Preparation method and application of super absorbent material

Abstract

The invention provides a preparation method and application of a super absorbent material, and relates to the technical field of materials.The preparation method comprises the following steps that firstly, metal salt, a ligand, a mineralizing agent and a solvent are weighed and placed in a beaker; step 2, heating and stirring, then transferring into a polytetrafluoroethylene lining of a hydrothermal high-temperature reaction kettle, cooling to room temperature, and centrifugally filtering out an MOFs crude product; 3, washing operation is conducted through a washing agent, then a final product is put in a vacuum drying oven overnight to reach the constant weight, finally, a solid material is smashed, and the water-absorbing MOFs are obtained. 4, PVA-COOH is obtained through a ring-opening reaction between the hydroxyl group and the acid anhydride group; 5, PVA-COOH, carboxyl in MOFs and amino in PDA are subjected to a cross-linking reaction, the MOFs mussel-imitating composite material is synthesized, and the method is easy to operate and wide in application range and has wide application prospects.

Description

Technical Field

[0001] The present invention relates to the field of material technology, and in particular to a preparation method and application of a highly water-absorbent material. Background Art

[0002] In modern society, air conditioning has become a necessity in our daily lives. Its cooling principle is essentially based on heat exchange. Under ideal conditions, where no losses are considered, air conditioning cools the room by transferring heat from the indoor space to the outdoors. To minimize energy consumption while maintaining the same temperature, we can consider reducing the specific heat capacity of the air. The lower the specific heat capacity, the less energy is released when the indoor air drops in temperature by the same amount. This reduces the amount of heat exchanged and energy consumption. Since the specific heat capacity of water vapor in air is much higher than that of other components, dehumidification can be used to reduce the amount of water vapor, thereby lowering the overall specific heat capacity of the air.

[0003] At present, there are many technologies that use dehumidification methods to reduce air conditioning energy consumption. For example, patent CN101818930B mentions a multifunctional air conditioning fan that can dehumidify the air and a dehumidification method thereof. The method uses an existing evaporative cooling fan and adds inorganic desiccant such as calcium chloride aqueous solution and lithium chloride aqueous solution. This method adds a dehumidification function on the basis of the traditional evaporative cooling fan to save energy. However, although this design is ingenious, it has limitations. The regeneration temperature of the inorganic desiccant is high, and a large amount of energy is required for regeneration. It is also inconsistent with the current development of low-carbon green concepts. Patent 115364822B introduces a hygroscopic The synthesis method and application of MOFs. The patent describes the synthesis and simple application of hygroscopic MOFs. However, the performance of the MOFs in the patent is poor, with a specific surface area of ​​only 900-1600m² / g and a water vapor adsorption capacity of only 0.35-0.68wt%. In actual use, a large amount of material is required, and desorption and adsorption dehumidification are frequently performed. The complex working conditions of adsorption and desorption treatment (large temperature and humidity differences and large air volume changes) will cause MOF powder to fall off, reducing the moisture absorption effect and posing a safety hazard. On the other hand, the use of the material is only applied in a few specific aspects and has not been expanded to various equipment. The universality of the material is not high. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the present invention provides a preparation method and application of a super absorbent material, which can effectively solve the problems in the background technology.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: A method for preparing a super absorbent material, specifically comprising the following steps:

[0006] Step 1: Weigh 0.01-0.2 mol of metal salt, 0.001-0.2 mol of ligand, 0.005-0.5 mol of mineralizer, and 5-100 ml of solvent into a beaker;

[0007] Step 2: Heat and stir for 2-8 hours, then transfer to the polytetrafluoroethylene lining of a hydrothermal high-temperature reactor, heat the autoclave at 100-240°C for 4-48 hours, cool to room temperature, and centrifuge to filter out the crude MOFs;

[0008] Step 3: Washing with detergent, then placing the final product in a vacuum oven overnight to reach a constant weight, and finally crushing the solid material to obtain water-absorbing MOFs;

[0009] Step 4: Weigh 0.2-10g of polyvinyl alcohol and dissolve it in 90-99.8g of water, stir and dissolve it thoroughly to obtain a polyvinyl alcohol solution, weigh 2-10g of succinic anhydride and dissolve it in 90-99.8g of water to obtain a succinic anhydride solution, add 50-70 parts of the polyvinyl alcohol solution to 30-50 parts of succinic anhydride, add 0.2-3g of ethylenediamine, and react at 50-80°C for 1-4h to obtain PVA-COOH through a ring-opening reaction between the hydroxyl group and the anhydride group;

[0010] Step 5: Dissolve 0.5-10g of polydopamine in 90-99.5g of water to obtain a polydopamine solution, add 15-30 parts of the polydopamine solution to a mixture of 5-20 parts of PVA-COOH solution and 50-80 parts of water-absorbing MOFs, then add 1-2 parts of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and 1-2 parts of N-hydroxysuccinimide, and synthesize MOFs-mimicking mussel composite materials through cross-linking reaction between PVA-COOH and the carboxyl groups in MOFs and the amino groups in PDA.

[0011] Preferably, the metal salt in step 1 is zirconium chloride, aluminum sulfate 18-hydrate, ferric chloride hexahydrate, chromium nitrate nonahydrate, or chromium hydroxide octahydrate.

[0012] Preferably, the ligand in step 1 is terephthalic acid, fumaric acid, trimeric acid, or 2-aminoterephthalic acid.

[0013] Preferably, the mineralizer in step 1 is acetic acid, sodium hydroxide or hydrofluoric acid.

[0014] Preferably, the solvent in step 1 is N,N-dimethylformamide, ethanol, water, tetrahydrofuran, or dimethylformamide.

[0015] Preferably, the heating and stirring temperature in step 2 is 60-100°C.

[0016] Preferably, the detergent in step 3 is water, ethanol, N,N-dimethylformamide, dimethylformamide, or ethyl acetate.

[0017] Preferably, the temperature of the vacuum oven in step 3 is 80-180°C.

[0018] Preferably, the stirring and dissolving temperature in step 4 is 70-95°C.

[0019] The highly absorbent material prepared by the method is used as follows: a prepared MOFs imitation mussel binder is poured into the feed port of a sprayer, and then the pressure and flow rate, spraying distance and speed of the spray gun are adjusted. The composite gel solution is then sprayed onto air conditioner fins, and then naturally cured for 30-120 minutes. The composite gel solution is then placed in a 50-120°C oven for curing for 2-48 hours to obtain a sprayed MOFs mussel composite material fin.

[0020] The present invention provides a method for preparing and applying a highly absorbent material. The method has the following beneficial effects:

[0021] The present invention first improves the material performance so that it can adsorb more water vapor under the same load, thereby enhancing the dehumidification effect. At the same time, in response to the challenges of high temperature difference, high humidity difference and large air volume changes brought about by frequent adsorption and desorption operations in existing dehumidification conditions, the mussel-like adhesive is combined with the MOFs material to prepare a MOFs mussel composite material. This composite material has improved adhesion, effectively prevents the adsorption material from falling off, and avoids the performance degradation and health risks caused by this. Secondly, it can achieve a more energy-saving and environmentally friendly effect. According to experimental results, under conditions of 70% relative humidity, energy consumption can be reduced by 41.76%. This data fully demonstrates the significant advantages in energy saving. Finally, a spraying method is used to form a MOFs mussel composite hygroscopic functional layer, which can provide energy for various materials that require dehumidification and water vapor removal. This method is simple to operate, has a wide range of applications, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a scanning electron microscope image of the MOFs mimicking mussel composite material of Example 1 of the present invention;

[0023] Figure 2 This is a scanning electron microscope image of the MOFs mimicking mussel composite material of Example 2 of the present invention;

[0024] Figure 3 This is a scanning electron microscope image of the MOFs-mimicking mussel composite material of Example 3 of the present invention;

[0025] Figure 4 This is the XRD pattern of the embodiment of the present invention;

[0026] Figure 5 Nitrogen adsorption and specific surface area graph of MOFs mussels composite in the application;

[0027] Figure 6 Isothermal adsorption curve graph of the example in the application;

[0028] Figure 7 Water vapor adsorption curve graph of the example in the application

[0029] Figure 8 Actual test data table graph of MOFs mussels composite in the application. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the application will be apparently and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the protection scope of the application.

[0031] Example 1:

[0032] A preparation method of a high water absorption material, specifically comprising the following steps:

[0033] Step one: weigh 0.15 mol of metal salt, 0.2 mol of ligand, 1.25 mol of mineralizer and 100 ml of solvent in a beaker;

[0034] Step two: heat and stir for 4 h, then transfer to the tetrafluoro lining of a hydrothermal high-temperature reaction kettle. The high-pressure kettle is heated at 240℃ for 48 h. After cooling to room temperature, centrifugal filtration is performed to obtain MOFs crude product;

[0035] Step three: perform washing operation using a detergent, then make the final product in a vacuum oven overnight to achieve constant weight. Finally, crush the solid material to obtain water absorption MOFs;

[0036] Step four: weigh 0.5 g of polyvinyl alcohol and dissolve in 99.5 g of water, stir to dissolve completely to obtain a polyvinyl alcohol solution. Weigh 2 g of succinic anhydride and dissolve in 98 g of water to obtain a succinic anhydride solution. Add 60 parts of the polyvinyl alcohol solution to 40 parts of the succinic anhydride, and add 0.5 g of ethylenediamine. React at 60℃ for 2 h to obtain PVA-COOH through ring-opening reaction between hydroxyl and anhydride groups;

[0037] Step 5: Dissolve 1g of polydopamine in 99g of water to obtain a polydopamine solution, add 15 parts of the polydopamine solution to a mixture of 10 parts of PVA-COOH solution and 80 parts of water-absorbing MOFs, then add 1 part of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and 1.5 parts of N-hydroxysuccinimide, and synthesize a MOFs-mimicking mussel composite material through cross-linking reaction between PVA-COOH and the carboxyl groups in MOFs and the amino groups in PDA.

[0038] Wherein, the metal salt in the step 1 is zirconium chloride, aluminum sulfate 18hydrate, ferric chloride hexahydrate, chromium nitrate nonahydrate, and chromium hydroxide octahydrate.

[0039] Wherein, the ligand in the step 1 is terephthalic acid, fumaric acid, trimeric acid, or 2-aminoterephthalic acid.

[0040] Wherein, the mineralizer in step 1 is acetic acid, sodium hydroxide, and hydrofluoric acid.

[0041] Wherein, the solvent in the step 1 is N,N-dimethylformamide, ethanol, water, tetrahydrofuran, and dimethylformamide.

[0042] Wherein, the heating and stirring temperature in the step 2 is 80°C.

[0043] Wherein, the detergent in step 3 is water, ethanol, N,N-dimethylformamide, dimethylformamide, and ethyl acetate.

[0044] Wherein, the temperature of the vacuum oven in step 3 is 150°C.

[0045] Wherein, the stirring and dissolving temperature in step 4 is 80°C.

[0046] The highly absorbent material prepared by the method is used as follows: the prepared MOFs imitation mussel binder is poured into the feed port of the sprayer, and then the pressure and flow rate of the spray gun, the spraying distance and speed are adjusted. The composite gel solution is then sprayed onto the air conditioner fin, and then naturally cured for 120 minutes. It is then placed in a 120°C oven for curing for 48 hours to obtain the sprayed MOFs mussel composite material fin.

[0047] Example 2:

[0048] A method for preparing a highly absorbent material comprises the following steps:

[0049] Step 1: Weigh 0.105 mol of metal salt, 0.1 mol of ligand, 0.25 mol of mineralizer, and 50 ml of solvent into a beaker;

[0050] Step 2: Heat and stir for 3 hours, then transfer to the polytetrafluoroethylene lining of a hydrothermal high-temperature reactor. The autoclave is heated at 170°C for 25 hours. After cooling to room temperature, the crude MOFs are centrifuged and filtered.

[0051] Step 3: Washing with detergent, then placing the final product in a vacuum oven overnight to reach a constant weight, and finally crushing the solid material to obtain water-absorbing MOFs;

[0052] Step 4: Weigh 1g of polyvinyl alcohol and dissolve it in 99g of water, stir and dissolve it thoroughly to obtain a polyvinyl alcohol solution, weigh 2g of succinic anhydride and dissolve it in 98g of water to obtain a succinic anhydride solution, add 60 parts of the polyvinyl alcohol solution to 40 parts of succinic anhydride, add 1g of ethylenediamine, and react at 60°C for 2h to obtain PVA-COOH through a ring-opening reaction between the hydroxyl group and the anhydride group;

[0053] Step 5: Dissolve 1g of polydopamine in 99g of water to obtain a polydopamine solution, add 30 parts of the polydopamine solution to a mixture of 10 parts of PVA-COOH solution and 60 parts of water-absorbing MOFs, then add 1 part of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and 1 part of N-hydroxysuccinimide, and synthesize a MOFs-mimicking mussel composite material through cross-linking reaction between PVA-COOH and the carboxyl groups in MOFs and the amino groups in PDA.

[0054] Wherein, the metal salt in the step 1 is zirconium chloride, aluminum sulfate 18hydrate, ferric chloride hexahydrate, chromium nitrate nonahydrate, and chromium hydroxide octahydrate.

[0055] Wherein, the ligand in the step 1 is terephthalic acid, fumaric acid, trimeric acid, or 2-aminoterephthalic acid.

[0056] Wherein, the mineralizer in step 1 is acetic acid, sodium hydroxide, and hydrofluoric acid.

[0057] Wherein, the solvent in the step 1 is N,N-dimethylformamide, ethanol, water, tetrahydrofuran, and dimethylformamide.

[0058] Wherein, the heating and stirring temperature in the step 2 is 60°C.

[0059] Wherein, the detergent in step 3 is water, ethanol, N,N-dimethylformamide, dimethylformamide, and ethyl acetate.

[0060] Wherein, the temperature of the vacuum oven in step 3 is 150°C.

[0061] Wherein, the stirring and dissolving temperature in step 4 is 80°C.

[0062] The highly absorbent material prepared by the method is used as follows: the prepared MOFs imitation mussel binder is poured into the feed port of the sprayer, and then the pressure and flow rate of the spray gun, the spraying distance and speed are adjusted. The composite gel solution is then sprayed onto the air conditioner fin, and then naturally cured for 75 minutes. It is then placed in an 80°C oven for curing for 12 hours to obtain the sprayed MOFs mussel composite material fin.

[0063] Example 3:

[0064] A method for preparing a highly absorbent material comprises the following steps:

[0065] Step 1: Weigh 0.01 mol of metal salt, 0.01 mol of ligand, 0.01 mol of mineralizer, and 100 ml of solvent into a beaker;

[0066] Step 2: Heat and stir for 2 hours, then transfer to the polytetrafluoroethylene lining of a hydrothermal high-temperature reactor. The autoclave is heated at 220°C for 8 hours. After cooling to room temperature, the crude MOFs are centrifuged and filtered.

[0067] Step 3: Washing with detergent, then placing the final product in a vacuum oven overnight to reach a constant weight, and finally crushing the solid material to obtain water-absorbing MOFs;

[0068] Step 4: Weigh 2 g of polyvinyl alcohol and dissolve it in 98 g of water, stir and dissolve it thoroughly to obtain a polyvinyl alcohol solution, weigh 2 g of succinic anhydride and dissolve it in 98 g of water to obtain a succinic anhydride solution, add 60 parts of the polyvinyl alcohol solution to 40 parts of succinic anhydride, add 0.5% ethylenediamine, and react at 60°C for 2 hours to obtain PVA-COOH through a ring-opening reaction between the hydroxyl group and the anhydride group;

[0069] Step 5: Dissolve 1g of polydopamine in 99g of water to obtain a polydopamine solution, add 15 parts of the polydopamine solution to a mixture of 10 parts of PVA-COOH solution and 75 parts of water-absorbing MOFs, then add 1 part of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and 1.5 parts of N-hydroxysuccinimide, and synthesize a MOFs-mimicking mussel composite material through cross-linking reaction between PVA-COOH and the carboxyl groups in MOFs and the amino groups in PDA.

[0070] Wherein, the metal salt in the step 1 is zirconium chloride, aluminum sulfate 18hydrate, ferric chloride hexahydrate, chromium nitrate nonahydrate, and chromium hydroxide octahydrate.

[0071] Wherein, the ligand in the step 1 is terephthalic acid, fumaric acid, trimeric acid, or 2-aminoterephthalic acid.

[0072] Wherein, the mineralizer in step 1 is acetic acid, sodium hydroxide, and hydrofluoric acid.

[0073] Wherein, the solvent in the step 1 is N,N-dimethylformamide, ethanol, water, tetrahydrofuran, and dimethylformamide.

[0074] Wherein, the heating and stirring temperature in the step 2 is 60°C.

[0075] Wherein, the detergent in step 3 is water, ethanol, N,N-dimethylformamide, dimethylformamide, and ethyl acetate.

[0076] Wherein, the temperature of the vacuum oven in step 3 is 120°C.

[0077] Wherein, the stirring and dissolving temperature in step 4 is 80°C.

[0078] The highly absorbent material prepared by the method is used as follows: the prepared MOFs imitation mussel binder is poured into the feed port of the sprayer, and then the pressure and flow rate of the spray gun, the spraying distance and speed are adjusted. The composite gel solution is then sprayed onto the air conditioner fin, and then naturally cured for 30 minutes. It is then placed in a 50°C oven for curing for 2 hours to obtain the sprayed MOFs mussel composite material fin.

[0079] like Figure 8 As shown, the MOFs mussel composite material of Example 3 was sprayed with a 2 mm coating on the air conditioner fins, and compared with the uncoated control group, the power consumption was tested at 30% RH, 40% RH, 50% RH, 60% RH, and 70% RH for 4 hours;

[0080] According to the test results of the synthesized MOFs mussel composite material, it was found that the material has high water absorption and high specific surface area. Compared with previous materials, its water absorption performance has been significantly improved. In addition, through actual comparative tests on the MOFs mussel composite material, it was also observed that: as the humidity decreases, the energy-saving effect of the embodiment also decreases; on the contrary, as the humidity increases, the energy-saving effect of the embodiment increases. In particular, under the condition of 70% RH (relative humidity), the maximum energy-saving effect of 41.76% was observed. This result shows that in a high humidity environment, the hygroscopic MOFs material can fully play its role and show excellent energy-saving effects.

[0081] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. Any obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. A method for preparing a super absorbent material, characterized in that: The specific steps include: Step 1: Weigh 0.01-0.2 mol of metal salt, 0.001-0.2 mol of ligand, 0.005-0.5 mol of mineralizer, and 5-100 ml of solvent into a beaker; Step 2: Heat and stir for 2-8 hours, then transfer to the polytetrafluoroethylene lining of a hydrothermal high-temperature reactor, heat the autoclave at 100-240°C for 4-48 hours, cool to room temperature, and centrifuge to filter out the crude MOFs; Step 3: Washing with detergent, then placing the final product in a vacuum oven overnight to reach a constant weight, and finally crushing the solid material to obtain water-absorbing MOFs; Step 4: Weigh 0.2-10g of polyvinyl alcohol and dissolve it in 90-99.8g of water, stir and dissolve it thoroughly to obtain a polyvinyl alcohol solution, weigh 2-10g of succinic anhydride and dissolve it in 90-99.8g of water to obtain a succinic anhydride solution, add 50-70 parts of the polyvinyl alcohol solution to 30-50 parts of succinic anhydride, add 0.2-3g of ethylenediamine, and react at 50-80°C for 1-4h to obtain PVA-COOH through a ring-opening reaction between the hydroxyl group and the anhydride group; Step 5: Dissolve 0.5-10g of polydopamine in 90-99.5g of water to obtain a polydopamine solution, add 15-30 parts of the polydopamine solution to a mixture of 5-20 parts of PVA-COOH solution and 50-80 parts of water-absorbing MOFs, then add 1-2 parts of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and 1-2 parts of N-hydroxysuccinimide, and synthesize MOFs-mimicking mussel composite materials through cross-linking reaction between PVA-COOH and the carboxyl groups in MOFs and the amino groups in PDA.

2. The method for preparing a super absorbent material according to claim 1, wherein: The metal salts in step 1 are zirconium chloride, aluminum sulfate 18-hydrate, ferric chloride hexahydrate, chromium nitrate nonahydrate, and chromium hydroxide octahydrate.

3. The method for preparing a super absorbent material according to claim 1, wherein: The ligand in step 1 is terephthalic acid, fumaric acid, trimeric acid, or 2-aminoterephthalic acid.

4. The method for preparing and using a super absorbent material according to claim 1, characterized in that: The mineralizer in step 1 is acetic acid, sodium hydroxide, and hydrofluoric acid.

5. The method for preparing a super absorbent material according to claim 1, wherein: The solvent in step 1 is N,N-dimethylformamide, ethanol, water, tetrahydrofuran, and dimethylformamide.

6. The method for preparing a super absorbent material according to claim 1, wherein: The heating and stirring temperature in the step 2 is 60-100°C.

7. The method for preparing a super absorbent material according to claim 1, wherein: The detergent in step 3 is water, ethanol, N,N-dimethylformamide, dimethylformamide, and ethyl acetate.

8. The method for preparing a super absorbent material according to claim 1, wherein: The temperature of the vacuum oven in step 3 is 80-180°C.

9. The method for preparing a super absorbent material according to claim 1, wherein: The stirring and dissolving temperature in the step 4 is 70-95°C.

10. Use of a super absorbent material prepared by the method according to any one of claims 1 to 9, characterized in that: Pour the prepared MOFs imitation mussel adhesive into the feed port of the sprayer, then adjust the pressure and flow rate of the spray gun, the spraying distance and speed, and then spray the composite gel solution onto the air-conditioning fins. Then naturally cure it for 30-120 minutes, and then place it in a 50-120℃ oven for curing for 2-48 hours to obtain the sprayed MOFs mussel composite material fins.

Images