Transmission electron microscope grid collection system and method for nanoparticles

Abstract

According to the transmission electron microscope grid collection system and method for the nanoparticles, the nanoparticles carried by carrier gas can be smoothly introduced into the system through the communication design of the connecting device and the external gas source, and the pollution risk caused by multiple times of transfer in a traditional method is avoided; the convergence pipeline is located above the clamping cavity, the outlet end of the convergence pipeline faces the supporting face of the carrying net, by means of the structure, airflow and particles can be guided to move directionally, the nano-particles are deposited on the carrying net in a concentrated mode, loss or attachment of the particles in the cavity is reduced, and the deposition efficiency is remarkably improved. The exhaust pipeline is communicated with the clamping cavity and the outside, carrier gas can be stably exhausted in the deposition process, a controllable airflow field is formed, and airflow vortex or backflow is prevented from interfering with deposition uniformity. According to the system, the operation process is simplified through structure integration, an intermediate collection medium is not needed, the transition from a gaseous environment to a transmission electron microscope grid is directly realized, and the possibility of particle aggregation and morphology change is reduced.

Description

Technical Field

[0001] This invention belongs to the field of nanomaterials technology, specifically relating to a transmission electron microscope (TEM) grid collection system and method for nanoparticles. Background Technology

[0002] Nanomaterials, with their unique characteristics such as large specific surface area, high surface energy, and microscopic properties including size and quantum effects, have broad application potential in fields such as catalysis, optoelectronic devices, biomedical materials, and energy conversion. These properties mean that parameters such as particle size distribution, morphology, and crystal structure directly determine the macroscopic properties of nanoparticles. Therefore, achieving reliable control and characterization of particle microscopic features is a crucial foundation in the research and development of high-precision nanomaterials.

[0003] To obtain high-purity, low-pollution nanoparticles, gaseous environment preparation methods (such as laser ablation and vapor deposition) are favored due to their controllable reactions and wide applicability. However, nanoparticles in the gaseous environment often exist in the form of aerosols, requiring efficient collection and deposition onto a transmission electron microscope (TEM) grid to utilize the high-resolution imaging of TEM for particle size, morphology, and defect analysis. This direct deposition method avoids errors introduced by intermediate steps and is a core element in ensuring the authenticity and statistical reliability of characterization data.

[0004] However, current methods for collecting nanoparticles in the gaseous environment mainly rely on membrane filtration, liquid trapping, or electrostatic deposition. These methods have significant drawbacks: First, the collection efficiency is low and the gas flow field control is unstable, resulting in uneven particle deposition on the TEM grid, which can easily lead to agglomeration or morphological changes. Second, the sample needs to be transferred to the grid twice, introducing the risk of contamination and human error. Finally, they cannot support in-situ characterization of short-lived or highly active nanoparticles. Therefore, there are technical problems that restrict the accuracy and efficiency of nanomaterial research. Summary of the Invention

[0005] To address the technical problem that current methods for collecting gaseous nanoparticles rely on membrane filtration, liquid trapping, or electrostatic deposition, which are prone to agglomeration or morphological changes, introduce pollution risks and human error, and have limited applicability, thus restricting the accuracy and efficiency of nanomaterial research, this invention provides a transmission electron microscope (TEM) mesh collection system and method for nanoparticles.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a transmission electron microscope (TEM) grid collection system for nanoparticles, comprising: A screen holder has an internal holding cavity for accommodating a transmission electron microscope screen, and the holding cavity has a screen support surface inside. A connecting device is detachably connected to the carrier net clamping device, and the connecting device is provided with an air intake channel communicating with an external air source; A convergence conduit is disposed inside the net holding device, located above the holding cavity, with the outlet end of the convergence conduit facing the net support surface; An exhaust pipe is installed inside the net clamping device, connecting the clamping cavity to the outside.

[0007] Optionally, the net holding device and the connecting device are detachably connected through a mutually cooperating threaded structure.

[0008] Optionally, the converging conduit has a funnel-shaped structure, with its inner wall forming an angle of 20° to 60° with the axis of the converging conduit.

[0009] Optionally, the angle between the inner wall of the converging conduit and the axis of the converging conduit is 30°.

[0010] Optionally, the exhaust pipe includes two symmetrically arranged cylindrical pipes, the inlet end of which is at the same horizontal height as the support surface of the net.

[0011] Optionally, the bottom of the net holding device is further provided with a net picking and placing channel communicating with the holding cavity.

[0012] Optionally, the external structure of the net holding device is further provided with a columnar external structure.

[0013] Secondly, the present invention provides a method for collecting nanoparticles using a transmission electron microscope (TEM) grid, implemented based on any of the above-described TEM grid collection systems for nanoparticles, comprising: S1: Place the transmission electron microscope grid into the clamping cavity of the grid holding device; S2: Introduce the airflow carrying nanoparticles into the system via a connecting device; S3: The airflow is guided through a converging duct and deposited on the transmission electron microscope grid; S4: The system discharges the gas after deposition through the exhaust pipe.

[0014] Optionally, in step S3, the airflow speed of the exhaust pipe is controlled to enable uniform deposition of nanoparticles on the carrier mesh.

[0015] Optionally, in step S1, a clamp is used to pick up and place the transmission electron microscope screen through the screen pick-up and drop channel.

[0016] The beneficial effects of this invention are: This invention provides a transmission electron microscope (TEM) mesh collection system for nanoparticles. Through the coordinated operation of four structures—a mesh clamping device, a connecting device, a convergence channel, and an exhaust channel—efficient direct deposition of nanoparticles in a gaseous environment is achieved. Specifically, the clamping cavity and mesh support surface within the mesh clamping device provide a stable and fixed space for the TEM mesh, ensuring that the mesh does not shift or tilt during deposition, thus guaranteeing the precise positioning of the nanoparticles. The connecting device's design, allowing communication with an external gas source, enables the smooth introduction of nanoparticles carried by the carrier gas into the system, avoiding the contamination risks associated with multiple transfers in traditional methods. The convergence channel, located above the clamping cavity with its outlet facing the mesh support surface, guides the airflow and particle directional movement, allowing nanoparticles to concentrate and deposit on the mesh, reducing particle loss or adhesion within the cavity and significantly improving deposition efficiency. The exhaust channel connects the clamping cavity to the outside, stably discharging the carrier gas during deposition, forming a controllable airflow field, and preventing airflow eddies or backflows from interfering with deposition uniformity. This system simplifies the operation process through structural integration, eliminating the need for intermediate collection media and directly transitioning from a gaseous environment to a transmission electron microscope (TEM) grid. This not only reduces the possibility of particle aggregation and morphological changes but also improves the reliability and repeatability of subsequent TEM characterization, making it particularly suitable for rapid in-situ analysis of highly active or short-lived nanoparticles. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the transmission electron microscope grid collection system for nanoparticles in this invention. Figure 2 This is a schematic diagram of the net clamping device in this invention; Figure 3 This is a schematic diagram of the connecting device in this invention; Figure 4 This is a schematic diagram of the carrier mesh clamping device and the transmission electron microscope carrier mesh in this invention; Figure 5 This is a perspective view of the net clamping device in this invention; Figure 6 This is an internal structural diagram of the connecting device in this invention.

[0018] Among them: 1. Net holding device; 11. Holding cavity; 12. Net support surface; 13. Convergence channel; 14. Exhaust channel; 141. Cylindrical channel; 15. Net picking and placing channel; 16. Columnar external structure; 2. Transmission electron microscope net; 3. Connecting device; 31. Air inlet channel; 4. External air source. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0021] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0022] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0023] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0024] Example 1 See Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 A schematic diagram of the transmission electron microscope (TEM) grid collection system for nanoparticles in this application is shown, including: The screen holder 1 has a holding cavity 11 inside for accommodating the transmission electron microscope screen 2, and a screen support surface 12 inside the holding cavity 11. The connecting device 3 is detachably connected to the net clamping device 1, and the connecting device 3 is provided with an air intake channel 31 that communicates with the external air source 4; The convergence pipe 13 is located inside the net holding device 1, above the holding cavity 11, with the outlet end of the convergence pipe 13 facing the net support surface 12. The exhaust pipe 14 is installed inside the net clamping device 1 and connects the clamping cavity 11 to the outside.

[0025] In this embodiment, the efficient direct deposition of nanoparticles in a gaseous environment is achieved through the coordinated operation of four structures: the carrier mesh clamping device 1, the connecting device 3, the convergence pipe 13, and the exhaust pipe 14. Specifically, the clamping cavity 11 and the carrier mesh support surface 12 inside the carrier mesh clamping device 1 provide a stable fixing space for the transmission electron microscope carrier mesh 2, ensuring that the carrier mesh does not shift or tilt during deposition, thereby guaranteeing the positioning accuracy of nanoparticle deposition. The connection design of the connecting device 3 with the external gas source 4 allows the nanoparticles carried by the carrier gas to be smoothly introduced into the system, avoiding the contamination risk caused by multiple transfers in traditional methods. The convergence pipe 13 is located above the clamping cavity 11 with its outlet facing the carrier mesh support surface 12. This structure guides the airflow and particle directional movement, causing the nanoparticles to be concentrated and deposited on the carrier mesh, reducing particle loss or adhesion within the cavity, and significantly improving deposition efficiency. The exhaust pipe 14 connects the clamping cavity 11 to the outside, stably discharging the carrier gas during deposition, forming a controllable airflow field, and preventing airflow eddies or backflows from interfering with deposition uniformity. This system simplifies the operation process through structural integration, eliminating the need for intermediate collection media and directly transitioning from a gaseous environment to a transmission electron microscope (TEM) grid. This not only reduces the possibility of particle aggregation and morphological changes but also improves the reliability and repeatability of subsequent TEM characterization, making it particularly suitable for rapid in-situ analysis of highly active or short-lived nanoparticles.

[0026] Optionally, the net holding device 1 and the connecting device 3 in this invention are detachably connected through a mutually cooperating threaded structure.

[0027] In this embodiment, the threaded connection provides a robust and sealed coupling method, ensuring that the gas flow does not leak from the connection point during deposition, thereby maintaining the stability of the internal gas flow field. Simultaneously, the detachable nature of the threaded structure allows for quick separation of the mesh holder 1 from the connecting device 3, facilitating cleaning of the clamping cavity 11 or replacement of the transmission electron microscope mesh 2, reducing equipment maintenance time and complexity. Furthermore, this design allows the system to flexibly adapt to different gas sources or experimental conditions. For example, when it is necessary to change the carrier gas type or clean the pipeline, disassembly can be achieved simply by loosening the threads, avoiding the scrapping of the entire device or complex debugging.

[0028] In addition, threaded connections have high mechanical strength and can withstand a certain airflow pressure, preventing the connection from loosening under high-speed carrier gas transport and ensuring long-term reliability. While ensuring functionality, they also improve the maintainability and applicability of the system, meeting the requirements of laboratory equipment for flexibility and durability.

[0029] Optionally, the converging channel 13 in this invention has a funnel-shaped structure, and the angle between its inner wall and the axis of the converging channel 13 is 20° to 60°.

[0030] Optionally, the angle between the inner wall of the converging conduit 13 and the axis of the converging conduit 13 in this invention is 30°.

[0031] In this embodiment, the converging channel 13 has a funnel-shaped structure, and the angle between the inner wall and the channel axis is 20° to 60°, preferably 30°. This optimizes the airflow dynamics and improves the deposition effect of nanoparticles. Specifically, the tapering design of the funnel-shaped structure allows the carrier gas flow to gradually converge before entering the clamping cavity 11, avoiding turbulence or particle collision with the inner wall caused by sudden airflow contraction, thereby reducing the loss of nanoparticles. At the same time, if the angle is too small, it will result in an excessively long channel, increasing the size of the equipment and making it difficult to pick up and put down the carrier net. If the angle is too large, it will cause airflow separation and eddies, causing particles to adhere to the inner wall of the channel rather than be deposited on the carrier net. This structure ensures that the airflow is smoothly guided to the carrier net support surface 12, so that the nanoparticles are evenly distributed on the carrier net, improving the clarity and statistical representativeness of transmission electron microscopy imaging.

[0032] Meanwhile, the funnel-shaped structure is simple and easy to process, reducing manufacturing costs, and is applicable to various nanoparticle preparation methods (such as laser ablation or vapor deposition), enhancing the system's versatility.

[0033] Optionally, refer to Figure 4 The exhaust pipe 14 in this invention includes two symmetrically arranged cylindrical pipes 141, the inlet end of the cylindrical pipe 141 being at the same horizontal height as the support surface 12.

[0034] In this embodiment, the symmetrical design of the two cylindrical pipes 141 ensures that the carrier gas is discharged evenly from both sides of the clamping cavity 11, avoiding airflow deflection or dead zones caused by unilateral exhaust, thereby preventing uneven distribution of nanoparticles on the carrier mesh; the inlet end being flush with the carrier mesh support surface 12 allows the airflow to transition smoothly near the deposition area, reducing the interference of backflow or turbulence on the deposited particles and ensuring the integrity of the particle morphology.

[0035] This layout also allows for the rapid removal of residual carrier gas, preventing gas accumulation within the cavity from affecting subsequent deposition and improving the system's continuous operation capability. The cylindrical pipe structure is simple, has low flow resistance, is easy to manufacture and clean, and reduces maintenance costs.

[0036] Optionally, the bottom of the net holding device 1 in this invention is also provided with a net taking and putting channel 15 that communicates with the holding cavity.

[0037] In this embodiment, the mesh placement channel 15 is located at the bottom of the mesh holding device 1 and communicates with the holding cavity 11. This structure greatly simplifies the operation process of the transmission electron microscope mesh 2. Specifically, the placement channel allows the user to directly use a clamp (such as tweezers) to poke the mesh from the side, causing the mesh to be moved from a flat state to an upright state. The mesh placement channel 15 at this time provides space for the mesh to move, and the edge of the mesh can be grasped with tweezers to remove the mesh. This design is particularly suitable for standard-sized transmission electron microscope meshes (such as 3.05 mm in diameter). In addition, the placement channel can be sealed during the deposition process to prevent air leakage, and the mesh placement channel 15 can be rinsed with clean gas before and after use to prevent nanoparticles from accumulating under the mesh. This enhances the flexibility and user-friendliness of the system, reduces the probability of sample contamination, and meets the needs of high-throughput characterization.

[0038] Optionally, refer to Figure 2 and Figure 5 The net holding device 1 of the present invention is further provided with a columnar external structure 16.

[0039] In this embodiment, a columnar external structure 16 is provided on the outside of the carrier clamping device 1. This design improves the operability and safety of the system. Specifically, the columnar external structure 16 makes it easier for the user to hold and rotate the device, especially providing a force point during connection or disassembly, reducing operational errors; at the same time, it can also protect the internal components from external impacts and extend the life of the equipment.

[0040] Example 2 Secondly, the present invention provides a method for collecting nanoparticles using a transmission electron microscope (TEM) mesh, implemented based on the TEM mesh collection system for nanoparticles described in Example 1, comprising: S1: Place the transmission electron microscope grid into the clamping cavity of the grid holding device; S2: Introduce the airflow carrying nanoparticles into the system via a connecting device; S3: The airflow is guided through a converging duct and deposited on the transmission electron microscope grid; S4: The system discharges the gas after deposition through the exhaust pipe.

[0041] In this embodiment, a method for collecting nanoparticles using a transmission electron microscope (TEM) grid is provided. This method is based on the TEM grid collection system for nanoparticles described in Embodiment 1. The usage process and beneficial effects are the same as in Embodiment 1, and therefore will not be described in detail.

[0042] Optionally, in step S3 of the present invention, the nanoparticles are uniformly deposited on the carrier by controlling the airflow speed of the exhaust pipe.

[0043] In this embodiment, deposition uniformity is optimized by adjusting the exhaust dynamics. Speed ​​control can match different nanoparticle characteristics (such as particle size or density), preventing excessively fast airflow from causing particle scattering or excessively slow airflow from causing uneven deposition, thereby improving the reliability of transmission electron microscopy data.

[0044] Optionally, in step S1 of the present invention, a clamp is used to perform the picking and placing operation of the transmission electron microscope screen through the screen picking and placing channel.

[0045] In this embodiment, a clamp is used to operate the netting through the loading and unloading channel. This method reduces contamination caused by manual contact and ensures that the netting remains clean during loading and unloading, making it suitable for research on high-purity nanomaterials.

[0046] For example, when using the transmission electron microscope (TEM) mesh collection system for nanoparticles of this invention to prepare nanoparticles by laser ablation, firstly, the TEM mesh (3.05 mm in diameter) is placed in the clamping cavity of the mesh holding device through the mesh pick-and-place channel, ensuring that the mesh is fixed by the mesh support surface. Then, the connecting device is coupled to the mesh holding device via a threaded connection, and the air inlet channel of the connecting device is connected to an external carrier gas source (such as an inert gas). The carrier gas carries the nanoparticles generated by laser ablation into the system, and after being guided through a converging channel (a funnel-shaped structure with a 30° tilt angle), the particles are directly deposited onto the TEM mesh. During deposition, the carrier gas is smoothly discharged through symmetrically arranged exhaust channels, forming a stable airflow field. After deposition, the threaded connection is loosened, and the mesh is removed for TEM characterization. This process eliminates the need for filter membranes or liquid media, reducing particle agglomeration.

[0047] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0048] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A transmission electron microscope (TEM) grid collection system for nanoparticles, characterized in that, include: The mesh holder (1) has a holding cavity (11) inside for accommodating the transmission electron microscope mesh (2), and the holding cavity (11) has a mesh support surface (12) inside. The connecting device (3) is detachably connected to the net holding device (1), and the connecting device (3) is provided with an air intake channel (31) that communicates with an external air source (4). A convergence pipe (13) is disposed inside the net holding device (1) and located above the holding cavity (11). The outlet end of the convergence pipe (13) faces the net support surface (12). An exhaust pipe (14) is installed inside the net clamping device (1) and connects the clamping cavity (11) to the outside.

2. The transmission electron microscope grid collection system for nanoparticles according to claim 1, characterized in that, The net holding device (1) and the connecting device (3) are detachably connected through a mutually cooperating threaded structure.

3. The transmission electron microscope (TEM) grid collection system for nanoparticles according to claim 1, characterized in that, The converging channel (13) has a funnel-shaped structure, and the angle between its inner wall and the axis of the converging channel (13) is 20° to 60°.

4. The transmission electron microscope grid collection system for nanoparticles according to claim 3, characterized in that, The angle between the inner wall of the converging conduit (13) and the axis of the converging conduit (13) is 30°.

5. The transmission electron microscope (TEM) grid collection system for nanoparticles according to claim 1, characterized in that, The exhaust pipe (14) includes two symmetrically arranged cylindrical pipes (141), the inlet end of the cylindrical pipe (141) being at the same horizontal height as the net support surface (12).

6. The transmission electron microscope (TEM) grid collection system for nanoparticles according to claim 1, characterized in that, The bottom of the net holding device (1) is also provided with a net taking and putting channel (15) that communicates with the holding cavity (11).

7. The transmission electron microscope (TEM) grid collection system for nanoparticles according to claim 1, characterized in that, The external structure of the net holding device (1) is also provided with a columnar external structure (16).

8. A method for collecting nanoparticles using a transmission electron microscope (TEM) grid, implemented based on any one of claims 1 to 7, characterized in that, include: S1: Place the transmission electron microscope grid (2) into the clamping cavity (11) of the grid clamping device (1); S2: Introduce the airflow carrying nanoparticles into the system through the connecting device (3); S3: The airflow is guided through the converging pipe (13) and deposited on the transmission electron microscope grid (2); S4: The gas flow after deposition is discharged from the system through the exhaust pipe (14).

9. The method for collecting nanoparticles using a transmission electron microscope grid according to claim 8, characterized in that, In step S3, the airflow speed of the exhaust pipe (14) is controlled to enable uniform deposition of nanoparticles on the carrier.

10. The method for collecting nanoparticles using a transmission electron microscope grid according to claim 8, characterized in that, In step S1, the transmission electron microscope screen (2) is picked up and placed using a clamp through the screen pick-up and drop channel (15).

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