipitates immediately appear, and at this time, the pH value of the suspension is about 9.

[0088] 4) After one hour of reaction, the suspension is filtered, washed with water several times until the pH value is 7, and rinsed with ethanol once to obtain a solid precursor. After being dried completely in a drying oven, it is annealed in a muffle furnace at 200°C for 2 hours. After cooling to room temperature, it is calcined in a muffle furnace at 850°C for 2 hours to obtain gadolinium, lanthanum, tin, barium rare earth co-doped nanopowders.

[0089] 5) The powder (50 g) was mixed with PMA solvent (453 mL) and dispersant (15 g) in a certain proportion and then ball-milled until the particle size was micrometer-level to obtain a gadolinium lanthanum tin barium rare earth co-doped non-nanoscale material.

[0090] Figure 1 It can be seen that the gadolinium, lanthanum, tin, barium rare earth co-doped powder appears light green.

[0091] Figure 2 This is the XRD diffraction pattern of the gadolinium, lanthanum, tin, barium rare earth co-doped powder prepared in Example 1. By comparing the characteristic peaks, it can be seen that the preparation method of the present invention achieves the co-doping of gadolinium, lanthanum, tin, and barium.

[0092] Figure 3 By comparing the transmittance curves of Example 2 and Comparative Examples 1-5, it can be seen that lanthanum-doped barium stannate has a good barrier effect in the near-infrared band, and a high transmittance in the far-infrared band; gadolinium-doped barium stannate has a good barrier effect in the far-infrared region, but does not have a good absorption compared to the near-infrared, but the curve of Example 2 shows a good barrier effect in the near-infrared and far-infrared bands, and at the same time ensures a high transmittance. At the same time, it can be seen that the nanomaterials described in the present invention have good ultraviolet infrared barrier properties and excellent transmittance, but the materials prepared by Comparative Examples 1-5 have poor barrier properties and transmittance effects in the infrared band, and cannot be used as thermal insulation materials.

[0093] Application Examples A glass curtain wall comprises a glass panel and an intermediate layer 2, a nano thermal insulation coating 3 and a protective layer 4 which are sequentially coated on the outer surface of the glass panel 1. The nano thermal insulation coating 3 is made of a nano thermal insulation material co-doped with gadolinium, lanthanum, tin and barium rare earths, the intermediate layer 2 is made of KH560, and the protective layer 4 is made of an organic silicone resin. The specific preparation method comprises the following steps: A method for preparing a gadolinium, lanthanum, tin, barium and rare earth co-doped nano-scale coating applied to a glass curtain wall comprises the following steps: (1) The surface of the glass panel needs to be washed with water or detergent to remove surface impurities. After that, use a blower to dry it for 3 hours to ensure that the surface of the substrate is clean and dry.

[0094] (2) Use an air spray gun to evenly spray the intermediate layer twice on the surface of the substrate.

[0095] (3) Use an air spray gun to evenly spray the heat insulation materials prepared in Example 2 and Comparative Examples 1-5 on the surface of the intermediate layer three times respectively. During the spraying process, it is necessary to observe the surface of the coating carefully to ensure that the coating has no obvious uneven thickness, no sagging, no bubbles, no patterns, and no omissions.

[0096] (4) Use an air spray gun to evenly spray the protective layer on the surface of the nano heat insulation layer three times. After the spraying is completed, a coating is formed and cured at 30 °C for 24 hours.

[0097] The thickness of the intermediate layer in the prepared glass curtain wall is 5 nm, the thickness of the nano heat insulation coating is 30 nm, and the thickness of the protective layer is 15 nm. The glass curtain walls prepared from the heat insulation materials of Example 2 and Comparative Examples 1-5 are named M1, M2, M3, M4, M5, and M6 respectively, and their ultraviolet blocking rate, infrared blocking rate, and visible light transmittance are tested.

[0098] Table 1 shows the data of the ultraviolet blocking rate, infrared blocking rate, and visible light transmittance of M1, M2, M3, M4, M5, and M6: Table 1

[0099] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. Gadolinium, lanthanum, tin, and barium rare earth co-doped nano thermal insulation material, characterized in that: By weight parts, it includes the following components: 12 - 18 parts of barium source; 25 - 28 parts of tin source; 0.5 - 3 parts of lanthanum source; 0.5 - 4 parts of gadolinium source; 5 - 8 parts of weak acid; 15 - 20 parts of oxidant; 5 - 10 parts of hydrolysis inhibitor; 20 - 30 parts of precipitant.

2. The gadolinium, lanthanum, tin, and barium rare earth co-doped nano thermal insulation material according to claim 1, wherein: The barium source is selected from one or more of barium chloride dihydrate, barium nitrate, barium sulfate, and barium carbonate.

3. The gadolinium, lanthanum, tin, and barium rare earth co-doped nano thermal insulation material according to claim 1, characterized in that: The tin source is selected from one or more of stannic chloride pentahydrate, stannous sulfide, stannic sulfate, and dimethyldichlorotin.

4. The gadolinium, lanthanum, tin, and barium rare earth co-doped nano thermal insulation material according to claim 1, wherein: The lanthanum source is selected from one or more of lanthanum chloride, lanthanum oxide, lanthanum sulfide, and lanthanum bromide.

5. The gadolinium-lanthanum-tin-barium rare earth co-doped nano thermal insulation material according to claim 1, characterized in that: The gadolinium source is selected from one or more of gadolinium chloride, gadolinium oxide, gadolinium sulfide, and gadolinium bromide.

6. The gadolinium, lanthanum, tin, and barium rare earth co-doped nano thermal insulation material according to claim 1, characterized in that: The weak acid is selected from one or more of citric acid, malic acid, tartaric acid, and ascorbic acid; the oxidant is selected from one or more of hydrogen peroxide, sodium peroxide, potassium peroxide, and calcium peroxide.

7. The gadolinium, lanthanum, tin, and barium rare-earth co-doped nano thermal insulation material according to claim 1, characterized in that: The hydrolysis inhibitor is selected from one or more of hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid; the precipitant is selected from one or more of ammonia water, sodium hydroxide, ammonium sulfate, and ammonium chloride.

8. The preparation method of the gadolinium, lanthanum, tin, barium rare earth co-doped nano thermal insulation material according to any one of claims 1-7, characterized in that: It includes the following steps: S1: Dissolve the barium source, tin source, lanthanum source, gadolinium source, and weak acid in the oxidant solution, and add the hydrolysis inhibitor to obtain a mixed solution; S2: Under the condition that the water bath temperature is 50 - 60 °C, put the precipitant into the mixed solution to react to obtain a suspension; S3: Filter the suspension by suction, wash it with water, rinse it, and dry it to obtain a solid precursor; S4: Put the solid precursor into a muffle furnace and anneal it at 200 - 300 °C for 1.5 - 2 hours. After cooling to room temperature, put it into the muffle furnace again and calcine it at 800 - 900 °C for 2 - 3 hours to obtain gadolinium - lanthanum - tin - barium rare - earth co - doped nano - powder; S5: Mix the gadolinium - lanthanum - tin - barium rare - earth co - doped nano - powder, solvent, and dispersant and then perform sand grinding to obtain a gadolinium - lanthanum - tin - barium rare - earth co - doped nano - thermal insulation material.

9. Application of the gadolinium - lanthanum - tin - barium rare - earth co - doped nano - thermal insulation material according to any one of claims 1 - 7 in the preparation of a glass curtain wall.

10. The application according to claim 9, characterized in that: The glass curtain wall includes a glass panel and an intermediate layer, a nano - thermal insulation coating, and a protective layer sequentially coated on the outer surface of the glass panel; the thickness of the nano - thermal insulation coating is 0.2 - 50 nm.

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