A method for preparing a graphene slurry
Patent Information
- Application Number
- CN202610899739.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-06-22
- Publication Date
- 2026-09-15
Smart Images
Figure REF-OBJ-1782093618452-000001 
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of graphene slurry technology, specifically, it relates to a method for preparing graphene slurry. Background Technology
[0002] In the development and application of graphene composite slurries, how to achieve long-term stable dispersion of graphene in the matrix and simultaneously impart good comprehensive properties such as mechanical properties, flame retardancy, and antibacterial properties to the material has always been a key research focus and challenge in this field.
[0003] Currently, common modification methods often employ physical adsorption or simple functional group grafting (such as silane coupling agents) to improve the dispersibility of graphene. However, these methods often fail to form strong chemical bonds between graphene and the polymer matrix, resulting in weak interfacial bonding, easy phase separation, poor slurry storage stability, and limited functionality. For example, physical adsorption alone cannot provide sufficient steric hindrance and chemical crosslinking points, and graphene is still prone to agglomeration and sedimentation. While graphene modified with ordinary coupling agents can partially improve dispersion, its structure lacks active groups that react with the matrix, making it difficult to introduce functional components such as flame retardants and antibacterial agents. This results in limited mechanical reinforcement and low functional integration of the composite material. Furthermore, existing functional modifications often focus on improving a single property, making it difficult to simultaneously address multiple requirements such as dispersion stability, mechanical reinforcement, high-efficiency flame retardancy, and long-lasting antibacterial properties, thus restricting the further application of graphene slurries in high-performance coatings, composite films, and other fields.
[0004] Therefore, developing a preparation method that can achieve efficient chemical modification of graphene surfaces and synergistically improve the overall performance of slurries is of great technical significance and application value. Summary of the Invention
[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing graphene slurry.
[0006] The objective of this invention can be achieved through the following technical solutions: A method for preparing a graphene slurry includes the following steps: Step 1: Disperse the modified graphene in deionized water to form a modified graphene dispersion with a mass fraction of 10%. Step 2: Mix polytetrahydrofuran ether glycol, hexamethylene diisocyanate and dibutyltin dilaurate at 50-60℃ and react for 1-2 hours. Then raise the temperature to 70-80℃, add 1,4-butanediol, modified graphene dispersion and deionized water, and continue the reaction at 80-90℃ for 1-2 hours to finally obtain the graphene slurry product. The preparation process of modified graphene is as follows: A1: Graphene oxide was added to N,N-dimethylformamide and ultrasonically dispersed for 1-2 hours. Then, the modified monomer and N,N'-dicyclohexylcarbodiimide were added and stirred at 90℃-100℃ for 2-3 hours. After the reaction was completed, the mixture was centrifuged, washed, dried, and ground to obtain pre-modified graphene. A2: Disperse the pre-modified graphene ultrasonically in deionized water, raise the temperature to 60-70℃, and slowly add copper nitrate aqueous solution dropwise. React for 10-12 hours to allow Cu to form a precipitate. 2+ The sodium molybdate is adsorbed onto the surface of pre-modified graphene through electrostatic interaction; then, an aqueous solution of sodium molybdate is slowly added dropwise, and the reaction is continued at 60-70℃ for 2-3 hours to allow the MoO4 to form. 2- With the adsorbed Cu 2+ CuMoO4 nanoparticles were generated through in-situ co-precipitation and firmly loaded onto the surface of the pre-modified graphene sheets. After the reaction was completed, the sheets were washed and dried to obtain the modified graphene.
[0007] In a more optimized manner, the preparation process of the modified monomer is as follows: S1: At room temperature, p-hydroxybenzaldehyde, anhydrous potassium carbonate, and acetone are mixed and stirred for 30-40 min. Then, 1,3-dibromopropane is slowly added dropwise, the temperature is raised to 70-80℃, and the reaction is stirred for 48 h. After the reaction is completed, the mixture is filtered, the solvent is removed by rotary evaporation, and after purification, product A is obtained. S2: Mix p-hydroxyphenylethanol, furfurylamine, paraformaldehyde and anhydrous ethanol, raise the temperature to 90-100℃, reflux for 4-5 hours, then evaporate the solution using a rotary evaporator to remove ethanol, wash and dry to obtain product B. S3: Add product A and product B to acetonitrile, raise the temperature to 70-80℃, stir the reaction for 2-3 hours, after the reaction is completed, cool to room temperature, and then perform post-processing to obtain product C; S4: Mix product C, melamine, triethylamine, and dimethyl sulfoxide, and stir the mixture at 0°C for 2-3 hours. After the reaction is complete, wash with water to remove inorganic salts, dry the organic phase, concentrate it, and purify it to obtain the modified monomer.
[0008] In this scheme, under alkaline conditions, the phenolic hydroxyl group of p-hydroxybenzaldehyde is first deprotonated to generate a phenoxy anion. This phenoxy anion acts as a nucleophile and reacts with 1,3-dibromopropane, resulting in nucleophilic substitution to form product A. Subsequently, formaldehyde produced from the depolymerization of paraformaldehyde reacts with furfurylamine to generate an imine ion intermediate. This intermediate undergoes electrophilic attack at the ortho position of the phenolic hydroxyl group of p-hydroxyphenylethanol to yield product B. Next, the nitrogen atom of product B nucleophilically attacks the terminal carbon atom of the bromopropyl group in product A, resulting in SN2 nucleophilic substitution to generate product C, which has a quaternary ammonium salt structure. Finally, the aldehyde group at the terminal of product C undergoes a condensation reaction with the two amino groups of melamine to generate the target modified monomer containing a Schiff base structure. The remaining amino group of the modified monomer reacts with the carboxyl group of graphene oxide to obtain pre-modified graphene. Furthermore, the hydroxyl groups at both ends of this structure, as additional crosslinking points, can not only promote the formation of the crosslinked network structure of the polyurethane matrix and improve the water resistance and mechanical strength of the slurry after curing into a film, but also enhance the interaction between graphene and the slurry matrix (waterborne polyurethane) and improve the dispersion effect of graphene in the matrix.
[0009] The structure of the modified monomer is shown below:
[0010] In a more optimized manner, the raw materials for preparing the graphene slurry product include the following components: by weight, 90-100 parts of polytetrahydrofuran ether diol, 30-40 parts of hexamethylene diisocyanate, 0.1-0.2 parts of dibutyltin dilaurate, 5-8 parts of 1,4-butanediol, 10-12 parts of modified graphene dispersion, and 200-220 parts of deionized water.
[0011] In a more optimized manner, the raw materials for preparing the pre-modified graphene include the following components: by weight, 2-3 parts graphene oxide, 50-60 parts N,N-dimethylformamide, 2-3 parts modified monomer, and 0.5-0.8 parts N,N'-dicyclohexylcarbodiimide.
[0012] In a more optimized manner, the raw materials for preparing the modified graphene include the following components: by weight, 2-3 parts of pre-modified graphene, 80-100 parts of deionized water, 30-40 parts of copper nitrate aqueous solution, and 30-40 parts of sodium molybdate aqueous solution; wherein the concentration of the copper nitrate aqueous solution is 0.02 wt%, and the concentration of the sodium molybdate aqueous solution is 0.02 wt%.
[0013] In a more optimized manner, the raw materials for preparing product A include the following components: by weight, 1-2 parts of p-hydroxybenzaldehyde, 2-3 parts of anhydrous potassium carbonate, 40-50 parts of acetone, and 1-1.5 parts of 1,3-dibromopropane.
[0014] In a more optimized manner, the raw materials for preparing product B include the following components: by weight, 1-2 parts of p-hydroxyphenylethanol, 0.7-0.8 parts of furfurylamine, 0.25-0.35 parts of paraformaldehyde, and 40-50 parts of anhydrous ethanol.
[0015] In a more optimized manner, the raw materials for preparing product C include the following components: by weight, 1-2 parts of product A, 0.8-1 parts of product B, and 40-50 parts of acetonitrile.
[0016] In a more optimized manner, the raw materials for preparing the modified monomer include the following components: by weight, 1-2 parts of product C, 0.2-0.3 parts of melamine, 0.2-0.3 parts of triethylamine, and 40-50 parts of dimethyl sulfoxide.
[0017] Beneficial effects of the invention: This invention achieves a comprehensive performance enhancement of graphene slurry by designing and synthesizing modified monomers containing dihydroxyl groups, quaternary ammonium salts, and rigid aromatic structures, and by utilizing their chemical grafting with graphene oxide and subsequent in-situ loading of CuMoO4 nanoparticles. On one hand, chemical grafting and steric hindrance ensure the long-term stable dispersion of graphene in aqueous systems; on the other hand, the two active hydroxyl groups carried by the modified monomers can directly participate in the crosslinking reaction of polyurethane, making graphene a covalent network node and significantly enhancing interfacial bonding and mechanical strength. Simultaneously, the grafted quaternary ammonium salt groups provide multiple antibacterial mechanisms, and the chemical bonds ensure long-lasting effectiveness. Regarding flame retardancy, the rigid aromatic structure composed of furan rings and benzene rings exhibits high thermal stability, effectively promoting the formation of a dense char layer; while the loaded CuMoO4 decomposes at high temperatures to generate Cu2O and MoO3, which can catalyze smoke suppression and stabilize the char layer. Thus, through the synergistic effect of condensed-phase and gas-phase flame retardancy, the material is endowed with excellent flame-retardant properties. Detailed Implementation
[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0019] It should be noted that the following parts are by weight, and there are no special restrictions on the manufacturers from which the raw materials involved in this invention can be purchased.
[0020] Example 1: A method for preparing graphene slurry, comprising the following steps: Step 1: Disperse the modified graphene in deionized water to form a modified graphene dispersion with a mass fraction of 10%. Step 2: Mix 90 parts of polytetrahydrofuran ether diol, 30 parts of hexamethylene diisocyanate and 0.1 parts of dibutyltin dilaurate at 50℃ and react for 1 hour. Then raise the temperature to 70℃, add 5 parts of 1,4-butanediol, 10 parts of modified graphene dispersion and 200 parts of deionized water and continue to react at 80℃ for 1 hour to finally obtain the graphene slurry product. The preparation process of modified graphene is as follows: A1: Add 2 parts of graphene oxide to 50 parts of N,N-dimethylformamide and disperse by ultrasonication for 1 hour. Then add 2 parts of modified monomer and 0.5 parts of N,N'-dicyclohexylcarbodiimide and stir at 90°C for 2 hours. After the reaction is completed, centrifuge, wash, dry and grind to obtain pre-modified graphene. A2: Two parts of pre-modified graphene were ultrasonically dispersed in 80 parts of deionized water. The temperature was raised to 60°C, and 30 parts of copper nitrate aqueous solution (concentration 0.02wt%) were slowly added dropwise. The reaction was carried out for 10 hours. Then, 30 parts of sodium molybdate aqueous solution (concentration 0.02wt%) were slowly added dropwise. The reaction was continued at 60°C for 2 hours. After the reaction was completed, the graphene was washed and dried to obtain the modified graphene. The preparation process of the modified monomer is as follows: S1: At room temperature, 1 part of p-hydroxybenzaldehyde, 2 parts of anhydrous potassium carbonate and 40 parts of acetone were mixed and stirred for 30 min. Then, 1 part of 1,3-dibromopropane was slowly added dropwise. The temperature was raised to 70 °C and the reaction was stirred for 48 h. After the reaction was completed, the mixture was filtered, the solvent was removed by rotary evaporation, and after purification, product A was obtained. S2: Mix 1 part p-hydroxyphenylethanol, 0.7 parts furfural, 0.25 parts paraformaldehyde, and 40 parts anhydrous ethanol, raise the temperature to 90°C, reflux for 4 hours, then evaporate the solution using a rotary evaporator to remove the ethanol, wash, and dry to obtain product B. S3: Add 1 part of product A and 0.8 parts of product B to 40 parts of acetonitrile, raise the temperature to 70°C, stir and react for 2 hours. After the reaction is completed, cool to room temperature and perform post-processing to obtain product C. S4: Mix 1 part of product C, 0.2 parts of melamine, 0.2 parts of triethylamine, and 40 parts of dimethyl sulfoxide. Stir and react at 0°C for 2 hours. After the reaction is complete, wash with water to remove inorganic salts. Dry the organic phase, concentrate it, and purify it to obtain the modified monomer.
[0021] Example 2: A method for preparing a graphene slurry, comprising the following steps: Step 1: Disperse the modified graphene in deionized water to form a modified graphene dispersion with a mass fraction of 10%. Step 2: Mix 100 parts of polytetrahydrofuran ether diol, 40 parts of hexamethylene diisocyanate and 0.2 parts of dibutyltin dilaurate at 60℃ and react for 2 hours. Then raise the temperature to 80℃, add 8 parts of 1,4-butanediol, 12 parts of modified graphene dispersion and 220 parts of deionized water and continue to react at 90℃ for 2 hours to finally obtain the graphene slurry product. The preparation process of modified graphene is as follows: A1: Add 3 parts of graphene oxide to 60 parts of N,N-dimethylformamide and disperse by ultrasonication for 2 hours. Then add 3 parts of modified monomer and 0.8 parts of N,N'-dicyclohexylcarbodiimide and stir at 100°C for 3 hours. After the reaction is completed, centrifuge, wash, dry and grind to obtain pre-modified graphene. A2: Disperse 3 parts of pre-modified graphene ultrasonically in 100 parts of deionized water, raise the temperature to 70°C, slowly add 40 parts of copper nitrate aqueous solution (concentration 0.02wt%), react for 12 hours, then slowly add 40 parts of sodium molybdate aqueous solution (concentration 0.02wt%), continue to react at 70°C for 3 hours. After the reaction is completed, wash and dry to obtain modified graphene. The preparation process of the modified monomer is as follows: S1: At room temperature, 2 parts of p-hydroxybenzaldehyde, 3 parts of anhydrous potassium carbonate and 50 parts of acetone were mixed and stirred for 40 min. Then, 1.5 parts of 1,3-dibromopropane were slowly added dropwise. The temperature was raised to 80 °C and the reaction was stirred for 48 h. After the reaction was completed, the mixture was filtered, the solvent was removed by rotary evaporation, and after purification, product A was obtained. S2: Mix 2 parts of p-hydroxyphenylethanol, 0.8 parts of furfural, 0.35 parts of paraformaldehyde and 50 parts of anhydrous ethanol, raise the temperature to 100℃, reflux for 5 hours, then evaporate the solution using a rotary evaporator to remove the ethanol, wash and dry to obtain product B. S3: Add 2 parts of product A and 1 part of product B to 50 parts of acetonitrile, raise the temperature to 80°C, stir and react for 3 hours. After the reaction is completed, cool to room temperature and perform post-processing to obtain product C. S4: Mix 2 parts of product C, 0.3 parts of melamine, 0.3 parts of triethylamine, and 50 parts of dimethyl sulfoxide. Stir and react at 0°C for 3 hours. After the reaction is complete, wash with water to remove inorganic salts. Dry the organic phase, concentrate it, and purify it to obtain the modified monomer.
[0022] Example 3: A method for preparing graphene slurry, comprising the following steps: Step 1: Disperse the modified graphene in deionized water to form a modified graphene dispersion with a mass fraction of 10%. Step 2: Mix 95 parts of polytetrahydrofuran ether diol, 35 parts of hexamethylene diisocyanate and 0.15 parts of dibutyltin dilaurate at 55℃ and react for 1.5h. Then raise the temperature to 75℃, add 6.5 parts of 1,4-butanediol, 11 parts of modified graphene dispersion and 210 parts of deionized water, and continue to react at 85℃ for 1.5h to finally obtain the graphene slurry product. The preparation process of modified graphene is as follows: A1: 2.5 parts of graphene oxide were added to 55 parts of N,N-dimethylformamide and ultrasonically dispersed for 1.5 h. Then, 2.5 parts of modified monomer and 0.65 parts of N,N'-dicyclohexylcarbodiimide were added and stirred at 95 °C for 2.5 h. After the reaction was completed, the mixture was centrifuged, washed, dried and ground to obtain pre-modified graphene. A2: 2.5 parts of pre-modified graphene were ultrasonically dispersed in 90 parts of deionized water, the temperature was raised to 65°C, and 35 parts of copper nitrate aqueous solution (concentration of 0.02wt%) were slowly added dropwise. The reaction was carried out for 11 hours, and then 35 parts of sodium molybdate aqueous solution (concentration of 0.02wt%) were slowly added dropwise. The reaction was continued at 65°C for 2.5 hours. After the reaction was completed, the graphene was washed and dried to obtain the modified graphene. The preparation process of the modified monomer is as follows: S1: At room temperature, 1.5 parts of p-hydroxybenzaldehyde, 2.5 parts of anhydrous potassium carbonate and 45 parts of acetone were mixed and stirred for 35 min. Then, 1.25 parts of 1,3-dibromopropane were slowly added dropwise. The temperature was raised to 75 °C and the reaction was stirred for 48 h. After the reaction was completed, the mixture was filtered, the solvent was removed by rotary evaporation, and the product A was obtained after purification. S2: Mix 1.5 parts of p-hydroxyphenylethanol, 0.75 parts of furfural, 0.3 parts of paraformaldehyde, and 45 parts of anhydrous ethanol, raise the temperature to 95°C, reflux for 4.5 h, then evaporate the solution using a rotary evaporator to remove the ethanol, wash, and dry to obtain product B. S3: Add 1.5 parts of product A and 0.9 parts of product B to 45 parts of acetonitrile, raise the temperature to 75°C, stir and react for 2.5 h. After the reaction is completed, cool to room temperature, and then perform post-processing to obtain product C. S4: Mix 1.5 parts of product C, 0.25 parts of melamine, 0.25 parts of triethylamine, and 45 parts of dimethyl sulfoxide. Stir and react at 0°C for 2.5 h. After the reaction is complete, wash with water to remove inorganic salts. Dry the organic phase, concentrate it, and purify it to obtain the modified monomer.
[0023] Comparative Example 1: Graphene oxide was modified using an aminosilane coupling agent (KH550), as detailed below: Step 1: Disperse the modified graphene in deionized water to form a modified graphene dispersion with a mass fraction of 10%. Step 2: Mix 95 parts of polytetrahydrofuran ether diol, 35 parts of hexamethylene diisocyanate and 0.15 parts of dibutyltin dilaurate at 55℃ and react for 1.5h. Then raise the temperature to 75℃, add 6.5 parts of 1,4-butanediol, 11 parts of modified graphene dispersion and 210 parts of deionized water, and continue to react at 85℃ for 1.5h to finally obtain the graphene slurry product. The preparation process of modified graphene is as follows: A1: 2.5 parts of graphene oxide were added to a mixed solvent of 10 parts of deionized water and 90 parts of anhydrous ethanol, and ultrasonically treated for 1 hour to obtain a uniform dispersion; then 2 parts of KH550 were dissolved in 10 parts of anhydrous ethanol and added to the above dispersion, and reacted at 80°C for 4 hours. After naturally cooling to room temperature, the mixture was washed and dried to obtain pre-modified graphene. A2: 2.5 parts of pre-modified graphene were ultrasonically dispersed in 90 parts of deionized water, the temperature was raised to 65°C, and 35 parts of copper nitrate aqueous solution (concentration of 0.02wt%) were slowly added dropwise. The reaction was carried out for 11 hours, and then 35 parts of sodium molybdate aqueous solution (concentration of 0.02wt%) were slowly added dropwise. The reaction was continued at 65°C for 2.5 hours. After the reaction was completed, the graphene was washed and dried to obtain modified graphene.
[0024] Comparative Example 2: No adsorption of copper molybdate was performed, as detailed below: Step 1: Disperse the modified graphene in deionized water to form a modified graphene dispersion with a mass fraction of 10%. Step 2: Mix 95 parts of polytetrahydrofuran ether diol, 35 parts of hexamethylene diisocyanate and 0.15 parts of dibutyltin dilaurate at 55℃ and react for 1.5h. Then raise the temperature to 75℃, add 6.5 parts of 1,4-butanediol, 11 parts of modified graphene dispersion and 210 parts of deionized water, and continue to react at 85℃ for 1.5h to finally obtain the graphene slurry product. The preparation process of modified graphene is as follows: 2.5 parts of graphene oxide are added to 55 parts of N,N-dimethylformamide and ultrasonically dispersed for 1.5 h. Then, 2.5 parts of modified monomer and 0.65 parts of N,N'-dicyclohexylcarbodiimide are added and stirred at 95 °C for 2.5 h. After the reaction is completed, the graphene is centrifuged, washed, dried and ground to obtain pre-modified graphene. The preparation process of the modified monomer is as follows: S1: At room temperature, 1.5 parts of p-hydroxybenzaldehyde, 2.5 parts of anhydrous potassium carbonate and 45 parts of acetone were mixed and stirred for 35 min. Then, 1.25 parts of 1,3-dibromopropane were slowly added dropwise. The temperature was raised to 75 °C and the reaction was stirred for 48 h. After the reaction was completed, the mixture was filtered, the solvent was removed by rotary evaporation, and the product A was obtained after purification. S2: Mix 1.5 parts of p-hydroxyphenylethanol, 0.75 parts of furfural, 0.3 parts of paraformaldehyde, and 45 parts of anhydrous ethanol, raise the temperature to 95°C, reflux for 4.5 h, then evaporate the solution using a rotary evaporator to remove the ethanol, wash, and dry to obtain product B. S3: Add 1.5 parts of product A and 0.9 parts of product B to 45 parts of acetonitrile, raise the temperature to 75°C, stir and react for 2.5 h. After the reaction is completed, cool to room temperature, and then perform post-processing to obtain product C. S4: Mix 1.5 parts of product C, 0.25 parts of melamine, 0.25 parts of triethylamine, and 45 parts of dimethyl sulfoxide. Stir and react at 0°C for 2.5 h. After the reaction is complete, wash with water to remove inorganic salts. Dry the organic phase, concentrate it, and purify it to obtain the modified monomer.
[0025] Comparative Example 3: No modification was made to the graphene oxide, as follows: Step 1: Disperse graphene oxide in deionized water to form a modified graphene dispersion with a mass fraction of 10%. Step 2: Mix 95 parts of polytetrahydrofuran ether diol, 35 parts of hexamethylene diisocyanate and 0.15 parts of dibutyltin dilaurate at 55℃ and react for 1.5h. Then raise the temperature to 75℃, add 6.5 parts of 1,4-butanediol, 11 parts of graphene dispersion and 210 parts of deionized water, and continue to react at 85℃ for 1.5h to finally obtain the graphene slurry product.
[0026] Testing and experimentation: The graphene slurry obtained in the examples and comparative examples was coated onto a 40 μm PET film using a wire rod. After drying, the following testing experiments were conducted: (1) Take 50 mL of slurry and place it in a sealed container. After sealing and standing at 25°C for 14 days, observe the appearance of the slurry. (2) The oxygen index of the samples of the examples and comparative examples was measured according to standard ISO 4589-3; (3) The smoky burning time of the samples of the examples and comparative examples was measured according to standard GB / T 5455; (4) Cut the dried composite film into dumbbell-shaped strips of 16mm*2mm and test the tensile strength of the cured film; wherein, the tensile rate is 10mm / min; (5) The samples obtained in the examples and comparative examples were soaked in PBS buffer for 24 h and sterilized by UV for 30 min. Then the samples were placed in petri dishes, bacterial solution was added, and cultured at 37 °C for 24 h. The number of colonies on the sample surface and the number of colonies in the blank control group were determined by plate counting method, and then the antibacterial rate was calculated (the strain tested was Staphylococcus aureus). The obtained data is shown in the table below:
[0027] Conclusion: This invention successfully prepared a graphene slurry with excellent comprehensive performance by designing and synthesizing a multifunctional modified monomer containing dihydroxyl, quaternary ammonium salt and rigid aromatic structure, and by utilizing its chemical grafting with graphene oxide and subsequent in-situ loading of CuMoO4 nanoparticles.
[0028] The experimental data show that all three examples remained stable without stratification within 14 days, with an oxygen index as high as 32.6%-33.4%, a smoky burning time of only 2.3-2.8 seconds, a tensile strength of over 44 MPa, and an antibacterial rate of over 95%, demonstrating good dispersibility, flame retardancy, mechanical strength, and antibacterial properties.
[0029] In contrast, Comparative Example 1, modified with the common silane coupling agent KH550, exhibited slight stratification in its slurry due to the lack of active hydroxyl groups participating in crosslinking and the rigid aromatic structure promoting char layer formation. Its oxygen index dropped to 28.4%, tensile strength was 35.6 MPa, and antibacterial rate was only 65.7%, indicating that its interfacial bonding, flame retardant, and antibacterial functions were significantly weaker than those of the present invention.
[0030] In Comparative Example 2, the unloaded CuMoO4 nanoparticles, although still well dispersed, exhibited significantly reduced flame retardant properties, with an oxygen index of 29.5%, a longer smoky burning time to 6.7 seconds, and a reduced antibacterial rate to 85.6%. This indicates that CuMoO4 plays an irreplaceable role in catalyzing smoke suppression and stabilizing the char layer.
[0031] Comparative Example 3 directly used unmodified graphene oxide. Due to the lack of any surface modification and functionalization, the slurry was severely delaminated, with an oxygen index as low as 27.5%, a tensile strength of only 34.5 MPa, and an antibacterial rate of only 45.6%, exhibiting the worst overall performance. This further demonstrates the key role of the "chemical grafting + nano-loading" dual modification strategy in this invention in improving the compatibility, interfacial bonding, and multifunctionality of graphene in the polymer matrix.
[0032] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0033] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.
Claims
1. A method of preparing a graphene slurry, characterized by, Includes the following steps: Step 1: Disperse the modified graphene in deionized water to form a modified graphene dispersion with a mass fraction of 10%. Step 2: Mix polytetrahydrofuran ether glycol, hexamethylene diisocyanate and dibutyltin dilaurate at 50-60℃ and react for 1-2 hours. Then raise the temperature to 70-80℃, add 1,4-butanediol, modified graphene dispersion and deionized water, and continue the reaction at 80-90℃ for 1-2 hours to finally obtain the graphene slurry product. The preparation process of modified graphene is as follows: A1: Graphene oxide was added to N,N-dimethylformamide and ultrasonically dispersed for 1-2 hours. Then, the modified monomer and N,N'-dicyclohexylcarbodiimide were added and stirred at 90℃-100℃ for 2-3 hours. After the reaction was completed, the mixture was centrifuged, washed, dried, and ground to obtain pre-modified graphene. A2: Disperse the pre-modified graphene ultrasonically in deionized water, raise the temperature to 60-70℃, slowly add copper nitrate aqueous solution, react for 10-12 hours, then slowly add sodium molybdate aqueous solution, continue to react at 60-70℃ for 2-3 hours, after the reaction is completed, wash and dry to obtain modified graphene.
2. The method of claim 1, wherein the graphene slurry is prepared by the steps of: The raw materials for preparing the graphene slurry product include the following components: by weight, 90-100 parts of polytetrahydrofuran ether diol, 30-40 parts of hexamethylene diisocyanate, 0.1-0.2 parts of dibutyltin dilaurate, 5-8 parts of 1,4-butanediol, 10-12 parts of modified graphene dispersion, and 200-220 parts of deionized water. 3. The method for preparing a graphene slurry according to claim 1, characterized in that, The raw materials for preparing the pre-modified graphene include the following components: by weight, 2-3 parts graphene oxide, 50-60 parts N,N-dimethylformamide, 2-3 parts modified monomer, and 0.5-0.8 parts N,N'-dicyclohexylcarbodiimide.
4. The method for preparing a graphene slurry according to claim 1, characterized in that, The raw materials for preparing the modified graphene include the following components: by weight, 2-3 parts of pre-modified graphene, 80-100 parts of deionized water, 30-40 parts of copper nitrate aqueous solution, and 30-40 parts of sodium molybdate aqueous solution; wherein, the concentration of copper nitrate aqueous solution is 0.02wt%, and the concentration of sodium molybdate aqueous solution is 0.02wt%.
5. The method for preparing a graphene slurry according to claim 1, characterized in that, The preparation process of the modified monomer is as follows: S1: At room temperature, p-hydroxybenzaldehyde, anhydrous potassium carbonate, and acetone are mixed and stirred for 30-40 min. Then, 1,3-dibromopropane is slowly added dropwise, the temperature is raised to 70-80℃, and the reaction is stirred for 48 h. After the reaction is completed, the mixture is filtered, the solvent is removed by rotary evaporation, and after purification, product A is obtained. S2: Mix p-hydroxyphenylethanol, furfurylamine, paraformaldehyde and anhydrous ethanol, raise the temperature to 90-100℃, reflux for 4-5 hours, then evaporate the solution using a rotary evaporator to remove ethanol, wash and dry to obtain product B. S3: Add product A and product B to acetonitrile, raise the temperature to 70-80℃, stir the reaction for 2-3 hours, after the reaction is completed, cool to room temperature, and then perform post-processing to obtain product C; S4: Mix product C, melamine, triethylamine, and dimethyl sulfoxide, and stir at 0°C for 2-3 hours. After the reaction is complete, wash with water to remove inorganic salts, dry the organic phase, concentrate, and purify to obtain the modified monomer.
6. The method for preparing a graphene slurry according to claim 5, characterized in that, The raw materials for preparing product A include the following components: by weight, 1-2 parts of p-hydroxybenzaldehyde, 2-3 parts of anhydrous potassium carbonate, 40-50 parts of acetone, and 1-1.5 parts of 1,3-dibromopropane.
7. The method for preparing a graphene slurry according to claim 5, characterized in that, The raw materials for preparing product B include the following components: by weight, 1-2 parts of p-hydroxyphenylethanol, 0.7-0.8 parts of furfurylamine, 0.25-0.35 parts of paraformaldehyde, and 40-50 parts of anhydrous ethanol.
8. The method for preparing a graphene slurry according to claim 5, characterized in that, The raw materials for preparing product C include the following components: by weight, 1-2 parts of product A, 0.8-1 parts of product B, and 40-50 parts of acetonitrile.
9. The method for preparing a graphene slurry according to claim 5, characterized in that, The raw materials for preparing the modified monomer include the following components: by weight, 1-2 parts of product C, 0.2-0.3 parts of melamine, 0.2-0.3 parts of triethylamine, and 40-50 parts of dimethyl sulfoxide.