Preparation method and application of flexible ladder-shaped polysilsesquioxane functionalized graphene oxide
By combining octaminophenyl polyhedral oligosilsesquioxane with graphene oxide to form a soft ladder structure, the problem of graphene materials in achieving superlubrication and long-term stability is solved, and the friction coefficient and service life are achieved. Long structured graphene oxide coating.
Patent Information
- Application Number
- CN202411282874.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-13
- Publication Date
- 2025-02-14
AI Technical Summary
Existing graphene materials require harsh conditions and special pretreatment processes when achieving superlubrication, which are difficult to apply on a large scale. At the same time, the coating of graphene oxide has poor stability in long-term applications.
By combining octaminophenyl polyhedral oligomeric silsesquioxane with graphene oxide, a soft ladder-like structure is formed, and polysilsesquioxane functionalized graphene oxide with three-dimensional structure is prepared by ultrasonic treatment, heating and stirring, etc. .
The structured graphene oxide coating with low friction coefficient and long service life is achieved, which improves its wear resistance and stability and has better application prospects.
Smart Images
Figure CN119431810A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of graphite materials, in particular to a preparation method and application of soft ladder-like polysilsesquioxane functionalized graphene oxide. Background Art
[0002] It is estimated that nearly one-third of the fuel used in a car is used to overcome friction, and wear limits the life and reliability of components. Reducing friction has a significant impact on energy security, energy conservation and environmental benefits. For most materials widely used in the automotive industry, the traditional way to reduce friction and wear is oil-based lubrication. However, this practice is becoming increasingly concerned, mainly because of the impact of waste oil on the environment, so it is necessary to improve the durability of oil-based lubricants by introducing some additives, and the viscosity of the liquid also limits the ultimate low friction achieved. In this context, two-dimensional materials such as graphene have broad application prospects as solid lubricants.
[0003] However, the conditions for graphene to achieve superlubricity are relatively harsh. It not only requires a relatively regular structure, but also requires a special pretreatment process, so it is difficult to apply on a large scale. Li Jinjin et al. achieved superlubricity between silicon probes and graphite at a pressure of up to 700 MPa. Yi Ming et al. used graphene-coated diamond nanoparticles to achieve superlubricity under dry nitrogen conditions. Li Panpan et al. achieved superlubricity by pre-grinding micro-convexities on an engineering steel substrate under a nitrogen environment. Li Ruiyan et al. achieved superlubricity by synthesizing graphene through hydrogen-enhanced amorphous carbon under vacuum conditions. Therefore, achieving better wear resistance of graphene-based coatings through structural design and functional modification is one of the effective ways to promote its large-scale application. Graphene oxide is the product of graphene oxidation. Although the wear resistance of graphene oxide is improved compared with graphene, the stability of its coating in long-term applications is still poor. Studies have found that further functional modification can obtain better friction and wear performance. Polyhedral oligomeric silsesquioxanes are cage-like structures composed of alternating silicon-oxygen bonds. The diversity of side groups provides more possibilities for microstructures based on polyhedral oligomeric silsesquioxanes.
[0004] Previous studies were limited to the two-dimensional functional modification of a single graphene oxide nanosheet, and there is a lack of research on the effect of the three-dimensional structure formed by connecting multiple graphene oxide nanosheets through polyhedral oligomeric silsesquioxane on the wear resistance. Summary of the invention
[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for preparing soft ladder-like polysilsesquioxane functionalized graphene oxide. The present application selects octaaminophenyl polyhedral oligomeric silsesquioxane containing eight amino groups to functionally modify graphene oxide, and assembles layered nanosheets into a three-dimensional soft ladder-like structure with special structural advantages to improve its wear resistance.
[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows:
[0007] A method for preparing soft ladder-like polysilsesquioxane functionalized graphene oxide, comprising:
[0008] S1: adding graphene oxide powder and octaaminophenyl polyhedral oligomeric silsesquioxane to tetrahydrofuran, and then adding a catalyst, and then performing ultrasonic treatment to obtain a mixture;
[0009] S2: heating the mixture and stirring it to react, and the temperature is controlled at 48-52°C;
[0010] S3: After the reaction is completed, the product is centrifuged, washed and dried to obtain the finished product.
[0011] Furthermore, in step S1, 200 ml of tetrahydrofuran was added into a three-necked flask, and then 0.5 g of graphene oxide powder and 2.0 g of octaaminophenyl polyhedral oligomeric silsesquioxane were added, and the amount of catalyst added was 1.0 g.
[0012] Furthermore, the catalyst is 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride.
[0013] Furthermore, the ultrasonic treatment time in step S1 is 1 h.
[0014] Furthermore, in step S2, the stirring reaction time is 45 to 50 hours, and the temperature is controlled at 50°C.
[0015] Furthermore, in step S3, after the reaction is completed, the product is centrifuged at 10000 rpm for 5 minutes to obtain a precipitate; the precipitate is washed three times with tetrahydrofuran and ethanol, and then dried in a vacuum oven at 48-52° C. for 10-12 hours to obtain a soft ladder-like polysilsesquioxane functionalized graphene oxide.
[0016] The application of the soft ladder-like polysilsesquioxane functionalized graphene oxide as a coating as described in any of the above items is specifically performed as follows:
[0017] The silicon wafer was ultrasonicated in deionized water and ethanol for 5 minutes respectively, and then dried in nitrogen to obtain a dry silicon wafer; soft ladder-like polysilsesquioxane functionalized graphene oxide was added to 50 ml of ethanol to obtain a dispersion; the dispersion was evenly sprayed on the dry silicon wafer under dry pure nitrogen conditions of 0.2 MPa; after spraying, it was vacuum dried at 70-80°C for 1 hour.
[0018] Furthermore, the mass concentration of the soft ladder-like polysilsesquioxane functionalized graphene oxide in the dispersion is 1 g / L.
[0019] Compared with the prior art, the present invention has the following beneficial effects:
[0020] The invention provides a method for synthesizing three-dimensional soft ladder-shaped polysilsesquioxane functionalized graphene oxide, realizes the structural modification of one-dimensional nanomaterials and two-dimensional nanomaterials, and prepares structured graphene oxide with low friction coefficient and long service life. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 This is a scan of soft ladder-like graphene oxide;
[0022] Figure 2 This is the transmission image of soft ladder-like graphene oxide;
[0023] Figure 3 Atomic force diagram of soft ladder graphene oxide;
[0024] Figure 4 The distribution diagram of the number of layers of soft ladder-like graphene oxide;
[0025] Figure 5 and Figure 6 The photoelectron spectrum and infrared image of soft ladder graphene oxide;
[0026] Figure 7 Scans and contours for graphene oxide and soft ladder graphene oxide-based coatings;
[0027] Figures 8 to 11 Time and friction coefficient curves of graphene oxide and soft ladder-like graphene oxide-based coatings. DETAILED DESCRIPTION
[0028] The present invention is further described below in conjunction with the accompanying drawings and embodiments. The embodiments of the present invention include but are not limited to the following embodiments.
[0029] Example 1
[0030] This embodiment provides a method for preparing soft ladder-like polysilsesquioxane functionalized graphene oxide, comprising the following steps:
[0031] 200 ml of tetrahydrofuran was added to a three-necked flask, followed by the slow addition of 0.5 g of graphene oxide powder and 2.0 g of octaaminophenyl polyhedral oligomeric silsesquioxane, and 1.0 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride as a catalyst. The mixture was then ultrasonically treated for 1 h (40 kHz), and then placed in an oil bath and magnetically stirred at 50 ° C for 48 h. After the reaction was completed, the product was centrifuged (10,000 rpm, 5 min). The precipitate was washed three times with tetrahydrofuran and ethanol. The product was dried in a vacuum oven at 50 ° C for 12 h to obtain soft ladder-like polysilsesquioxane functionalized graphene oxide.
[0032] The preparation method of the soft ladder-like polysilsesquioxane functionalized graphene oxide coating is as follows:
[0033] The coating was prepared by atmospheric pressure spraying. Before spraying, the silicon wafer was ultrasonicated in deionized water and ethanol for 5 minutes respectively, and then dried in nitrogen to obtain a dry silicon wafer. A soft ladder-like polysilsesquioxane functionalized graphene oxide with a mass concentration of 1g / L was added to 50ml of ethanol to obtain a dispersion. Under the condition of dry high-purity nitrogen at 0.2 MPa, the dispersion was evenly sprayed onto the dry silicon wafer. After spraying, the coating was vacuum dried at 70-80°C for 1h to remove residual solvent.
[0034] The morphological characteristics of the soft ladder-like polysilsesquioxane functionalized graphene oxide prepared in this example were observed. Figure 1 This is a scan of soft ladder-shaped graphene oxide. It can be seen from the figure that the surface wrinkles increase and become more obvious. Figure 2 This is a transmission image of soft ladder-like graphene oxide. In the transmission image, it can be seen that octaaminophenyl polyhedral oligomeric silsesquioxane is evenly distributed on the graphene oxide nanosheets. Figure 3 This is an atomic force diagram of soft ladder-like graphene oxide. From the pictures with different atomic force sizes, it can be seen that the graphene oxide nanosheets are distributed in a soft ladder-like manner layer by layer, and the three-dimensional soft ladder-like structure is obvious. Figure 4 This is the distribution diagram of the number of layers of soft ladder-like graphene oxide. It can be seen from the figure that the soft ladder-like is mainly distributed in three to four layers. Figure 5 and Figure 6 The photoelectron spectrum and infrared image of soft ladder-like graphene oxide show additional peaks at around 100 eV (Si 2p), 150 eV (Si 2s) and 400 eV (N 1s) in the X-ray photoelectron spectrum, proving that octaaminophenyl polyhedral oligomeric silsesquioxane has been successfully grafted onto graphene oxide nanosheets. In the Fourier transform infrared spectrum, it can be seen that the Si-O-Si group in the octaaminophenyl polyhedral oligomeric silsesquioxane is at 1108 cm -1 A strong absorption band is generated near 1650cm -1 The peak at is the characteristic peak of -NH group, which proves the ring-opening reaction between octaaminophenyl polyhedral oligomeric silsesquioxane and graphene oxide.
[0035] The soft ladder-like polysilsesquioxane functionalized graphene oxide coating prepared in this example was also subjected to morphological observation and performance testing. Figure 7 These are scanning images and contour images of graphene oxide and soft ladder-like graphene oxide-based coatings. It can be seen from the figures that the soft ladder-like graphene oxide coating is distributed very regularly on the silicon wafer and has good affinity with the substrate; compared with the graphene oxide coating, the soft ladder-like graphene oxide-based coating has smaller roughness. Figures 8 to 11The time and friction coefficient curves of graphene oxide and soft ladder-shaped graphene oxide-based coatings. When the load is 0.1N, both graphene oxide and soft ladder-shaped graphene oxide-based coatings are not worn through. As the load increases, the wear resistance of the graphene oxide coating decreases significantly, and the service life is 83min (0.3N), 49min (0.5N) and 34min (0.7N), respectively. Compared with the graphene oxide coating, the soft ladder-shaped graphene oxide-based coating does not wear through during the entire friction process. The results show that the soft ladder-shaped graphene oxide-based coating has a lower friction coefficient and a longer service life under loads of 0.1N, 0.3N, 0.5N and 0.7N.
[0036] Example 2
[0037] This embodiment provides a method for preparing soft ladder-like polysilsesquioxane functionalized graphene oxide, comprising the following steps:
[0038] Add 200 ml of tetrahydrofuran to a three-necked flask, then slowly add 0.5 g of graphene oxide powder and 2.0 g of octaaminophenyl polyhedral oligomeric silsesquioxane, and add 1.0 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride as a catalyst. The mixture is then ultrasonically treated for 1 h (40 kHz), then placed in an oil bath and magnetically stirred at 48 ° C for 45 h. After the reaction is completed, the resultant is centrifuged (10,000 rpm, 5 min). The precipitate is washed three times with tetrahydrofuran and ethanol. The product is dried in a vacuum oven at 45 ° C for 10 h to obtain soft ladder-like polysilsesquioxane functionalized graphene oxide.
[0039] The preparation method of the soft ladder-like polysilsesquioxane functionalized graphene oxide coating is as follows:
[0040] The coating was prepared by atmospheric pressure spraying. Before spraying, the silicon wafer was ultrasonicated in deionized water and ethanol for 5 minutes respectively, and then dried in nitrogen to obtain a dry silicon wafer. A soft ladder-like polysilsesquioxane functionalized graphene oxide with a mass concentration of 1g / L was added to 50ml of ethanol to obtain a dispersion. Under the condition of dry high-purity nitrogen at 0.2 MPa, the dispersion was evenly sprayed onto the dry silicon wafer. After spraying, the coating was vacuum dried at 70-80°C for 1h to remove residual solvent.
[0041] The soft ladder-shaped graphene oxide synthesized by the present invention is a structural modification of a one-dimensional nanomaterial (octaaminophenyl polysilsesquioxane) and a two-dimensional material (graphene oxide). The synthesized soft ladder-shaped graphene oxide is a soft ladder-shaped structure with polysilsesquioxane in the middle and graphene oxide on both sides, and has a lower friction coefficient and a longer service life than a two-dimensional graphene oxide coating.
[0042] The above embodiment is only one of the preferred implementation modes of the present invention and should not be used to limit the protection scope of the present invention. Any changes or modifications that are made to the main design concept and spirit of the present invention and have no substantive significance, and the technical problems they solve are still consistent with the present invention, should be included in the protection scope of the present invention.
Claims
1. A method for preparing soft ladder-like polysilsesquioxane functionalized graphene oxide, characterized in that: include: S1: adding graphene oxide powder and octaaminophenyl polyhedral oligomeric silsesquioxane to tetrahydrofuran, and then adding a catalyst, and then performing ultrasonic treatment to obtain a mixture; S2: heating the mixture and stirring it to react, and the temperature is controlled at 48-52°C; S3: After the reaction is completed, the product is centrifuged, washed and dried to obtain the finished product.
2. The method for preparing a soft ladder-like polysilsesquioxane functionalized graphene oxide according to claim 1, characterized in that: In step S1, 0.5 g of graphene oxide powder and 2.0 g of octaaminophenyl polyhedral oligomeric silsesquioxane were added to 200 ml of tetrahydrofuran, and the amount of catalyst added was 1.0 g.
3. The method for preparing a soft ladder-like polysilsesquioxane functionalized graphene oxide according to claim 2, characterized in that: The catalyst is 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride.
4. The method for preparing a soft ladder-like polysilsesquioxane functionalized graphene oxide according to claim 3, characterized in that: The time of ultrasonic treatment in step S1 is 1 h.
5. The method for preparing a soft ladder-like polysilsesquioxane functionalized graphene oxide according to claim 4, characterized in that: The stirring reaction time in step S2 is 45 to 50 hours, and the temperature is controlled at 50°C.
6. A method for preparing a soft ladder-like polysilsesquioxane functionalized graphene oxide according to claim 1 or 5, characterized in that: In step S3, after the reaction is completed, the product is centrifuged at 10000 rpm for 5 minutes to obtain a precipitate; the precipitate is washed three times with tetrahydrofuran and ethanol, and then dried in a vacuum oven at 45-50° C. for 10-12 hours to obtain a soft ladder-like polysilsesquioxane functionalized graphene oxide.
7. Use of the soft ladder-like polysilsesquioxane functionalized graphene oxide as a coating according to any one of claims 1 to 6, characterized in that: The specific operations are as follows: The silicon wafer was ultrasonicated in deionized water and ethanol for 5 minutes respectively, and then dried in nitrogen to obtain a dry silicon wafer; soft ladder-like polysilsesquioxane functionalized graphene oxide was added to 50 ml of ethanol to obtain a dispersion; the dispersion was evenly sprayed on the dry silicon wafer under dry pure nitrogen conditions of 0.2 MPa; after spraying, it was vacuum dried at 70-80°C for 1 hour.
8. The use of soft ladder-like polysilsesquioxane functionalized graphene oxide according to claim 7, characterized in that: The mass concentration of soft ladder polysilsesquioxane functionalized graphene oxide in the dispersion is 1 g / L.