Preparation method of an infrared radiation composite phase aluminum phosphate material

Abstract

A preparation method of an infrared radiation composite aluminum phosphate material of the present invention synthesizes a triclinic / cubic aluminum phosphate and lanthanum phosphate composite material at a relatively low temperature by using an easily controllable sol-gel method; the reaction conditions are single, the preparation process is simple, the yield is relatively high, compared with other methods, the morphology and structure of the material can be better controlled, the target product is easy to mass-produce, and the cost is low, which is easy for industrial production; the synthesized composite material has excellent solar reflectivity; and has a high mid-infrared and far-infrared emissivity in the atmospheric window band; it has a good cooling effect in actual temperature measurement tests, so it shows excellent performance in the field of radiative cooling.

Description

Technical Field

[0001] The present invention relates to the technical field of radiation refrigeration materials, and particularly relates to a preparation method of an infrared radiation composite phase aluminum phosphate material. Background Art

[0002] At present, the problem of global warming has become increasingly serious, and the weather is getting hotter and hotter. In order to obtain a comfortable living environment, our demand for refrigeration is constantly increasing. Now, we mostly adopt active refrigeration methods, such as refrigeration devices like fans and air conditioners, which not only require a large amount of power support but also cause environmental pollution. Radiation refrigeration is a new type of clean and efficient passive refrigeration method that can achieve the refrigeration effect without consuming additional energy. And new and efficient radiation refrigeration materials have become the focus of research.

[0003] Currently, radiation refrigeration materials mainly include: hydrothermal method, solvothermal method, template method, and co-precipitation method. These methods can make the radiation refrigeration materials have the characteristics of high purity and controllable morphology, but they all require relatively complex and precise equipment, a long synthesis time, and a low yield, which is not conducive to batch production. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a preparation method of an infrared radiation composite phase aluminum phosphate material that uses the sol-gel method and then through microwave solid-phase sintering method to synthesize a composite material of lanthanum phosphate and aluminum phosphate with triclinic and cubic composite crystal forms, and the prepared material has excellent solar reflectivity and excellent mid-infrared emissivity, showing excellent performance in the field of radiation refrigeration.

[0005] In order to achieve the above purpose, the technical solution adopted by the present invention is as follows: A preparation method of an infrared radiation composite phase aluminum phosphate material, comprising the following steps:

[0006] (1) Prepare solution A with the content of Al(NO3)3·9H2O being 0.1 - 1 mol / L, and prepare solution B with the content of La(NO3)3·6H2O being 0.1 - 0.5 mol / L; Mix solution A and solution B, and control the molar ratio of Al 3+ to La 3+ to be 1:(0.1 - 1) to obtain solution C;

[0007] (2) Add ammonia water to the said solution C to adjust the pH of the solution to 3 - 5; Then stir at a temperature of 50 - 100 °C for 3 - 8 h to obtain solution D;

[0008] (3) Dissolve potassium phosphate and triethylenetriamine in deionized water and stir well to obtain solution E; add solution E to the aforementioned solution D, then add polyvinyl alcohol, and stir at a temperature of 50-90 °C for 2-6 h to obtain solution F; wherein, control the molar ratio of PO4 3- :Al 3+ to be (1-3):(1-3); control the mass ratio of triethylenetriamine to potassium phosphate to be (2-3):(1-2); control the solid content of polyvinyl alcohol to be 5-8 wt%;

[0009] (4) Perform freeze-drying treatment on the aforementioned solution F, and grind to obtain mixture G;

[0010] (5) Heat the aforementioned mixture G at a rate of 14-16 °C / min to 340-360 °C, and keep it warm for 1-3 h; then heat it at a rate of 9-11 °C / min to 1000-1200 °C, keep it warm for 0.8-1.2 h, and grind to obtain the infrared radiation composite aluminum phosphate material.

[0011] Further, in the aforementioned step (1), mix solution A and solution B, and control the molar ratio of Al 3+ to La 3+ to be 1:(0.5-1) to obtain solution C.

[0012] Further, the volume concentration of ammonia water added in the aforementioned step (2) is 20-30%.

[0013] Further, in the aforementioned step (2), add ammonia water to the aforementioned solution C, and adjust the pH of the solution to 4-5; then stir at a temperature of 70-100 °C for 4-8 h to obtain solution D.

[0014] Further, in the aforementioned step (3), add solution E to the aforementioned solution D, then add polyvinyl alcohol, and stir at a temperature of 50-90 °C for 4-6 h to obtain solution F; wherein, control the molar ratio of PO4 3- :Al 3+ to be (1.5-3):(1.5-3); control the mass ratio of triethylenetriamine to potassium phosphate to be (2.5-3):(1.5-2); control the solid content of polyvinyl alcohol to be 5-8 wt%.

[0015] Further, in the aforementioned step (3), the addition amount of polyvinyl alcohol is 5-15% of the weight of solution D.

[0016] Further, in the aforementioned step (4), perform freeze-drying treatment on the aforementioned solution F at -10 to -40 °C, and grind to obtain mixture G.

[0017] Further, in the step (4), the F solution is freeze-dried at -10 to -15 °C for 2 to 3 h, then at -20 to -25 °C for 6 to 8 h, then at -26 to -28 °C for 4 to 6 h, and then at -35 to -40 °C for 30 to 40 h, and after grinding, a mixture G is obtained.

[0018] Further, in the step (4), the F solution is freeze-dried at -12 to -15 °C for 2 to 3 h, then at -22 to -25 °C for 6 to 8 h, then at -27 to -28 °C for 4 to 6 h, and then at -38 to -40 °C for 30 to 40 h, and after grinding, a mixture G is obtained.

[0019] Further, in the step (5), the mixture G is heated to 350 to 360 °C at a rate of 15 to 16 °C / min and held for 2 to 3 h; then heated to 1100 to 1200 °C at a rate of 10 to 11 °C / min and held for 0.9 to 1.2 h, and after grinding, the infrared radiation composite phase aluminum phosphate material is obtained.

[0020] The preparation method of an infrared radiation composite phase aluminum phosphate material of the present invention has the following beneficial effects:

[0021] 1. The present invention uses an easily controllable sol-gel method to synthesize a triclinic / cubic phase aluminum phosphate and lanthanum phosphate composite material at a lower temperature.

[0022] 2. The reaction conditions of the present invention are single, the preparation process is simple, the yield is high, and compared with other methods, the morphology and structure of the material can be better controlled, the target product is easy to be mass-produced, and the cost is low, which is easy for industrial production.

[0023] 3. The synthesized composite material has excellent solar reflectivity; and has a high mid- and far-infrared emissivity in the atmospheric window band; has a good temperature reduction effect in the actual temperature measurement test, so it shows excellent performance in the field of radiative cooling. Its application in ceramic green bodies has a certain cooling effect and is expected to be applied to the field of outdoor building materials.

[0024] The preparation method of an infrared radiation composite phase aluminum phosphate material of the present invention prepares an infrared radiation composite phase aluminum phosphate material with a flaky morphology, about 1 μm in size; the infrared radiation composite phase aluminum phosphate material has a high reflectivity, reaching about 98%; has a high emissivity in the range of 8 to 13 μm, reaching about 91%; the infrared radiation composite phase aluminum phosphate material has a maximum temperature reduction of about 6 °C in the actual environment; the temperature reduction effect of the infrared radiation composite phase aluminum phosphate material is about 4 °C higher than that of the green body without addition.

[0025] The preparation method of an infrared radiation composite phase aluminum phosphate material of the present invention optimizes the freeze-drying treatment process, enabling the composite material to undergo morphological changes. Subsequently, the heating rate and cooling rate are controlled during solid-phase sintering to further control the morphological changes of the composite material, which can further improve the various properties of the infrared radiation composite phase aluminum phosphate material. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is the XRD pattern of the infrared radiation composite phase aluminum phosphate material prepared by the present invention; Figure 1 It can be seen that the crystal form of this aluminum phosphate is a composite crystal form of triclinic and cubic, and the standard card of lanthanum phosphate also has the same peak positions as those of lanthanum phosphate;

[0027] Figure 2 It is the SEM image of the infrared radiation composite phase aluminum phosphate material prepared by the present invention; Figure 2 It can be seen that the morphology of the infrared radiation composite phase aluminum phosphate material is sheet-like, and the size is about 1 μm;

[0028] Figure 3 It is the reflectivity spectrum of the infrared radiation composite phase aluminum phosphate material prepared by the present invention in the solar band; Figure 3 It can be seen that the infrared radiation composite phase aluminum phosphate material has a relatively high reflectivity, reaching about 98%;

[0029] Figure 4 It is the emissivity spectrum of the infrared radiation composite phase aluminum phosphate material prepared by the present invention; Figure 4 It can be seen that the infrared radiation composite phase aluminum phosphate material has a relatively high emissivity in the range of 8 - 13 μm, reaching about 91%;

[0030] Figure 5 It is the cooling effect diagram of the infrared radiation composite phase aluminum phosphate material prepared by the present invention in the actual environment; Figure 5 It can be seen that the maximum cooling of the infrared radiation composite phase aluminum phosphate material in the actual environment is about 6°C;

[0031] Figure 6 It is the cooling effect diagram of the infrared radiation composite phase aluminum phosphate material prepared by the present invention when applied in a ceramic green body; Figure 6 It can be seen that the cooling effect of the infrared radiation composite phase aluminum phosphate material is about 4°C higher than that of the green body without addition. SPECIFIC EMBODIMENTS

[0032] The following examples can help those skilled in the art to more comprehensively understand the present invention, but the present invention cannot be limited in any way.

[0033] Example 1

[0034] A preparation method of an infrared radiation composite phase aluminum phosphate material comprises the following steps:

[0035] Step 1: Weigh a certain amount of Al(NO3)3·9H2O and dissolve it in deionized water to prepare solution A with a concentration of 0.5 mol / L. Weigh a certain amount of La(NO3)3·6H2O and dissolve it in deionized water to prepare solution B with a concentration of 0.1 mol / L. Mix solutions A and B to obtain solution C. Ensure that the molar ratio of Al 3+ to La 3+ is 1:0.1.

[0036] Step 2: Add a certain amount of ammonia water with a concentration of 25% (volume concentration) to C, adjust the pH to 3, and stir well at 80 °C for 3 h to obtain D.

[0037] Step 3: Dissolve a certain amount of potassium phosphate and triethylenetriamine in deionized water and stir well to obtain solution E. Add solution E to D, then add a certain amount of polyvinyl alcohol, and stir at 80 °C for 2 h to obtain F. Ensure that the molar ratio of PO4 3- to Al 3+ is 1:1; ensure that the mass ratio of triethylenetriamine to potassium phosphate is 2:1; ensure that the solid content of polyvinyl alcohol is 5 wt%. The addition amount of polyvinyl alcohol is 5% of the weight of solution D.

[0038] Step 4: Perform freeze-drying treatment on the obtained solution F, and grind it to obtain G. The freeze-drying treatment process is as follows: Freeze-dry the solution F at -10 °C for 2 h, then at -20 °C for 6 h, then at -26 °C for 4 h, and then at -35 °C for 30 h, and grind it to obtain the mixture G.

[0039] Step 5: Put the obtained mixture G into a crucible, place it in a microwave solid-phase sintering furnace, heat it to 350 °C at a rate of 15 °C / min, hold for 1 h, then heat it to 1000 °C at a rate of 10 °C / min, hold for 1 h, and then grind it to obtain H, and H is the infrared radiation composite phase aluminum phosphate material.

[0040] Example 2

[0041] A preparation method of an infrared radiation composite phase aluminum phosphate material comprises the following steps:

[0042] Step 1: Weigh a certain amount of Al(NO3)3·9H2O and dissolve it in deionized water to prepare solution A with a concentration of 0.6 mol / L. Weigh a certain amount of La(NO3)3·6H2O and dissolve it in deionized water to prepare solution B with a concentration of 0.2 mol / L. Mix solutions A and B to obtain solution C. Ensure that the molar ratio of Al 3+ to La3+ The molar ratio is 1:0.15.

[0043] Step 2: Add a certain amount of ammonia water with a concentration of 26% (volume concentration) to C, adjust the pH to 5, and stir well at a temperature of 85 °C for 4 h to obtain D.

[0044] Step 3: Dissolve a certain amount of potassium phosphate and triethylenetriamine in deionized water and stir well to obtain solution E. Add solution E to D, then add a certain amount of polyvinyl alcohol, and stir at a temperature of 85 °C for 3 h to obtain F. Among them, ensure that the molar ratio of PO4 3- :Al 3+ is 1:1.5; ensure that the mass ratio of triethylenetriamine to potassium phosphate is 2.5:1; ensure that the solid content of polyvinyl alcohol is 5 wt%. The addition amount of polyvinyl alcohol is 15% of the weight of solution D.

[0045] Step 4: Perform freeze-drying treatment on the obtained solution F, and grind it to obtain G. The freeze-drying treatment process is as follows: freeze-dry the solution F at -15 °C for 3 h, then at -25 °C for 8 h, then at -28 °C for 6 h, and then at -40 °C for 40 h, and grind it to obtain the mixture G.

[0046] Step 5: Put the obtained mixture G into a crucible, place it in a microwave solid-phase sintering furnace, heat it to 350 °C at a rate of 15 °C / min, keep it warm for 1.5 h, then heat it to 1100 °C at a rate of 10 °C / min, keep it warm for 1 h and then grind it to obtain H, and H is the infrared radiation composite phase aluminum phosphate material.

[0047] Example 3

[0048] A preparation method of an infrared radiation composite phase aluminum phosphate material has the following steps:

[0049] Step 1: Weigh a certain amount of Al(NO3)3·9H2O and dissolve it in deionized water to prepare solution A with a concentration of 0.7 mol / L. Weigh a certain amount of La(NO3)3·6H2O and dissolve it in deionized water to prepare solution B with a concentration of 0.1 mol / L. Mix solutions A and B to obtain solution C. Ensure that the molar ratio of Al 3+ and La 3+ is 1:0.2.

[0050] Step 2: Add a certain amount of ammonia water with a concentration of 27% (volume concentration) to C, adjust the pH to 4, and stir well at a temperature of 90 °C for 4 h to obtain D.

[0051] Step 3: Dissolve a certain amount of potassium phosphate and triethylenetriamine in deionized water and stir well to obtain Solution E. Add Solution E to D, then add a certain amount of polyvinyl alcohol, and stir at 90 °C for 4 h to obtain F. Ensure that the molar ratio of PO4 3- :Al 3+ is 3:1; ensure that the mass ratio of triethylenetriamine to potassium phosphate is 1:1; ensure that the solid content of polyvinyl alcohol is 7 wt%. The addition amount of polyvinyl alcohol is 10% of the weight of Solution D.

[0052] Step 4: Subject the obtained Solution F to freeze-drying treatment, and grind it to obtain G. The freeze-drying treatment process is as follows: Freeze-dry the said Solution F at -12 °C for 2 h, then at -22 °C for 6 h, then at -27 °C for 4 h, and then at -38 °C for 30 h, and grind it to obtain the mixture G.

[0053] Step 5: Put the obtained mixture G into a crucible, place it in a microwave solid-phase sintering furnace, heat it up to 350 °C at a rate of 15 °C / min, hold for 1.5 h, then heat it up to 1150 °C at a rate of 10 °C / min, hold for 1 h and then grind it to obtain H, and H is the infrared radiation composite phase aluminum phosphate material.

[0054] Example 4

[0055] A preparation method of an infrared radiation composite phase aluminum phosphate material, which has the following steps:

[0056] Step 1: Weigh a certain amount of Al(NO3)3·9H2O and dissolve it in deionized water to prepare Solution A with a concentration of 0.8 mol / L. Weigh a certain amount of La(NO3)3·6H2O and dissolve it in deionized water to prepare Solution B with a concentration of 0.2 mol / L. Mix Solutions A and B to obtain Solution C. Ensure that the molar ratio of Al 3+ to La 3+ is 1:0.3.

[0057] Step 2: Add a certain amount of ammonia water with a concentration of 28% (volume concentration) to C, adjust the pH to 4, and stir well at 100 °C for 8 h to obtain D.

[0058] Step 3: Dissolve a certain amount of potassium phosphate and triethylenetriamine in deionized water and stir well to obtain Solution E. Add Solution E to D, then add a certain amount of polyvinyl alcohol, and stir at 90 °C for 6 h to obtain F. Ensure that the molar ratio of PO4 3- :Al 3+ is 3:1; ensure that the mass ratio of triethylenetriamine to potassium phosphate is 3:2; ensure that the solid content of polyvinyl alcohol is 8 wt%. The addition amount of polyvinyl alcohol is 12% of the weight of Solution D.

[0059] Step 4: Subject the obtained F solution to freeze-drying treatment, and grind it to obtain G. The freeze-drying treatment process is as follows: Freeze-dry the F solution at -13°C for 2.5 h, then at -23°C for 7 h, then at -27°C for 5 h, and then at -38°C for 35 h, and grind it to obtain the mixture G.

[0060] Step 5: Put the obtained mixture G into a crucible, place it in a microwave solid-phase sintering furnace, heat it to 350°C at a rate of 15°C / min, hold for 2 h, then heat it to 1200°C at a rate of 10°C / min, hold for 1 h and then grind it to obtain H, and H is the infrared radiation composite phase aluminum phosphate material.

[0061] Example 5

[0062] A preparation method of an infrared radiation composite phase aluminum phosphate material has the following steps:

[0063] Step 1: Weigh a certain amount of Al(NO3)3·9H2O and dissolve it in deionized water to prepare an A solution with a concentration of 0.1 mol / L. Weigh a certain amount of La(NO3)3·6H2O and dissolve it in deionized water to prepare a B solution with a concentration of 0.5 mol / L. Mix the A and B solutions to obtain a C solution. Ensure that the molar ratio of Al 3+ to La 3+ is 1:0.3.

[0064] Step 2: Add a certain amount of ammonia water with a concentration of 20% (volume concentration) to C, adjust the pH to 4, and stir well at a temperature of 100°C for 8 h to obtain D.

[0065] Step 3: Dissolve a certain amount of potassium phosphate and triethylenetriamine in deionized water and stir well to obtain an E solution. Add the E solution to D, and then add a certain amount of polyvinyl alcohol. Stir at a temperature of 90°C for 6 h to obtain F. Among them, ensure that the molar ratio of PO4 3- to Al 3+ is 3:1; ensure that the mass ratio of triethylenetriamine to potassium phosphate is 3:2; ensure that the solid content of polyvinyl alcohol is 8 wt%. The addition amount of polyvinyl alcohol is 12% of the weight of the D solution.

[0066] Step 4: Subject the obtained F solution to freeze-drying treatment at -10°C, and grind it to obtain G.

[0067] Step 5: Put the obtained mixture G into a crucible, place it in a microwave solid-phase sintering furnace, heat it to 340°C at a rate of 14°C / min, hold for 1 h, then heat it to 1000°C at a rate of 9°C / min, hold for 0.8 h and then grind it to obtain H, and H is the infrared radiation composite phase aluminum phosphate material.

[0068] Example 6

[0069] A preparation method of an infrared radiation composite phase aluminum phosphate material comprises the following steps:

[0070] Step 1: Weigh a certain amount of Al(NO3)3·9H2O and dissolve it in deionized water to prepare a 1 mol / L solution A. Weigh a certain amount of La(NO3)3·6H2O and dissolve it in deionized water to prepare a 0.5 mol / L solution B. Mix solutions A and B to obtain solution C. Ensure that the molar ratio of Al 3+ to La 3+ is 1:0.3.

[0071] Step 2: Add a certain amount of 20% ammonia water (volume concentration) to C, adjust the pH to 4, and stir well at 50 °C for 8 h to obtain D.

[0072] Step 3: Dissolve a certain amount of potassium phosphate and triethylenetriamine in deionized water and stir well to obtain solution E. Add solution E to D, then add a certain amount of polyvinyl alcohol, and stir at 50 °C for 2 h to obtain F. Among them, ensure that the molar ratio of PO4 3- to Al 3+ is 3:1; ensure that the mass ratio of triethylenetriamine to potassium phosphate is 3:2; ensure that the solid content of polyvinyl alcohol is 8 wt%. The addition amount of polyvinyl alcohol is 12% of the weight of solution D.

[0073] Step 4: Freeze-dry the obtained solution F at -40 °C, and grind it to obtain G.

[0074] Step 5: Put the obtained mixture G into a crucible, place it in a microwave solid-phase sintering furnace, heat it to 360 °C at a rate of 16 °C / min, keep it warm for 3 h, then heat it to 1200 °C at a rate of 11 °C / min, and grind it after keeping it warm for 1.2 h to obtain H, and H is the infrared radiation composite phase aluminum phosphate material.

[0075] Comparative Example 1

[0076] A preparation method of an infrared radiation composite phase aluminum phosphate material comprises the following steps:

[0077] Step 1: Weigh a certain amount of Al(NO3)3·9H2O and dissolve it in deionized water to prepare a 0.8 mol / L solution A. Weigh a certain amount of La(NO3)3·6H2O and dissolve it in deionized water to prepare a 0.2 mol / L solution B. Mix solutions A and B to obtain solution C. Ensure that the molar ratio of Al 3+ to La 3+ is 1:0.3.

[0078] Step 2: Add a certain amount of ammonia water with a concentration of 28% (volume concentration) to C, adjust the pH to 4, and stir well at a temperature of 100 °C for 8 h to obtain D.

[0079] Step 3: Dissolve a certain amount of potassium phosphate and triethylenetriamine in deionized water and stir well to obtain solution E. Add solution E to D, and then add a certain amount of polyvinyl alcohol. Stir at a temperature of 90 °C for 6 h to obtain F. Ensure that the molar ratio of PO4 3- :Al 3+ is 3:1; ensure that the mass ratio of triethylenetriamine to potassium phosphate is 3:2; ensure that the solid content of polyvinyl alcohol is 8 wt%. The addition amount of polyvinyl alcohol is 12% of the weight of solution D.

[0080] Step 4: Carry out normal-temperature drying treatment on the obtained solution F, and grind it to obtain G.

[0081] Step 5: Put the obtained mixture G into a crucible, place it in a microwave solid-phase sintering furnace, heat it to 350 °C at a rate of 15 °C / min, keep it warm for 2 h, then heat it to 1200 °C at a rate of 10 °C / min, and grind it after keeping it warm for 1 h to obtain H, and H is the infrared radiation composite phase aluminum phosphate material described.

[0082] Comparative Example 2

[0083] A preparation method of an infrared radiation composite phase aluminum phosphate material has the following steps:

[0084] Step 1: Weigh a certain amount of Al(NO3)3·9H2O and dissolve it in deionized water to prepare solution A with a concentration of 0.8 mol / L. Weigh a certain amount of La(NO3)3·6H2O and dissolve it in deionized water to prepare solution B with a concentration of 0.2 mol / L. Mix solutions A and B to obtain solution C. Ensure that the molar ratio of Al 3+ to La 3+ is 1:0.3.

[0085] Step 2: Add a certain amount of ammonia water with a concentration of 28% (volume concentration) to C, adjust the pH to 4, and stir well at a temperature of 100 °C for 8 h to obtain D.

[0086] Step 3: Dissolve a certain amount of potassium phosphate and triethylenetriamine in deionized water and stir well to obtain solution E. Add solution E to D, and then add a certain amount of polyvinyl alcohol. Stir at a temperature of 90 °C for 6 h to obtain F. Ensure that the molar ratio of PO4 3- :Al 3+ is 3:1; ensure that the mass ratio of triethylenetriamine to potassium phosphate is 3:2; ensure that the solid content of polyvinyl alcohol is 8 wt%. The addition amount of polyvinyl alcohol is 12% of the weight of solution D.

[0087] Step 4: Freeze-dry the obtained F solution at -10°C, and grind it to obtain G.

[0088] Step 5: Put the obtained mixture G into a crucible, keep it at 1200°C for 3 h and then grind it to obtain H, and H is the infrared radiation composite phase aluminum phosphate material.

[0089] The test results of the performance parameters of the infrared radiation composite phase aluminum phosphate materials prepared in the above Examples 1-6 and Comparative Examples 1-2 are shown in Table 1 below;

[0090]

[0091] As can be seen from the test results of the above examples, in the preparation method of an infrared radiation composite phase aluminum phosphate material of the present invention, a triclinic / cubic phase aluminum phosphate and lanthanum phosphate composite material is synthesized at a lower temperature by using a sol-gel method which is easy to control. The reaction conditions of the present invention are single, the preparation process is simple, the yield is high, the morphology and structure of the material can be better controlled compared with other methods, the target product is easy to be mass-produced, and the cost is low, which is easy for industrial production. The synthesized composite material has excellent solar reflectivity; and has a high mid-infrared and far-infrared emissivity in the atmospheric window band; has a good temperature reduction effect in the actual temperature measurement test, so it shows excellent performance in the field of radiative cooling. Its application in ceramic green bodies has a certain temperature reduction effect and is expected to be applied to the field of outdoor building materials. The morphology of the prepared infrared radiation composite phase aluminum phosphate material is flaky, with a size of about 1 μm; the infrared radiation composite phase aluminum phosphate material has a high reflectivity, reaching about 98%; has a high emissivity in the range of 8-13 μm, reaching about 91%; the maximum temperature reduction of the infrared radiation composite phase aluminum phosphate material in the actual environment is about 6°C; the temperature reduction effect of the infrared radiation composite phase aluminum phosphate material is about 4°C higher than that of the green body without addition. Optimizing the freeze-drying process enables the composite material to change its morphology, and controlling the heating rate and cooling rate during subsequent solid-phase sintering further controls the morphology change of the composite material, which can further improve the performance of the infrared radiation composite phase aluminum phosphate material; the reflectivity is increased from less than 98.5% to more than 98.5%; the emissivity in the range of 8-13 μm is increased from less than 91.5% to more than 91.5%; the maximum temperature reduction in the actual environment is increased from less than 6.5°C to more than 6.5°C; the temperature reduction during application in ceramic green bodies is increased from less than 4.5°C to more than 4.5°C.

[0092] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made thereto based on the present invention, which will be obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of the present invention claimed.

Claims

1. A preparation method of an infrared radiation composite phase aluminum phosphate material, characterized in that, It includes the following steps: (1) Prepare solution A with the content of Al(NO3)3·9H2O being 0.1 - 1 mol / L, and prepare solution B with the content of La(NO3)3·6H2O being 0.1 - 0.5 mol / L; mix solution A and solution B, and control the molar ratio of Al 3+ to La 3+ to be 1:(0.1 - 1) to obtain solution C; (2) Add ammonia water to the said C solution to adjust the pH of the solution to 3 - 5; then stir for 3 - 8 h at a temperature of 50 - 100 °C to obtain solution D; (3) Dissolve potassium phosphate and triethylenetriamine in deionized water and stir well to obtain solution E; Add the said E solution to the said D solution, then add polyvinyl alcohol, and stir for 2 to 6 h at a temperature of 50 to 90 °C to obtain F solution; wherein, control the molar ratio of PO4 3- :Al 3+ to be (1 to 3):(1 to 3); control the mass ratio of triethylenetriamine to potassium phosphate to be (2 to 3):(1 to 2); control the solid content of polyvinyl alcohol to be 5 to 8 wt%; (4) Carry out freeze-drying treatment on the said F solution, and grind it to obtain mixture G; (5) Heat the said mixture G at a rate of 14 - 16 °C / min to 340 - 360 °C, and keep it warm for 1 - 3 h; then heat it at a rate of 9 - 11 °C / min to 1000 - 1200 °C, keep it warm for 0.8 - 1.2 h, and grind it to obtain the infrared radiation composite phase aluminum phosphate material.

2. The preparation method of an infrared radiation composite aluminum phosphate material according to claim 1, characterized in that In the step (1), the A solution and the B solution are mixed, and the molar ratio of Al 3+ to La 3+ is controlled to be 1:(0.5~1) to obtain the C solution.

3. The preparation method of an infrared radiation composite aluminum phosphate material according to claim 1, characterized in that, In the said step (2), the volume concentration of the added ammonia water is 20 - 30%.

4. The preparation method of an infrared radiation composite aluminum phosphate material according to claim 1, characterized in that, In the said step (2), add ammonia water to the said C solution to adjust the pH of the solution to 4 - 5; then stir for 4 - 8 h at a temperature of 70 - 100 °C to obtain solution D.

5. The preparation method of an infrared radiation composite aluminum phosphate material according to claim 1, characterized in that, In the step (3), the E solution is added to the D solution, and then polyvinyl alcohol is added, followed by stirring at a temperature of 50-90 °C for 4-6 h to obtain the F solution; wherein, the molar ratio of PO4 3- :Al 3+ is controlled to be (1.5-3):(1.5-3); the mass ratio of triethylenetriamine to potassium phosphate is controlled to be (2.5-3):(1.5-2); the solid content of polyvinyl alcohol is controlled to be 5-8 wt%.

6. The preparation method of an infrared radiation composite aluminum phosphate material according to claim 1, characterized in that, In the said step (3), the addition amount of polyvinyl alcohol is 5 - 15% of the weight of solution D.

7. The preparation method of an infrared radiation composite aluminum phosphate material according to claim 1, characterized in that, In the said step (4), carry out freeze-drying treatment on the said F solution at - 10 - - 40 °C, and grind it to obtain mixture G.

8. The preparation method of an infrared radiation composite aluminum phosphate material according to claim 7, characterized in that, In the said step (4), freeze-dry the said F solution at - 10 - - 15 °C for 2 - 3 h, then at - 20 - - 25 °C for 6 - 8 h, then at - 26 - - 28 °C for 4 - 6 h, and then at - 35 - - 40 °C for 30 - 40 h, and grind it to obtain mixture G.

9. The preparation method of an infrared radiation composite aluminum phosphate material according to claim 8, characterized in that, In the said step (4), freeze-dry the said F solution at - 12 - - 15 °C for 2 - 3 h, then at - 22 - - 25 °C for 6 - 8 h, then at - 27 - - 28 °C for 4 - 6 h, and then at - 38 - - 40 °C for 30 - 40 h, and grind it to obtain mixture G.

10. The preparation method of an infrared radiation composite aluminum phosphate material according to claim 1, characterized in that, In the said step (5), heat the said mixture G at a rate of 15 - 16 °C / min to 350 - 360 °C, and keep it warm for 2 - 3 h; then heat it at a rate of 10 - 11 °C / min to 1100 - 1200 °C, keep it warm for 0.9 - 1.2 h, and grind it to obtain the infrared radiation composite phase aluminum phosphate material.

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