A porous zeolitic imidazolate framework oil storage microcapsule, a preparation method and application thereof
By preparing oil-storing microcapsules using porous zeolite imidazole framework materials, the problem of lubricating oil leakage in core-shell structures was solved, achieving stable release of lubricating oil and efficient operation of equipment, and improving friction performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- JIHUA LAB
- Filing Date
- 2023-11-21
- Publication Date
- 2026-06-16
Smart Images
Figure CN117586637B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the technical field of oil storage microcapsules, and particularly to a porous zeolite imidazole framework oil storage microcapsule, its preparation method, and its application. Background Technology
[0002] Self-lubricating materials refer to a series of functional materials that can provide continuous lubrication on their own without the need for external lubricating oil. Oil-storage microencapsulation technology involves encapsulating lubricating substances (lubricating oil, grease, etc.) into a matrix material through various methods. During operation, under the action of various forces, the encapsulation layer ruptures, releasing the lubricating substance and providing lubrication, thereby achieving the purpose of reducing friction and increasing wear resistance. This type of functional material not only solves the problems of leakage and contamination that are easily caused by adding external lubricants, but also has advantages over solid self-lubricating materials, which suffer from high wear rates and insufficient heat resistance. It is particularly suitable for special working conditions such as high speed, high load, and high temperature, and is of great significance to the operation and development of high-end equipment such as aerospace.
[0003] Existing microcapsule oil storage and self-lubricating technologies typically employ core-shell structures, where lubricating oil is encapsulated within a shell. However, microcapsule materials prepared using this method suffer from unpredictable and random variations in pore size, channel distribution, and channel connectivity. This makes it difficult to resolve the contradiction between high oil storage capacity and disordered grease leakage. In other words, during operation, if the shell of a traditional core-shell structure breaks, the lubricating oil encapsulated within the shell will leak out uncontrollably, failing to achieve a stable and continuous release of the grease stored inside the shell.
[0004] It is evident that existing technologies still need improvement and enhancement. Summary of the Invention
[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a porous zeolite imidazole framework oil storage microcapsule, its preparation method and application, aiming to solve the problem of disordered oil seepage under the action of multiple forces when the oil storage cavity of traditional core-shell structure microcapsules is miniaturized.
[0006] To achieve the above objectives, the present invention adopts the following technical solution:
[0007] A method for preparing porous zeolite imidazole framework oil-storing microcapsules includes the following steps:
[0008] S1. Preparation of ZIF-X powder: Dissolve 2-methylimidazole and nitrate separately in aqueous solution, and stir to dissolve to obtain 2-methylimidazole solution and nitrate solution; pour the nitrate solution into 2-methylimidazole solution, stir at room temperature to obtain ZIF-X solution; wash and dry the ZIF-X solution, and grind to obtain ZIF-X powder;
[0009] S2. Preparation of ZIF-X@lubricating oil storage microcapsules: The ZIF-X powder obtained above is mixed with an excess of lubricating oil and stirred under vacuum at room temperature; the product is cleaned and dried to obtain ZIF-X@lubricating oil storage microcapsules.
[0010] The method for preparing porous zeolite imidazole framework oil-storing microcapsules, wherein the specific surface area of the ZIF-X powder is ≥500 m² / g. 2 g -1 The ZIF-X powder has a pore size of 1 to 5 mm.
[0011] The method for preparing porous zeolite imidazole framework oil-storing microcapsules, wherein the thermal weight loss temperature of the ZIF-X powder is ≥300℃.
[0012] The method for preparing porous zeolite imidazole framework oil storage microcapsules, wherein the nitrate is one of cobalt nitrate or zinc nitrate, and when the nitrate is cobalt nitrate, the ZIF-X is ZIF-67; when the nitrate is zinc nitrate, the ZIF-X is ZIF-8.
[0013] The method for preparing porous zeolite imidazole framework oil-storing microcapsules, wherein the lubricating oil is a low-viscosity lubricating oil; the viscosity coefficient of the lubricating oil is ≤150 Pa·s.
[0014] The method for preparing the porous zeolite imidazole framework oil-storing microcapsules, wherein the lubricating oil is one or more of PAO2, PAO4, PAO6, PAO8, PAO10, and PAO40.
[0015] The method for preparing porous zeolite imidazole framework oil storage microcapsules, wherein the concentration ratio of 2-methylimidazolium solution and nitrate solution obtained in step S1 is (1.5-2):1; and the nitrate solution is added to the 2-methylimidazolium solution at a volume ratio of 1:(5-8).
[0016] A porous zeolite imidazole framework oil storage microcapsule is prepared by the method described above; the porous zeolite imidazole framework oil storage microcapsule comprises ZIF-X and lubricating oil impregnated in the porous structure of ZIF-X.
[0017] An application of a porous zeolite imidazole framework oil storage microcapsule involves mixing and doping the porous zeolite imidazole framework oil storage microcapsule with a polymer substrate to improve the frictional properties of the polymer substrate; the molding temperature of the polymer substrate is lower than the decomposition temperature of the lubricating oil in the porous zeolite imidazole framework oil storage microcapsule.
[0018] The application of the porous zeolite imidazole framework oil storage microcapsules, wherein the polymer substrate includes one or more of ultra-high molecular weight polyethylene, epoxy resin, polyurethane, phenolic resin, and nylon.
[0019] Beneficial effects:
[0020] This invention provides a porous zeolite imidazole framework oil-storing microcapsule, its preparation method, and its application. Unlike previous core-shell microcapsules, this porous zeolite imidazole framework oil-storing microcapsule utilizes the microporous structure and ultra-high specific surface area within the framework to adsorb and store lubricating oil. Furthermore, the oil-storing cavities of the framework are nanoscaled, creating tens of thousands of microchannels for oil storage. This not only increases the oil storage capacity but also allows for the continuous and stable release of lubricating oil from the microchannels as the shell ruptures to varying degrees. Under multiple forces, it prevents the disorderly seepage of excess oil, achieving more efficient utilization of lubricating oil and enabling efficient, long-term operation of equipment. Co-doping this porous zeolite imidazole framework oil-storing microcapsule with a polymer substrate significantly improves the tribological properties of the polymer substrate incorporating the microcapsule. Attached Figure Description
[0021] Figure 1 This is a comparison diagram of the existing technical solution and the technical solution of the present invention.
[0022] Figure 2 This is a schematic diagram of the preparation process of the porous zeolite imidazole framework oil storage microcapsules of the present invention.
[0023] Figure 3 X-ray characterization of ZIF-67 powder prepared in Example 1.
[0024] Figure 4 The nitrogen adsorption curve (a) and pore size distribution diagram (b) of the ZIF-67 powder prepared in Example 1 are shown.
[0025] Figure 5 Thermogravimetric analysis curves of ZIF-67 before and after impregnation with PAO6 lubricating oil, and the thermogravimetric analysis curves of PAO6 lubricating oil.
[0026] Figure 6 This is a comparison of the friction coefficient curves of UHMWPE doped with ZIF-67@PAO6 oil storage microcapsules prepared in Example 1 and pure UHMWPE samples under certain working conditions. Detailed Implementation
[0027] This invention provides a porous zeolite imidazole framework oil-storing microcapsule, its preparation method, and its application. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the scope of protection of the invention.
[0028] Please see Figure 2 This invention provides a method for preparing porous zeolite imidazole framework oil-storing microcapsules, comprising the following steps:
[0029] (1) Preparation of ZIF-X powder: 2-methylimidazole and nitrate were dissolved separately in aqueous solution and stirred for half an hour to obtain 2-methylimidazole solution and nitrate solution (concentration ratio of 2-methylimidazole solution to nitrate solution was (1.5:1 to 2:1)). Then, the nitrate solution was slowly poured into the 2-methylimidazole solution at a volume ratio of 1:5 to 1:8 and stirred overnight at room temperature to obtain ZIF-X solution. The ZIF-X solution was subjected to repeated centrifugation and washing with methanol and water to remove unreacted raw materials. Then, the ZIF-X solution was dried overnight in a vacuum oven at 120°C and ground to obtain ZIF-X powder. In this complexation reaction, nitrates act as metal ion donors, providing coordinateable metal ions. 2-Methylimidazole, a functional compound with a coordinating group, has its nitrogen atom capable of forming coordinate bonds with the metal ion. During the reaction, the lone pair of electrons on the nitrogen atom of 2-methylimidazole forms coordinate bonds with the metal ion, creating the structural unit of the complex. The structure and coordination number of the complex formed depends on factors such as reaction conditions, reaction temperature, ligand concentration, and pH. A 2-methylimidazole solution within a specific ligand concentration range and a metal ion within that range will result in a high coordination number complex, meaning multiple ligands can form coordinate bonds with the metal ion, leading to a high coordination number complex.
[0030] (2) Preparation of ZIF-X@Lubricating Oil Storage Microcapsules: The ZIF-X powder obtained above was mixed with an excess of lubricating oil and stirred under vacuum overnight at room temperature. Vacuuming was used to fully remove air from the microporous structure of the ZIF-X powder, facilitating thorough impregnation of the lubricating oil and allowing more lubricating oil to enter the channels inside the ZIF-X powder. Subsequently, the product was thoroughly washed with methanol and water and centrifuged to remove residual lubricating oil from the surface of the ZIF-X powder. The product was then dried overnight in a vacuum oven at 120°C to obtain ZIF-X@lubricating oil storage microcapsules.
[0031] Zeolite imidazole frameworks (ZIFs) are a class of porous crystalline materials that link metal ions to organic ligands via coordination bonds. They possess high specific surface area, high porosity, well-ordered pore structure, and high design tunability, making them excellent candidate materials for oil-storage microcapsules. Please refer to [link to relevant documentation]. Figure 1 By fully utilizing the microporous structure of ZIFs, specifically the tens of thousands of tiny channels within ZIFs for oil storage, the porous zeolite imidazole framework oil storage microcapsules, as the shell ruptures to varying degrees, continuously and stably release the grease stored in the tiny channels from within the ruptured shell. Compared to traditional core-shell microcapsules that miniaturize the oil storage cavity, this solution, under the influence of multiple forces, can prevent the disorderly seepage of excess grease, achieving more efficient utilization of lubricating oil and efficient long-term operation of the equipment.
[0032] Specifically, the nitrate is either cobalt nitrate or zinc nitrate. When the nitrate is cobalt nitrate, ZIF-X is ZIF-67; when the nitrate is zinc nitrate, ZIF-X is ZIF-8. The porous zeolite imidazole framework is suitable for ZIF-67 synthesized from 2-methylimidazole and cobalt nitrate via hydrothermal synthesis, and is also suitable for ZIF-8 synthesized from 2-methylimidazole and zinc nitrate via hydrothermal synthesis. It is also suitable for a series of products with high specific surface area (BET specific surface area ≥ 500 m²). 2 g -1 This is in contrast to other porous zeolite imidazole framework materials with abundant and well-defined microporous and mesoporous structures (pore size 1–5 mm) and high thermal stability (thermal weight loss temperature ≥ 300℃). The specific surface area and pore size range defined above significantly affect the oil storage and adsorption capacity of lubricating oils. When the specific surface area of the porous zeolite imidazole framework material is ≥ 500 m², the effect is significant. 2 g -1 At this temperature, the porous zeolite imidazole framework exhibits a greater number and size of pores and channels, providing more adsorption sites and thus enhancing its adsorption capacity. Furthermore, the higher specific surface area of the porous zeolite imidazole framework provides more contact interfaces for lubricating oil, enabling continuous and effective release and improving the self-lubricating properties of the polymer substrate. This thermogravimetric temperature needs to match the molding temperature of the polymer substrate and also allows the inorganic framework to withstand ambient temperatures below 300°C, preventing thermal decomposition, channel collapse, or structural reorganization at lower temperatures. In high-temperature operating environments above 300°C, the porous zeolite imidazole framework undergoes a weightlessness process, allowing the lubricating oil within its channels to be released.
[0033] Specifically, the lubricating oil is a low-viscosity lubricating oil; the viscosity coefficient of the lubricating oil is ≤150 Pa·s. More specifically, the lubricating oil is one or more of PAO2, PAO4, PAO6, PAO8, PAO10, and PAO40. The lubricating oils listed above are all polyalphaolefins, preferably PAO6, with a viscosity coefficient of 143 Pa·s and a thermal decomposition temperature of 220℃. Using a low-viscosity lubricating oil system, which has a smaller molecular volume, allows it to more easily enter the pores of the porous zeolite imidazole framework and interact with it, improving the adsorption efficiency of micropores and mesopores, and increasing the oil storage capacity of the porous zeolite imidazole framework. Furthermore, the diffusion rate of lubricating oil molecules in the porous zeolite imidazole framework depends on its dynamic viscosity; lubricating oils with a viscosity coefficient below 150 Pa·s have a faster molecular diffusion rate, allowing for faster transport and diffusion within the porous zeolite imidazole framework, increasing the reaction rate and the efficiency of mass exchange. Moreover, the porous zeolite imidazole framework oil storage microcapsules prepared need to be used under high temperature or high shear force conditions. The low viscosity coefficient lubricating oil can be released and flow in this working environment, making lubrication more effective and helping to reduce energy consumption and friction loss.
[0034] This invention also provides a porous zeolite imidazole framework oil storage microcapsule, prepared by the method described above, comprising ZIF-X and lubricating oil impregnated in the porous structure of ZIF-X. This porous zeolite imidazole framework oil storage microcapsule differs from previous core-shell structure microcapsules. It utilizes the microporous structure and ultra-high specific surface area within the porous zeolite imidazole framework to adsorb and store lubricating oil. Simultaneously, the oil storage cavity of the porous zeolite imidazole framework is nanoscaled, allowing tens of thousands of microchannels to be used for oil storage. This not only increases the oil storage capacity of the porous zeolite imidazole framework oil storage microcapsule but also allows for the continuous and stable release of lubricating oil from the microchannels as the shell ruptures to varying degrees. Under the action of multiple forces, it avoids the disorderly seepage of excess oil, achieving more efficient utilization of lubricating oil and efficient long-term operation of equipment.
[0035] This invention also provides an application of porous zeolite imidazole framework oil storage microcapsules, which are mixed and doped with a polymer substrate at a specific doping ratio of 5-10%. Within the above doping range, the porous zeolite imidazole framework oil storage microcapsules gradually enhance the lubrication performance as the doping amount increases.
[0036] Specifically, the molding temperature of the polymer substrate is lower than the decomposition temperature of the lubricating oil in the porous zeolite imidazole framework oil storage microcapsules. The polymer substrate includes one or more of ultra-high molecular weight polyethylene, epoxy resin, polyurethane, phenolic resin, and nylon. Taking PAO6 as an example, its thermogravimetric decomposition temperature is 220°C. Therefore, the molding temperature of the selected polymer substrate must be lower than 220°C so that after the polymer substrate cracks at the operating temperature, the lubricating oil in the porous zeolite imidazole framework oil storage microcapsules remains stable, thus avoiding adverse effects on the performance of the lubricating oil.
[0037] To further illustrate the porous zeolite imidazole framework oil storage microcapsule provided by the present invention, its preparation method, and its application, the following examples are provided.
[0038] Example 1
[0039] A method for preparing porous zeolite imidazole framework oil-storing microcapsules includes the following steps:
[0040] (1) Preparation of ZIF-67 powder: 2-methylimidazole and cobalt nitrate were dissolved in aqueous solution and stirred for half an hour to obtain 2-methylimidazole solution and cobalt nitrate solution (concentration ratio of 2-methylimidazole solution to cobalt nitrate solution was (1.5:1). Then, the cobalt nitrate solution was slowly poured into the 2-methylimidazole solution at a volume ratio of 1:5 and stirred overnight at room temperature to obtain a purple ZIP-67 solution. The ZIP-67 solution was subjected to repeated centrifugation and washing with methanol and water, and then dried overnight in a vacuum oven at 120°C. The ZIP-67 powder product was obtained by grinding.
[0041] (2) Preparation of ZIF-67@PAO6 oil-storing microcapsules: The ZIF-67 powder obtained above was mixed with an excess of PAO6 and stirred under vacuum overnight at room temperature. The product was then thoroughly washed with methanol and water and centrifuged. It was dried overnight in a vacuum oven at 120°C to obtain ZIF-67@PAO6 oil-storing microcapsules.
[0042] ZIF-67@PAO6 oil-storing microcapsules were mixed and doped with ultra-high molecular weight polyethylene (UHMWPE) at 10% by weight. After hot molding, their friction properties were tested. Figure 6 The results show that UHMWPE doped with ZIF-67@PAO6 oil storage microcapsules has excellent friction properties, which are far superior to pure UHMWPE samples under the same working conditions.
[0043] Example 2
[0044] A method for preparing porous zeolite imidazole framework oil-storing microcapsules includes the following steps:
[0045] (1) Preparation of ZIF-8 powder: 2-methylimidazole and zinc nitrate were dissolved in aqueous solution and stirred for half an hour to obtain 2-methylimidazole solution and zinc nitrate solution (concentration ratio of 2-methylimidazole solution to zinc nitrate solution was (1.5:1). Then, zinc nitrate solution was slowly poured into 2-methylimidazole solution at a volume ratio of 1:8 and stirred overnight at room temperature to obtain ZIP-8 solution. ZIP-8 solution was subjected to repeated centrifugation and washing with methanol and water, and then placed in a vacuum oven at 120℃ for overnight drying. ZIF-8 powder product was obtained by grinding.
[0046] (2) Preparation of ZIF-8@PAO4 oil-storing microcapsules: The ZIF-8 powder obtained above was mixed with an excess of PAO4 and stirred under vacuum overnight at room temperature. The product was then thoroughly washed with methanol and water and centrifuged. It was dried overnight in a vacuum oven at 120°C to obtain ZIF-8@PAO4 oil-storing microcapsules.
[0047] ZIF-8@PAO4 oil-storing microcapsules were mixed and doped with epoxy resin at 8% of the epoxy resin weight. After casting and molding, their friction properties were tested. The epoxy resin doped with ZIF-8@PAO4 oil-storing microcapsules had excellent friction properties, which were far superior to those of pure epoxy resin samples under the same working conditions.
[0048] Example 3
[0049] A method for preparing porous zeolite imidazole framework oil-storing microcapsules includes the following steps:
[0050] (1) Preparation of ZIF-67 powder: 2-methylimidazole and cobalt nitrate were dissolved in aqueous solution and stirred for half an hour to obtain 2-methylimidazole solution and cobalt nitrate solution (concentration ratio of 2-methylimidazole solution to cobalt nitrate solution was (2:1). Then, the cobalt nitrate solution was slowly poured into the 2-methylimidazole solution at a volume ratio of 1:6 and stirred overnight at room temperature to obtain ZIP-67 solution. The ZIP-67 solution was subjected to repeated centrifugation and washing with methanol and water, and then placed in a vacuum oven at 120℃ to dry overnight. The ZIF-67 powder product was obtained by grinding.
[0051] (2) Preparation of ZIF-67@PAO10 oil-storing microcapsules: The ZIF-67 powder obtained above was mixed with an excess of PAO10 and stirred under vacuum overnight at room temperature. The product was then thoroughly washed with methanol and water and centrifuged. It was dried overnight in a vacuum oven at 120°C to obtain ZIF-67@PAO10 oil-storing microcapsules.
[0052] ZIF-67@PAO10 oil storage microcapsules were mixed and doped with polyurethane at 5% of the weight of polyurethane. After casting, the friction properties were tested. The polyurethane doped with ZIF-67@PAO10 oil storage microcapsules had excellent friction properties, which were far superior to those of pure polyurethane samples under the same working conditions.
[0053] The relevant physicochemical properties of ZIF-67 powder and ZIF-67@PAO6 oil-storing microcapsules prepared in Example 1 were confirmed by a series of characterizations.
[0054] Figure 3 Here is the X-ray diffraction characterization pattern of ZIF-67 powder. Figure 3 The strong diffraction peaks in the X-ray diffraction characterization diagram confirm that ZIF-67 has a regular and ordered crystal structure, and these diffraction peaks are consistent with the standard crystal simulation data of ZIF-67.
[0055] Figure 4 The images show the nitrogen adsorption curve (a) and pore size distribution (b) of ZIF-67 powder. The nitrogen adsorption curve (a) shows that ZIF-67 powder has an extremely high specific surface area (1787 m²). 2 g -1 The pore size distribution diagram (b) of ZIF-67 powder shows that ZIF-67 also has a rich microporous structure (1.1 nm). This specific surface area and microporous structure have unique structural advantages for the adsorption and storage of lubricating oil.
[0056] Figure 5 Thermogravimetric analysis (TGA) curves of ZIF-67 before and after impregnation with PAO6 lubricating oil, and of PAO6 lubricating oil, are shown. By performing TGA on the ZIF-67@PAO6 oil storage microcapsules and comparing the TGA with that of ZIF-67 and PAO6, the adsorption and storage capacity of ZIF-67 for PAO6 was determined to be 40%.
[0057] Figure 6 The graph shows a comparison of the friction coefficient curves of UHMWPE doped with ZIF-67@PAO6 oil storage microcapsules and pure UHMWPE samples under certain working conditions, demonstrating that UHMWPE doped with ZIF-67@PAO6 oil storage microcapsules has excellent friction properties.
[0058] In summary, the porous zeolite imidazole framework oil-storing microcapsules, their preparation method, and applications provided by this invention differ from previous core-shell microcapsules. They utilize the microporous structure and ultra-high specific surface area within the porous zeolite imidazole framework to adsorb and store lubricating oil. Furthermore, the oil-storing cavities of the porous zeolite imidazole framework are nanoscaled, resulting in tens of thousands of microchannels suitable for oil storage. This not only increases the oil storage capacity of the microcapsules but also allows for the continuous and stable release of lubricating oil from the microchannels as the shell ruptures to varying degrees. Under the influence of multiple forces, the disorderly seepage of excess oil is prevented, achieving more efficient utilization of lubricating oil and efficient, long-term operation of equipment. Furthermore, co-doping these porous zeolite imidazole framework oil-storing microcapsules with a polymer substrate significantly improves the tribological properties of the polymer substrate incorporating the microcapsules.
[0059] It is understood that those skilled in the art can make equivalent substitutions or changes to the technical solution and inventive concept of the present invention, and all such changes or substitutions should fall within the protection scope of the present invention.
Claims
1. A method for preparing porous zeolite imidazole framework oil-storing microcapsules, characterized in that, Includes the following steps: S1. Preparation of ZIF-X powder: Dissolve 2-methylimidazole and nitrate separately in aqueous solution, and stir to dissolve to obtain 2-methylimidazole solution and nitrate solution; The nitrate solution was poured into the 2-methylimidazole solution and stirred at room temperature to obtain the ZIP-X solution; the ZIP-X solution was washed, dried, and ground to obtain ZIF-X powder; S2. Preparation of ZIF-X@lubricating oil storage microcapsules: The ZIF-X powder obtained above is mixed with an excess of lubricating oil and stirred under vacuum at room temperature; the product is cleaned and dried to obtain ZIF-X@lubricating oil storage microcapsules; The nitrate is either cobalt nitrate or zinc nitrate.
2. The method for preparing porous zeolite imidazole framework oil-storing microcapsules according to claim 1, characterized in that, The specific surface area of the ZIF-X powder is ≥500m². 2 g -1 The ZIF-X powder has a pore size of 1 to 5 mm.
3. The method for preparing porous zeolite imidazole framework oil-storing microcapsules according to claim 2, characterized in that, The thermogravimetric temperature of the ZIF-X powder is ≥300℃.
4. The method for preparing porous zeolite imidazole framework oil-storing microcapsules according to claim 3, characterized in that, When the nitrate is cobalt nitrate, the ZIF-X is ZIF-67; when the nitrate is zinc nitrate, the ZIF-X is ZIF-8.
5. The method for preparing porous zeolite imidazole framework oil-storing microcapsules according to claim 1, characterized in that, The lubricating oil is a low-viscosity lubricating oil; the viscosity coefficient of the lubricating oil is ≤150 Pa·s.
6. The method for preparing porous zeolite imidazole framework oil-storing microcapsules according to claim 5, characterized in that, The lubricating oil is one or more of PAO2, PAO4, PAO6, PAO8, PAO10, and PAO40.
7. The method for preparing porous zeolite imidazole framework oil-storing microcapsules according to claim 1, characterized in that, The concentration ratio of the 2-methylimidazole solution and the nitrate solution obtained in step S1 is (1.5-2):1; and the nitrate solution is added to the 2-methylimidazole solution at a volume ratio of 1:(5-8).
8. A porous zeolite imidazole framework oil-storing microcapsule, characterized in that, The porous zeolite imidazole framework oil-storing microcapsules are prepared by the method described in any one of claims 1-7; the porous zeolite imidazole framework oil-storing microcapsules comprise ZIF-X and lubricating oil impregnated in the porous structure of ZIF-X.
9. An application of a porous zeolite imidazole framework oil storage microcapsule, characterized in that, Application of mixing and doping the porous zeolite imidazole framework oil storage microcapsules of claim 8 with a polymer substrate to improve the frictional properties of the polymer substrate; wherein the molding temperature of the polymer substrate is lower than the decomposition temperature of the lubricating oil in the porous zeolite imidazole framework oil storage microcapsules.
10. The application of the porous zeolite imidazole framework oil storage microcapsules according to claim 9, characterized in that, The polymer substrate includes one or more of ultra-high molecular weight polyethylene, epoxy resin, polyurethane, phenolic resin, and nylon.