In-situ intercalation hydrotalcite nano composite material as well as preparation method and application thereof
The in-situ intercalated hydrotalcite nanocomposite material was synthesized in one step by hydrothermal method, which solved the problems of high-temperature decomposition and poor dispersibility of traditional lubricants. This resulted in a highly efficient and green synthesized nanocomposite material with excellent friction-reducing, wear-resistant and lubricating properties.
Patent Information
- Application Number
- CN202511451903.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-11
- Publication Date
- 2026-01-13
AI Technical Summary
Traditional lubricants decompose at high temperatures, producing harmful substances, and the problem of friction and wear has not been effectively solved. Existing nano lubricating materials have poor dispersibility, making it difficult to meet the needs of green environmental protection and high-efficiency lubrication.
In-situ intercalated hydrotalcite nanocomposites were synthesized in one step via a hydrothermal method. Fatty acid salts were used as alkali sources and intercalation guests to directly insert fatty acid radicals into the interlayer of hydrotalcite, forming a regular interlayer structure and improving dispersibility and lubrication performance.
A highly efficient and green synthesized nanocomposite material has been developed, which has excellent friction-reducing and anti-wear properties, significantly improves the dispersibility and lubrication performance of lubricating oil, and reduces friction and wear.
Smart Images
Figure CN121320003A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of lubricating materials technology, and in particular to an in-situ intercalated hydrotalcite nanocomposite material, its preparation method, and its application. Background Technology
[0002] The energy loss, shortened maintenance cycles, and increased production costs caused by friction and wear during the operation of mechanical equipment remain unresolved. Globally, approximately 23% of energy consumption is attributed to friction. Therefore, developing a lubricant additive with readily available raw materials, a simple synthesis route, and a stable structure is a current goal for improving energy efficiency.
[0003] Traditional additives containing sulfur (S), phosphorus (P), and chlorine (Cl) can generate a chemical reaction film on metal surfaces to reduce wear, but their high-temperature decomposition products contain harmful substances and pollute the environment, contradicting the "green and environmentally friendly" concept. Nanomaterials have come into the researchers' view: their advantages lie in their nanoscale size, some in sheet-like forms, which can fill wear pits in frictional environments, achieving self-repair; simultaneously, they can generate a uniform and dense friction film on friction surfaces. In layered materials of nanoscale systems, the layers are supported by van der Waals forces, hydrogen bonds, or electrostatic interactions. When subjected to external forces, relative slippage easily occurs, thus exhibiting excellent friction-reducing and wear-resistant properties. Hydrotalcite (LDH) is composed of Mg²⁺... + Al³ + Fe³ + Composed of octahedral metal hydroxides with anions in the interlayer, LDH is an ideal material for solving the problem of poor dispersibility in nano-additives. The raw materials for LDH synthesis are only low-cost and readily available inorganic salts such as Al(NO3)3·9H2O and Zn(NO3)2·6H2O. It can be prepared using co-precipitation and hydrothermal methods, which are simple processes, free of toxic solvents, and produce easily treatable waste, conforming to green and environmentally friendly principles. Most importantly, the -OH groups in LDH can form hydrogen bonds or covalent bonds with polar functional groups such as carboxylic acids and phosphate esters, which helps improve its dispersion stability in base oils.
[0004] Intercalated functionalized LDH composites offer advantages in many fields. Current research on functionalized hydrotalcites largely focuses on adsorption and catalysis, with limited application in the friction domain. However, their application in lubrication could address the persistent problems of traditional lubricants. The lubrication performance of intercalated LDH composites is influenced by various factors, including the properties of the intercalated material and the intercalation method. For example, ionic liquid intercalated LDHs utilize the electrostatic interactions and hydrogen bond networks formed by ILs at the friction interface to achieve low friction. Therefore, research on intercalated LDH lubricating additives can focus on innovations in the properties of the raw materials themselves and the preparation process. Summary of the Invention
[0005] This application provides an in-situ intercalated hydrotalcite nanocomposite material, its preparation method, and its application, in order to solve the problems mentioned in the background art.
[0006] In a first aspect, this application provides a method for preparing in-situ intercalated hydrotalcite nanocomposite materials, the method comprising the following steps: Al(NO3)3•9H2O and Zn(NO3)2•6H2O were mixed and added to a solvent and stirred to dissolve, resulting in a salt solution. Under stirring, a fatty acid salt was added to the salt solution, and the mixture was reacted at 100-150℃ for 48 hours to obtain an in-situ intercalated hydrotalcite nanocomposite material.
[0007] Optionally, the molar ratio of Al(NO3)3•9H2O to Zn(NO3)2•6H2O is 1:1-3.
[0008] Optionally, the solvent is a mixture of methanol and water in a volume ratio of 1:1. In the salt solution, the mass-volume ratio of the total mass of Al(NO3)3•9H2O and Zn(NO3)2•6H2O to the solvent is 5-10 g / 100 mL.
[0009] Optionally, the molar ratio of fatty acid salt to Al(NO3)3•9H2O is 2.5:1.
[0010] Optionally, the fatty acid salt is selected from any of the fatty acid salts with a chain length of C4-C12 carbon atoms.
[0011] Optionally, the fatty acid salt is selected from any one of sodium butyrate, sodium octanoate, sodium decanoate, and sodium dodecanoate.
[0012] Optionally, the preparation method of in-situ intercalated hydrotalcite nanocomposite material further includes: after the reaction is completed, cooling to room temperature to obtain in-situ intercalated hydrotalcite nanocomposite material primary product, washing the in-situ intercalated hydrotalcite nanocomposite material primary product with deionized water by centrifugation until the pH value is neutral, and freeze-drying to obtain in-situ intercalated hydrotalcite nanocomposite material.
[0013] Secondly, this application provides an in-situ intercalated hydrotalcite nanocomposite material, which is prepared by the above-described method.
[0014] Optionally, the interlayer spacing of the in-situ intercalated hydrotalcite nanocomposite is 1-1.5 nm.
[0015] Thirdly, this application provides an application of in-situ intercalated hydrotalcite nanocomposite material as a lubricating additive.
[0016] This application synthesizes in-situ intercalated hydrotalcite nanocomposite materials in one step via hydrothermal reaction, which has the following advantages compared to existing technologies: (1) This application involves adding Al(NO3)3•9H2O, Zn(NO3)2•6H2O, and fatty acid salts to a solvent to form a mixed reaction solution. 3+ With Zn 2+ This method provides metal cations that constitute the layers of layered double hydroxides (LDH), while fatty acid salts serve as both alkali sources and intercalation guests, providing intercalation anions. The mixed reaction solution undergoes a one-step hydrothermal reaction, directly inserting fatty acid ions into the LDH interlayer while simultaneously synthesizing the LDH layers. This results in the one-step synthesis of in-situ intercalated LDH nanocomposites with higher intercalation rates and more regular interlayer structures. This avoids the problems of limited exchange capacity and incomplete reaction that may occur in traditional methods that first synthesize nitrate-type LDH and then perform ion exchange with fatty acid ions. It aligns with the principles of green chemistry and improves the synthesis efficiency and quality of in-situ intercalated LDH nanocomposites.
[0017] (2) In the preparation process of the in-situ intercalated hydrotalcite nanocomposite material of this application, a mixed solvent of methanol and water with a volume ratio of 1:1 is used as the solvent. The addition of methanol greatly improves the solubility of fatty acid salts, which is conducive to the uniform dispersion of reaction raw materials and realizes efficient and uniform intercalation of fatty acid ions. At the same time, the addition of methanol reduces the dielectric constant and surface tension of the solution, slows down the nucleation and growth rate of LDH crystals, and is conducive to the formation of nanosheets with smaller size and more uniform particle size distribution, thereby regulating crystal nucleation and growth. In the closed reaction vessel, the presence of methanol makes the reaction environment milder than that of pure water system, which helps to generate composite materials with fewer defects and higher crystallinity. Preferably, the water in the solvent is deionized water.
[0018] (3) The in-situ intercalated hydrotalcite nanocomposite material provided in this application is a sheet-like structure with a diameter of 50-80 nm. The sheet-like structure can form interlayer slip during friction. When used as a lubricating oil additive, it continuously provides a lubricating medium in the friction environment, thereby achieving self-lubrication and improving anti-wear and friction-reducing performance. At the same time, it combines the advantages of hydrotalcite and fatty acids. The hydrophobic ends of the long carbon chains of fatty acids are outward, which significantly improves the compatibility between LDH and base oil, and improves the uniformity and stability of the in-situ intercalated hydrotalcite nanocomposite material in base oil. When the in-situ intercalated hydrotalcite nanocomposite material provided in this application is used as a lubricating additive and dispersed in base lubricating oil at different mass fractions, it provides more space for oil molecule adsorption and shear slip during friction, thereby improving the lubrication performance of base lubricating oil.
[0019] (4) This application takes the dual functionality of fatty acid salts as its innovation point. Fatty acid salts not only provide an alkali source, but also act as intercalators to increase the interlayer spacing. In situ intercalated hydrotalcite nanocomposite materials are prepared. The raw materials are readily available, the experimental steps are simple, there are no harmful products, the yield is high and the cost is low, which is suitable for mass production. This provides a new idea for the efficient and rapid preparation of functional hydrotalcite nanolubricating oil additives. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0021] Explanation of reference numerals in the attached figures: Figure 1 The images shown are electron microscope (EM) images of the in-situ intercalated hydrotalcite nanocomposites obtained in Examples 2, 4, 5, and 6 of this application. Figure 1 Image (A) in the image is an electron micrograph of the unmodified hydrotalcite (LDH) provided in Example 2. Figure 1 Image (a) is an electron microscope image of C4-LDH provided in Example 4. Figure 1 Image (b) is an electron microscope image of the C8-LDH provided in Example 2. Figure 1 (c) is an electron microscope image of the C10-LDH provided in Example 5. Figure 1 (d) is an electron microscope image of C12-LDH provided in Example 6; Figure 2 The XRD patterns are of the in-situ intercalated hydrotalcite nanocomposites obtained in Examples 2, 4, 5, and 6 of this application. Figure 3 The infrared spectra of the in-situ intercalated hydrotalcite nanocomposites obtained in Examples 2, 4, 5, and 6 of this application are shown. Figure 4 Friction curves of the in-situ intercalated hydrotalcite nanocomposite materials obtained in Examples 2, 4, 5, and 6 of this application added to base oil PAO10; Figure 5 Wear volume diagrams of in-situ intercalated hydrotalcite nanocomposites obtained in Examples 2, 4, 5, and 6 of this application added to base oil PAO10; Figure 6 The wear track profile curves of the in-situ intercalated hydrotalcite nanocomposite materials obtained in Examples 2, 4, 5, and 6 of this application added to base oil PAO10. Figure 7 Friction curves of the in-situ intercalated hydrotalcite nanocomposites obtained in Examples 2, 4, 5, and 6 of this application added to base oil 500SN; Figure 8 Wear volume diagrams of in-situ intercalated hydrotalcite nanocomposites obtained in Examples 2, 4, 5, and 6 of this application added to base oil 500SN. Detailed Implementation
[0022] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are also within the scope of protection of this application.
[0023] In a first aspect, this application provides a method for preparing in-situ intercalated hydrotalcite nanocomposite materials, the method comprising the following steps: Al(NO3)3•9H2O and Zn(NO3)2•6H2O were mixed and added to a solvent and stirred to dissolve, resulting in a salt solution. Under stirring, a fatty acid salt was added to the salt solution, and the mixture was reacted at 100-150℃ for 48 hours to obtain an in-situ intercalated hydrotalcite nanocomposite material.
[0024] Specifically, the in-situ intercalated hydrotalcite nanocomposite material provided in this application is synthesized in one step via a hydrothermal method. Al(NO3)3•9H2O and Zn(NO3)2•6H2O are used as raw materials to provide the metal cations Al that constitute the hydrotalcite (LDH) layers. 3+ With Zn 2+ Al 3+ Zn can provide a stable trivalent charge to form positively charged layers. 2+ It possesses good chemical stability and certain catalytic activity, which is beneficial for the efficient execution of subsequent reactions. The selection of nitrates containing water of crystallization allows for the gradual release of this water during the subsequent high-temperature reaction, further providing a continuous and mild aquatic environment for the nucleation and growth of hydrotalcite.
[0025] Fatty acid salts act as both a base source and an intercalation guest, providing intercalation anions. Fatty acid salt solutions are typically alkaline, and during the reaction, they gradually increase the pH of the reaction system, promoting the growth of Zn. 2+ And Al 3+ Hydrolysis and co-precipitation form LDH laminations, and the slow increase in pH value is conducive to the formation of LDH with better crystallinity. This application utilizes a hydrothermal method to synthesize in-situ intercalated layered double hydroxide (LDH) nanocomposites in one step. During the reaction, a large number of fatty acid ions are present in the reaction environment simultaneously with lamination formation. These fatty acid ions directly compete for and enter the interlayer domains of LDH, achieving efficient intercalation. This avoids the problems of limited exchange capacity and incomplete reaction that may be encountered in traditional methods that first synthesize nitrate-type LDH and then use fatty acid ions for ion exchange, thus improving the synthesis efficiency and quality of in-situ intercalated LDH nanocomposites.
[0026] The reaction conditions in this application involve reacting at 100-150℃ for 48 hours. Controlling the appropriate reaction temperature is crucial for the growth of hydrotalcite crystals and the intercalation reaction. High temperatures not only enhance ionic reactivity but also provide sufficient energy to promote the dissolution and recrystallization of the initially formed amorphous precursor, thereby generating LDH crystals with higher crystallinity, more regular lamellar structures, and more uniform particle size. Simultaneously, controlling the reaction time ensures that the intercalation reaction has sufficient time to reach thermodynamic equilibrium, allowing fatty acid ions ample time to insert and adjust their orientation and arrangement between layers. This, in turn, plays a positive role in regulating the size and morphology of the in-situ intercalated hydrotalcite nanocomposite material.
[0027] The above-described method provided in this application successfully synthesized an in-situ intercalated hydrotalcite nanocomposite material. This was achieved by adding Al(NO3)3•9H2O, Zn(NO3)2•6H2O, and fatty acid salts to a solvent to form a mixed reaction solution. 3+ With Zn 2+ This method provides metal cations that constitute the layers of layered double hydroxides (LDH), while fatty acid salts serve as both alkali sources and intercalation guests, providing intercalation anions. The mixed reaction solution undergoes a one-step hydrothermal reaction, directly inserting fatty acid ions into the LDH interlayer while simultaneously synthesizing the LDH layers. This results in the one-step synthesis of in-situ intercalated LDH nanocomposites with higher intercalation rates and more regular interlayer structures. This avoids the problems of limited exchange capacity and incomplete reaction that may occur in traditional methods that first synthesize nitrate-type LDH and then perform ion exchange with fatty acid ions. It aligns with the principles of green chemistry and improves the synthesis efficiency and quality of in-situ intercalated LDH nanocomposites.
[0028] Optionally, the molar ratio of Al(NO3)3•9H2O to Zn(NO3)2•6H2O is 1:1-3.
[0029] Specifically, controlling AI 3+ With Zn 2+ The ratio of [specific ratio] is conducive to the formation of a regular layered crystal structure in in-situ intercalated hydrotalcite nanocomposites, rather than the formation of impurity phases such as Al(OH)3.
[0030] Optionally, the solvent is a mixture of methanol and water in a volume ratio of 1:1. In the salt solution, the mass-volume ratio of the total mass of Al(NO3)3•9H2O and Zn(NO3)2•6H2O to the solvent is 5-10 g / 100 mL.
[0031] Specifically, fatty acid salts have limited solubility in pure water. The addition of methanol significantly improves their solubility, facilitating the uniform dispersion of reactants and enabling efficient and uniform intercalation of fatty acid ions. Simultaneously, the addition of methanol lowers the dielectric constant and surface tension of the solution, slowing down the nucleation and growth rate of LDH crystals, which is beneficial for forming smaller, more uniformly sized nanosheets and regulating crystal nucleation and growth. In a closed reactor, the presence of methanol creates a milder reaction environment than in a pure water system, contributing to the formation of composite materials with fewer defects and higher crystallinity. Preferably, deionized water is used as the solvent.
[0032] Optionally, the molar ratio of fatty acid salt to Al(NO3)3•9H2O is 2.5:1.
[0033] Specifically, fatty acid radicals ensure that there are enough molecules in the interlayer domains to adjust their spatial conformation, thereby obtaining structurally regular composite materials.
[0034] Optionally, the fatty acid salt is selected from any fatty acid salt with a chain length of C4-C12. A carbon chain that is too long or too short will affect the intercalation of the fatty acid.
[0035] Optionally, the fatty acid salt is selected from any one of sodium butyrate, sodium octanoate, sodium decanoate, and sodium dodecanoate.
[0036] Optionally, the preparation method of in-situ intercalated hydrotalcite nanocomposite materials further includes: after the reaction is completed, cooling to room temperature to obtain a preliminary in-situ intercalated hydrotalcite nanocomposite material; washing the preliminary in-situ intercalated hydrotalcite nanocomposite material with deionized water by centrifugation until the pH value is neutral, preferably 7-7.5; and freeze-drying to obtain the in-situ intercalated hydrotalcite nanocomposite material. Freeze-drying is performed under drying conditions well known to those skilled in the art, as long as the purpose of drying the nanocomposite material is achieved; specific freeze-drying conditions are not limited here.
[0037] Secondly, this application provides an in-situ intercalated hydrotalcite nanocomposite material, which is prepared by the above-described method.
[0038] Optionally, the interlayer spacing of the in-situ intercalated hydrotalcite nanocomposite material is 1-1.5 nm, which provides more space for subsequent oil molecule adsorption and shear slip, thereby improving lubrication performance.
[0039] Thirdly, this application provides an application of in-situ intercalated hydrotalcite nanocomposite material as a lubricating additive.
[0040] Specifically, the in-situ intercalated hydrotalcite nanocomposite material provided in this application combines the advantages of hydrotalcite and fatty acids. The hydrophobic ends of the long carbon chains of the fatty acid intercalation are outward, which significantly improves the compatibility between LDH and base oil and enhances the uniformity and stability of the in-situ intercalated hydrotalcite nanocomposite material in base oil.
[0041] The in-situ intercalated hydrotalcite nanocomposite material provided in this application is used as a lubricating additive and dispersed in base lubricating oil at different mass fractions. During the friction process, it provides more space for oil molecules to adsorb and shear slip, thereby improving the lubrication performance of the base lubricating oil.
[0042] The base lubricant is selected from at least one of PAO10, 500SN, and base oil 5750.
[0043] The technical solutions of this application are illustrated in detail below with specific embodiments, but they should not be construed as limiting the scope of protection of this invention. Example 1
[0044] A method for preparing in-situ intercalated hydrotalcite nanocomposite materials, the method comprising the following steps: Take Al(NO3)3•9H2O and Zn(NO3)2•6H2O with a molar ratio of 1:1, add them to the solvent and stir to dissolve them to obtain a salt solution. Under stirring, add sodium octanoate to the salt solution and react at 100℃ for 48h. After the reaction is completed, the mixture is cooled to room temperature to obtain a preliminary in-situ intercalated hydrotalcite nanocomposite material. The preliminary in-situ intercalated hydrotalcite nanocomposite material is washed with deionized water by centrifugation until the pH value is neutral, preferably 7.2. It is then freeze-dried to obtain the in-situ intercalated hydrotalcite nanocomposite material.
[0045] The molar ratio of fatty acid salt to Al(NO3)3•9H2O is 2.5:1, and the solvent is a mixture of methanol and water with a volume ratio of 1:1. In the salt solution, the mass-volume ratio of the total mass of Al(NO3)3•9H2O and Zn(NO3)2•6H2O to the solvent is 5 g / 100 mL. Example 2
[0046] A method for preparing in-situ intercalated hydrotalcite nanocomposite materials, the method comprising the following steps: Al(NO3)3•9H2O and Zn(NO3)2•6H2O were mixed in a molar ratio of 1:2 and added to a solvent and stirred to dissolve, resulting in a salt solution. Sodium octanoate was added to the salt solution under stirring and the mixture was reacted at 120°C for 48 hours. After the reaction is completed, the mixture is cooled to room temperature to obtain a preliminary in-situ intercalated hydrotalcite nanocomposite material. The preliminary in-situ intercalated hydrotalcite nanocomposite material is washed with deionized water by centrifugation until the pH value is neutral, preferably 7. The mixture is then freeze-dried to obtain the in-situ intercalated hydrotalcite nanocomposite material.
[0047] The molar ratio of fatty acid salt to Al(NO3)3•9H2O is 2.5:1, and the solvent is a mixture of methanol and water with a volume ratio of 1:1. In the salt solution, the mass-volume ratio of the total mass of Al(NO3)3•9H2O and Zn(NO3)2•6H2O to the solvent is 7 g / 100 mL. Example 3
[0048] A method for preparing in-situ intercalated hydrotalcite nanocomposite materials, the method comprising the following steps: Al(NO3)3•9H2O and Zn(NO3)2•6H2O were mixed in a molar ratio of 1:3 and added to a solvent and stirred to dissolve, resulting in a salt solution. Sodium octanoate was added to the salt solution under stirring and the mixture was reacted at 150°C for 48 hours. After the reaction is completed, the mixture is cooled to room temperature to obtain a preliminary in-situ intercalated hydrotalcite nanocomposite material. The preliminary in-situ intercalated hydrotalcite nanocomposite material is washed with deionized water by centrifugation until the pH value is neutral, preferably 7.5. It is then freeze-dried to obtain the in-situ intercalated hydrotalcite nanocomposite material.
[0049] The molar ratio of fatty acid salt to Al(NO3)3•9H2O is 2.5:1, and the solvent is a mixture of methanol and water with a volume ratio of 1:1. In the salt solution, the mass-volume ratio of the total mass of Al(NO3)3•9H2O and Zn(NO3)2•6H2O to the solvent is 10g / 100mL. Example 4
[0050] A method for preparing in-situ intercalated hydrotalcite nanocomposite materials, the method comprising the following steps: The difference from Example 2 is that: The fatty acid salt is selected from sodium butyrate. Example 5
[0051] A method for preparing in-situ intercalated hydrotalcite nanocomposite materials, the method comprising the following steps: The difference from Example 2 is that: The fatty acid salt is selected from sodium decanoate. Example 6
[0052] A method for preparing in-situ intercalated hydrotalcite nanocomposite materials, the method comprising the following steps: The difference from Example 2 is that: The fatty acid salt is selected from sodium dodecanoate.
[0053] Experimental Example 1 Characterization of in-situ intercalated hydrotalcite nanocomposites In-situ intercalated hydrotalcite nanocomposites were successfully synthesized using the methods provided in Examples 1-6. The morphology of the nanocomposites synthesized in Examples 2, 4, 5, and 6 was tested.
[0054] The in-situ intercalated hydrotalcite nanocomposite material obtained in Example 2 was named C8-LDH, the in-situ intercalated hydrotalcite nanocomposite material obtained in Example 4 was named C4-LDH, the in-situ intercalated hydrotalcite nanocomposite material obtained in Example 5 was named C10-LDH, and the in-situ intercalated hydrotalcite nanocomposite material obtained in Example 6 was named C12-LDH. The morphology of the above intercalated hydrotalcite nanocomposite materials was characterized by electron microscopy, and the results are as follows: Figure 1 As shown, Figure 1 The images show the electron microscope morphology of the in-situ intercalated hydrotalcite nanocomposites obtained in Examples 2, 4, 5, and 6.
[0055] observe Figure 1 , Figure 1 Image (A) in the image is an electron micrograph of the unmodified hydrotalcite (LDH) provided in Example 2. Figure 1 Image (a) is an electron microscope image of C4-LDH provided in Example 4. Figure 1 Image (b) is an electron microscope image of the C8-LDH provided in Example 2. Figure 1 (c) is an electron microscope image of the C10-LDH provided in Example 5. Figure 1 Image (d) is an electron micrograph of C12-LDH provided in Example 6. It can be seen that the modified hydrotalcite has a lamellar structure and the particle size is smaller than that before modification, which is conducive to interlayer slippage and the formation of a friction film.
[0056] Experiment Example 2 Characterization of in-situ intercalated hydrotalcite nanocomposites Taking the nanocomposites synthesized in Examples 2, 4, 5, and 6 as examples, the morphology of the above-mentioned intercalated hydrotalcite nanocomposites was characterized by XRD, and the results are as follows: Figure 2 As shown, Figure 2 The images show the XRD patterns of the in-situ intercalated hydrotalcite nanocomposites obtained in Examples 2, 4, 5, and 6.
[0057] from Figure 2As can be seen from the XRD patterns, C4-LDH, C8-LDH, C10-LDH, and C12-LDH all exhibited typical (003), (006), and (009) characteristic diffraction peaks of hydrotalcite. The XRD patterns show that these four intercalated functional hydrotalcites have good crystallinity, with sharp and complete peak shapes. The diffraction angle 2θ corresponding to the (003) crystal plane of LDH is 11.68°, and the interlayer spacing, calculated using Bragg's formula, is d = 0.7571 nm. The 003 characteristic diffraction peaks of the modified hydrotalcite (C4-LDH, C8-LDH, C10-LDH, C12-LDH) show a significant forward shift. Calculations show that dC4-LDH = 1.0113 nm, dC8-LDH = 1.0559 nm, dC10-LDH = 1.2265 nm, and dC12-LDH = 1.4827 nm. It can be seen that the interlayer spacing (d value) of the four modified LDHs has increased, indicating that sodium butyrate, sodium octanoate, sodium decanoate, and sodium dodecanoate have been successfully inserted into the hydrotalcite.
[0058] Experimental Example 3 Characterization of in-situ intercalated hydrotalcite nanocomposites Taking the nanocomposites synthesized in Examples 2, 4, 5, and 6 as examples, the above-mentioned in-situ intercalated hydrotalcite nanocomposites were characterized by FT-IR analysis, and the results are as follows: Figure 3 As shown, Figure 3 The infrared spectra of the in-situ intercalated hydrotalcite nanocomposites obtained in Examples 2, 4, 5, and 6 are shown.
[0059] Figure 3 Common absorption peaks in unmodified hydrotalcite include: 3500 cm⁻¹ -1 The lamination exhibits -OH stretching vibration; 1620 cm -1 Adsorbed water bending vibration; 600–400 cm -1 The lattice vibrations of the metal oxides are observed. After modification, C4-LDH, C8-LDH, C10-LDH, and C12-LDH exhibit lattice vibrations at 2964 cm⁻¹. -1 Left and right display - CH3 asymmetric stretching vibration; 2939cm -1 Left and right display -CH2- asymmetric stretching vibration; 1558 cm -1 COO displayed on the left and right - Asymmetric stretching vibration; 1406 cm -1 COO displayed on the left and right - Symmetrical stretching vibrations further confirmed that butyrate, octanoate, decanoate, and dodecanoate ions were inserted into the interlayer of the hydrotalcite.
[0060] Characterization from Experiments 1-3 confirms that sodium butyrate, sodium octanoate, sodium decanoate, and sodium dodecanoate have been successfully inserted into the hydrotalcite.
[0061] Experiment Example 4 The in-situ intercalated hydrotalcite nanocomposites obtained in Examples 2 (C8-LDH), 4 (C4-LDH), 5 (C10-LDH), and 6 (C12-LDH) of this application, as well as unmodified hydrotalcite (LDH), were added to the base oil and stably dispersed. The lubrication performance of the obtained in-situ intercalated hydrotalcite nanocomposites as lubricating additives was evaluated using an SRV-V micro-vibration friction and wear tester manufactured by Optimol Grease GmbH, Germany. The wear volume of the samples was measured by a BRUKER-NPFLEX three-dimensional optical profilometer.
[0062] The in-situ intercalated hydrotalcite nanocomposites obtained in Examples 2 (C8-LDH), 4 (C4-LDH), 5 (C10-LDH), and 6 (C12-LDH), as well as unmodified hydrotalcite (LDH), were added to base oil PAO10 at a mass concentration of 0.5% for friction tests. Each test was performed in at least three parallel experiments, and the average value was taken. The test results are shown in Table 1. Figure 4 , Figure 5 , Figure 6 As shown.
[0063] The test conditions were: load 200 N, temperature 25℃, frequency 25 Hz, amplitude 1 mm, and test time 30 min; the test ball was a Φ10 mm AISI 52100 steel ball; in the steel / steel friction pair, the lower sample was a Φ24 mm, 7.9 mm thick AISI 52100 steel block with a hardness of 750-850 HV.
[0064] Table 1 Steel-to-steel friction pair concentration Average coefficient of friction <![CDATA[Average wear volume (μm 3 )]]> PAO10 0.5% 0.180182 2218782.976 LDH 0.5% 0.110739 546559.424 C4-LDH 0.5% 0.102324 277763.104 C8-LDH 0.5% 0.102324 449966.048 C10-LDH 0.5% 0.109426 310276.992 C12-LDH 0.5% 0.107267 321478.464 From Table 1, Figure 4 It is evident that the in-situ intercalated hydrotalcite nanocomposite material provided in this application, as a lubricating additive, possesses excellent friction-reducing and anti-wear properties. When added to the base oil PAO10, the wear volume of the lubricant significantly decreases, and compared to unmodified hydrotalcite, the wear volume is also significantly reduced. Furthermore, observations... Figure 6 It can be seen that when the in-situ intercalated hydrotalcite nanocomposite material provided in this application is used as an additive for base oil PAO10, the depth and width of the resulting wear tracks are significantly smaller than those of base oil PAO10 and unmodified hydrotalcite precursor, indicating that the in-situ intercalated hydrotalcite nanocomposite material provided in this application has excellent lubrication performance as a lubricating additive.
[0065] Experimental Example 5 The in-situ intercalated hydrotalcite nanocomposites obtained in Examples 2 (C8-LDH), 4 (C4-LDH), 5 (C10-LDH), and 6 (C12-LDH), as well as unmodified hydrotalcite (LDH), were added to base oil 500SN at a mass concentration of 0.5% for friction tests. Each test was performed in at least three parallel trials, and the average value was taken. The test results are shown in Table 2. Figure 7 , Figure 8 As shown.
[0066] Table 2 Steel-to-steel friction pair concentration Average coefficient of friction <![CDATA[Average wear volume (μm 3 )]]> 500SN 0.5% 0.178266 1643293.696 LDH 0.5% 0.110689 441159.968 C4-LDH 0.5% 0.105153 262803.408 C8-LDH 0.5% 0.107021 187348 C10-LDH 0.5% 0.106083 152945.648 C12-LDH 0.5% 0.110181 197502.512 Observation Table 2 Figure 7 , Figure 8 The in-situ intercalated hydrotalcite nanocomposite material provided in this application, as a lubricating additive, significantly improves the friction-reducing and anti-wear properties of base oil 500SN. Especially... Figure 8 As shown, the reduction in wear volume is most significant when the fatty acid salt is selected from sodium decanoate.
[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.
Claims
1. A method for preparing an in-situ intercalated hydrotalcite nanocomposite material, characterized in that, The preparation method includes the following steps: Al(NO3)3•9H2O and Zn(NO3)2•6H2O were mixed and added to a solvent and stirred to dissolve, resulting in a salt solution. Under stirring, a fatty acid salt was added to the salt solution, and the mixture was reacted at 100-150℃ for 48 hours to obtain an in-situ intercalated hydrotalcite nanocomposite material.
2. The method for preparing in-situ intercalated hydrotalcite nanocomposite materials according to claim 1, characterized in that, The molar ratio of Al(NO3)3•9H2O to Zn(NO3)2•6H2O is 1:1-3.
3. The method for preparing in-situ intercalated hydrotalcite nanocomposite materials according to claim 1, characterized in that, The solvent is a mixture of methanol and water in a volume ratio of 1:
1. In the salt solution, the total mass of Al(NO3)3•9H2O and Zn(NO3)2•6H2O is in a mass-volume ratio of 5-10 g / 100 mL to the solvent.
4. The method for preparing in-situ intercalated hydrotalcite nanocomposite materials according to claim 1, characterized in that, The molar ratio of the fatty acid salt to the Al(NO3)3•9H2O is 2.5:
1.
5. The method for preparing in-situ intercalated hydrotalcite nanocomposite materials according to claim 1, characterized in that, The fatty acid salt is selected from any one of the fatty acid salts with a chain length of C4-C12 carbon atoms.
6. The method for preparing in-situ intercalated hydrotalcite nanocomposite materials according to claim 5, characterized in that, The fatty acid salt is selected from any one of sodium butyrate, sodium octanoate, sodium decanoate, and sodium dodecanoate.
7. The method for preparing in-situ intercalated hydrotalcite nanocomposite materials according to claim 1, characterized in that, The method for preparing the in-situ intercalated hydrotalcite nanocomposite material further includes: after the reaction is completed, cooling to room temperature to obtain a preliminary in-situ intercalated hydrotalcite nanocomposite material; washing the preliminary in-situ intercalated hydrotalcite nanocomposite material with deionized water by centrifugation until the pH value is neutral; and freeze-drying to obtain the in-situ intercalated hydrotalcite nanocomposite material.
8. An in-situ intercalated hydrotalcite nanocomposite material, characterized in that, The in-situ intercalated hydrotalcite nanocomposite material is prepared by the method described in any one of claims 1-7.
9. The in-situ intercalated hydrotalcite nanocomposite material according to claim 8, characterized in that, The interlayer spacing of the in-situ intercalated hydrotalcite nanocomposite material is 1-1.5 nm.
10. The application of the in-situ intercalated hydrotalcite nanocomposite material as described in claim 9 as a lubricating additive.