阅读说明：本技术 一种高强高韧mof玻璃的制备方法及其所制备的mof玻璃 (Preparation method of high-strength high-toughness MOF glass and MOF glass prepared by same ) 是由 闫少华 聂媛 于 2021-09-07 设计创作，主要内容包括：一种高强高韧MOF玻璃的制备方法及其所制备的MOF玻璃,所述制备方法步骤如下：S1、按照以下质量百分比准备制备原料：10％-15％六水硝酸钠、70％-75％咪唑、10％-15％苯并咪唑,采用溶剂热合成法制备粉体MOF；S2、通过热等静压成型将粉体MOF压缩为块体MOF玻璃,所述热等静压成型在真空条件下进行,热等静压成型的压力为P,P＝30MPa-50MPa,温度为T-(2),T-(2)＝750K-850K；S3、采用聚焦离子束在块体MOF玻璃表面制备微型圆柱阵列,即完成高强高韧MOF玻璃的制备；所述微型圆柱阵列中微型圆柱的高度为0.3um-2um,直径为100nm-500nm,微型圆柱阵列的密度为每1mm～(2)内1700-3600个微型圆柱。本发明解决了现有技术中MOF玻璃可靠性和耐久性不足的问题,克服了MOF玻璃低强度脆性的内在特性,为工业应用提供了保障。(A preparation method of high-strength high-toughness MOF glass and the MOF glass prepared by the same comprises the following steps: s1, preparing raw materials according to the following mass percentages: 10-15% of sodium nitrate hexahydrate, 70-75% of imidazole and 10-15% of benzimidazole, and preparing powder MOF by adopting a solvothermal synthesis method; s2, compressing the powder MOF into the bulk MOF glass through hot isostatic pressing, wherein the hot isostatic pressing is carried out under the vacuum condition, the pressure of the hot isostatic pressing is P, the P is 30-50 MPa, and the temperature is T 2 ，T 2 750K-850K; s3, preparing a micro cylindrical array on the surface of the block MOF glass by using focused ion beams, namely completing the preparation of the high-strength high-toughness MOF glass; the height of the miniature cylinder in the miniature cylinder array is 0.3um-2um, the diameter is 100nm-500nm, and the miniature cylinder arrayDensity of 1mm per 2 Inner 1700 + 3600 micro-cylinders. The invention solves the problems of insufficient reliability and durability of the MOF glass in the prior art, overcomes the inherent characteristic of low-strength brittleness of the MOF glass, and provides guarantee for industrial application.)

1. A preparation method of high-strength high-toughness MOF glass comprises the following steps:

s1, preparing raw materials according to the following mass percentages: 10-15% of sodium nitrate hexahydrate, 70-75% of imidazole and 10-15% of benzimidazole, and preparing powder MOF by adopting a solvothermal synthesis method;

s2, compressing the powder MOF into the bulk MOF glass through hot isostatic pressing, wherein the hot isostatic pressing is carried out under the vacuum condition, the pressure of the hot isostatic pressing is P, the P is 30-50 MPa, and the temperature is T₂，T₂＝750K-850K；

S3, preparing a micro cylindrical array on the surface of the block MOF glass by using focused ion beams, namely completing the preparation of the high-strength high-toughness MOF glass; the height of the miniature cylinder in the miniature cylinder array is 0.3um-2um, the diameter is 100nm-500nm, and the density of the miniature cylinder array is every 1mm²Inner 1700 + 3600 micro-cylinders.

2. A method for preparing a high strength and toughness MOF glass according to claim 1, wherein: the mass percentages of the components in the raw materials prepared in the step S1 are as follows: 12 to 13 percent of sodium nitrate hexahydrate, 72 to 74 percent of imidazole and 11.5 to 13.5 percent of benzimidazole.

3. A method for preparing a high strength and toughness MOF glass according to claim 1, wherein: the solvent used in the solvent thermal synthesis method in the step S1 is N, N-dimethylformamide, and the reaction temperature of the solvent thermal synthesis method is T₁，T₁＝120℃-140℃。

4. A method for preparing high strength and toughness MOF glass according to claim 3, wherein: the specific operation of preparing the powder MOF by adopting the solvothermal synthesis method in the step S1 is as follows:

s11, adding the preparation raw materials and N, N-dimethylformamide into a hydrothermal bottle, performing ultrasonic dispersion and stirring until the raw materials and the N, N-dimethylformamide are fully dissolved to obtain a mixed solution;

s12, heating the mixed solution to the reaction temperature T₁Preserving heat for 24-48 h, and removing N, N-dimethylformamide to obtain powder MOF;

s13, sequentially adopting N, N-dimethylformamide and dichloromethane to clean the powder MOF, and soaking the cleaned powder MOF in dichloromethane for 24-48 h;

s14, removing dichloromethane, and putting the powder MOF in a vacuum drying oven for vacuum drying until the quality is unchanged.

5. A method for preparing a high strength and toughness MOF glass according to claim 1, wherein: the pressure P of the step S2 for hot isostatic pressing is 35MPa-45MPa, and the temperature T₂Is 800K-850K.

6. A method for preparing a high strength and toughness MOF glass according to claim 1, wherein: the step S2 is to compress the MOF powder into the MOF glass by hot isostatic pressing, specifically: adding the powder MOF into a mold of a hot isostatic pressing furnace, applying pressure P to the MOF powder, and heating to the temperature T at the speed of 2-5K/min under vacuum condition₂Keeping the temperature for 8-12 min, then cooling to room temperature and taking out.

7. A method for preparing a high strength and toughness MOF glass according to claim 1, wherein: in the step S3, the height of the micro cylinders in the micro cylinder array prepared on the surface of the block MOF glass by adopting focused ion beams is 0.9um-2um, and the diameter is 300nm-500 nm.

8. A method for preparing a high strength and toughness MOF glass according to claim 1, wherein: the step S3 is a specific method for preparing each micro cylinder in the micro cylinder array on the surface of the bulk MOF glass by using focused ion beams, which comprises: the focused ion beam scans along a circular scanning path with gradually reduced diameter until a miniature cylinder is formed, and the current is gradually reduced in the scanning process to ensure the good forming of the miniature cylinder.

9. A method for preparing high strength and toughness MOF glass according to claim 8, wherein said method comprises the steps of: keeping the voltage of the focused ion beam at 25kV-35kV in the scanning process of the focused ion beam; when the diameter of the circular scanning path of the focused ion beam is larger than 3.5um, the current of the focused ion beam is kept between 0.1nA and 5nA, and when the diameter of the circular scanning path of the focused ion beam is smaller than 3.5um, the current of the focused ion beam is reduced to between 0.02nA and 0.05 nA.

10. A high-strength high-toughness MOF glass is characterized in that: the high strength and high toughness MOF glass is prepared by the preparation method of any one of claims 1 to 9.

Technical Field

The invention relates to a preparation method of high-strength high-toughness MOF glass and the MOF glass prepared by the same, belonging to the technical field of metal organic framework material preparation.

Background

The Metal-Organic Framework (MOF) refers to a zeolite-like Framework material which is formed by self-assembling oxygen-containing, nitrogen-containing and other polydentate Organic ligands and transition Metal ions and has a special pore channel structure. The composite material has the advantages of high porosity, large specific surface area, small density, adjustable pore size structure, composition and functional design and the like, can be used for transporting clean energy, adsorbing carbon dioxide and the like, and has important functions of realizing carbon neutralization and relieving climate warming. However, MOF materials are inconvenient to carry and transport and are not strong. MOF glasses can alleviate the above problems to some extent, but MOF glasses are brittle materials that severely limit reliability and durability in applications such as high pressure or high stress applications (pipes, pressure vessels, etc.) where conventional MOF glasses tend to fail during use due to their low strength and brittleness. Therefore, how to prepare the high-strength and high-toughness MOF glass is a great problem to be solved urgently.

Disclosure of Invention

The invention aims to solve the problem of insufficient reliability and durability of the MOF glass in the prior art, develop and prepare the high-strength and high-toughness MOF glass, overcome the inherent characteristic of low-strength brittleness of the MOF glass, and provide guarantee for industrial application.

The invention realizes the aim of the invention and firstly provides a preparation method of high-strength high-toughness MOF glass, which comprises the following steps:

s1, preparing raw materials according to the following mass percentages: 10-15% of sodium nitrate hexahydrate, 70-75% of imidazole and 10-15% of benzimidazole, and preparing powder MOF by adopting a solvothermal synthesis method;

s2, compressing the powder MOF into the bulk MOF glass through hot isostatic pressing, wherein the hot isostatic pressing is carried out under the vacuum condition, the pressure of the hot isostatic pressing is P, the P is 30-50 MPa, and the temperature is T₂，T₂＝750K-850K；

S3, preparing a micro cylindrical array on the surface of the block MOF glass by using focused ion beams, namely completing the preparation of the high-strength high-toughness MOF glass; the height of the miniature cylinder in the miniature cylinder array is 0.3um-2um, the diameter is 100nm-500nm, and the density of the miniature cylinder array is every 1mm²Inner 1700 + 3600 micro-cylinders.

Further, in the preparation method of the present invention, the raw materials prepared in step S1 include the following components by mass: 12 to 13 percent of sodium nitrate hexahydrate, 72 to 74 percent of imidazole and 11.5 to 13.5 percent of benzimidazole.

Further, in the step S1 of the preparation method of the present invention, the solvent used in the solvothermal synthesis method is N, N-dimethylformamide, and the reaction temperature in the solvothermal synthesis method is T₁，T₁＝120℃-140℃。

Further, in the preparation method of the present invention, in the step S1, the specific operation of preparing the powder MOF by using the solvothermal synthesis method is:

s11, adding the preparation raw materials and N, N-dimethylformamide into a hydrothermal bottle, performing ultrasonic dispersion and stirring until the raw materials and the N, N-dimethylformamide are fully dissolved to obtain a mixed solution;

s12, heating the mixed solution to the reaction temperature T₁Preserving heat for 24-48 h, and removing N, N-dimethylformamide to obtain powder MOF;

s13, sequentially adopting N, N-dimethylformamide and dichloromethane to clean the powder MOF, and soaking the cleaned powder MOF in dichloromethane for 24-48 h;

s14, removing dichloromethane, and putting the powder MOF in a vacuum drying oven for vacuum drying until the quality is unchanged.

Furthermore, the pressure P of the step S2 for hot isostatic pressing forming is 35MPa-45MPa, and the temperature T is₂Is 800K-850K.

Further, the step S2 of the preparation method of the present invention is to compress the MOF powder into the bulk MOF glass by hot isostatic pressing, and includes the following specific operations: adding the powder MOF into a mold of a hot isostatic pressing furnace, applying pressure P to the MOF powder, and heating to the temperature T at the speed of 2-5K/min under vacuum condition₂Keeping the temperature for 8-12 min, then cooling to room temperature and taking out.

Further, in the step S3 of the preparation method of the present invention, the focused ion beam is used to prepare a micro cylinder array on the surface of the bulk MOF glass, wherein the height of the micro cylinder is 0.9um-2um, and the diameter is 300nm-500 nm.

Further, the step S3 of the preparation method of the present invention is a specific method for preparing each micro cylinder in the micro cylinder array on the surface of the bulk MOF glass by using a focused ion beam, which comprises: the focused ion beam scans along a circular scanning path with gradually reduced diameter until a miniature cylinder is formed, and the current is gradually reduced in the scanning process to ensure the good forming of the miniature cylinder.

Furthermore, in the scanning process of the focused ion beam, the voltage of the focused ion beam is kept between 25kV and 35 kV; when the diameter of the circular scanning path of the focused ion beam is larger than 3.5um, the current of the focused ion beam is kept between 0.1nA and 5nA, and when the diameter of the circular scanning path of the focused ion beam is smaller than 3.5um, the current of the focused ion beam is reduced to between 0.02nA and 0.05 nA.

The invention also provides the high-strength high-toughness MOF glass prepared by the preparation method.

Compared with the prior art, the invention has the beneficial effects that:

according to the invention, firstly, powder MOF is prepared through a solvothermal synthesis method, hot isostatic pressing is carried out on the block MOF glass to form block MOF glass, and then a micro cylindrical array with a certain size is prepared on the surface of the block MOF glass by adopting focused plasma beams, so that the MOF glass with high strength and high toughness is obtained. Applicants analyzed that machining arrays of micro-cylinders on the surface of the bulk MOF glass produced and precise control of micro-cylinder dimensions are key to obtaining high strength and toughness MOF glass. The micro cylindrical array processed on the surface of the block MOF glass utilizes the size effect, realizes the proportional ductile-to-brittle transition of the MOF and the breakthrough of theoretical strength, successfully overcomes the inherent characteristics of low-strength brittleness of the MOF glass, and enables the MOF glass to successfully have ultrahigh strength and toughness, thereby having the capability of resisting external force and providing guarantee for industrial application. Moreover, the method for preparing the powder MOF and the block MOF glass is simple, low in cost and beneficial to large-scale industrial application.

Drawings

FIG. 1 is a schematic diagram of a process for making a bulk MOF glass according to step S2 of the present invention.

FIG. 2 is an XRD pattern of powder MOF prepared in step S1 of the example of the invention.

FIG. 3 is a scanning electron microscope morphology map of the powdered MOF prepared in step S1 according to the embodiment of the present invention.

FIG. 4 is an XRD pattern of a bulk MOF glass prepared in step S2 according to an embodiment of the present invention.

FIG. 5 is a SEM image of micro-cylinders fabricated on the surface of bulk MOF glass in step S3 according to example of the present invention.

FIG. 6 is a stress-strain curve for different diameter micro-cylinder compression experiments made on bulk MOF glass surfaces for examples and comparative examples.

FIG. 7 is a scanning electron microscope topography after deformation of compression experiments of micro cylinders with different diameters prepared on the surface of bulk MOF glass in examples and comparative examples.

FIG. 8 is a stress-strain curve for a miniature cylindrical bending test performed on the surface of bulk MOF glass at step S3 in accordance with an embodiment of the present invention.

Detailed Description

The invention is described in further detail below with reference to the figures and the detailed description.

A preparation method of high-strength high-toughness MOF glass and the MOF glass prepared by the same comprises the following steps:

s1, preparing raw materials according to the following mass percentages: 10-15% of sodium nitrate hexahydrate, 70-75% of imidazole and 10-15% of benzimidazole, and preparing powder MOF by adopting a solvothermal synthesis method;

s2, compressing the powder MOF into the bulk MOF glass through hot isostatic pressing, wherein the hot isostatic pressing is carried out under the vacuum condition, the pressure of the hot isostatic pressing is P, the P is 30-50 MPa, and the temperature is T₂，T₂＝750K-850K；

S3, preparing a micro cylindrical array on the surface of the block MOF glass by using focused ion beams, namely completing the preparation of the high-strength high-toughness MOF glass; the height of the miniature cylinder in the miniature cylinder array is 0.3um-2um, the diameter is 100nm-500nm, and the density of the miniature cylinder array is every 1mm²Inner 1700 + 3600 micro-cylinders.

Preferably, the raw materials prepared in step S1 include the following components in percentage by mass: 12 to 13 percent of sodium nitrate hexahydrate, 72 to 74 percent of imidazole and 11.5 to 13.5 percent of benzimidazole.

Preferably, said stepsStep S1 the solvent used in the solvothermal synthesis method is N, N-dimethylformamide, and the reaction temperature in the solvothermal synthesis method is T₁，T₁＝120℃-140℃。

Preferably, the specific operation of preparing the powdered MOF by the solvothermal synthesis method in step S1 is as follows:

s11, adding the preparation raw materials and N, N-dimethylformamide into a hydrothermal bottle, performing ultrasonic dispersion and stirring until the raw materials and the N, N-dimethylformamide are fully dissolved to obtain a mixed solution;

s12, heating the mixed solution to the reaction temperature T₁Preserving heat for 24-48 h, and removing N, N-dimethylformamide to obtain powder MOF;

s13, sequentially adopting N, N-dimethylformamide and dichloromethane to clean the powder MOF, and soaking the cleaned powder MOF in dichloromethane for 24-48 h;

s14, removing dichloromethane, and putting the powder MOF in a vacuum drying oven for vacuum drying until the quality is unchanged.

Preferably, the hot isostatic pressing at step S2 has a pressure P of 35MPa to 45MPa and a temperature T₂Is 800K-850K.

Preferably, the step S2 is a specific operation of compressing the MOF powder into the bulk MOF glass by hot isostatic pressing: adding the powder MOF into a mold of a hot isostatic pressing furnace, applying pressure P to the MOF powder, and heating to the temperature T at the speed of 2-5K/min under vacuum condition₂Keeping the temperature for 8-12 min, then cooling to room temperature and taking out. The preparation process is shown in figure 1.

Preferably, the step S3 is to use a focused ion beam to prepare micro cylinders with a height of 0.9um-2um and a diameter of 300nm-500nm on the surface of the bulk MOF glass.

Preferably, the specific method for preparing each micro cylinder in the micro cylinder array on the surface of the bulk MOF glass by using the focused ion beam in the step S3 is as follows: the focused ion beam scans along a circular scanning path with gradually reduced diameter until a miniature cylinder is formed, and the current is gradually reduced in the scanning process to ensure the good forming of the miniature cylinder.

More preferably, the focused ion beam keeps the voltage of the focused ion beam at 25kV to 35kV in the scanning process; when the diameter of the circular scanning path of the focused ion beam is larger than 3.5um, the current of the focused ion beam is kept between 0.1nA and 5nA, and when the diameter of the circular scanning path of the focused ion beam is smaller than 3.5um, the current of the focused ion beam is reduced to between 0.02nA and 0.05 nA.

Examples

A preparation method of high-strength high-toughness MOF glass and the MOF glass prepared by the same comprises the following steps:

s1, preparing raw materials: preparing powder MOF by using 7.92g of sodium nitrate hexahydrate, 42.72g of imidazole and 7.44g of benzimidazole through a solvothermal synthesis method, which comprises the following specific operations:

s11, adding the preparation raw materials and 360ml of N, N-dimethylformamide into a hydrothermal bottle, and carrying out ultrasonic dispersion and stirring until the raw materials and the N, N-dimethylformamide are fully dissolved to obtain a mixed solution;

s12, heating the mixed solution to a reaction temperature of 130 ℃, preserving heat for 48 hours, and then removing N, N-dimethylformamide to obtain powder MOF;

s13, sequentially adopting N, N-dimethylformamide and dichloromethane to clean the powder MOF, and placing the cleaned powder MOF in dichloromethane to soak for 24 hours;

s14, remove dichloromethane, and place powdered MOF in a vacuum oven for vacuum drying at 100 ℃ until the mass is unchanged.

S2, compressing the powdered MOF into the bulk MOF glass through hot isostatic pressing, and specifically: adding the powder MOF into a mold of a hot isostatic pressing furnace, applying pressure of 40MPa to the MOF powder, heating to 833K at a speed of 5K/min under a vacuum condition, preserving heat for 10min, cooling to room temperature, and taking out to obtain bulk MOF glass;

s3, preparing a micro cylindrical array on the surface of the block MOF glass by using focused ion beams, namely completing the preparation of the high-strength high-toughness MOF glass; the height of the miniature cylinder in the miniature cylinder array is 0.9um-2um, the diameter is 300nm-500nm, and the density of the miniature cylinder array is every 1mm²The inner 2500 miniature cylinders. The specific method for preparing each micro cylinder in the micro cylinder array on the surface of the bulk MOF glass by adopting the focused ion beams comprises the following steps: circle with gradually reduced diameter for focused ion beamScanning the micro cylinder by the scanning path until the micro cylinder is formed; in the scanning process, the voltage of the focused ion beam is kept at 30kV, and the current is gradually reduced to ensure the good forming of the miniature cylinder: when the diameter of the circular scanning path of the focused ion beam is larger than 3.5um, the current of the focused ion beam is kept between 0.1nA and 5nA, and when the diameter of the circular scanning path of the focused ion beam is smaller than 3.5um, the current of the focused ion beam is reduced to between 0.02nA and 0.05 nA.

FIG. 2 is an XRD pattern of the powdered MOF prepared in step S1 of this example. It can be seen that the powdered MOF prepared by this example has crystalline properties. FIG. 3 is a scanning electron microscope image of the powder MOF prepared in step S1 of the present embodiment. It can be seen from the figure that the powder MOF microsurface is a block with micron size. FIG. 4 is an XRD pattern of the bulk MOF glass prepared in step S2 of this example, showing that the material obtained in step S2 is a bulk MOF glass. FIG. 5 is a scanning electron micrograph of 500nm diameter microcylinders fabricated on the surface of bulk MOF glass in step S3 of this example.

Comparative example

A preparation method of MOF glass and the MOF glass prepared by the same comprises the following steps:

s1, preparing raw materials: preparing powder MOF by using 7.92g of sodium nitrate hexahydrate, 42.72g of imidazole and 7.44g of benzimidazole through a solvothermal synthesis method, which comprises the following specific operations:

s11, adding the preparation raw materials and 360ml of N, N-dimethylformamide into a hydrothermal bottle, and carrying out ultrasonic dispersion and stirring until the raw materials and the N, N-dimethylformamide are fully dissolved to obtain a mixed solution;

s12, heating the mixed solution to a reaction temperature of 130 ℃, preserving heat for 48 hours, and then removing N, N-dimethylformamide to obtain powder MOF;

s13, sequentially adopting N, N-dimethylformamide and dichloromethane to clean the powder MOF, and placing the cleaned powder MOF in dichloromethane to soak for 24 hours;

s14, remove dichloromethane, and place powdered MOF in a vacuum oven for vacuum drying at 100 ℃ until the mass is unchanged.

S2, compressing the powdered MOF into the bulk MOF glass through hot isostatic pressing, and specifically: adding the powder MOF into a mold of a hot isostatic pressing furnace, applying pressure of 40MPa to the MOF powder, heating to 833K at a speed of 5K/min under a vacuum condition, preserving heat for 10min, cooling to room temperature, and taking out to obtain bulk MOF glass;

s3, preparing a micro cylindrical array on the surface of the block MOF glass by using focused ion beams, wherein the height of a micro cylinder in the micro cylindrical array is 0.9um-2um, and the diameter of the micro cylinder is 1um-3 um. The specific method for preparing each micro cylinder in the micro cylinder array on the surface of the bulk MOF glass by adopting the focused ion beams comprises the following steps: the focused ion beam scans along a circular scanning path with gradually reduced diameter until a miniature cylinder is formed; in the scanning process, the voltage of the focused ion beam is kept at 30kV, and the current is gradually reduced to ensure the good forming of the miniature cylinder: when the diameter of the circular scanning path of the focused ion beam is larger than 3.5um, the current of the focused ion beam is kept between 0.1nA and 5nA, and when the diameter of the circular scanning path of the focused ion beam is smaller than 3.5um, the current of the focused ion beam is reduced to between 0.02nA and 0.05 nA.

The strength and toughness of the MOF materials prepared in the examples and the comparative examples are tested, and the toughness of micro cylinders with different diameters to be prepared on the surface of the block MOF glass is analyzed from a microscopic level. Micro cylinders with the diameters of 300nm and 500nm prepared on the surface of the bulk MOF glass in the examples and micro cylinders with the diameters of 1um, 2um and 3um prepared on the surface of the bulk MOF glass in the comparative example 1 are placed in a nanoindentor, a compression test is carried out on the micro cylinders in a displacement control mode, data of displacement and force are recorded in the experimental process, and the data are converted into strain and stress data according to the cross sectional area and the height of the micro cylinders. The stress-strain curve obtained by the compression experiment is shown in fig. 6, and in fig. 6, it can be seen that the stress-strain curve shows a shape of a strain jump as the diameter of the micro cylinder is reduced. When the diameter of the micro cylinder is 3um, the stress increases with the increase of the strain, and when 7% of the strain is reached, a stress step (about 400MPa) appears first, and then the stress is reduced sharply, which indicates that brittle fracture may occur (see FIG. 7 (a)); when the diameter of the micro cylinder is 2um, the stress linearly increases with the increase of the strain in the elastic stage, when the stress is 500MPa, the stress suddenly decreases, and the stress slowly increases with the increase of the strain, which indicates that brittle fracture may occur (see fig. 7 (b)). When the diameter of the micro cylinder is 1um, the stress linearly increases with the increase of strain in the elastic stage, and when the stress is 600MPa, the phenomenon of slow decrease of stress occurs, indicating that brittle fracture may occur (see fig. 7 (c)). When the diameter of the micro cylinder is 0.5um, the stress increases linearly with the increase of the strain, and when the stress is 700MPa, the stress drop phenomenon occurs, then the stress starts to increase, and the stress level is far higher than that of the micro cylinder with other diameter in the whole plastic stage, which indicates that the ductile deformation may occur (see fig. 7 (d)). It can also be seen from fig. 6 that the diameter of the mini-cylinder directly determines its variation in intensity. When the diameter of the cylinder is 500nm, the elastic modulus (E) of the MOF glass is 4.29GPa-10.64GPa, and the strength is 415 MPa-1.24 GPa, namely the strength of the MOF glass cylinder with the diameter of 500nm is in the range of E/10, and the limit of the theoretical strength of the glass material is broken through. FIG. 7 is a scanning electron microscope topography after deformation of compression experiments of different diameter micro cylinders prepared on the surface of bulk MOF glass in examples and comparative examples, and shows the deformation mechanism of the different diameter micro cylinders. FIG. 7(a) shows that when the diameter of the micro cylinder is 3um, slip bands appear in the deformed morphology, which is a typical brittle fracture; FIG. 7(b) shows that when the diameter of the micro-cylinder is 2um, slip bands and cracks appear in the deformed shape, which is typical brittle fracture; FIG. 7(c) shows that when the diameter of the mini-cylinder is 1um, its deformation morphology is cracks and slip bands, which are typical brittle fractures; fig. 7(d) shows that when the diameter of the micro cylinder is 0.5 μm, the deformed morphology does not show brittle fracture characteristics such as cracks, but ductile fracture.

Based on the limitation of test conditions, when the diameter of the micro cylinder is less than 500nm, the compression test is limited, and the toughness of the micro cylinder is verified through a bending test. The micro cylinder with the diameter of 300nm prepared on the surface of the bulk MOF glass in the embodiment is placed in a nanoindentor, a bending test is carried out on the micro cylinder in a displacement control mode, the data of displacement and force are recorded in the experimental process, and the data of strain and stress are converted according to the cross sectional area and the height of the micro cylinder. The stress-strain curve obtained by the bending test is shown in FIG. 8, which shows that the micro-cylinder has a diameter of 300nm and exhibits continuous strengthening capability in a bent state, and shows that the small cylinder with a diameter of 300nm has toughness in bending.

From the analysis of FIGS. 6, 7 and 8, it can be seen that when the cylinder diameter is less than or equal to 500nm, the MOF glass is no longer sensitive to defects, changes from brittle to ductile and can withstand 25% strain (as can be seen from the stress-strain curve of FIG. 6). A large number of experiments prove that the MOF glass has excellent properties of high strength and high toughness and has a thickness of 100-500 nm.