Material preparation device and preparation method based on water heat pipe sealing method
Through a material preparation device based on the water-heat sealing tube method, hydrothermal reaction is carried out in a closed and controllable environment, which solves the problem of supercritical hydrothermal synthesis demanding environment and equipment, and achieves more suitable material growth conditions and higher quality crystal materials.
Patent Information
- Application Number
- CN202411674720.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-21
- Publication Date
- 2025-04-04
AI Technical Summary
Supercritical hydrothermal synthesis in the prior art has strict requirements on the environment and equipment and is not convenient to achieve.
A material preparation device based on the water heat sealing tube method is adopted, including a vacuum assembly, a gas storage chamber, a gas mixing chamber, a filter, a sample test tube and a heating assembly. By controlling the atmosphere and air pressure, hydrothermal reaction is achieved in a closed and controllable environment.
Growing materials in a closed and controlled atmosphere or liquid environment, especially hydrogen-containing compounds that are difficult to grow, such as hydroxy halides, achieves more suitable growth conditions and improves the size and quality of the material.
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Figure CN119746717A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of material preparation, and in particular to a material preparation device and method based on a hydrothermal tube sealing method. Background Art
[0002] In the field of material synthesis, although the traditional high-temperature flux method and vacuum sealing method have been successful in preparing certain crystalline materials, there are also some difficult-to-overcome problems. In particular, when growing hydrogen-containing compounds such as hydroxy halides, hydrogen atoms easily combine with oxygen atoms to form water molecules and escape, making it impossible to effectively grow such materials. In addition, the use of flux often makes it difficult to obtain a single target phase, and the target product may be wrapped by impurities, making it difficult to separate.
[0003] In order to overcome these challenges, researchers have been exploring new synthesis methods. As a mild synthesis method, the hydrothermal method creates a high-temperature and high-pressure reaction state by adding the solution of the reactants as a filler into the reactor for continuous heating, prompting the material to react in the direction of small Gibbs free energy, thereby controlling the reaction, nucleation, and recrystallization of the raw materials. Depending on the reaction temperature, the hydrothermal synthesis method can be divided into subcritical hydrothermal synthesis and supercritical hydrothermal synthesis (temperature>374 degrees Celsius, pressure>22.12 MPa). Among them, the subcritical hydrothermal synthesis method is widely used because of its simple operation and low cost. However, the subcritical hydrothermal synthesis method itself has many limitations. For example, the heterogeneous low-temperature state during the reaction process affects the contact and interaction between substances, and there are problems such as large mass transfer resistance, low transfer efficiency, and low reaction activity in the internal structure of the solution and the material.
[0004] The critical condition temperature of water is 374 degrees Celsius and the pressure is 22.12 MPa. When the environmental state of water is higher than the critical point, the strong hydrogen bonds inside are broken in large numbers, the dielectric constant drops sharply, and a superfluid state between gas and liquid is formed, which is supercritical water. In the process of supercritical hydrothermal synthesis, the polarity of the solvent changes to non-polarity, and the density and viscosity change greatly, causing the solubility of the solute to change, which is more conducive to the synthesis of special materials. However, the experimental environment and equipment required for supercritical hydrothermal are extremely harsh, and are accompanied by great safety hazards. Therefore, the existing technology needs to be improved. Summary of the invention
[0005] In view of the above-mentioned deficiencies in the prior art, the purpose of the present application is to provide a material preparation device and method based on the hydrothermal tube sealing method, aiming to solve the problem in the prior art that supercritical hydrothermal synthesis has strict requirements on the environment and equipment and is not easy to implement.
[0006] The technical solution of this application is as follows:
[0007] According to a first aspect of the present application, there is provided a material preparation device based on a hydrothermal tube sealing method, comprising: a vacuum pumping component, a first gas storage chamber, a gas mixing chamber, a filter, a sample test tube and a heating component; the vacuum pumping component is connected to the filter via a first pipe, the first gas storage chamber is connected to the gas mixing chamber via a second pipe, the gas mixing chamber is connected to the first pipe via a third pipe, and the filter is connected to the sample test tube via a fourth pipe; wherein the heating component is configured to heat the sample test tube, the first gas storage chamber is configured to store gas, the sample test tube comprises a test tube body and a test tube plug, one end of the test tube body is detachably connected to the fourth pipe, and the test tube plug is inserted into the test tube body.
[0008] Preferably, a first valve is provided on the first pipeline, and the first valve is located between the connection point of the first pipeline and the third pipeline and the connection point of the first pipeline and the vacuum assembly on the first pipeline, a second valve is provided on the second pipeline, and a third valve is provided on the third pipeline.
[0009] Preferably, the test tube body is one of a quartz tube, a borosilicate glass tube, and a metal tube.
[0010] Preferably, the filler in the filter includes at least one of quartz sand, anthracite, activated carbon and ceramic fiber.
[0011] Preferably, the material preparation device based on the water heat sealing tube method further comprises a second gas storage chamber, the second gas storage chamber is configured to store gas, and the second gas storage chamber is connected to the gas mixing chamber via a fifth pipeline.
[0012] Preferably, a fourth valve is provided on the fifth pipeline.
[0013] The second aspect of the present application provides a material preparation method based on hydrothermal synthesis, which is prepared using the material preparation device based on the hydrothermal tube sealing method of the first aspect of the present application, including the following steps: (1) providing a reaction solution, filling the reaction solution into a test tube body, inserting a test tube plug, and connecting it to a fourth pipeline; (2) closing the first valve and the third valve, opening the second valve, and introducing the gas in the first gas storage chamber into the mixing chamber; (3) closing the second valve, opening the first valve and the vacuum pumping component, and vacuuming the sample test tube; (4) closing the first valve, opening the third valve, and allowing the gas in the mixing chamber to flow into the sample test tube; (5) welding the test tube body and the test tube plug; (6) placing the sample test tube in a heating component for firing, and obtaining the material through a hydrothermal reaction of the reaction solution.
[0014] Preferably, the method further includes the step of: firing the test tube body on the heating assembly so that a groove appears at the position where the test tube body abuts the test tube plug.
[0015] Preferably, the method further includes the steps of repeating (2), (3) and (4) three times before (5).
[0016] Preferably, the firing temperature in (6) is 40-374 degrees Celsius.
[0017] Beneficial effects of the present application: The material preparation device based on the hydrothermal tube sealing method in the present application can grow materials in a closed and controllable atmosphere or liquid environment, providing a more suitable growth condition for the material, especially for hydrogen-containing compounds such as hydroxy halides, which are difficult to grow in traditional vacuum tube sealing methods and low-temperature hydrothermal synthesis methods. Large single crystal materials. In addition, the material preparation device based on the hydrothermal tube sealing method in the present application can directly observe the growth state of the material during the material growth process, which provides convenience for real-time monitoring and adjustment of growth conditions, so that the material growth process can be controlled more accurately. In this way, the time and process parameters of material growth can be regulated, making the preparation process more flexible and controllable, which helps to optimize the performance and quality of the material, and ultimately grow larger and better quality crystalline materials. It has significant technical advantages and application prospects in the preparation of materials based on hydrothermal synthesis. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for describing the embodiments are briefly introduced below.
[0019] Figure 1 A material preparation device based on a hydrothermal tube sealing method provided in an embodiment of the present application;
[0020] Figure 2 Another material preparation device based on the hydrothermal tube sealing method provided in an embodiment of the present application;
[0021] Figure 3 A schematic diagram of the structure of a sample test tube provided in an embodiment of the present application;
[0022] Figure 4 A diagram showing the pressure variation of a sample test tube during heating provided in an embodiment of the present application;
[0023] Figure 5 This is a morphology diagram of a finished product under a microscope that is prepared using a material preparation device based on a hydrothermal tube sealing method provided in an embodiment of the present application.
[0025] 100. Material preparation device based on water-heat sealing tube method; 11. Vacuuming component; 12. First gas storage chamber; 13. Gas mixing chamber; 14. Filter; 15. Sample test tube; 151. Test tube body; 152. Test tube plug; 16. Heating component; 17. Second gas storage chamber; 21. First pipeline; 22. Second pipeline; 23. Third pipeline; 24. Fourth pipeline; 25. Fifth pipeline; 31. First valve; 32. Second valve; 33. Third valve; 34. Fourth valve. DETAILED DESCRIPTION
[0026] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings and embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the protection scope of the present application. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.
[0027] It should be noted that if there are descriptions involving "first", "second", etc. in the implementation of this application, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance and implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that ordinary technicians in the field can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.
[0028] See also Figure 1 The embodiment of the present application provides a material preparation device 100 based on the water heat sealing method, which generally includes a vacuum assembly 11, a first gas storage chamber 12, a gas mixing chamber 13, a filter 14, a sample test tube 15 and a heating assembly 16; the vacuum assembly 11 is connected to the filter 14 through a first pipe 21, the first gas storage chamber 12 is connected to the gas mixing chamber 13 through a second pipe 22, the gas mixing chamber 13 is connected to the first pipe 21 through a third pipe 23, and the filter 14 is connected to the sample test tube 15 through a fourth pipe 24.
[0029] The heating component 16 is configured to heat the sample tube 15, and the heating component 16 can be an oxyhydrogen flame machine and a tube furnace. The first gas storage chamber 12 is configured to store gas, including at least one of an inert gas (nitrogen, argon, helium), carbon dioxide, and hydrogen. Figure 2As shown, the sample tube 15 includes a tube body 151 and a tube plug 152. One end of the tube body 151 is detachably connected to the fourth pipe 24, and the tube plug 152 can be inserted into the tube body 151. It should be noted that the tube plug 152 can be any shape that can block one end of the tube body 151.
[0030] In some embodiments, the first pipe 21 is provided with a first valve 31, which is located on the first pipe 21, specifically between the connection point between the first pipe 21 and the third pipe 23 and the connection point between the first pipe 21 and the vacuum assembly 11, the second pipe 22 is provided with a second valve 32, and the third pipe 23 is provided with a third valve 33. By providing the first valve 31, the second valve 32, and the third valve 33, the opening and closing of the gas channel formed by the first pipe 21, the second pipe 22, and the third pipe 23 between the vacuum assembly 11, the first gas storage chamber 12, the gas mixing chamber 13, and the filter 14 can be better controlled, thereby accurately controlling the atmosphere and air pressure in the sample test tube 15, and providing an ideal environment for the growth of materials.
[0031] In some embodiments, the test tube body 151 is a quartz tube, a borosilicate glass tube, or a metal tube.
[0032] In some embodiments, the filler in the filter includes at least one of quartz sand, anthracite, activated carbon, and ceramic fiber. The filter is used to prevent the reagents in the test tube from entering the gas pipeline and contaminating the experimental equipment, while eliminating safety hazards.
[0033] In some embodiments, Figure 2 As shown, the material preparation device 100 based on the water heat sealing tube method also includes a second gas storage chamber 17, which is configured to store gas, including at least one of an inert gas (nitrogen, argon, helium), carbon dioxide, and hydrogen. The second gas storage chamber 17 is connected to the gas mixing chamber 13 through a fifth pipeline 25. By setting the second gas storage chamber 17, it can be used in conjunction with the first gas storage chamber 12 to mix a gas atmosphere with richer components in the gas mixing chamber 13 to meet the different requirements of the material growth for the atmosphere. In some embodiments, a fourth valve 34 is provided on the fifth pipeline 25.
[0034] The present application also provides a method for preparing a material based on hydrothermal synthesis, which is prepared by using the material preparation device based on the hydrothermal tube sealing method as described above, and specifically includes the following steps:
[0035] S1. Provide a reaction solution, fill the reaction solution into a test tube body, insert a test tube stopper, and connect it to a fourth pipeline;
[0036] S2, close the first valve and the third valve, open the second valve (or the second valve and the fourth valve), and introduce the gas in the first gas storage chamber (or the first gas storage chamber and the second gas storage chamber) into the gas mixing chamber;
[0037] S3, close the second valve, open the first valve and the vacuum assembly, and vacuum the sample tube;
[0038] S4, close the first valve, open the third valve, and allow the gas in the gas mixing chamber to flow into the sample test tube;
[0039] S5. Weld the test tube body and the test tube plug to form a sealed environment for the test tube body. Figure 3 As shown, the reaction liquid and the atmosphere are in a sealed environment formed by the test tube body and the test tube plug for subsequent firing;
[0040] S6. Place the sample test tube in a heating assembly for firing, and obtain the material through a hydrothermal reaction of the reaction solution.
[0041] In some embodiments, S1 also includes the step of: firing the test tube body on a heating assembly to form a groove at the abutment position of the test tube body and the test tube plug, so as to facilitate the engagement of the test tube plug with the inner wall of the test tube body, thereby further ensuring the airtightness between the test tube body and the test tube plug.
[0042] In some embodiments, before S5, the step of repeating S2, S3, and S4 three times is also included. Steps S2, S3, and S4 can extract the original gas in the sample test tube and introduce the gas in the gas mixing chamber into the sample test tube, thereby completing the gas washing treatment of the sample test tube. Repeating S2, S3, and S4 three times can better control the atmosphere in the sample test tube to avoid the presence of oxygen and the like affecting the growth of subsequent materials. If a vacuum atmosphere is required, the first valve can be opened, the third valve can be closed, and the sample test tube can be vacuumed again.
[0043] Furthermore, the water vapor pressure in the sample tube can be controlled. For example, the specific calculation method can be:
[0044] A quartz tube with an outer diameter of 20 mm and a wall thickness of 1 mm is used. The quartz tube is designed to withstand a pressure of up to 30 MPa. In the process of preparing the medium-temperature water heat-sealed tube material technology, the water system is usually evacuated to -0.08 MPa, so that the water vapor pressure formed inside the quartz tube can reach 30 MPa. The sealing process is usually carried out at 18 cm of the quartz tube. Before sealing the tube, the reagent aqueous solution is added to the quartz tube. The raw material generally occupies a space of 1 cm in height inside the tube, and the amount of water added is 6 ml, which corresponds to approximately 1 / 3 mole of water. The volume of the entire system is 4.326×10 -5 Square meters. According to the ideal gas state equation:
[0045] PV=nRT (1)
[0046] It can be calculated that the maximum temperature that the quartz tube can withstand is 468.29 Kelvin (K), which is 195.14 degrees Celsius. When the water content of the reagent aqueous solution is slightly reduced, such as Figure 4 As shown, when the water content is 5 ml (0.278 mol), the quartz tube can withstand a temperature of 288.80 degrees Celsius, which is below the supercritical temperature of water. This indicates that the material preparation device based on the water heat sealing tube method in the embodiment of the present application can complete the material preparation process under the critical water environment.
[0047] In some embodiments, the firing temperature in S6 is 40-374 degrees Celsius. For example, the firing temperature is 40 degrees Celsius, 50 degrees Celsius, 80 degrees Celsius, 100 degrees Celsius, 150 degrees Celsius, 200 degrees Celsius, 250 degrees Celsius, 300 degrees Celsius, 350 degrees Celsius, 360 degrees Celsius or 374 degrees Celsius.
[0048] The following is further described by means of specific examples.
[0049] Example 1
[0050] This embodiment prepares hydrogen-containing crystals of divalent cobalt compounds. The heating components in the material preparation device based on the water-heat sealing tube method include a hydrogen-oxygen flame machine and a combustion furnace, argon gas is stored in the first gas storage chamber, and hydrogen gas is stored in the second gas storage chamber. The reaction solution used is 4 ml of distilled water. The specific steps are as follows:
[0051] (1) Adjust the first valve, the second valve, the third valve, and the fourth valve to the closed state, fix the sample test tube on the fourth pipe, turn on the vacuum assembly, and evacuate the sample test tube; turn on the oxyhydrogen flame machine, place the sample test tube on the oxyhydrogen flame machine for firing, and burn a groove on the test tube body for fixing the test tube plug; turn off the oxyhydrogen flame machine, and remove the sample test tube after it cools down.
[0052] (2) Fill the sample test tube with the reaction solution and fill the test tube plug at one end. After completion, reconnect the sample test tube to the fourth pipeline; open the second valve and the fourth valve to introduce the gas in the first gas storage chamber and the second gas storage chamber into the gas mixing chamber; open the first valve and the vacuum pumping assembly to evacuate the sample test tube to a vacuum state, then close the first valve. After completion, open the third valve to allow the gas in the gas mixing chamber to fill the sample test tube until it returns to normal pressure, thereby completing the gas washing;
[0053] (3) After repeating (2) three times, close the third valve. At this time, the sample test tube is in the required atmosphere. Place the sample test tube on the oxyhydrogen flame machine, weld the inner wall of the test tube and the test tube plug, remove them after welding, and place the welded test tube sample in a tube furnace for firing at a temperature of 185 degrees Celsius for 14 days. After firing, take out the product in the sample test tube, such as Figure 5 As shown, from Figure 5 It can be seen that the product has the purple characteristic of divalent cobalt and the crystal growth is pure.
[0054] In summary, the material preparation device based on the hydrothermal sealing tube method in the present application can grow materials in a closed and controllable atmosphere or liquid environment, providing a more suitable growth condition for the material, especially for hydrogen-containing compounds such as hydroxyl halides, which are difficult to grow larger single crystal materials in traditional vacuum sealing tube methods and low-temperature hydrothermal synthesis methods.
[0055] It should be understood that the application of the present application is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to this application.
Claims
1. A material preparation device based on a hydrothermal tube sealing method, characterized in that: include: A vacuum assembly, a first gas storage chamber, a gas mixing chamber, a filter, a sample test tube, and a heating assembly; The vacuum pumping assembly is connected to the filter via a first pipe, the first gas storage chamber is connected to the gas mixing chamber via a second pipe, the gas mixing chamber is connected to the first pipe via a third pipe, and the filter is connected to the sample tube via a fourth pipe; Wherein, the heating assembly is configured to heat the sample test tube, the first gas storage chamber is configured to store gas, the sample test tube includes a test tube body and a test tube plug, one end of the test tube body is detachably connected to the fourth pipeline, and the test tube plug is inserted in the test tube body.
2. The material preparation device based on the water heat sealing method according to claim 1 is characterized in that: A first valve is provided on the first pipeline, and the first valve is located between the connection point of the first pipeline and the third pipeline and the connection point of the first pipeline and the vacuum pumping component on the first pipeline, a second valve is provided on the second pipeline, and a third valve is provided on the third pipeline.
3. The material preparation device based on the water heat sealing method according to claim 1 is characterized in that: The test tube body is one of a quartz tube, a borosilicate glass tube and a metal tube.
4. The material preparation device based on the water heat sealing method according to claim 1, characterized in that: The filler in the filter includes at least one of quartz sand, anthracite, activated carbon and ceramic fiber.
5. The material preparation device based on the water heat sealing method according to claim 1 is characterized in that: The material preparation device based on the water heat sealing tube method also includes a second gas storage chamber, which is configured to store gas, and the second gas storage chamber is connected to the gas mixing chamber through a fifth pipeline.
6. The material preparation device based on the water heat sealing method according to claim 5, characterized in that: The fifth pipeline is provided with a fourth valve.
7. A method for preparing a material based on hydrothermal synthesis, characterized in that: The material preparation device based on the water heat sealing tube method according to claim 2 is used for preparation, comprising the steps of: (1) providing a reaction solution, filling the reaction solution into a test tube body, inserting a test tube stopper, and connecting the test tube body to a fourth pipeline; (2) closing the first valve and the third valve, opening the second valve, and introducing the gas in the first gas storage chamber into the gas mixing chamber; (3) Close the second valve, open the first valve and the vacuum assembly, and evacuate the sample tube; (4) closing the first valve and opening the third valve to allow the gas in the gas mixing chamber to flow into the sample test tube; (5) Welding the test tube body and the test tube plug; (6) The sample test tube is placed in a heating assembly for firing, and the reaction solution undergoes a hydrothermal reaction to obtain a material.
8. The preparation method according to claim 7, characterized in that: The method further includes the following steps before (1): The test tube body is fired on the heating assembly so that a groove appears at the position where the test tube body abuts against the test tube plug.
9. The preparation method according to claim 7, characterized in that: The method also includes the steps of repeating (2), (3) and (4) three times before step (5).
10. The preparation method according to claim 7, characterized in that: The firing temperature in (6) is 40-374 degrees Celsius.