Method and device for preparing diamond micro-nano particles based on laser liquid phase ablation

Abstract

The invention relates to a method and device for preparing diamond micro-nano particles based on laser liquid phase ablation, and relates to the technical field of micro-nano material preparation.The method and device for preparing the diamond micro-nano particles based on laser liquid phase ablation comprise the steps of equipment setting, light path building, laser ablation and collection. According to the method and device for preparing the diamond micro-nano particles based on laser liquid phase ablation, the diamond micro-nano particles can be efficiently and adjustably produced.

Description

Technical Field

[0001] The present invention relates to the technical field of micro-nano material preparation, and in particular to a method and device for preparing diamond micro-nano particles based on laser liquid phase ablation. Background Art

[0002] Micro / nano particles are widely used in medicine, materials science, biotechnology and other fields due to their unique physical and chemical properties. Traditional methods for preparing micro / nano particles include chemical synthesis, mechanical grinding and vapor deposition.

[0003] In recent years, the rapid development of laser technology has provided new ideas for the preparation of micro-nano particles. The article with doi number 10.1016 / j.diamond.2003.08.027 and published on April 1, 2004 proposed the preparation of nanodiamonds by laser ablation at the solid-liquid interface, which disclosed a method for preparing nanodiamonds by laser ablation at the solid-liquid interface, including the following steps: the laser wavelength used is 532nm, the maximum power is 130mJ per pulse, the pulse duration is 10ns, the repetition rate is 10Hz, the beam is guided vertically downward through a prism, and a 25cm focal length lens is used to focus on a solid target in a glass reaction container. A telephoto lens is used to prevent liquid from splashing onto the lens. The beam is focused to a spot diameter of approximately 0.5 mm by translating the lens or reaction vessel. The target is placed at the bottom of the reaction vessel. Deionized water or cyclohexane is poured into the vessel until the target is covered to a depth of 1 cm. When using flammable liquids (such as cyclohexane), a continuous stream of argon is flowed into the top of the reaction vessel to prevent possible combustion of the liquid. Deposition typically lasts 15 minutes, equivalent to approximately 9,000 laser irradiations. During this period, liquid is lost due to sputtering and evaporation, so the liquid level needs to be replenished regularly. Diamond nanocrystals can be generated by pulsed laser ablation of graphite in two liquids (water and cyclohexane) at room temperature and pressure.

[0004] With regard to the above technical solution, the yield of diamond nanocrystals generated is very low. Therefore, it is of great practical significance to develop an efficient and adjustable laser liquid phase ablation system to produce diamond micro-nano particles. Summary of the invention

[0005] In order to produce diamond micro-nano particles efficiently and in an adjustable manner, the present invention provides a method and device for preparing diamond micro-nano particles based on laser liquid phase ablation.

[0006] In a first aspect, the present invention provides a method for preparing diamond micro-nano particles based on laser liquid phase ablation, comprising the following steps: Equipment setup: clean the quartz container with deionized water, fix the graphite target on the bracket, put the fixed graphite target and the bracket into the quartz container, set the graphite target close to the side wall of the quartz container close to the pulse laser in the direction of laser intake, inject the solution, the solution is deionized water or ethanol, the liquid height is maintained at 10-20mm above the target, the quartz container is a single crystal quartz synthesis container, the graphite target has a purity of 99.99-99.9999% and the surface of the graphite target is smooth.

[0007] Build the optical path: align the quartz container with the horizontal position of the laser emitter, and set the focus of the laser beam at a distance of ±5mm from the surface of the graphite target.

[0008] Laser ablation: Start the laser with an output power of 1-10 W, a pulse frequency of 1-100 Hz, a pulse time of 10-12 ms, and perform 30,000-40,000 pulse laser ablations.

[0009] Collection: After laser ablation, the generated diamond micro-nanoparticles are collected by centrifugation or filtration and washed with deionized water to remove unreacted materials and impurities.

[0010] By adopting the above technical solution, the quartz container is thoroughly cleaned with deionized water to remove any impurity particles to ensure the purity of the experiment. The quartz container is resistant to high temperature and corrosion to ensure that it will not break or leak in a high temperature environment, thereby improving the safety and stability of the experiment. The target is close to the front wall of the container to reduce the laser energy loss caused by solution turbidity. The laser focus is to ensure that the laser energy is concentrated on the surface of the target material and optimize the particle generation effect. The distance between the laser focus and the outer surface of the target material is accurately adjusted through the focusing lens to ensure that the laser beam has the best focusing effect during the ablation process. The interaction between the pulsed laser and the graphite target generates high temperature and high pressure by instantaneously heating the target surface, which causes the target surface to melt or vaporize, thereby promoting the generation of diamond particles. The high energy density of the laser pulse causes the target surface to heat up rapidly and produce explosive bubbles, thereby forming uniform micro-nano particles. In this process, the high temperature and high pressure conditions in the solution help to increase the yield of nanodiamonds and promote controllable changes in particle morphology.

[0011] Optionally, the solution is deionized water.

[0012] By adopting the above technical solution, the deionized water solution helps to evenly distribute the particles.

[0013] Optionally, the solution further comprises a surfactant, and the surfactant is at least one of sodium dodecyl sulfate and polyvinyl alcohol.

[0014] By adopting the above technical solution, the addition of surfactant can improve the dispersibility of particles, thereby avoiding particle aggregation and further adjusting the size and morphology of particles.

[0015] In a second aspect, the present invention provides a device for preparing diamond micro-nano particles based on laser liquid phase ablation, comprising: a pulsed laser, a focusing lens, a bracket, a quartz container and a scissor lift.

[0016] The quartz container includes a quartz container base and a quartz container cover. The quartz container is arranged above the scissor lifter. The height of the quartz container is vertically adjusted by the scissor lifter so as to be aligned with the horizontal position of the laser emission port. The graphite target is fixed on a bracket, the bracket is placed in a quartz container, and the graphite target is arranged in the direction of laser intake. The focusing lens is arranged between the quartz container and the pulse laser, and is used to focus the laser onto the surface of the graphite target.

[0017] By adopting the above technical solution, the height of the quartz container is adjusted vertically by a scissor lift to align it with the horizontal position of the laser emission port, the graphite target is fixed on the bracket to ensure the stability of the target during the ablation process to prevent displacement caused by laser shock, the optical path is built, the focusing lens is adjusted to make the laser accurately focus on the graphite surface, the pulse laser is installed, the wire plug and the pulse laser trigger are connected, the equipment is ensured to be well connected and the system is tested.

[0018] Optionally, the bracket is a polytetrafluoroethylene bracket.

[0019] The polytetrafluoroethylene bracket comprises: a polytetrafluoroethylene bracket base and a polytetrafluoroethylene bracket support seat, A placement groove having the same shape as the graphite target is provided on one side of the polytetrafluoroethylene support base close to the pulse laser. The graphite target is fixed in the placement groove of the polytetrafluoroethylene support base. The polytetrafluoroethylene support base is close to a side wall of the quartz container close to the pulse laser.

[0020] The polytetrafluoroethylene support base is supported between the polytetrafluoroethylene support base and a side wall of the quartz container away from the pulse laser, and is used to fix the polytetrafluoroethylene support base.

[0021] By adopting the above technical solution, the graphite target is fixed on the polytetrafluoroethylene bracket, which can further ensure the stability of the target during the ablation process to prevent displacement caused by laser impact. The polytetrafluoroethylene bracket base makes the target as close to the front wall of the container as possible to reduce the laser energy loss caused by solution turbidity.

[0022] Optionally, a high-temperature silicone sealing ring is used to seal the joint between the quartz container base and the quartz container cover.

[0023] By adopting the above technical solution, the quartz container is prevented from leaking during the laser ablation process, and the container joints are sealed with high-temperature silicone sealing rings to ensure that the liquid does not leak, thereby improving the safety and stability of the experiment.

[0024] In summary, the present invention includes at least one of the following beneficial technical effects: 1. The quartz container selected in the present invention is resistant to high temperature and corrosion to ensure that it does not break or leak in a high temperature environment, thereby improving the safety and stability of the experiment. The target material is close to the front wall of the container to reduce the laser energy loss caused by solution turbidity. The laser focus ensures that the laser energy is concentrated on the target surface to optimize the particle generation efficiency.

[0025] 2. The interaction between the pulsed laser and the graphite target of the present invention generates high temperature and high pressure by instantaneously heating the surface of the target, which causes the surface of the target to melt or vaporize, thereby promoting the generation of diamond particles. The high energy density of the laser pulse causes the surface of the target to heat up rapidly and produces explosive bubbles, thereby forming uniform micro-nano particles. In this process, the high temperature and high pressure conditions in the solution help to increase the yield of nanodiamonds and promote controllable changes in particle morphology. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the structure of the device of the present invention; Figure 2 It is a schematic diagram of the structure in which a graphite target is fixed on a polytetrafluoroethylene support base; Figure 3 is the X-ray diffraction phase analysis diagram of the product; Figure 4 Scanning electron micrograph of the product.

[0027] Explanation of the accompanying drawings: 1. Pulse laser; 2. Focusing lens; 3. Quartz container cover; 4. Quartz container base; 5. Graphite target; 6. Polytetrafluoroethylene bracket base; 7. Polytetrafluoroethylene bracket support seat; 8. Scissor lift. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below with reference to the embodiments.

[0029] Example 1: This example discloses a method for preparing diamond micro-nano particles based on laser liquid phase ablation, which adopts the following steps: Equipment setup: clean the quartz container with deionized water, fix the graphite target on the bracket, put the fixed graphite target and the bracket into the quartz container, set the graphite target close to the side wall of the quartz container close to the pulse laser in the direction of laser intake, inject the solution, the solution is deionized water or ethanol, the liquid height is maintained at 10-20mm above the target, the quartz container is a single crystal quartz synthesis container, the graphite target has a purity of 99.99-99.9999% and the surface of the graphite target is smooth.

[0030] Build the optical path: align the quartz container with the horizontal position of the laser emitter, and set the focus of the laser beam at a distance of ±5mm from the surface of the graphite target.

[0031] Laser ablation: Start the laser with an output power of 1-10 W, a pulse frequency of 1-100 Hz, a pulse time of 10-12 ms, and perform 30,000-40,000 pulse laser ablations.

[0032] Collection: After laser ablation, the generated diamond micro-nanoparticles are collected by centrifugation or filtration and washed with deionized water to remove unreacted materials and impurities.

[0033] A device for preparing diamond micro-nano particles based on laser liquid phase ablation comprises: a pulse laser 1, a focusing lens 2, a bracket, a quartz container and a scissor lift 8.

[0034] The quartz container includes a quartz container base 4 and a quartz container cover 3. The quartz container is arranged above the scissor lift 8. The height of the quartz container is vertically adjusted by the scissor lift 8 so as to be aligned with the horizontal position of the laser emission port. The graphite target 5 is fixed on a bracket, the bracket is placed in a quartz container, and the graphite target 5 is arranged in the direction of laser intake. The focusing lens 2 is disposed between the quartz container and the pulse laser 1 , and is used to focus the laser onto the surface of the graphite target 5 .

[0035] The polytetrafluoroethylene bracket comprises: a polytetrafluoroethylene bracket base 6 and a polytetrafluoroethylene bracket support seat 7, A placement groove having the same shape as the graphite target 5 is provided on the side of the polytetrafluoroethylene support base 6 close to the pulse laser 1 . The graphite target 5 is fixed in the placement groove of the polytetrafluoroethylene support base 6 . The polytetrafluoroethylene support base 6 is close to a side wall of the quartz container close to the pulse laser 1 .

[0036] The polytetrafluoroethylene support seat 7 is supported between the polytetrafluoroethylene support base 6 and a side wall of the quartz container away from the pulse laser 1 , and is used to fix the polytetrafluoroethylene support base 6 .

[0037] The joint between the quartz container base 4 and the quartz container cover 3 is sealed with a high-temperature silicone sealing ring.

[0038] The collected diamond micro-nano particles were analyzed, and the material structure of the diamond micro-nano particles was determined by X-ray diffraction phase analysis. The morphology and size of the particles were characterized by scanning electron microscopy, and their distribution was analyzed to evaluate the uniformity and particle size distribution of the particles.

[0039] Phase analysis by X-ray diffraction ( Figure 3 ), the peak at 43.931° corresponds to the (111) face of diamond, the peak at 75.297° corresponds to the (220) face of diamond, and there are no obvious impurity peaks. It can be seen that the purity of the obtained diamond micro-nanoparticles is very high, and the efficiency of obtaining diamond micro-nanoparticles is very high.

[0040] The morphology and size of the particles were characterized by scanning electron microscopy ( Figure 4 ), it can be seen that the obtained diamond micro-nano particles are uniform.

[0041] The above are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing diamond micro-nano particles based on laser liquid phase ablation, characterized in that: The following steps are involved: Equipment setup: clean the quartz container with deionized water, fix the graphite target on the bracket, put the fixed graphite target and the bracket into the quartz container, set the graphite target close to the side wall of the quartz container close to the pulse laser in the direction of laser intake, inject the solution, the solution is deionized water or ethanol, the liquid height is kept 10-20mm above the target, the quartz container is a single crystal quartz synthesis container, the purity of the graphite target is 99.99-99.9999% and the surface of the graphite target is smooth; Build the optical path: align the horizontal position of the quartz container and the laser emitter, and set the focus of the laser beam at a distance of ±5mm from the surface of the graphite target; Laser ablation: start the laser, the output power of the laser is 1-10W, the pulse frequency is 1-100Hz, the pulse time is 10-12ms, and 30000-40000 pulse laser ablation is performed; Collection: After laser ablation, the generated diamond micro-nanoparticles are collected by centrifugation or filtration and washed with deionized water to remove unreacted materials and impurities.

2. The method for preparing diamond micro-nano particles based on laser liquid phase ablation according to claim 1, characterized in that: The solution is deionized water.

3. The method for preparing diamond micro-nano particles based on laser liquid phase ablation according to claim 1, characterized in that: The solution further comprises a surfactant, and the surfactant is at least one of sodium lauryl sulfate and polyvinyl alcohol.

4. A laser liquid phase ablation device, used to implement the method for preparing diamond micro-nano particles based on laser liquid phase ablation as described in any one of claims 1 to 3, characterized in that: It comprises a pulse laser (1), a focusing lens (2), a bracket, a quartz container and a scissor lift (8), The quartz container comprises a quartz container base (4) and a quartz container cover (3); the quartz container is arranged above the scissor lift (8); the height of the quartz container is vertically adjusted by the scissor lift (8) so as to be aligned with the horizontal position of the laser emission port. The graphite target (5) is fixed on a bracket, the bracket is placed in a quartz container, and the graphite target (5) is arranged in the direction of laser intake. The focusing lens (2) is arranged between the quartz container and the pulse laser (1), and the focusing lens (2) is adjusted so that the laser is accurately focused on the surface of the graphite target material (5).

5. The laser liquid phase ablation device according to claim 4, characterized in that: The stent is a polytetrafluoroethylene stent, The polytetrafluoroethylene bracket comprises: a polytetrafluoroethylene bracket base (6) and a polytetrafluoroethylene bracket support base (7); A placement groove having the same shape as the graphite target (5) is provided on a side of the polytetrafluoroethylene support base (6) close to the pulse laser (1); the graphite target (5) is fixed in the placement groove of the polytetrafluoroethylene support base (6); and the polytetrafluoroethylene support base (6) is closely attached to a side wall of the quartz container close to the pulse laser (1); The polytetrafluoroethylene support base (7) is supported between the polytetrafluoroethylene support base (6) and a side wall of the quartz container away from the pulse laser (1), and is used to fix the polytetrafluoroethylene support base (6).

6. The laser liquid phase ablation device according to claim 4, characterized in that: The joint between the quartz container base (4) and the quartz container cover (3) is sealed with a high-temperature silicone sealing ring.

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