An apparatus and method for surface-dispersed spray of nanodiamonds

Abstract

The present application relates to the field of electrohydrodynamic atomization technology and quantum physics, and discloses a device and method for surface dispersion spraying nanodiamonds, which comprises a transmission module, a fixing module and a high-voltage module, wherein the transmission module continuously supplies the prepared sample with the prepared liquid and controls the preparation speed of the sample to ensure the preparation effect; the fixing module is used for fixing the spray head to realize stable spraying; the high-voltage module is used for releasing high voltage and applying it to the tip of the electric spray sample spray head to generate spray; the electric control rotary stepper motor rotates to push the syringe, so that the liquid in the syringe flows to push the prepared liquid in the sample spray pipe, the spraying speed of the sample spray head is controlled, under the joint action of high-voltage electricity and vertical lifting displacement table, a layer of nanodiamond particles is sprayed on the surface of the sample carrier by the atomization spraying method, and the nanodiamond sample prepared by the spraying method of the device has the advantages of uniformity and dispersion.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electrohydrodynamic atomization technology and quantum physics, in particular to a device and method for surface dispersion spraying of nanodiamonds. BACKGROUND

[0002] As a transition between classical systems and quantum systems, suspended mesoscopic nanoparticles can be highly controlled in dynamics and environmental coupling, and have phonon energy levels, compared with the control degree of suspended macroscopic objects. Compared with more microscopic atomic ion systems, they have smaller de Broglie wavelengths, and are expected to further improve sensing sensitivity in precision measurement. However, the first step for using them for quantum sensing is to isolate them from the external environment, i.e. stable suspension of particles.

[0003] For the suspension process of nanoparticles, the first step is to separate the nanoparticle sample from the planar carrier to which it is attached, and to lift it. However, due to the adhesion of the microparticle sample attached to the surface of the planar carrier by van der Waals force, capillary force and electrostatic force, the lifting process needs to overcome the above-mentioned forces. There are three common ways to do this: piezoelectric ceramic vibration method, spray method and pulsed laser separation method. Among them, the piezoelectric ceramic vibration method is not suitable for particles with a size below microns; the spray method has uncontrollable random processes and can cause contamination of the vacuum chamber, which is not conducive to the repetition of the experiment; the pulsed laser separation method uses pulsed laser to bombard the carrier to overcome the adhesion effect and achieve lifting and capture, which can controllably achieve single-particle lifting and suspension and repeated use.

[0004] Pulsed laser lifting requires that the nanoparticles on the planar carrier be uniform and dispersed. The use of traditional atomizers for spraying planar carrier samples often results in clumping and uneven distribution of particles, greatly reducing the success rate of lifting. At present, there is still a lack of a spraying device for uniformly dispersing nanoparticles to achieve stable pulsed laser lifting and repeated use.

[0005] The diamond nitrogen vacancy center (NV color center) is a luminescent point defect in the diamond structure, which has stable spin characteristics and can be used as a probe for optical detection magnetic resonance (ODMR) technology. For the diamond NV color center sample required for ODMR, a planar carrier sample of dispersed NV color center-containing nanodiamond particles is also needed to facilitate the operation of the NV color center.

[0006] To solve the above problems, people have been looking for a spraying technology solution. SUMMARY

[0007] In view of the deficiencies of the prior art, the present application provides a device and method for surface dispersion spraying of nanodiamonds, solving the problem of particle agglomeration and uneven distribution in the planar carrier sample sprayed by using a traditional atomizer, and reducing the yield.

[0008] To achieve the above object, the present application is implemented by the following technical scheme: a device for surface dispersion spraying of nanodiamonds, comprising:

[0009] A transmission module comprises an injector placement platform on which an injector is fixed, a top side of the injector placement platform is provided with an electrically controlled rotary stepper motor for pushing the piston of the injector to spray sample liquid, a liquid outlet of the injector is provided with a liquid guide pipe, and one end of the liquid guide pipe is connected with a sample spray pipe.

[0010] A fixing module comprises a vertical lifting displacement table for fixing the sample spray pipe in a nitrogen-filled spraying environment component and enabling vertical movement of the sample spray pipe, a plastic piston is arranged in the sample spray pipe, a displacement knob is arranged on one side of the vertical lifting displacement table, a sample spray head is arranged at the front end of the sample spray pipe, a spraying support is further arranged on the moving table of the vertical lifting displacement table, the spraying support comprises a plurality of threaded rods, the threaded rods are cooperatively arranged with a grounding electrode through a plastic nut, and the spraying support forms a fixed whole, a rubber head buffer screw is used to align the center of the sample spray head and the grounding electrode, spraying is downward, the sample carrier surface on the upper part of the grounding electrode is sprayed downward, and the distance between the sample spray head and the grounding electrode is 15mm-20mm.

[0011] A high-voltage module is used to generate a high voltage of 5kV-10kV, which is applied between the sample spray head and the grounding electrode to change the shape of the spray.

[0012] The liquid in the injector is guided to the piston at the rear end of the sample spray pipe through the liquid guide pipe, the electrically controlled rotary stepper motor is rotated to push the injector, the liquid in the injector flows to push the prepared liquid in the sample spray pipe, the spraying speed of the sample spray head is regulated, under the joint action of high-voltage electricity and the vertical lifting displacement table, a layer of nanodiamond particles is sprayed on the surface of the sample carrier by using the atomization spraying method.

[0013] Preferably, the injector placement platform is composed of three plastic blocks and two guide rails, the plastic blocks at both ends are used to fix the guide rails and the injector, a threaded column is fixedly arranged on the output end of the electrically controlled rotary stepper motor and is screwed in the middle plastic block, and the two guide rails are arranged through the two sides of the middle plastic block.

[0014] Preferably, the sample nozzle is made of insulating transparent plastic material, with pistons separating the front and rear ends of the nozzle. The front end of the nozzle is loaded with a sample, and the rear end is connected to a syringe. The sample nozzle head is made of conductive stainless steel and is attached to the front end of the sample nozzle, with an inner diameter of 0.35 mm. The grounding electrode is made of conductive aluminum and forms a small platform with a thickness of 2 mm 20 mm below the sample nozzle head. It is grounded using a wire, and the grounding wire is placed close to the outside of the spray environment component.

[0015] Preferably, the spray environment component is an acrylic box composed of five acrylic plates, with openings on the sides for the entry of liquid conduits, high-voltage lines, grounding wires, and nitrogen pipes.

[0016] A method for surface dispersion spraying of nanodiamonds, using the aforementioned apparatus for surface dispersion spraying of nanodiamonds, includes the following method steps:

[0017] S1. Sample solution preparation: Dilute the 1 mg / ml nanodiamond stock solution with anhydrous ethanol to 0.025-0.1 mg / ml and then sonicate for 15-20 min.

[0018] S2. Loading Solution: Inject the ultrasonically diluted nanodiamond solution into the front end of the sample nozzle and separate it from the rear end of the sample nozzle using a plastic piston. Connect the rear end of the sample nozzle to a liquid conduit, which is connected to a syringe. Fill the syringe with anhydrous ethanol, then start the transmission module to fill the front end of the sample nozzle with the diluted nanodiamond solution.

[0019] S3. Sample carrier preset: Place the sample carrier to be sprayed on the top of the grounding electrode, and adjust the distance between the grounding electrode and the sample nozzle to 15mm to 20mm. Then turn on the nitrogen gas and use the nitrogen gas tube to introduce the nitrogen gas into the spray environment component through the side hole of the spray environment component for a period of time until the sparking wood strip at the hole can no longer reignite. Then turn off the nitrogen gas and use modeling clay to block the hole.

[0020] S4. Test spraying: Ground the fixed module, connect the high voltage module and the fixed module, start the high voltage module, adjust the voltage within 5kv~10kv, use a red laser lamp to irradiate the sample nozzle (3) below, observe the spray to end when the spray is a stable single cone, and stop the high voltage module.

[0021] S5. Start Spraying: Using the atomization spraying method, start the transmission module and high-pressure module, control the spraying time, obtain a layer of nano-diamond coating, and complete the nano-diamond coating production.

[0022] Preferably, in step S1, the preparation step of the nanodiamond diluent specifically includes:

[0023] First, a nanodiamond solution with an average particle size of 40 nm and a concentration of 1 mg / ml containing NV color centers was diluted with anhydrous ethanol to 0.025 mg / ml. Then, the diluted suspension was placed in an ultrasonic device for ultrasonic vibration treatment for 15 min to 20 min to obtain a nanodiamond diluted solution.

[0024] Preferably, in step S5, the atomization spraying method is electrohydrodynamic atomization.

[0025] Preferably, the specific process of the electrohydrodynamic atomization method is as follows: under the conditions of a flow rate of 3 ml / h and a voltage of 5 kV to 10 kV, the nanodiamond diluent is jetted into fine droplets under the influence of an external electric field and sprayed vertically downward in a cone shape onto the sample carrier surface above the grounding electrode.

[0026] This invention provides an apparatus and method for surface dispersion spraying of nanodiamonds. It has the following beneficial effects:

[0027] 1. The nanodiamond coating prepared by this invention utilizes the dispersed distribution of particles to provide sample material for the stable trapping of nanoparticles in optical tweezers or ion traps by using pulsed laser support in a vacuum, and at the same time provides sample material for the stable realization of ODMR detection.

[0028] 2. The dispersed nanodiamond coating prepared using the equipment and method provided by this invention was subjected to SEM testing. The spraying effect of the nanodiamond coating was analyzed from three aspects: particle agglomeration, dispersion degree, and distribution uniformity. Pulsed laser support test was also performed on the mesoscopic particles suspended in a vacuum ion trap, which can achieve stable suspension of nanodiamond particles. At the same time, the nanodiamond coating prepared by this invention was subjected to ODMR detection, and a suitable ODMR signal was successfully found.

[0029] 3. The equipment and method provided by the present invention, through the structure of fixed modules, combined with the optimal operation of the equipment, the selection of required materials, and equipment parameters, effectively improves the matching problem between voltage, spray size and particle size in the process of nanodiamond electrospray coating, and stably realizes the preparation of samples required for mesoscopic quantum sensing, and solves the problems of easy agglomeration, unevenness and ineffective dispersion of nanoparticles in the preparation of particles by traditional atomization methods. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0031] Figure 2 This is a schematic diagram of the internal structure of the present invention;

[0032] Figure 3 This is a schematic diagram of the overall structure of the fixing module in this invention;

[0033] Figure 4 This is a schematic diagram of the internal structure of the syringe in this invention;

[0034] Figure 5 This is a schematic diagram of the overall structure of the transmission module of the present invention;

[0035] Figure 6 This is a diagram showing the overall structural layout and structural relationships of the present invention;

[0036] Figure 7 The above are SEM results of the sample coatings obtained by the equipment and method of the present invention.

[0037] Figure 8 This is a photograph of nanodiamond particles suspended in a vacuum ion trap, as demonstrated by experiments of this invention.

[0038] Figure 9 The ODMR detection results are experimentally verified for this invention.

[0039] The components include: 1. Vertical lifting displacement stage; 2. Sample nozzle; 3. Sample nozzle head; 4. Grounding electrode; 5. Spray bracket; 6. Syringe placement platform; 7. Electrically controlled rotary stepper motor; 8. Displacement knob; 9. Plastic piston; 10. Rubber head buffer screw; 11. Plastic nut; 12. Threaded rod; 13. Syringe; 14. Threaded column; 15. Guide rail; 16. Liquid conduit; and 17. Spray environment components. Detailed Implementation

[0040] The technical solutions in 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. 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.

[0041] Please see the appendix Figure 1 - Appendix Figure 9 This invention provides an apparatus and method for surface dispersion spraying of nanodiamonds. The apparatus comprises three main parts: a transmission module, a fixing module, and a high-voltage module, wherein:

[0042] Please see the appendix Figure 1 - Appendix Figure 5As shown, the transmission module includes a syringe placement platform 6 on the upper part, on which a syringe 13 is fixed. An electrically controlled rotary stepper motor 7 is installed on the top side of the syringe placement platform 6 to push the piston of the syringe 13 to spray out the sample liquid. A liquid conduit 16 is installed at the liquid outlet of the syringe 13. One end of the liquid conduit 16 is connected to a sample nozzle 2. The sample nozzle 2 is formed by using at least one of vinyl chloride resin, polyphenylene sulfide resin, polyurethane resin, and polytetrafluoroethylene resin as an insulating material. The sample nozzle 2 stores nanodiamond diluent, which is stored on the side close to the sample nozzle 3. The nanodiamond diluent is separated from the anhydrous ethanol propellant at the rear end by a plastic piston 9.

[0043] In the above structure, the syringe placement platform 6 is composed of three plastic blocks and two guide rails 15. The plastic blocks at both ends are used to fix the guide rails 15 and the syringe 13. The output end of the electrically controlled rotary stepper motor 7 is fixedly installed with a threaded post 14 threadedly connected to the middle plastic block. The two guide rails 15 are arranged through both sides of the middle plastic block.

[0044] The fixed module includes a vertical lifting displacement stage 1, used to fix the sample nozzle 2 within the nitrogen-filled spray environment component 17 and allow it to move vertically. A plastic piston 9 is installed inside the sample nozzle 2. A displacement knob 8 with graduations for quantitative control is located on one side of the vertical lifting displacement stage 1, with a range of 200 mm. A sample nozzle 3 is installed at the front end of the sample nozzle 2. The sample nozzle 3 is a hollow cylindrical needle formed from a conductive stainless steel material, with an inner diameter of 0.35 mm. The sample is squeezed from the sample nozzle 2 into the sample nozzle 3. A spray support 5 is also installed on the moving platform of the vertical lifting displacement stage 1. The spray support 5 includes multiple threaded rods 12, and the multiple threaded rods 12 are fitted with grounding electrodes 4 through plastic nuts 11, forming a fixed whole. Electrode 4 is made of conductive aluminum metal and forms a small platform with a thickness of 2mm 20mm below the sample nozzle 3. It has three small holes through which threaded rod 12 can be passed for fixation. It is connected to the ground wire by a wire. The ground wire is extended with copper braided tape and closely attached to the external spray environment component 17. The spray environment component 17 is a bottomless box made of five acrylic plates. The sides of the box have openings to enter the liquid conduit 16, high voltage wire, ground wire, and nitrogen pipe. The liquid conduit 16 is made of PEEK material. One end is connected to the syringe 13 by a Luer male connector, and the other end is connected to the sample nozzle 2 by an adapter. The ground electrode 4 also serves as a spray platform to place the sample carrier. The sample nozzle 3 and the center of the ground electrode 4 are aligned using a rubber-tipped buffer screw 10 above the spray bracket 5. The spray is sprayed downwards.

[0045] Specifically, the upper end of the spray bracket 5 is made of aluminum alloy, and the lower end is fixed with three plastic threaded rods 12. The upper end is fixed to the vertical lifting displacement stage 1 and is equipped with rubber-headed buffer screws 10 for fixing the sample spray pipe 2 to achieve the alignment of the sample nozzle 3. The lower end uses six plastic nuts 11 to fix the grounding electrode 4 on the threaded rods 12. The distance between the sample nozzle 3 and the grounding electrode 4 is 15mm to 20mm.

[0046] The high-voltage module is used to generate a high voltage of 5kV to 10kV, which is applied between the sample nozzle 3 and the grounding electrode 4 to produce a spray.

[0047] The basic working principle of the device is as follows: First, the sample carrier to be sprayed is placed on the upper part of the grounding electrode 4. At the same time, the distance between the grounding electrode 4 and the sample nozzle 3 is adjusted. The propellant liquid in the syringe 13 is guided to the piston at the rear end of the sample nozzle 2 through the liquid conduit 16. The syringe 13 is rotated by the electrically controlled rotary stepper motor 7, which causes the liquid inside to flow and push the prepared liquid inside the sample nozzle 2, thereby controlling the spraying speed of the prepared liquid from the sample nozzle 3. The high voltage generated between the sample nozzle 3 and the grounding electrode 4 by adjusting the high voltage module is adjusted to adjust the shape of the spray cone of the nanodiamond diluent. A layer of nanodiamond particles is sprayed onto the surface of the sample carrier using the atomization spray method.

[0048] Furthermore, the present invention also provides a method for surface dispersion spraying of nanodiamonds, comprising the following method steps:

[0049] S1. Sample solution preparation: Dilute the nanodiamond stock solution with anhydrous ethanol to 0.025 mg / ml and then sonicate for 15 min to 20 min.

[0050] S2, Loading solution: Inject the ultrasonically diluted nanodiamond solution into the front end of the sample nozzle 2 and separate it from the rear end of the sample nozzle 2 using a plastic piston 9. The rear end of the sample nozzle 2 is connected to a liquid conduit 16, which is connected to a syringe 13. The syringe 13 is filled with anhydrous ethanol. Then, the transmission module is activated to fill the front end of the sample nozzle 2 with the diluted nanodiamond solution.

[0051] S3. Sample carrier preset: Place the sample carrier to be sprayed on the top of the grounding electrode 4, and adjust the distance between the grounding electrode 4 and the sample nozzle 3 to 15mm-20mm. Then turn on the nitrogen gas and use the nitrogen gas tube to introduce the nitrogen gas into the spray environment component 17 through the side hole of the spray environment component 17 for a period of time until the sparking wood strip can no longer be reignited at the hole. Then turn off the nitrogen gas and use modeling clay to block the hole.

[0052] S4. Test spraying: Ground the fixed module, connect the high voltage module to the fixed module, start the high voltage module, adjust the voltage within 5kV to 10kV, use a red laser lamp to irradiate the sample nozzle 3, and stop when the spray from the sample nozzle 3 is a stable single cone. Turn off the high voltage power output and stop the high voltage module from running.

[0053] S5. Start spraying: Using the atomized spraying method, the transmission module and high-pressure module are turned on, so that the sample nozzle 3 sprays the surface of the sample carrier. After a certain period of time, a nano-diamond coating is obtained on the surface of the sample carrier, thus completing the nano-diamond coating production.

[0054] The invention will be further described below with reference to specific embodiments:

[0055] Example 1:

[0056] This embodiment provides a method for surface dispersion spraying of nanodiamonds, using the aforementioned equipment for surface dispersion spraying of nanodiamonds, specifically including the following steps:

[0057] S1. Dilute the original nanoparticle solution with anhydrous ethanol solvent to 0.025 mg / ml. Use plastic piston 9 to separate the front and rear ends of sample nozzle 2. Then, put the prepared suspension into an ultrasonic machine for ultrasonic vibration for 15 min to 20 min to obtain nanodiamond diluted solution.

[0058] S2. Clean the syringe 13, liquid conduit 16, sample nozzle 2, sample nozzle 3, and plastic piston 9 with anhydrous ethanol. Connect the syringe 13 and liquid conduit 16 using a Luer male connector. Fill the syringe 13 and liquid conduit 16 with anhydrous ethanol. Reset the position of the plastic block in the middle of the transmission module and fix the syringe 13. Inject the sample nozzle 2 into the front end. The other end of the liquid conduit 16 enters the fixing module through the side hole of the spray environment component 17. After filling the rear end of the sample nozzle 2 with anhydrous ethanol, connect it to the liquid conduit 16 that enters the fixing module using an adapter. Start the electrically controlled rotary stepper motor 7 in the transmission module and adjust the propulsion flow rate to 3 ml / m. Stop propulsion when liquid starts to flow from the nozzle. Wipe the grounding electrode 4 dry and keep the grounding electrode 4 dry. Change the propulsion flow rate to 3 ml / h.

[0059] S3. If the sample is used for pulsed laser of vacuum suspended mesoscopic particles, use an aluminum sheet with a thickness of 0.3 mm as a planar carrier. If the sample is used for quantum sensing research of nanodiamond system, use a glass slide with a thickness of 1 mm as a planar carrier. Hold the sample carrier to be sprayed, such as aluminum sheet or glass slide, with tweezers and put it directly into the grounding electrode 4 below the sample nozzle 3. Align the geometric center of the planar carrier with the sample nozzle 3, turn on the nitrogen gas, and use the nitrogen gas tube to introduce nitrogen gas into the spray environment component 17 through the side hole of the spray environment component 17 for a period of time until the sparking wood strip at the hole can no longer be reignited. Turn off the nitrogen gas and use modeling clay to plug the hole.

[0060] S4. Turn on the electronically controlled rotary stepper motor 7, set the voltage to 5kV and turn on the high-voltage power supply. Use a red laser light to observe the spray shape and slowly increase the voltage until you observe that the spray forms a stable single cone spray. Then stop increasing the voltage and turn off the high-voltage power supply.

[0061] S5. Turn on the high voltage and start spraying with the stepping electrode 7. Control the spraying time as needed within 2 minutes to obtain a dispersed nano-diamond coating.

[0062] Example 2:

[0063] Example 2 provides a method for preparing a nanodiamond coating, which differs from the method provided in Example 1 above in that:

[0064] The solvent used to dilute the nanodiamond stock solution is dichloromethane.

[0065] Because dioxane and anhydrous ethanol are immiscible, the sample nozzle 2 is not separated at both ends by plastic pistons 9.

[0066] The nanodiamond coating prepared in Example 1 was subjected to SEM testing using the same method as in Example 1. The results showed that the nanodiamond coating obtained in Example 2 had a more concentrated area and an irregular texture in its distribution.

[0067] Comparative Experiment Example 1:

[0068] Comparative Experiment 1 provides a method for preparing a nanodiamond coating. This method is basically the same as the method provided in Example 1, except that: Comparative Experiment 1 does not include the ultrasonic vibration step mentioned above, and the nanodiamond stock solution is directly added to the front end of the sample nozzle 2 after dilution.

[0069] Comparative Experiment Example 2:

[0070] Comparative Test Example 2 provides a method for preparing a nanodiamond coating, which is basically the same as the method provided in Example 1, except that: Comparative Test 2 does not include the step of introducing nitrogen gas into the spray environment component 17.

[0071] Comparative Experiment Example 3:

[0072] Comparative Experiment 3 provides a method for preparing a nanodiamond coating. This method is basically the same as the method provided in Example 1, except that the ground wire connected to the ground electrode 4 in Comparative Experiment 3 is farther away from the fixed module.

[0073] Experiments have shown that: SEM testing of the dispersed nanodiamond coating prepared using the equipment and method provided in this embodiment was performed using a scanning electron microscope to analyze the spraying effect of the nanodiamond coating from three aspects: particle agglomeration, dispersion degree, and distribution uniformity; pulsed laser loading test of mesoscopic particles suspended in a vacuum ion trap was performed on the nanodiamond coating prepared using the equipment and method provided in this invention; and ODMR detection was performed on the nanodiamond coating prepared using the equipment and method provided in this invention.

[0074] The experimental results show that:

[0075] The nanodiamond coated particles prepared by comparative experiment 1 showed severe agglomeration in SEM images, resulting in a slight decrease in the success rate of pulsed laser support for vacuum ion traps and partial overexposure of the detected ODMR signal.

[0076] The nanodiamond coated particles prepared by comparative experiment 2 showed uneven particle distribution in SEM images, resulting in a decreased success rate in pulsed laser support of the ion trap in vacuum and unstable ODMR signals.

[0077] The nanodiamond coating particles prepared by comparative experiment 3 showed that the particle spraying range was too dispersed in the SEM image, which greatly reduced the success rate of pulsed laser support for ion trap in vacuum and made it difficult to scan out the ODMR signal.

[0078] like Figure 7 As shown, the nanodiamond coated particles prepared in Example 1 showed no obvious agglomeration in the SEM image, and the dispersion was appropriate and the distribution was relatively uniform; Figure 8 As shown, the nanodiamond coated particles prepared in Example 1 have a high success rate in achieving pulsed laser support for ion traps in vacuum.

[0079] like Figure 9 As shown, the nanodiamond coating particles prepared in Example 1 exhibit a significant ODMR signal. Therefore, the nanodiamond coating preparation method provided in Example 1 can significantly improve the spraying effect of dispersed nanoparticles.

[0080] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art 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 appended claims and their equivalents.

Claims

1. An apparatus for surface dispersion spraying of nanodiamonds, characterized in that, include: The transmission module includes a syringe placement platform (6) on the upper part of which a syringe (13) is fixed. An electrically controlled rotary stepper motor (7) for pushing the piston of the syringe (13) to spray out sample liquid is installed on one side of the top of the syringe placement platform (6). A liquid conduit (16) is installed at the liquid outlet of the syringe (13). One end of the liquid conduit (16) is connected to a sample nozzle (2). The fixed module includes a vertical lifting displacement stage (1) for fixing the sample nozzle (2) in a nitrogen-filled spray environment component (17) and allowing it to move vertically. The sample nozzle (2) is equipped with a plastic piston (9). A displacement knob (8) is provided on one side of the vertical lifting displacement stage (1). A sample nozzle (3) is installed at the front end of the sample nozzle (2). A spray bracket (5) is also installed on the moving platform of the vertical lifting displacement stage (1). The spray bracket (5) includes multiple threaded rods (12), and the multiple threaded rods (12) are fitted with a grounding electrode (4) through plastic nuts (11) to form a fixed whole. A rubber-headed buffer screw (10) is used above the spray bracket (5) to align the sample nozzle (3) with the center of the grounding electrode (4). The spray is sprayed downward onto the sample carrier surface above the grounding electrode (4). The distance between the sample nozzle (3) and the grounding electrode (4) is 15mm to 20mm. A high voltage module is used to generate a high voltage of 5kV to 10kV, which is applied between the sample nozzle (3) and the ground electrode (4) to change the spray shape; The liquid in the syringe (13) is guided to the piston at the rear end of the sample nozzle (2) through the liquid conduit (16). The syringe (13) is rotated and propelled by the electrically controlled rotary stepper motor (7), so that the liquid inside it flows to push the prepared liquid inside the sample nozzle (2), thereby controlling the spraying speed of the prepared liquid from the sample nozzle (3). Under the combined action of high voltage and vertical lifting displacement stage (1), a layer of nanodiamond particles is sprayed onto the surface of the sample carrier using the atomization spray method.

2. The apparatus for surface dispersion spraying of nanodiamonds according to claim 1, characterized in that, The syringe placement platform (6) consists of three plastic blocks and two guide rails (15). The plastic blocks at both ends are used to fix the guide rails (15) and the syringe (13). The output end of the electrically controlled rotary stepper motor (7) is fixedly installed with a threaded post (14) threaded to the middle plastic block. The two guide rails (15) are arranged through the two sides of the middle plastic block.

3. The apparatus for surface dispersion spraying of nanodiamonds according to claim 1, characterized in that, The sample nozzle (2) is made of insulating transparent plastic material. The front and rear ends of the nozzle are separated by pistons. The front end of the nozzle is loaded with a sample, and the rear end is connected to the syringe (13). The sample nozzle (3) is made of conductive stainless steel metal material and is connected to the front end of the sample nozzle (2). The inner diameter is 0.35mm. The grounding electrode (4) is made of conductive aluminum metal material and is grounded by a wire. The grounding wire is placed close to the outside of the spray environment component (17).

4. The apparatus for surface dispersion spraying of nanodiamonds according to claim 1, characterized in that, The spray environment component (17) is an acrylic box composed of five acrylic plates, with openings on the sides for the liquid conduit (16), high-voltage line, grounding line, and nitrogen pipe to enter.

5. A method for surface dispersion spraying of nanodiamonds, characterized in that, Using the apparatus for surface dispersion spraying of nanodiamonds according to any one of claims 1-4, the method includes the following steps: S1. Sample solution preparation: Dilute 1 mg / ml of nano-diamond stock solution with anhydrous ethanol, and then sonicate for 15 min to 20 min. S2, Loading solution: Inject the ultrasonically diluted nanodiamond solution into the front end of the sample nozzle (2) and separate it from the rear end of the sample nozzle (2) using a plastic piston (9). The rear end of the sample nozzle (2) is connected to a liquid conduit (16), and the liquid conduit (16) is connected to a syringe (13). The syringe (13) is filled with anhydrous ethanol. Then, the transmission module is started to fill the front end of the sample nozzle (2) with the nanodiamond solution. S3, Sample carrier preset: Place the sample carrier to be sprayed on the top of the grounding electrode (4), and adjust the distance between the grounding electrode (4) and the sample nozzle (3) to 15mm~20mm. Then turn on the nitrogen gas and use the nitrogen gas tube to pass the nitrogen gas through the side hole of the spray environment component (17) into the spray environment component (17) for a period of time until the sparking wood strip at the hole can no longer be reignited. Then turn off the nitrogen gas and use modeling clay to block the hole. S4. Test spraying: Ground the fixed module, connect the high voltage module and the fixed module, start the high voltage module, adjust the voltage within 5kv~10kv, use a red laser lamp to irradiate the sample nozzle (3) below, observe the spray to end when the spray is a stable single cone, and stop the high voltage module. S5. Start Spraying: Using the atomization spraying method, start the transmission module and high-pressure module, control the spraying time, obtain a layer of nano-diamond coating, and complete the nano-diamond coating production.

6. The method for surface dispersion spraying of nanodiamonds according to claim 5, characterized in that, In step S1, the preparation steps of the nanodiamond diluent specifically include: First, a nanodiamond solution with an average particle size of 40 nm and a concentration of 1 mg / ml was diluted with anhydrous ethanol to 0.025 mg / ml. Then, the diluted suspension was placed in an ultrasonic device for ultrasonic vibration treatment for 15 min to 20 min to obtain a diluted nanodiamond solution.

7. A method for surface dispersion spraying of nanodiamonds according to claim 5, characterized in that, In step S5, the atomization spray method is electrohydrodynamic atomization.

8. A method for surface dispersion spraying of nanodiamonds according to claim 7, characterized in that, The specific process of the electrohydrodynamic atomization method is as follows: under the conditions of a flow rate of 3 ml / h and a voltage of 5 kV to 10 kV, the nanodiamond diluent is decomposed into fine droplets under the influence of an external electric field and sprayed vertically downward in a cone shape onto the sample carrier surface above the grounding electrode (4).

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