Waste cotton fabric based cellulose aerogel fiber and preparation method thereof
By dissolving waste cotton fabric into cellulose spinning liquid and loading metal organic skeleton compounds in cellulose gel fibers, the problem of insufficient toughness of cellulose aerogel fibers is solved, and aerogel fibers with good toughness and developed pores are prepared, which is suitable for a variety of application fields.
Patent Information
- Application Number
- CN202510234848.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-28
- Publication Date
- 2025-05-06
AI Technical Summary
The toughness of existing cellulose aerogel fibers is poor, resulting in poor toughness of the products after secondary processing and poor processing characteristics.
Cellulose spinning liquid is prepared by dissolving waste cotton fabrics with a solvent that dissolves cellulose, and cellulose gel fibers are prepared by wet spinning technology. The metal organic framework compound is loaded in cellulose gel fibers and its structural stability is enhanced by freeze-thaw cycle and freeze-drying processes.
The prepared waste cotton fabric-based cellulose aerogel fiber has good toughness, porosity and adsorption capacity, and can impart different characteristics through surface regulation and functional composite, and is suitable for environmental governance, biomedicine and other fields.
Smart Images
Figure CN119926369A_ABST
Abstract
Description
Technical Field
[0001] The invention discloses a waste cotton fabric-based cellulose aerogel fiber and a preparation method thereof, and belongs to the technical field of composite materials. Background Art
[0002] Aerogels can be used as adsorbent materials to remove pollutants from wastewater and repair the water environment due to their high specific surface area, highly porous structure and excellent adsorption capacity. Among them, cellulose aerogel is the third generation of aerogel after inorganic aerogel and polymer aerogel. It combines the low density, high porosity, large specific surface area of aerogel and the green and renewable advantages of cellulose materials. In particular, with the continuous development of new processes and technologies, cellulose aerogels of different sizes and dimensional structures (such as block cellulose aerogels, cellulose aerogel microbeads / microspheres, cellulose aerogel membranes, and cellulose aerogel fibers) have been developed. At present, the main research at home and abroad focuses on the preparation, modification and application of three-dimensional block aerogels. However, the secondary processing of block aerogels is difficult, which limits its feasibility in more scenarios. The one-dimensional cellulose aerogel fiber has good flexibility, multi-scale, and weavability, overcoming the current problem of difficult secondary processing based on three-dimensional block aerogel materials. However, the existing cellulose aerogel fibers have poor toughness, resulting in that although the cellulose aerogel fibers can be processed secondary, the products obtained from the secondary processing have poor toughness and short life. Summary of the invention
[0003] The object of the present invention is to provide a waste cotton fabric-based cellulose aerogel fiber and a preparation method thereof, so as to solve the technical problems of poor toughness and poor processing characteristics of the existing cellulose aerogel fibers.
[0004] A first aspect of the present invention provides a method for preparing waste cotton fabric-based cellulose aerogel fibers, comprising: Step 1, dissolving waste cotton fabric with a solvent that can dissolve cellulose to obtain a cellulose spinning solution; Step 2, preparing cellulose gel fiber using the cellulose spinning solution; Step 3: loading the metal organic framework compound into the cellulose gel fiber and then freeze-drying it to obtain waste cotton fabric-based cellulose aerogel fiber.
[0005] Preferably, step 3 specifically includes: After the cellulose gel fiber is subjected to multiple freeze-thaw cycles, it is immersed in a mixed solution containing a metal compound and an organic ligand, left to stand for a preset time, and then freeze-dried to obtain waste cotton fabric-based cellulose aerogel fibers.
[0006] Preferably, the metal compound is zinc nitrate or cobalt nitrate; The organic ligand is an imidazole ligand.
[0007] Preferably, the molar ratio of the metal compound to the organic ligand is 1:3-5.
[0008] Preferably, after the cellulose gel fiber is subjected to multiple freeze-thaw cycles, the method further comprises: replacing water in the cellulose gel fiber with an alcohol compound; Correspondingly, the replaced cellulose gel fiber is immersed in a mixed solution containing a metal compound and an organic ligand, and then freeze-dried after standing for a preset time to obtain waste cotton fabric-based cellulose aerogel fibers.
[0009] Preferably, step 2 specifically includes: The cellulose spinning solution is added into a syringe for wet spinning to obtain cellulose gel fibers.
[0010] Preferably, the concentration of the cellulose spinning solution is 0.02-0.1 g / L.
[0011] Preferably, the needle diameter of the syringe is 0.8-1.5 mm.
[0012] Preferably, the flow rate of the syringe is 1-3 ml / min.
[0013] A second aspect of the present invention provides a waste cotton fabric-based cellulose aerogel fiber, which is prepared based on the above-mentioned method for preparing the waste cotton fabric-based cellulose aerogel fiber.
[0014] Compared with the prior art, the waste cotton fabric-based cellulose aerogel fiber and the preparation method thereof of the present invention have the following beneficial effects: The present invention utilizes waste cotton fabric to prepare cellulose gel fiber, and loads metal organic framework compound in the cellulose gel fiber, so as to obtain aerogel fiber with good toughness, developed porosity and strong adsorption capacity. The aerogel fiber has good processability, so it can be endowed with different properties through surface regulation, functional composite and other methods. It has broad application prospects in the fields of environmental governance, biomedicine, electromagnetic interference, packaging and intelligent electronics. At the same time, the present invention is of great significance to the recycling and reuse of waste cotton fabric. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 The present invention is a flowchart of a method for preparing waste cotton fabric-based cellulose aerogel fibers according to an embodiment of the present invention.
[0016] Figure 2 This is a scanning electron microscope image of the cellulose aerogel fiber prepared in Comparative Example 2.
[0017] Figure 3This is a scanning electron microscope image of the cellulose aerogel fiber prepared in Example 1.
[0018] Figure 4 This is a scanning electron microscope image of the cellulose aerogel fiber prepared in Example 1 under a high-magnification scanning electron microscope.
[0019] Figure 5 It is a comparison chart of the mechanical properties of aerogel fibers obtained in the comparative example and the example. DETAILED DESCRIPTION
[0020] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.
[0021] The first aspect of the present invention provides a method for preparing waste cotton fabric-based cellulose aerogel fibers, such as Figure 1 As shown, including: Step 1: dissolving waste cotton fabric with a solvent that can dissolve cellulose to obtain a cellulose spinning solution.
[0022] In the embodiment of the present invention, the solvent capable of dissolving cellulose may be a lithium hydroxide / urea aqueous solution or a sodium hydroxide / urea aqueous solution.
[0023] The above-mentioned solvent capable of dissolving cellulose needs to dissolve the waste cotton fabric under low temperature environment so that the waste cotton fabric can be completely dissolved to obtain cellulose spinning solution. The concentration of the cellulose spinning solution in the embodiment of the present invention is 0.02-0.1 g / L.
[0024] Exemplarily, first, 50-200 ml of lithium hydroxide / urea aqueous solution is prepared according to the ratio of lithium hydroxide: urea: water of 8 wt%: 15 wt%: 77 wt%, and the prepared aqueous solution is placed in a refrigerator at a temperature of -15 ~-20 ° C for 60~180 min. Secondly, 1 to 5 g of recycled waste cotton fabric is dissolved in the frozen lithium hydroxide / urea aqueous solution prepared above, and then frozen for 6-12 h. Again, the frozen solution is thawed at room temperature, mechanically stirred for 20 min, and then placed in a refrigerator, and this step is repeated 2-3 times. Finally, the obtained solution is filtered to obtain a completely dissolved and uniform cellulose spinning solution.
[0025] Step 2, preparing cellulose gel fiber by using cellulose spinning solution, specifically comprising: adding cellulose spinning solution into a syringe for wet spinning to obtain cellulose gel fiber.
[0026] The embodiment of the present invention uses wet spinning to prepare cellulose gel fibers, which can accurately control the diameter, structure and performance of the fibers, so that the quality of the prepared cellulose gel fibers is more stable and the toughness is improved.
[0027] In order to improve the toughness of the waste cotton fabric-based cellulose aerogel fibers finally prepared in the embodiment of the present invention, the needle diameter of the syringe is limited to 0.8-1.5 mm, and the cellulose spinning solution is squeezed into the coagulation bath ethanol at a flow rate of 1-3 ml / min to form gel fibers.
[0028] Step 3, loading the metal organic framework compound in the cellulose gel fiber and then freeze-drying it to obtain the waste cotton fabric-based cellulose aerogel fiber, specifically comprising: After soaking the cellulose gel fiber in water for 2-3 days to remove the alkalinity, the cellulose gel fiber is subjected to multiple freeze-thaw cycles, and the cellulose gel fiber after the freeze-thaw cycle is immersed in a mixed solution containing metal compounds and organic ligands, and then freeze-dried after standing for a preset time to obtain waste cotton fabric-based cellulose aerogel fiber.
[0029] The metal compound is zinc nitrate or cobalt nitrate; the organic ligand is an imidazole ligand, wherein the imidazole ligand can be specifically 2-methylimidazole.
[0030] In the embodiment of the present invention, the molar ratio of the metal compound to the organic ligand is 1:3-5. The molar ratio of zinc nitrate or cobalt nitrate is less than 2 mmol, and the molar ratio of the imidazole ligand is less than 8 mmol.
[0031] The embodiment of the present invention grows metal organic framework compounds (MOFs) inside the cellulose gel fiber by an in-situ growth method, thereby greatly improving the adsorption capacity of the prepared waste cotton fabric-based cellulose aerogel fiber, so that the waste cotton fabric-based cellulose aerogel fiber not only has the characteristics of slender fibers, but also has the typical properties of aerogel materials, such as ultra-low density, ultra-high porosity and high specific surface area. The waste cotton fabric-based cellulose aerogel fiber of the present invention can be endowed with different properties by surface regulation, functional composite and other methods, and has broad application prospects in the fields of environmental governance, biomedicine, electromagnetic interference, packaging and smart electronics.
[0032] In order to ensure the stability of the skeleton structure in the prepared waste cotton fabric-based cellulose aerogel fibers, the embodiment of the present invention further includes: replacing water in the cellulose gel fibers with alcohol compounds after subjecting the cellulose gel fibers to multiple freeze-thaw cycles; accordingly, immersing the replaced cellulose gel fibers in a mixed solution containing metal compounds and organic ligands, standing for a preset time and then freeze-drying to obtain waste cotton fabric-based cellulose aerogel fibers.
[0033] The alcohol compound may specifically be tert-butanol or ethanol, preferably tert-butanol.
[0034] Illustratively, in an embodiment of the present invention, the cellulose gel fiber is soaked in water for 2-3 days, placed in a refrigerator for 12 hours, taken out and left at room temperature for 6 hours, and then placed in a refrigerator. This step is repeated 3-5 times, and then replaced with tert-butyl alcohol.
[0035] Dissolve less than 2 mmol of zinc nitrate and less than 8 mmol of 2-methylimidazole in 25 ml of methanol solution respectively, and mix and stir, wherein the molar ratio of zinc nitrate to 2-methylimidazole is 1:3-5.
[0036] The cellulose gel fiber replaced with tert-butyl alcohol was immersed in a mixed solution of zinc nitrate and 2-methylimidazole and allowed to stand for 24-48 hours, and then dried in a freeze dryer for 24-36 hours to prepare waste cotton fabric-based cellulose aerogel fibers.
[0037] A second aspect of the present invention provides a waste cotton fabric-based cellulose aerogel fiber, which is prepared based on the above-mentioned method for preparing the waste cotton fabric-based cellulose aerogel fiber.
[0038] The present invention converts waste cotton fabric into aerogel fibers with good toughness and developed pores through a green method, which is of great significance for the recycling and reuse of waste cotton fabric, and the compounding with MOFs material greatly promotes the adsorption effect. The waste cotton fabric-based cellulose aerogel fibers of the present invention can be endowed with different properties through surface regulation, functional compounding and other methods, and have broad application prospects in the fields of environmental governance, biomedicine, electromagnetic interference, packaging and smart electronics.
[0039] The present invention further verifies the mechanical properties of the prepared waste cotton fabric-based cellulose aerogel fibers.
[0040] Comparative Example 1
[0041] 4 g of lithium hydroxide and 7.5 g of urea were dissolved in 38.5 g of deionized water and then placed in a refrigerator for 60 min. 1 g of recycled pretreated waste cotton fabric was dissolved in the lithium hydroxide / urea aqueous solution prepared above, stirred at low temperature for 20 min, and then frozen for 12 h. The frozen solution was taken out, thawed at room temperature, mechanically stirred for 20 min, and then placed in a refrigerator. This step was repeated twice. Then the solution was filtered to obtain a completely dissolved and uniform cellulose spinning solution for wet spinning. The needle diameter was 0.8 mm, the coagulation bath was ethanol, and the flow rate was 1 ml / min to obtain cellulose gel fiber. The prepared cellulose gel fiber was soaked in water for 2 days to remove the alkalinity, placed in a refrigerator for 12 h, taken out and placed at room temperature for 6 h, and then placed in a refrigerator. This step was repeated 3 times and then replaced with tert-butyl alcohol. Finally, the composite aerogel fiber was prepared after drying in a freeze dryer for 24 h. The mechanical strength of the aerogel fiber was poor due to the low cellulose concentration.
[0042] Comparative Example 2
[0043] 4 g of lithium hydroxide and 7.5 g of urea were dissolved in 38.5 g of deionized water and then placed in a refrigerator for 60 min. 4 g of recycled pretreated waste cotton fabric was dissolved in the lithium hydroxide / urea aqueous solution prepared above, stirred at low temperature for 20 min, and then frozen for 12 h. The frozen solution was taken out, thawed at room temperature, mechanically stirred for 20 min and placed in a refrigerator again, and this step was repeated twice. The solution was then filtered to obtain a completely dissolved and uniform cellulose spinning solution for wet spinning. The needle diameter was 1.1 mm, the coagulation bath was ethanol, and the flow rate was 1 ml / min to obtain cellulose gel fiber. The prepared cellulose gel fiber was soaked in water for 2 days to remove the alkalinity inside. After freezing it in a refrigerator for 12 h, it was taken out and left at room temperature for 6 h and then put into the refrigerator. This step was repeated 5 times and replaced with tert-butyl alcohol. Composite aerogel fibers were then prepared after drying in a freeze dryer for 24 h. Its scanning electron microscope image is as follows Figure 2 As shown, the results show that the aerogel fiber structure is dense and the existence of pore structure is difficult to observe.
[0044] Example 1
[0045] 4 g of lithium hydroxide and 7.5 g of urea were dissolved in 38.5 g of deionized water and then placed in a refrigerator for 60 min. 2 g of recycled pretreated waste cotton fabric was dissolved in the lithium hydroxide / urea aqueous solution prepared above, stirred at low temperature for 20 min, and then frozen for 12 h. The frozen solution was taken out, thawed at room temperature, mechanically stirred for 20 min, and then placed in a refrigerator, and this step was repeated twice. Then the solution was filtered to obtain a completely dissolved and uniform cellulose spinning solution for wet spinning, with a needle diameter of 1.1 mm, a coagulation bath of ethanol, and a flow rate of 1.5 ml / min to obtain cellulose gel fibers. The prepared cellulose gel fibers were soaked in water for 2 days to remove the alkalinity inside. 1 mmol of zinc nitrate and 4 mmol of 2-methylimidazole were respectively dissolved in 25 ml of methanol solution, and then the two solutions were mixed and stirred for 10 min. The prepared cellulose gel fibers were immersed in the mixed solution and allowed to stand for 12 h. Then, the waste cotton fabric-based cellulose aerogel fibers were prepared after drying in a freeze dryer for 24 h. The scanning electron microscope image is as follows Figure 3 As shown in the high magnification scanning electron microscope image Figure 4 As shown, the porous structure inside the aerogel fibers can be clearly observed.
[0046] Example 2
[0047] 4 g of lithium hydroxide and 7.5 g of urea were dissolved in 38.5 g of deionized water and then placed in a refrigerator for 60 min. 3 g of recycled pretreated waste cotton fabric was dissolved in the lithium hydroxide / urea aqueous solution prepared above, stirred at low temperature for 20 min, and then frozen for 12 h. The frozen solution was taken out, thawed at room temperature, mechanically stirred for 20 min, and then placed in a refrigerator again, and this step was repeated twice. Then the solution was filtered to obtain a completely dissolved and uniform cellulose spinning solution for wet spinning, with a needle diameter of 1.3 mm, a coagulation bath of ethanol, and a flow rate of 2 ml / min to obtain cellulose gel fiber. The prepared cellulose gel fiber was soaked in water for 2 days to remove the alkalinity inside. After being placed in a refrigerator for 12 h, it was taken out and placed at room temperature for 6 h and then placed in a refrigerator. This step was repeated 5 times and replaced with tert-butyl alcohol to obtain a stable wet gel fiber. 2 mmol of zinc nitrate and 8 mmol of 2-methylimidazole were prepared and dissolved in 25 ml of methanol solution respectively, and then the two solutions were mixed and stirred for 10 min. The prepared gel fiber was immersed in the mixed solution and allowed to stand for 12 h. Then, it was dried in a freeze dryer for 48 h to obtain the composite aerogel fiber.
[0048] Example 3
[0049] 4 g of lithium hydroxide and 7.5 g of urea were dissolved in 38.5 g of deionized water and then placed in a refrigerator for 60 min. 2 g of recycled pretreated waste cotton fabric was dissolved in the lithium hydroxide / urea aqueous solution prepared above, stirred at low temperature for 20 min, and then frozen for 12 h. The frozen solution was taken out, thawed at room temperature, mechanically stirred for 20 min, and then placed in a refrigerator again, and this step was repeated twice. Then the solution was filtered to obtain a completely dissolved and uniform cellulose spinning solution for wet spinning, with a needle diameter of 1.5 mm, a coagulation bath of ethanol, and a flow rate of 3 ml / min to obtain cellulose gel fiber. The prepared cellulose gel fiber was soaked in water for 2 days to remove the alkalinity inside. After being placed in a refrigerator for 12 h, it was taken out and placed at room temperature for 6 h and then placed in a refrigerator. This step was repeated 5 times and replaced with tert-butyl alcohol to obtain a stable wet gel fiber. 2 mmol of zinc nitrate and 8 mmol of 2-methylimidazole were respectively dissolved in 25 ml of methanol solution, and then the two solutions were mixed and stirred for 10 min. The prepared gel fiber was immersed in the mixed solution and allowed to stand for 12 h. Then, it was dried in a freeze dryer for 48 h to obtain the composite aerogel fiber.
[0050] The mechanical properties of the gel fibers prepared in the above comparative examples and embodiments are as follows: Figure 5 shown.
[0051] Depend on Figure 5 It can be seen that the in-situ loading of MOFs can help improve the mechanical properties of aerogel fibers.
[0052] The invention relates to a waste cotton fabric-based cellulose aerogel fiber. The recycled waste cotton fabric is dissolved and regenerated to obtain a cellulose spinning solution. The cellulose gel fiber is obtained by means of a wet spinning technique, and then its structural stability is enhanced by a freeze-thaw process. Then, MOFs material is grown inside the gel fiber by an in-situ growth method, and finally a composite aerogel is obtained in one step in combination with freeze-drying technology. The present invention prepares cellulose gel fibers from waste cotton fabrics, and loads metal organic framework compounds in the cellulose gel fibers, thereby obtaining aerogel fibers with good toughness, developed pores, and strong adsorption capacity. The aerogel fibers have good processability, so they can be given different characteristics by methods such as surface regulation and functional composite, and have broad application prospects in the fields of environmental governance, biomedicine, electromagnetic interference, packaging, and smart electronics; at the same time, the present invention is of great significance to the recycling and reuse of waste cotton fabrics.
[0053] The above are only several embodiments of the present invention and are not intended to limit the present invention in any form. Although the present invention is disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any technician familiar with the profession, without departing from the scope of the technical solution of the present invention, using the above disclosed technical content to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.
Claims
1. A method for preparing waste cotton fabric-based cellulose aerogel fibers, characterized in that: include: Step 1, dissolving waste cotton fabric with a solvent that can dissolve cellulose to obtain a cellulose spinning solution; Step 2, preparing cellulose gel fiber using the cellulose spinning solution; Step 3: loading the metal organic framework compound into the cellulose gel fiber and then freeze-drying it to obtain waste cotton fabric-based cellulose aerogel fiber.
2. The method for preparing waste cotton fabric-based cellulose aerogel fibers according to claim 1, characterized in that: Step 3 specifically includes: After the cellulose gel fiber is subjected to multiple freeze-thaw cycles, it is immersed in a mixed solution containing a metal compound and an organic ligand, left to stand for a preset time, and then freeze-dried to obtain waste cotton fabric-based cellulose aerogel fibers.
3. The method for preparing waste cotton fabric-based cellulose aerogel fibers according to claim 2, characterized in that: The metal compound is zinc nitrate or cobalt nitrate; The organic ligand is an imidazole ligand.
4. The method for preparing waste cotton fabric-based cellulose aerogel fibers according to claim 3, characterized in that: The molar ratio of the metal compound to the organic ligand is 1:3-5.
5. The method for preparing waste cotton fabric-based cellulose aerogel fibers according to claim 2, characterized in that: After subjecting the cellulose gel fiber to multiple freeze-thaw cycles, the method further comprises: replacing water in the cellulose gel fiber with an alcohol compound; Correspondingly, the replaced cellulose gel fiber is immersed in a mixed solution containing a metal compound and an organic ligand, and then freeze-dried after standing for a preset time to obtain waste cotton fabric-based cellulose aerogel fibers.
6. The method for preparing waste cotton fabric-based cellulose aerogel fibers according to any one of claims 1 to 5, characterized in that: Step 2 specifically includes: The cellulose spinning solution is added into a syringe for wet spinning to obtain cellulose gel fibers.
7. The method for preparing waste cotton fabric-based cellulose aerogel fibers according to claim 6, characterized in that: The concentration of the cellulose spinning solution is 0.02-0.1 g / L.
8. The method for preparing waste cotton fabric-based cellulose aerogel fibers according to claim 6, characterized in that: The needle diameter of the syringe is 0.8-1.5 mm.
9. The method for preparing waste cotton fabric-based cellulose aerogel fibers according to claim 6, characterized in that: The flow rate of the syringe was 1-3 ml / min.
10. A waste cotton fabric-based cellulose aerogel fiber, characterized in that: The aerogel fiber is prepared by using the method for preparing waste cotton fabric-based cellulose aerogel fibers according to any one of claims 1 to 9.