Preparation method of mesoporous calcium hydroxide
In the preparation process of mesoporous calcium hydroxide, the slow-polymerization liquid and nanocellulose with a three-dimensional network structure are gradually added, and combined with the bubble effect of nitrogen, the problem of high pore structure control and production cost in the preparation of mesoporous calcium hydroxide is solved, and the preparation of mesoporous calcium hydroxide is achieved with high efficiency, low cost and environmentally friendly mesoporous calcium hydroxide.
Patent Information
- Application Number
- CN202510268192.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-07
- Publication Date
- 2025-06-13
AI Technical Summary
In the prior art, the preparation of mesoporous calcium hydroxide has problems such as difficulty in controlling pore structure, harsh reaction conditions, high cost, poor product stability, environmental pollution problems and large-scale production difficulties.
By mixing the water-soluble calcium salt with water, adding lye dropwise to conduct a hydrothermal reaction, and gradually adding a slow-cooling liquid with a three-dimensional network structure while adding lye dropwise to control the content and reaction conditions of organic macromolecules, mesoporous calcium hydroxide was prepared by combining the bubble action of nitrogen and the addition of nanocellulose.
It realizes effective control of the integrity and uniformity of mesoporous calcium hydroxide pores, improves the performance and stability of materials, reduces production costs, reduces environmental pollution, and is suitable for large-scale production.
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Abstract
Description
Technical Field
[0001] The present invention relates to the field of construction technology, and particularly relates to a preparation method of mesoporous calcium hydroxide. Background Art
[0002] Mesoporous calcium hydroxide is a calcium hydroxide material with a mesoporous structure. Mesopores refer to pores with a pore diameter between 2 and 50 nanometers. This structure endows the material with a large specific surface area and high adsorption performance. Mesoporous calcium hydroxide can be prepared by various methods, such as the template method, sol-gel method, etc.
[0003] Mesoporous calcium hydroxide has potential application value in the field of building materials. For example, adding mesoporous calcium hydroxide to concrete can improve the microscopic structure of concrete, enhance its compressive strength and crack resistance; mesoporous calcium hydroxide can improve the environmental performance of building materials by adsorbing and neutralizing harmful substances. For example, adding mesoporous calcium hydroxide to interior decoration materials can effectively adsorb harmful gases such as formaldehyde and improve indoor air quality; mesoporous calcium hydroxide can improve the weather resistance of building materials, enabling them to maintain good performance in harsh environments. For example, adding mesoporous calcium hydroxide to exterior wall coatings can improve the water resistance and UV resistance of the coatings and extend the service life of the coatings. Mesoporous calcium hydroxide can be added as a functional filler to various building materials to improve the functionality and added value of the materials. For example, adding mesoporous calcium hydroxide to waterproof materials can improve the waterproof performance and anti-aging performance of the materials.
[0004] In summary, mesoporous calcium hydroxide has broad application prospects in the field of building materials, can significantly improve the performance and added value of building materials, and promote the technological progress and sustainable development of the building materials industry.
[0005] However, in the prior art, mesoporous calcium hydroxide still has the following problems:
[0006] (1) Difficult to control the pore structure: During the preparation process, how to precisely control the size and distribution of pores is a challenge. An overly large or small pore diameter will affect the performance of the material.
[0007] (2) Harsh reaction conditions: Preparing mesoporous calcium hydroxide usually requires specific temperature, pressure, and reaction time. Controlling these conditions is difficult, and a slight mistake may result in unqualified products.
[0008] (3) High cost: Due to the complex preparation process, the required equipment and raw material costs are high, which limits its large-scale production and application.
[0009] (4) Poor product stability: The prepared mesoporous calcium hydroxide is prone to pore collapse or blockage during storage and use, affecting its performance and service life.
[0010] (5) Environmental pollution problem: Some preparation methods may produce harmful by-products, causing environmental pollution. Therefore, more environmentally friendly preparation processes need to be developed.
[0011] (6) Difficulty in large-scale production: The methods for preparing mesoporous calcium hydroxide under laboratory conditions are often difficult to be directly applied to industrial production, and a large number of process optimizations and scale-up tests are required.
[0012] Solving these problems requires further research and technological development to achieve an efficient, low-cost, and environmentally friendly method for preparing mesoporous calcium hydroxide. Summary of the Invention
[0013] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art, and to provide a method for preparing mesoporous calcium hydroxide.
[0014] The technical solution of the present invention is as follows:
[0015] A method for preparing mesoporous calcium hydroxide, comprising the following steps:
[0016] Mix a water-soluble calcium salt and water to obtain a precursor solution; then dropwise add an alkali solution and conduct a hydrothermal reaction. After the hydrothermal reaction, centrifuge, wash with water, and dry to obtain mesoporous calcium hydroxide;
[0017] While dropping the alkali solution, add a retarder solution with a gradually increasing content;
[0018] The preparation method of the retarder solution is as follows:
[0019] Mix 10 - 12 parts of polyether block amide, 80 - 100 parts of n-butanol, and 0.5 - 1.2 parts of 1-zinc-based-3-vinylimidazolium hexafluorophosphate evenly at 60 - 70 °C, then continue to add 0.3 - 0.6 parts of a crosslinking agent and 0.1 - 0.3 parts of an initiator, and react at 60 - 70 °C for 10 - 15 hours to obtain it.
[0020] As a preferred embodiment of the present invention, adding the retarder solution with a gradually increasing content while dropping the alkali solution is specifically as follows: Add the retarder solution accounting for 1 - 3 wt% of the precursor solution for the first time, add the retarder solution accounting for 3 - 5 wt% of the precursor solution for the second time, and add the retarder solution accounting for 5 - 7 wt% of the precursor solution for the third time.
[0021] As a preferred embodiment of the present invention, the interval time between each addition of the retarder solution is 5 - 10 min.
[0022] As a preferred embodiment of the present invention, nitrogen is introduced while adding the retarder solution.
[0023] As a preferred embodiment of the present invention, the water-soluble calcium salt includes calcium chloride or calcium dihydrogen phosphate.
[0024] As a preferred embodiment of the present invention, the alkali solution includes sodium hydroxide solution or potassium hydroxide solution.
[0025] As a preferred embodiment of the present invention, the hydrothermal reaction temperature is 150 - 250 °C, and the hydrothermal reaction time is 8 - 10 h.
[0026] As a preferred embodiment of the present invention, the initiator is azobisisobutyronitrile, and the crosslinking agent is 1,6 - hexanediol diacrylate, ethylene glycol dimethacrylate or divinylbenzene.
[0027] As a preferred embodiment of the present invention, nano - cellulose accounting for 1 - 3 wt% of the precursor solution is further added to the precursor solution.
[0028] The beneficial effects of the present invention are as follows:
[0029] A preparation method of mesoporous calcium hydroxide of the present invention is to gradually add organic substances with a three - dimensional network structure in different contents to the precursor solution. On the one hand, the purpose is to prolong the contact time between the alkali solution and the calcium salt, avoid too fast reaction, prevent the calcium hydroxide from growing too fast and agglomerating, so that the pore channels of calcium hydroxide are more complete. On the other hand, through the control of the content, the strength of the blocking ability of the organic macromolecules can realize the control of the mesoporous channels. Moreover, combined with the bubbling effect of nitrogen, it can also block to a certain extent. In addition, combined with the added nano - cellulose, the crystallization rate of calcium hydroxide is increased, the strength of the pore structure is improved, its pore channels are not easy to collapse, and the pore channel uniformity is good. Moreover, the specific structure of the retarder macromolecules of the present invention makes it more conducive to blocking calcium hydroxide. Specific Embodiments
[0030] The embodiments of the present invention are 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. For those without specific technical or conditions noted in the embodiments, the technologies or conditions described in the literature in the field or according to the product specifications are followed. For reagents or instruments without indicating the manufacturer, they are all conventional products that can be obtained through commercial purchase.
[0031] Example 1
[0032] A preparation method of mesoporous calcium hydroxide includes the following steps:
[0033] Mix a water - soluble calcium salt and water to obtain a precursor solution; then dropwise add an alkali solution and carry out a hydrothermal reaction. After the hydrothermal reaction, centrifuge, wash with water and dry to obtain mesoporous calcium hydroxide;
[0034] While dropping the alkali solution, add a retarder with a gradually increasing content;
[0035] The preparation method of the retarder solution is as follows:
[0036] Mix 10 parts of polyether block amide, 90 parts of n-butanol, and 0.7 part of 1-zinc-based-3-vinylimidazolium hexafluorophosphate evenly at 65°C, then continue to add 0.4 part of crosslinking agent and 0.2 part of initiator, and react at 65°C for 12 hours to obtain it.
[0037] When adding the alkali solution dropwise, add the retarder solution with a gradually increasing content as follows: add the retarder solution accounting for 2 wt% of the precursor solution for the first time, add the retarder solution accounting for 4 wt% of the precursor solution for the second time, and add the retarder solution accounting for 6 wt% of the precursor solution for the third time.
[0038] The interval time between each addition of the retarder solution is 7 min.
[0039] Introduce nitrogen gas while adding the retarder solution.
[0040] The water-soluble calcium salt includes calcium chloride, and the calcium ion concentration of the precursor solution is 0.5 mol / L.
[0041] The alkali solution includes a sodium hydroxide solution with a concentration of 2 mol / L.
[0042] The hydrothermal reaction temperature is 200°C, and the hydrothermal reaction time is 9 h.
[0043] The initiator is azobisisobutyronitrile, and the crosslinking agent is 1,6-hexanediol diacrylate, ethylene glycol dimethacrylate or divinylbenzene.
[0044] 1 wt% of nanocellulose based on the precursor solution is further added to the precursor solution.
[0045] Example 2
[0046] A preparation method of mesoporous calcium hydroxide includes the following steps:
[0047] Mix the water-soluble calcium salt and water to obtain a precursor solution; then add the alkali solution dropwise, conduct a hydrothermal reaction, and after the hydrothermal reaction, obtain mesoporous calcium hydroxide through centrifugation, washing with water, and drying;
[0048] Add the retarder solution with a gradually increasing content while adding the alkali solution dropwise;
[0049] The preparation method of the retarder solution is as follows:
[0050] Mix 10 parts of polyether block amide, 80 parts of n-butanol, and 1 part of 1-zinc-based-3-vinylimidazolium hexafluorophosphate evenly at 65°C, then continue to add 0.5 part of crosslinking agent and 0.2 part of initiator, and react at 65°C for 12 hours to obtain it.
[0051] While adding the alkaline solution, a retarder solution with a gradually increasing content is added as follows: for the first time, a retarder solution accounting for 3 wt% of the precursor solution is added; for the second time, a retarder solution accounting for 5 wt% of the precursor solution is added; for the third time, a retarder solution accounting for 7 wt% of the precursor solution is added.
[0052] The interval time between each addition of the retarder solution is 6 min.
[0053] Nitrogen is introduced while adding the retarder solution.
[0054] The water-soluble calcium salt includes calcium chloride, and the calcium ion concentration of the precursor solution is 0.5 mol / L.
[0055] The alkaline solution includes a sodium hydroxide solution with a concentration of 2 mol / L.
[0056] The hydrothermal reaction temperature is 200 °C, and the hydrothermal reaction time is 9 h.
[0057] The initiator is azobisisobutyronitrile, and the crosslinking agent is 1,6 - hexanediol diacrylate, ethylene glycol dimethacrylate or divinylbenzene.
[0058] 2 wt% of nanocellulose based on the precursor solution is further added to the precursor solution.
[0059] Example 3
[0060] A preparation method of mesoporous calcium hydroxide includes the following steps:
[0061] Mix the water-soluble calcium salt and water to obtain a precursor solution; then add the alkaline solution dropwise and carry out a hydrothermal reaction. After the hydrothermal reaction, centrifuge, wash with water and dry to obtain mesoporous calcium hydroxide;
[0062] While adding the alkaline solution, a retarder solution with a gradually increasing content is added;
[0063] The preparation method of the retarder solution is as follows:
[0064] Mix 12 parts of polyether block amide, 100 parts of n-butanol and 1.2 parts of 1-zinc-based-3-vinylimidazolium hexafluorophosphate evenly at 70 °C, then continue to add 0.6 part of crosslinking agent and 0.3 part of initiator, and react at 70 °C for 15 hours to obtain it.
[0065] While adding the alkaline solution, a retarder solution with a gradually increasing content is added as follows: for the first time, a retarder solution accounting for 2 wt% of the precursor solution is added; for the second time, a retarder solution accounting for 5 wt% of the precursor solution is added; for the third time, a retarder solution accounting for 7 wt% of the precursor solution is added.
[0066] The interval time between each addition of the retarder solution is 10 min.
[0067] While adding the retarder solution, nitrogen gas is introduced.
[0068] The water-soluble calcium salt includes calcium chloride, and the calcium ion concentration in the precursor solution is 0.5 mol / L.
[0069] The lye includes a sodium hydroxide solution with a concentration of 2 mol / L.
[0070] The hydrothermal reaction temperature is 250 °C, and the hydrothermal reaction time is 10 h.
[0071] The initiator is azobisisobutyronitrile, and the crosslinking agent is 1,6-hexanediol diacrylate, ethylene glycol dimethacrylate or divinylbenzene.
[0072] 3 wt% of nanocellulose based on the precursor solution is further added to the precursor solution.
[0073] Example 4
[0074] A preparation method of mesoporous calcium hydroxide includes the following steps:
[0075] Mix a water-soluble calcium salt and water to obtain a precursor solution; then dropwise add lye and conduct a hydrothermal reaction. After the hydrothermal reaction, centrifuge, wash with water and dry to obtain mesoporous calcium hydroxide;
[0076] While dropping the lye, add a retarder solution with a gradually increasing content;
[0077] The preparation method of the retarder solution is as follows:
[0078] Mix 12 parts of polyether block amide, 95 parts of n-butanol, and 0.7 part of 1-zinc-based-3-vinylimidazole hexafluorophosphate evenly at 70 °C, then continue to add 0.6 part of crosslinking agent and 0.3 part of initiator, and react at 70 °C for 12 hours to obtain it.
[0079] The specific operation of adding a retarder solution with a gradually increasing content while dropping the lye is as follows: add a retarder solution accounting for 1 wt% of the precursor solution for the first time, add a retarder solution accounting for 5 wt% of the precursor solution for the second time, and add a retarder solution accounting for 7 wt% of the precursor solution for the third time.
[0080] The interval time between each addition of the retarder solution is 7 min.
[0081] While adding the retarder solution, nitrogen gas is introduced.
[0082] The water-soluble calcium salt includes calcium chloride, and the calcium ion concentration in the precursor solution is 0.5 mol / L.
[0083] The lye includes a sodium hydroxide solution with a concentration of 2 mol / L.
[0084] The hydrothermal reaction temperature is 250 °C and the hydrothermal reaction time is 10 h.
[0085] The initiator is azobisisobutyronitrile, and the crosslinking agent is 1,6 - hexanediol diacrylate, ethylene glycol dimethacrylate or divinylbenzene.
[0086] The precursor solution is also added with nanocellulose accounting for 3 wt% of the precursor solution.
[0087] Example 5
[0088] A preparation method of mesoporous calcium hydroxide includes the following steps:
[0089] Mix a water - soluble calcium salt and water to obtain a precursor solution; then dropwise add an alkali solution and carry out a hydrothermal reaction. After the hydrothermal reaction, centrifuge, wash with water and dry to obtain mesoporous calcium hydroxide;
[0090] Add a retarder with a gradually increasing content while dropping the alkali solution;
[0091] The preparation method of the retarder is as follows:
[0092] Mix 12 parts of polyether block amide, 100 parts of n - butanol, and 0.9 part of 1 - zinc - based - 3 - vinylimidazolium hexafluorophosphate evenly at 70 °C, then continue to add 0.6 part of crosslinking agent and 0.3 part of initiator, and react at 70 °C for 15 hours to obtain it.
[0093] Adding a retarder with a gradually increasing content while dropping the alkali solution is specifically as follows: add the retarder accounting for 2 wt% of the precursor solution for the first time, add the retarder accounting for 4 wt% of the precursor solution for the second time, and add the retarder accounting for 7 wt% of the precursor solution for the third time.
[0094] The interval time for each addition of the retarder is 8 min.
[0095] Pass nitrogen while adding the retarder.
[0096] The water - soluble calcium salt includes calcium chloride, and the calcium ion concentration of the precursor solution is 0.5 mol / L.
[0097] The alkali solution includes a sodium hydroxide solution with a concentration of 2 mol / L.
[0098] The hydrothermal reaction temperature is 200 °C and the hydrothermal reaction time is 9 h.
[0099] The initiator is azobisisobutyronitrile, and the crosslinking agent is 1,6 - hexanediol diacrylate, ethylene glycol dimethacrylate or divinylbenzene.
[0100] The precursor solution is also added with nanocellulose accounting for 1.5 wt% of the precursor solution.
[0101] Comparative Example 1
[0102] Different from Example 2, a retarder solution accounting for 14 wt% of the precursor solution was added while adding the alkali solution dropwise.
[0103] Comparative Example 2
[0104] Different from Example 2, nano-cellulose was not added to the precursor solution.
[0105] Comparative Example 3
[0106] Different from Example 2, nitrogen was not introduced while adding the retarder solution.
[0107] The performances of the above-mentioned examples and comparative examples were tested, and the test results are shown in Table 1.
[0108] Table 1 Performance test results of examples and comparative examples
[0109]
[0110]
[0111] As can be seen from the above table, the performance of the examples is better than that of the comparative examples. The main reasons may be as follows: From the analysis of Comparative Example 1, different contents of organic substances with a three-dimensional network structure were gradually added in the examples. On the one hand, the purpose was to prolong the contact time between the alkali solution and the calcium salt, avoid too fast reaction, prevent the rapid growth and agglomeration of calcium hydroxide, so that the pores of calcium hydroxide are more complete. On the other hand, through the control of the content, the barrier ability of the organic macromolecules can be used to control the mesoporous channels; From the analysis of Comparative Example 2, the added nano-cellulose in the examples increased the crystallization rate of calcium hydroxide, improved the strength of the pore structure, made its pores not easy to collapse, and made the pore uniformity good. From the analysis of Comparative Example 3, the bubbling effect of nitrogen can also play a role in blocking to a certain extent.
[0112] The above-mentioned embodiments only represent the preferred embodiments of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, according to the technical solutions and concepts described above, various other corresponding changes and deformations can also be made, and all these changes and deformations should fall within the protection scope of the claims of the present invention.
Claims
1. A method for preparing mesoporous calcium hydroxide, characterized in that, The following steps are involved: Mixing a water-soluble calcium salt and water to obtain a precursor solution; then dropping an alkali solution to carry out a hydrothermal reaction, centrifuging, washing with water, and drying after the hydrothermal reaction to obtain mesoporous calcium hydroxide; While adding the alkali solution dropwise, a gradually increasing amount of retarding liquid is added; The preparation method of the slow polymerization solution is as follows: After 10-12 parts of polyether block amide, 80-100 parts of n-butanol and 0.5-1.2 parts of 1-zinc-3-vinyl imidazole hexafluorophosphate are uniformly mixed at 60-70°C, 0.3-0.6 parts of crosslinking agent and 0.1-0.3 parts of initiator are added, and the mixture is reacted at 60-70°C for 10-15 hours to obtain the product.
2. The method for preparing mesoporous strong calcium oxide according to claim 1, characterized in that: The step of adding gradually increasing amounts of retarding liquid while dropping the alkali solution is as follows: the first time, 1-3 wt% of the precursor solution is added; the second time, 3-5 wt% of the precursor solution is added; and the third time, 5-7 wt% of the precursor solution is added.
3. The method for preparing mesoporous strong calcium oxide according to claim 1, characterized in that: The interval between each addition of the buffer solution is 5-10 minutes.
4. A method for preparing mesoporous calcium hydroxide according to claim 1, characterized in that, Nitrogen was introduced while adding the slow polymerization solution.
5. A method for preparing mesoporous calcium hydroxide according to claim 1, characterized in that, The water-soluble calcium salt includes calcium chloride or calcium dihydrogen phosphate.
6. A method for preparing mesoporous calcium hydroxide according to claim 1, characterized in that, The alkali solution includes sodium hydroxide solution or potassium hydroxide solution.
7. A method for preparing mesoporous calcium hydroxide according to claim 1, characterized in that, The hydrothermal reaction temperature is 150-250° C., and the hydrothermal reaction time is 8-10 hours.
8. A method for preparing mesoporous calcium hydroxide according to claim 1, characterized in that, The initiator is azobisisobutyronitrile, and the crosslinking agent is 1,6-hexanediol diacrylate, ethylene glycol dimethacrylate or divinylbenzene.
9. A method for preparing mesoporous calcium hydroxide according to claim 1, characterized in that, The precursor solution is further added with nanocellulose accounting for 1-3wt% of the precursor solution.