A grid base for transmission electron microscope

Abstract

The present invention provides a grid base for a transmission electron microscope, the grid is located on the grid base, the grid base is prepared by mixing and stirring 5%-20% of a curing agent, 0%-5% of a hydrophilic additive, and the balance of an organic silane to obtain a mixture, the mixture is poured into a mold, the mold is demoulded after molding, and the mixture is naturally dried. Compared with the prior art, the grid in the present invention is easy to adhere to the surface of the organic silicon polymer, is not easy to slide, can improve the stability of the grid on the grid base, and reduces the difficulty of operation during the nano-sample preparation process and the sample transfer process; and the grid base is simple to prepare, low in cost, easy to clean, and can be repeatedly used, and is suitable for grids of various materials; in addition, the grid base has a stable structure, which avoids the problem of introducing impurities into the sample to be tested and interfering with the experimental results of the transmission electron microscope.

Description

Technical Field

[0001] The invention belongs to the technical field of transmission electron microscopes, and in particular relates to a grid base for a transmission electron microscope. Background Art

[0002] In the field of nanoscience research, studying the structure, morphology, and aggregation pattern of nanoparticles at the microscopic scale has become an important means of characterizing nanomaterials, among which transmission electron microscopy (TEM) is one of the important tools.

[0003] TEM grids are used to support nano-samples for transmission characterization analysis. Commercially available TEM grids are usually circular structures with a diameter of several millimeters, including skeletons of various materials, such as copper mesh, molybdenum mesh, gold mesh, titanium mesh, nickel mesh, palladium mesh, nylon mesh, etc.

[0004] When using a grid to characterize nanosamples, the nanosample to be tested is usually first dispersed in a liquid to obtain a mixed liquid. Some of the mixed liquid is then absorbed with a pipette or the like and dropped onto a dedicated transmission electron microscope grid to allow the mixed liquid to adhere to the grid. After the liquid evaporates, the morphology and structure of the nanosample to be tested attached to the grid can be clearly characterized in the transmission electron microscope.

[0005] At present, filter paper is usually used as the grid base for nanomaterial sample preparation, which has many defects: first, the grid is easy to move on the surface of the filter paper. After the nano sample is attached to the grid, the grid and the filter paper need to be moved to the transmission electron microscope sample box. During the movement, the grid is very easy to move on the surface of the filter paper, especially when the sample preparation room and the electron microscope room are generally not together during the actual test. In order to test the microstructure characteristics and element content characteristics of the nanomaterial, the sample needs to be prepared in the sample preparation room in advance and then transferred to the electron microscope room for testing. During the transfer to the electron microscope room, the grid is very easy to move on the surface of the filter paper, which increases the difficulty of operation on the one hand and leads to confusion of sample numbers and deviations in test results on the other hand. Secondly, the surface of the filter paper is easy to adsorb impurities, thereby interfering with the experimental results of the transmission electron microscope. In addition, the viscosity of the mixed liquid containing the nano sample to be tested is relatively low, and it is easy to be quickly absorbed by the filter paper but not easy to load on the grid. Therefore, it is necessary to repeatedly absorb the mixed liquid and titrate, which makes sample preparation difficult. Summary of the invention

[0006] In view of the above technical status, the present invention provides a grid base for a transmission electron microscope, which has the advantages of being easy to manufacture and low in cost. When it is used in combination with a grid for nano-sample preparation and transmission electron microscope detection, the grid is not easy to slide on it, thereby reducing the difficulty of operation, and it is not easy to introduce impurities to affect the transmission electron microscope experimental results.

[0007] The technical solution provided by the present invention is: a grid base for a transmission electron microscope, the grid is located on the grid base, and is characterized in that: the grid base is obtained by mixing and stirring an organic silane, a curing agent and a hydrophilic additive to obtain a mixture, pouring the mixture into a mold, demoulding after molding, and naturally drying;

[0008] In terms of mass percentage, in the mixture, the curing agent accounts for 5%-20%, the hydrophilic additive accounts for 0%-5%, and the rest is organic silane.

[0009] The organosilane is not limited, and includes a mixture of one or more of trimethylchlorosilane, methyltrichlorosilane, dimethyldichlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, and methylphenyldichlorosilane.

[0010] The curing agent is not limited, and includes a mixture of one or more of an organic tin coupling agent, a titanate coupling agent, and diethylenetriamine.

[0011] The hydrophilic additive is a hydrophilic molecule, including but not limited to one or more of ethanolamine, melamine, polyethylenediamine, etc.

[0012] In the mixture, the amount of curing agent added is controlled at 5%-20%. Too much will make it difficult to demould the grid base, while too little will make molding difficult and the base will be attached with difficult-to-remove mucus, making it unusable.

[0013] The material of the carrier mesh is not limited, including one or more of copper mesh, molybdenum mesh, gold mesh, titanium mesh, nickel mesh, copper mesh, palladium mesh, and nylon mesh.

[0014] As an implementation method, the nano-sample to be tested is an aqueous solution sample, that is, the aqueous solution contains nano-materials; the grid is located on the grid base; the aqueous solution sample is dropped on the grid, and after the liquid evaporates, the grid and the grid base are placed in a clean sample box, and the morphology and structure of the nano-sample are observed under a transmission electron microscope. The hydrophilic additive is mainly used to increase the hydrophilicity of the grid base. When the aqueous solution sample is dropped on the grid and then seeps onto the grid base, it is beneficial to absorb the moisture in the aqueous solution sample. The aqueous solution can be a collected natural water body or an artificially prepared solution.

[0015] The present invention adopts organic silane to form the grid base, which has the following beneficial effects:

[0016] (1) The grid is easy to adhere to the surface of the silicone polymer and is not easy to slide, so the stability of the grid on the grid base can be improved. When the grid is operated during the nano-sample preparation process and the sample transfer process, the grid is not easy to slide, which reduces the difficulty of operation and improves the operation accuracy.

[0017] (2) The silicone on the grid base is a cross-linked polymer with a stable structure. It will not introduce impurities into the sample to be tested and will not interfere with the experimental results of the transmission electron microscope.

[0018] (3) When the grid base contains a hydrophilic additive, it is easy to absorb water in the aqueous solution sample, which can accelerate sample preparation.

[0019] (4) The grid base is simple to prepare, low-cost, easy to clean, and reusable; and it can be applied to grids of various materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is an infrared characterization image of the grid base in Example 1 of the present invention.

[0021] Figure 2 This is an infrared characterization image of the grid base in Example 2 of the present invention.

[0022] Figure 3 It is a schematic diagram of the supporting structure of the nano-sample in Example 1 of the present invention.

[0023] The accompanying drawings are marked as follows: 1-mixed liquid; 2-copper mesh; 3-mesh base; 4-glass container. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below in conjunction with the embodiments and drawings. It should be pointed out that the embodiments described below are intended to facilitate the understanding of the present invention and do not have any limiting effect on the present invention.

[0025] Embodiment 1:

[0026] (1) After 10.50 g of trimethylsilyl chloride and 1.22 g of titanate coupling agent were mixed and stirred, the mixture was poured into a glass mold and cured for 1.5 hours to form the mixture. After demolding, the mixture was washed with water and ethanol and dried naturally to obtain a grid base.

[0027] Take a small piece of the carrier grid base for characterization, infrared characterization is as follows Figure 1 As shown, the organosilicon polymer contains silicon-oxygen bonds, silicon-carbon bonds, etc. obtained by polymerization of trimethylchlorosilane.

[0028] (2) placing a transmission electron microscope copper grid on the grid base obtained in step (1);

[0029] (3) The nano-sample to be tested is first dispersed in water to obtain a mixed liquid 1; Figure 3 As shown, the copper mesh 2 is located on the mesh base 3; some mixed liquid 1 is sucked and dropped on the copper mesh 2 with a pipette, so that the mixed liquid adheres to the copper mesh 2. After the liquid evaporates, the copper mesh and the mesh base are placed in a clean glass container 4, and placed in a transmission electron microscope to observe the morphology and structure of the nano sample, which can clearly characterize its morphology and structure.

[0030] Embodiment 2:

[0031] (1) 14.97 g of trimethylsilyl chloride, 1.30 g of titanate coupling agent and 0.07 g of melamine were mixed and stirred, poured into a glass mold, and cured for 2 hours before forming. After demolding, the mold was washed with water and ethanol, and naturally dried to obtain a grid base.

[0032] Take a small piece of the carrier grid base for characterization, infrared characterization is as follows Figure 2 As shown, the organosilicon polymer contains silicon-oxygen bonds, silicon-carbon bonds, silicon-nitrogen bonds, carbon-nitrogen bonds, etc. obtained by the mixed polymerization of trimethylchlorosilane and melamine.

[0033] (2) placing the nickel mesh on the mesh support base obtained in step (1);

[0034] (3) The nano-sample to be tested is an aqueous solution sample, that is, the aqueous solution contains nano-materials; the aqueous solution sample is dropped onto the nickel mesh, and after the liquid evaporates, the mesh and the mesh base are placed in a clean sample box, and the morphology and structure of the nano-sample are observed under a transmission electron microscope, so that its morphology and structure can be clearly characterized.

[0035] The embodiments described above provide a detailed description of the technical solutions of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, supplements or similar substitutions made within the scope of the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A grid base for a transmission electron microscope, wherein the grid is located on the grid base, and wherein: The grid base is obtained by mixing and stirring an organic silane, a curing agent and a hydrophilic additive to obtain a mixture, pouring the mixture into a mold, demoulding after molding, and naturally drying; In terms of mass percentage, in the mixture, the curing agent accounts for 5%-20%, the hydrophilic additive accounts for 0%-5%, and the rest is organic silane; The organosilane includes a mixture of one or more of trimethylchlorosilane, methyltrichlorosilane, dimethyldichlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, and methylphenyldichlorosilane; The curing agent is a mixture of one or more of an organic tin coupling agent, a titanate coupling agent, and diethylenetriamine; The hydrophilic additive is a hydrophilic molecule, including one or more of ethanolamine, melamine, and polyethylenediamine.

2. The grid base according to claim 1, characterized in that: The carrier mesh includes one or more of a copper mesh, a molybdenum mesh, a gold mesh, a titanium mesh, a nickel mesh, a palladium mesh, and a nylon mesh.

3. The grid base according to claim 1 or 2, characterized in that: The nano-sample to be tested is an aqueous solution sample, that is, the aqueous solution contains nano-materials; the grid is located on the grid base; the aqueous solution sample is dropped onto the grid, and after the liquid evaporates, the grid and the grid base are placed in a clean sample box, and the morphology and structure of the nano-sample are observed under a transmission electron microscope.

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