A continuous preparation device and method of magnetic micro-nano structures

Abstract

The application discloses a kind of continuous preparation device and method of magnetic micro-nano structure, belong to micro-nanoparticle preparation equipment field.Device includes particle emission component, reaction component and collection component;Particle emission component is charged by gas source piece, powder pump, charged acceleration component to make magnetic micro-nano particle;Reaction container is divided into front section, middle section, rear section, and built-in ground conductive sheet realizes electric field acceleration, electromagnetic spin driver drives magnetic micro-nano particle spin, laser emitting component divides light and monitors energy on line and fuses magnetic micro-nano particle, and rear section multi-slot collection sheet fractionally collects product.Preparation is first to make magnetic micro-nano particle charged acceleration, while opening rotating magnetic field and laser, inert atmosphere is passed into after conveying powder, and magnetic micro-nano particle is fused under rotating centrifugal force to overcome surface tension, and the magnetic micro-nano particle after deformation is obtained.The application realizes the integrated continuous preparation of magnetic micro-nano particle.

Description

Technical Field

[0001] This invention belongs to the technical field of micro and nanoparticle preparation equipment, and specifically relates to a continuous preparation device and method for magnetic micro and nano structures. Background Technology

[0002] In the field of micro and nanomaterial preparation, optimizing the specific surface area and catalytic and electromagnetic properties by controlling the morphology of magnetic micro and nanoparticles is one of the research hotspots in this field.

[0003] Liquid-phase laser irradiation coupled with an electromagnetic field is a commonly used device for fabricating non-spherical micro / nanostructures. This device typically includes a reaction vessel, a laser emitter, and an electromagnetic field generator. The reaction vessel contains an organic solvent precursor liquid in which magnetic nanoparticles are dispersed. The laser emitter heats the magnetic nanoparticles to melt them, and the electromagnetic field generator produces an external electromagnetic field to guide the magnetic nanoparticles to deform into non-spherical structures. Because the magnetic nanoparticles are in a liquid environment, their degrees of freedom of movement are greatly restricted, preventing continuous processing in flight. Therefore, this device can only be used for intermittent batch production. Summary of the Invention

[0004] To address the aforementioned problems, the purpose of this invention is to provide a continuous fabrication apparatus and method for magnetic micro / nano structures, enabling the continuous fabrication of magnetic micro / nano particles.

[0005] The technical solution of the present invention is: a continuous fabrication device for magnetic micro-nano structures, which includes, from front to back, a particle emission component, a reaction component, and a collection component along the direction of travel of the magnetic micro-nano particles.

[0006] The particle emission assembly includes a gas source, a powder pump, and a charged acceleration assembly. The gas source is connected to the air inlet of the powder pump through a pipeline. The charged acceleration assembly includes a high-voltage electrode disposed around the nozzle of the powder pump. The high-voltage electrode forms a high-voltage ionization region at the nozzle, which is used to cause the magnetic micro-nano particles ejected by the powder pump to capture ions and become charged when passing through the region.

[0007] The reaction assembly includes a reaction container, a conductive sheet, an electromagnetic spin actuator, and a laser emitter. The front end of the reaction container is positioned opposite the nozzle of the powder pump. The conductive sheet and the electromagnetic spin actuator are sequentially arranged on the reaction container along the flight path of the magnetic micro / nano particles. The conductive sheet is grounded and forms a potential difference with the high-voltage ionization region to accelerate the charged magnetic micro / nano particles with an electric field, thereby increasing their flight speed and maintaining motion stability. The electromagnetic spin actuator generates a rotating magnetic field to drive the magnetic micro / nano particles to rotate. The laser emitter is fixed to the outside of the reaction container, and its laser beam path is directly opposite the flight path of the magnetic micro / nano particles downstream of the electromagnetic spin actuator. The collection assembly is located at the rear end of the reaction container and is used to collect the magnetic micro / nano particles deformed by the laser beam path.

[0008] Furthermore, the reaction vessel comprises, from front to back, a front section, a middle section, and a rear section connected in series along the direction of travel of the magnetic micro / nano particles.

[0009] The front section has a first through channel distributed along its length, and the inlet of the first through channel is positioned opposite to the nozzle of the powder pump as the front end of the reaction vessel.

[0010] The middle section has a second through channel distributed along its length, the inlet of the second through channel being connected to the outlet of the first through channel; the side wall of the middle section near its inlet has a conductive plate groove connected to the second through channel, the conductive plate being embedded in the conductive plate groove; the side wall of the middle section near its outlet has a laser injection hole connected to the second through channel, the laser beam of the laser emitter being injected into the second through channel through the laser injection hole; the electromagnetic spin actuator is sleeved on the side wall of the middle section and located between the conductive plate groove and the laser injection hole.

[0011] The rear section has a third through channel distributed along its length, the inlet of the third through channel being connected to the outlet of the second through channel; the third through channel has multiple slots from front to back along the direction of travel of the magnetic micro-nano particles, and the collection component is fixed in any of the slots.

[0012] Furthermore, the conductive sheet includes a conductive sheet body and an aluminum foil covering the conductive sheet body. Both the conductive sheet body and the aluminum foil are provided with through holes corresponding to the second through channel, and the aluminum foil is grounded.

[0013] Furthermore, the electromagnetic spin actuator includes a first base and four sets of coils. The first base is sleeved on the outer side of the middle section. The four sets of coils are distributed on the first base in a cross structure. The two sets of coils in opposite positions are connected in sequence and then connected to the frequency converter through wires. The frequency converter is connected to an external power supply, and the external power supply is used to supply power to the coils through the frequency converter.

[0014] Furthermore, the laser emitting device includes a laser emitter, a beam splitter, and an energy meter. The beam splitter is disposed on the output optical path of the laser emitter and transmits the laser light into the second through-channel from the laser injection hole. The energy meter is disposed on the reflected optical path of the beam splitter.

[0015] Furthermore, the collection assembly includes a support plate and a collection plate, with the support plate inserted into the rear section; the collection plate is fixed on the support plate and is made of silicon wafer, which is used to collect the deformed magnetic micro / nano particles in the third through channel.

[0016] Furthermore, the preparation device also includes a gas washing component. A particle output hole is provided on the side wall of the front section. The gas washing component has a cavity that is connected to the particle output hole. The cavity is used to hold water. The particle output hole discharges the magnetic micro-nano particles that diverge in the first through-channel into the water in the cavity. The diverging magnetic micro-nano particles are magnetic micro-nano particles whose running direction deviates from the channel direction of the first through-channel.

[0017] Furthermore, the gas scrubbing assembly includes a second base and a holding tank; the second base has an internal cavity, and the second base is sleeved on the front section, the cavity being connected to the particle output hole; the holding tank is opened on the second base and is connected to the cavity through a channel; the holding tank is used to hold water and the water level is higher than the channel; the cavity serves as a container for collecting the dispersed magnetic micro-nano particles.

[0018] A method for continuous fabrication of magnetic micro / nano structures includes the following steps: Magnetic micro- and nano-particles are emitted and charged after passing through a high-voltage ionization region. The charged magnetic micro- and nano-particles are accelerated by an electric field using a potential difference and driven to rotate by a rotating magnetic field. The rotating magnetic micro- and nano-particles are irradiated with a laser to melt them. The molten magnetic micro- and nano-particles are deformed under the action of centrifugal force to overcome surface tension, resulting in deformed magnetic micro- and nano-particles, which are then collected.

[0019] Furthermore, the laser irradiation time is 2 min to 5 min.

[0020] Compared with existing technologies, the advantages of this invention are as follows: This invention achieves continuous supply of magnetic micro / nano particles in a gaseous environment through a particle emission assembly. Conductive sheets, electromagnetic spin actuators, and laser emitters arranged sequentially along the flight path in the reaction vessel accelerate, rotate, and irradiate the magnetic micro / nano particles in flight. A collection assembly continuously collects the deformed magnetic micro / nano particles, achieving integrated continuous fabrication of magnetic micro / nano particles. Simultaneously, by synergistically adjusting the frequency of the rotating magnetic field and the laser power, controllable fabrication of various non-spherical micro / nano structures such as C-shaped, ring-shaped, trilobal, and dumbbell-shaped structures can be achieved. The resulting products have uniform morphology and high specific surface area, making them suitable for catalysis, energy storage, and electromagnetic materials. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a partial structural schematic diagram of the present invention; Figure 3 This is a schematic diagram of the structure of the reaction vessel of the present invention; Figure 4 This is a schematic diagram of the structure of the conductive sheet of the present invention; Figure 5 This is a schematic diagram of the structure of the electromagnetic spin actuator of the present invention; Figure 6 This is a top view of the electromagnetic spin actuator of the present invention; Figure 7 This is a schematic diagram of the structure of the air washing assembly of the present invention; Figure 8 This is a SEM image of the original α-Fe2O3 nanoparticles used in this invention. Figures 9 to 13 These are SEM images of the deformed magnetic micro / nano particles used in this invention; wherein, Figure 9 , Figure 10 These are ring-shaped Fe2O3 magnetic micro / nano particles; Figure 11 These are dumbbell-shaped Fe2O3 magnetic micro / nano particles. Figure 12 These are trilobed Fe2O3 magnetic micro / nano particles. Figure 13 It consists of C-shaped Fe2O3 magnetic micro / nano particles.

[0022] Among them, 1-particle emission assembly, 11-gas source component, 12-powder pump, 13-charged acceleration assembly, 2-reaction assembly, 20-reaction container, 201-front section, 202-middle section, 203-rear section, 2030-slot, 2021-conductive sheet groove, 2022-laser injection hole, 21-conductive sheet, 211-conductive sheet body, 212-aluminum foil, 22-electromagnetic spin actuator, 221-first base, 222-coil, 23-laser emission component, 231-laser emitter, 232-beam splitter, 233-energy meter, 3-collection assembly, 31-support sheet, 32-collection sheet, 4-gas washing assembly, 41-second base, 42-containment tank. Detailed Implementation

[0023] The following is combined with Figures 1 to 13 The specific embodiments of the present invention will be described in detail below. In the description of the present invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description, and are not intended to 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 of the present invention.

[0024] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0025] It should be noted that the circuit connections involved in this invention all adopt conventional circuit connection methods and do not involve any innovation.

[0026] Example 1 like Figure 1 The apparatus shown is a continuous fabrication device for magnetic micro / nano structures. The device uses a powder pump 12 to emit magnetic micro / nano particles, which are accelerated by an electric field and then driven to rotate by a magnetic field. The magnetic micro / nano particles are then molten by laser irradiation. During rotation, the surface tension of the magnetic micro / nano particles is overcome, and C-shaped / ring-shaped / trilobal / dumbbell-shaped magnetic micro / nano particles are successfully fabricated. The magnetic micro / nano particles after the reaction are collected in the collection component 3.

[0027] The fabrication device includes, from front to back, a particle emission component 1, a reaction component 2, and a collection component 3 along the direction of travel of the magnetic micro / nano particles.

[0028] The particle emission assembly 1 includes a gas source 11, a powder pump 12, and a charged acceleration assembly 13. The gas source 11 is connected to the air inlet of the powder pump 12 via a pipeline. The charged acceleration assembly 13 includes a high-voltage electrode disposed around the nozzle of the powder pump 12. The high-voltage electrode forms a high-voltage ionization zone at the nozzle, ionizing the surrounding air to generate ions. This causes the magnetic micro / nano particles ejected by the powder pump 12 to capture ions and become charged as they pass through this zone. When the charged magnetic micro / nano particles fly to the grounded conductive plate 21, the potential difference between the high-voltage ionization zone and the grounded conductive plate accelerates them under the influence of the electric field, resulting in higher flight speeds. The powder pump 12 is a pneumatic powder pump with a detachably mounted powder bottle for storing magnetic micro / nano particles, which can be α-Fe2O3 powder. The protective atmosphere output from the gas source 11 enters the powder pump 12 via a pipeline, is continuously ejected from the nozzle of the powder pump 12, and then enters the interior of the reaction vessel 20 to achieve atmosphere replacement within the reaction vessel.

[0029] like Figure 2 As shown, the reaction assembly 2 includes a reaction container 20, a conductive sheet 21, an electromagnetic spin actuator 22, and a laser emitter 23. The front end of the reaction container 20 is positioned opposite the nozzle of the powder pump 12. The conductive sheet 21 and the electromagnetic spin actuator 22 are sequentially arranged on the reaction container 20 along the flight path of the magnetic micro / nano particles. The conductive sheet 21 is grounded and forms a potential difference with the high-voltage ionization region to accelerate the magnetic micro / nano particles. The electromagnetic spin actuator 22 generates a rotating magnetic field to drive the magnetic micro / nano particles to rotate. The laser emitter 23 is fixed to the outside of the reaction container 20, and the laser beam path of the laser emitter 23 is directly opposite the flight path of the magnetic micro / nano particles downstream of the electromagnetic spin actuator 22. The collection assembly 3 is located at the rear end of the reaction container 20 and is used to collect the C-shaped / ring / trefoil / dumbbell-shaped magnetic micro / nano particles deformed by the laser beam path.

[0030] It should be noted that the charged acceleration component 13 has a dual function: First, it forms a high-voltage ionization region around the nozzle of the powder pump 12 through a high-voltage electrode, ionizing the surrounding air molecules. This causes the magnetic micro-nano particles passing through this region to capture ions and become charged; this is the "charging" function. Second, the electromagnetically charged micro-nano particles continue to fly to the downstream grounded conductive plate 21. Due to the potential difference between the high-voltage ionization region and the grounded conductive plate 21, the magnetic micro-nano particles are accelerated under the action of this electric field; this is the "acceleration" function. The above two stages of "charging" and "acceleration" work together to ensure that the magnetic micro-nano particles arrive at the laser irradiation area at a sufficient speed, ensuring the smooth progress of the subsequent deformation process.

[0031] This invention operates in a gaseous environment, by introducing a protective atmosphere into the reaction vessel 20 through the gas source 11, so that magnetic micro-nano particles can be continuously processed in flight.

[0032] Preferred, such as Figure 3 As shown, the reaction vessel 20, along the direction of travel of the magnetic micro / nano particles, comprises a front section 201, a middle section 202, and a rear section 203 connected in series from front to back. In this embodiment, the front section 201, the middle section 202, and the rear section 203 are all cuboid structures and are sealed in series. The cuboid structure of the front section 201 has the same height as the cuboid structure of the middle section 202, and the cuboid structure of the middle section 202 has the same width as the cuboid structure of the rear section 203; the rear section 203 has a removable cover.

[0033] The front section 201 has a first through channel distributed along its length, and the inlet of the first through channel is positioned opposite to the nozzle of the powder pump 12 as the front end of the reaction vessel 20. The middle section 202 has a second through channel distributed along its length, and the inlet of the second through channel is connected to the outlet of the first through channel. Near its inlet, the side wall of the middle section 202 has a conductive plate groove 2021 that communicates with the second through channel, and the conductive plate 21 is embedded in the conductive plate groove 2021. Near its outlet, the side wall of the middle section 202 has a laser injection hole 2022 that communicates with the second through channel, and the laser beam of the laser emitter 23 is injected into the second through channel through the laser injection hole 2022. The electromagnetic spin actuator 22 is sleeved on the side wall of the middle section 202 and located between the conductive plate groove 2021 and the laser injection hole 2022. The rear section 203 has a third through-channel distributed along its length, the inlet of which is connected to the outlet of the second through-channel. Multiple slots 2030 are located within the third through-channel from front to back along the direction of travel of the magnetic micro / nano particles. The collection component 3 can be fixed to any slot 2030. Since magnetic micro / nano particles of different morphologies have different aerodynamic characteristics in airflow, their flight trajectories vary depending on their morphology. By setting multiple slots 2030 within the third through-channel along the direction of travel of the magnetic micro / nano particles, the collection component 3 can be fixed to different slot positions, allowing magnetic micro / nano particles of different morphologies to be deposited at different slots, thus achieving graded collection of magnetic micro / nano particles of different shapes.

[0034] Preferred, such as Figure 2 , Figure 4 As shown, the conductive sheet 21 includes a conductive sheet body 211 and an aluminum foil 212 covering the conductive sheet body 211. Both the conductive sheet body 211 and the aluminum foil 212 are provided with through holes corresponding to the second through channel, and the aluminum foil 212 is grounded. The aperture size of the through hole determines the amount of magnetic micro / nano particles that can pass through. In practical use, the aperture size can be adjusted adaptively when opening the through hole according to requirements.

[0035] Preferred, such as Figure 5 , Figure 6As shown, the electromagnetic spin actuator 22 includes a first base 221 and four sets of coils 222. The first base 221 is sleeved on the outside of the middle section 202. The four sets of coils 222 are distributed in a cross structure on the first base 221. The tail ends of two diagonally opposite sets of coils 222 are interconnected to form a common neutral point and grounded. For two adjacent sets of coils 222, one set is connected to the single-phase AC power output of the frequency converter, and the other set is connected to the same power supply after the first end is connected across a phase-shifting capacitor, thereby forming a 90° two-phase phase difference to synthesize a rotating magnetic field on the outside of the middle section 202.

[0036] Preferably, the laser emitting element 23 includes a laser emitter 231, a beam splitter 232, and an energy meter 233. The beam splitter 232 is disposed on the output optical path of the laser emitter 231 and transmits the laser light into the second through-channel from the laser inlet hole 2022. The energy meter 233 is disposed on the reflected optical path of the beam splitter 232. It should be noted that in this embodiment, the laser emitter 231 and the beam splitter 232 are fixed directly above the laser inlet hole 2022 by an iron frame. A quartz plate is disposed at the inlet end of the laser inlet hole 2022 and is fixed to the laser inlet hole 2022 with glue to prevent the laser from directly hitting the reaction vessel 20 and causing damage to the reaction vessel 20.

[0037] Preferably, the collecting component 3 includes a support plate 31 and a collecting plate 32. The support plate 31 is inserted into any slot 2030; the collecting plate 32 is fixed to the support plate 31. The collecting plate 32 is made of silicon wafer and is used to collect C-shaped / ring-shaped / trilobal / dumbbell-shaped magnetic micro / nano particles in the third through-channel. The position of the collecting plate 32 can be adjusted by inserting the support plate 31 into slots 2030 at different positions to collect magnetic micro / nano particles with different morphologies. It should be noted that: in this embodiment, the support plate 31 can be inserted into any slot 2030 and is perpendicular to the third through-channel. The collecting plate 32 is fixed at an angle on the side of the support plate 31 near the middle section 202. The angle between the collecting plate 32 and the support plate 31 is in the range of 25°~45°, and is preferably 33° in this embodiment.

[0038] like Figure 3The purpose of having multiple slots 2030 along the direction of magnetic micro / nano particles traveling from front to back in the third through-channel shown is to allow the support plate 31 to be inserted into slots 2030 at different positions, thereby changing the actual position of the collecting plate 32 and collecting magnetic micro / nano particles of different morphologies. In this embodiment, the length of the third through-channel is 7.5 cm, and eight slots 2030 are arranged along the direction of magnetic micro / nano particles traveling, numbered first, second, third, fourth, fifth, sixth, seventh, and eighth, respectively. Inserting the support plate 31 into the third slot 2030 can collect annular magnetic micro / nano particles, inserting the support plate 31 into the fifth slot 2030 can collect dumbbell-shaped magnetic micro / nano particles, inserting the support plate 31 into the sixth slot 2030 can collect trilobal magnetic micro / nano particles, and inserting the support plate 31 into the eighth slot 2030 can collect C-shaped magnetic micro / nano particles.

[0039] Preferably, the preparation device further includes a gas washing component 4. A particle output hole 2120 is provided on the side wall of the front section 201. The gas washing component 4 has a cavity 40, which is connected to the particle output hole 2120. The cavity 40 is used to hold water. The particle output hole 2120 discharges the magnetic micro-nano particles that diverge in the first through channel into the water in the cavity 40. The diverging magnetic micro-nano particles are magnetic micro-nano particles whose running direction deviates from the channel direction of the first through channel.

[0040] Preferably, the gas scrubbing assembly 4 includes a second base 41 and a holding tank 42; the second base 41 has a cavity 410 inside, the second base 41 is sleeved on the front section 201, and the cavity 410 is connected to the particle output hole 2120; the holding tank 42 is opened on the second base 41 and is connected to the cavity 410 through a channel; the holding tank 42 is used to hold water and the water level is higher than the channel; the cavity 410 serves as a container 40 for collecting the dispersed magnetic micro-nano particles.

[0041] It should be noted that, due to the large quantity and omnidirectional dispersion of particles ejected by the powder pump 12, a particle output hole 2120 is opened on the front section 201. This allows the relatively dispersed magnetic micro / nano particles passing through the first through-channel to be discharged through the particle output hole 2120 and then collected in the cavity 410. These dispersed magnetic micro / nano particles are referred to as "excess particles," while the magnetic micro / nano particles passing through the first through-channel enter the second through-channel for further processing. If the particle output hole 2120 is not opened and the dispersed magnetic micro / nano particles are not treated by the gas scrubbing assembly 4, these "excess particles" will cause channel accumulation, interfere with the flow field, and contaminate the conductive sheet 21 and quartz sheet at the rear. Therefore, the gas scrubbing assembly 4 is used to collect these "excess particles" while simultaneously discharging them. The cavity 410 of the gas washing component 4 and the holding tank 42 form a multi-stage water seal. This design can effectively absorb particles splashed by the airflow, prevent back splashing pollution, and achieve green recycling, thereby ensuring stable reaction and long-term cleanliness of core components. The cavity 410 forms a buffer space for "excess particles", while the liquid level of the holding tanks 42 on both sides is higher than the channel to prevent dust from overflowing and polluting the air.

[0042] Example 2 A method for continuous fabrication of magnetic micro / nano structures, using the fabrication apparatus proposed in Example 1, includes the following steps: S1. Load the magnetic micro-nano particles into the powder bottle and fix them to the powder pump 12; add clean water to the two side holding tanks 42 of the gas washing component 4, and the liquid level should cover the channel; the conductive sheet 21 is wrapped with aluminum foil 212 and embedded in the middle section 202 conductive sheet groove 2021, and the aluminum foil 212 is reliably grounded; the quartz sheet is bonded and sealed to the laser injection hole 2022; the gas source component 11 is connected to the powder pump 12; complete the preheating and parameter preset of all functional components in advance in sequence: turn on the charging acceleration component 13 for preheating standby; start the electromagnetic spin driver 22 and the matching frequency converter, preset the rotating magnetic field frequency of 1Hz~50Hz, so that the four sets of coils 222 arranged in a cross shape inside the electromagnetic spin driver 22 can stably output a uniform rotating magnetic field; turn on the laser emitter 23, and the laser emitter 231, beam splitter 232 and energy meter 233 are simultaneously powered on and standby, and the energy meter 233 enters the real-time power monitoring state.

[0043] S2. Open the gas cylinder of the gas source component 11 and introduce a stable protective atmosphere into the entire reaction vessel 20. After the atmosphere fills the cavity and all external components of the equipment are operating stably, start the powder pump 12 to transport the powder. The high-voltage electrode of the charged acceleration component 13 forms a high-voltage ionization zone around the nozzle of the powder pump 12, ionizing the air to generate ions. When the magnetic micro-nano particles of the powder pass through, they capture the ions and become charged, forming electromagnetic micro-nano particles, which are continuously ejected from the nozzle into the front section 201 of the reaction vessel 20. After the electromagnetic micro-nano particles enter the middle section 202, they pass through the through-hole of the grounded conductive plate 21. The electric field acceleration is completed by the potential difference between the high-voltage ionization zone and the grounded conductive plate 21, which improves the flight speed and motion stability of the magnetic micro-nano particles.

[0044] S3. After the powder enters the front section 201, the excess magnetic micro-nano particles enter the gas washing component 4 cavity 40 through the particle output hole 2120 of the front section 201 and are intercepted by the aqueous solution. Only a quantitative amount of magnetic micro-nano particles are retained to enter the second through channel of the middle section 202. The electromagnetic micro-nano particles pass through the through hole of the grounded conductive sheet 21 and rely on the potential difference formed by the high voltage ionization region of the charged acceleration component 13 and the grounded aluminum foil 212 to complete the electric field acceleration, thereby improving the flight speed and motion stability of the magnetic micro-nano particles. The magnetic micro-nano particles are in the pre-started rotating magnetic field environment throughout the flight path, and continuously maintain a high-speed spin state.

[0045] S4. High-speed spinning magnetic micro / nanoparticles continuously pass through the laser injection hole 2022 corresponding to the irradiation area. The pre-started standby laser emitter 231 outputs laser light, which is then split by the beam splitter 232 and transmitted into the reaction vessel 20 cavity, continuously irradiating the high-speed rotating magnetic micro / nanoparticles. The laser energy causes the magnetic micro / nanoparticles to melt instantly. Under the action of centrifugal force, the molten magnetic micro / nanoparticles counteract the surface tension spheroidization tendency and undergo plastic deformation along the rotational stretching direction. The total laser irradiation time is controlled between 2 and 5 minutes. After the molten magnetic micro / nanoparticles leave the laser irradiation area, they cool naturally and solidify to form C-shaped / ring-shaped / trilobal / dumbbell-shaped micro / nano structures. The beam splitter 232 reflects the light path and connects to the energy meter 233. The energy meter 233 collects the laser output power in real time throughout the process and dynamically corrects the laser parameters according to the power fluctuations to ensure that the molten state of the magnetic micro / nanoparticles is stable and controllable.

[0046] S5. After deformation and cooling, the C-shaped / ring-shaped / trilobal / dumbbell-shaped magnetic micro / nano particles enter the third through-channel of the rear section 203 of the reaction vessel 20 and are deposited on the inclined collection plates 32 on the support plates 31 in different slots 2030. After the experiment, all equipment is shut down, and the collection plates 32 in different slots 2030 are taken out. Magnetic micro / nano particles of different sizes and morphologies are distinguished and collected according to the position of the slots 2030.

[0047] It should be noted that the final morphology of the molten magnetic micro / nanoparticles is closely related to the frequency of the rotating magnetic field and the laser power. When the magnetic field frequency is low, i.e., 1Hz to 10Hz, the centrifugal force on the magnetic micro / nanoparticles is moderate, and the molten magnetic micro / nanoparticles extend uniformly during rotation, forming a ring structure. When the frequency increases to 10Hz to 35Hz, the centrifugal force increases, and the magnetic micro / nanoparticles are stretched along the direction of rotation, forming dumbbell-shaped or C-shaped structures. When the frequency is further increased to 30Hz to 50Hz and the laser power is high, the magnetic micro / nanoparticles form a trilobal structure under the action of forces in multiple directions. After the magnetic micro / nanoparticles are removed from the laser irradiation area, they cool rapidly, and their morphology is fixed.

[0048] Application Example 1 Using the preparation apparatus proposed in Example 1 and the preparation method proposed in Example 2, the following preparation was prepared: Figure 9 , Figure 10 The ring-shaped Fe2O3 magnetic micro / nano particles shown specifically include the following steps: The α-Fe2O3 nanopowder is loaded into the powder bottle that is matched with the powder pump 12, and the support plate 31 is inserted into the third slot 2030.

[0049] Turn on the charging acceleration component 13, set the working high voltage to 65kV, and the high voltage electrode forms a stable high voltage ionization region around the nozzle of the powder pump 12; start the electromagnetic spin driver 22 and its matching frequency converter, preset the output frequency range to 1Hz~10Hz, and the four sets of cross-shaped coils 222 generate a stable rotating magnetic field with a 90° phase difference; turn on the laser emitter 23, and the laser emitter 231, beam splitter 232, and energy meter 233 are powered on synchronously, and the energy meter 233 enters the real-time laser power monitoring mode; preset laser parameters: wavelength 355nm unfocused pulsed laser, single pulse energy 135mJ / pulse・cm², irradiation time is 3min.

[0050] Open the gas cylinder 11 and introduce a high-purity argon / nitrogen inert protective atmosphere into the reaction vessel 20, continuously purging and replacing the air inside the cavity. Once the atmosphere is stable and the charged acceleration component 13, magnetic field, and laser monitoring are all operating smoothly, start the powder pump 12 to deliver the powder. The powder passes through the high-voltage ionization region of the charged acceleration component 13 around the nozzle of the powder pump 12, capturing air ions to form electromagnetic micro-nano particles, which are continuously sprayed into the first through-channel 201 at the front of the reaction vessel 20.

[0051] After the powder enters the front section 201, the excess α-Fe2O3 magnetic micro-nano particles are discharged into the clean water in the gas washing component 4 cavity 40 through the particle output hole 2120 and retained. Only a quantitative amount of magnetic micro-nano particles are retained to enter the second through channel of the middle section 202. The electromagnetic micro-nano particles pass through the through hole of the grounded conductive sheet 21 and are accelerated by the electric field by the potential difference between the high voltage ionization region of the charged acceleration component 13 and the grounded aluminum foil 212, which increases the flight speed of the magnetic micro-nano particles. The magnetic micro-nano particles are in the rotating magnetic field formed by the electromagnetic spin actuator 22 throughout the process, continuously spin at high speed, and have a stable centrifugal deformation driving force.

[0052] High-speed spinning α-Fe₂O₃ magnetic micro / nanoparticles travel to the irradiation area of ​​the laser entry hole 2022. The laser emitter 231 outputs a preset 355nm pulsed laser. The beam is split by the beam splitter 232, with 95% of the transmitted light entering the second through-channel to continuously irradiate the magnetic micro / nanoparticles, and the 5% reflected light being guided to the energy meter 233 to monitor the output energy in real time. The total laser irradiation time is controlled to be 3 minutes. The laser energy causes the α-Fe₂O₃ magnetic micro / nanoparticles to rapidly heat up to complete melting. Under the centrifugal force generated by their own high-speed rotation, the molten magnetic micro / nanoparticles counteract the surface tension spheroidization effect and undergo plastic tensile deformation along the rotation direction. After leaving the laser irradiation area, the magnetic micro / nanoparticles naturally cool and solidify in an inert atmosphere, forming a ring-shaped micro / nano structure.

[0053] After deformation and cooling, the α-Fe2O3 magnetic micro-nano particles enter the third through-channel of the rear section 203 of the reaction vessel 20 and are deposited on the surface of the silicon collection plates 32, which are tilted and installed in different slots 2030. After the entire preparation process is completed, the laser, magnetic field, high-voltage electrode, powder pump and gas source are turned off in sequence, the detachable end cap of the rear section 203 is removed, and the collection plates 32 at different positions are taken out to achieve the hierarchical collection of the annular α-Fe2O3 magnetic micro-nano particles.

[0054] The silicon wafer collection plate 32 with α-Fe2O3 magnetic micro / nano particles attached was directly fed into a scanning electron microscope for morphological observation. The original α-Fe2O3 raw material, such as... Figure 8 As shown, the SEM image of the α-Fe2O3 magnetic micro / nanoparticles prepared in this application example is as follows. Figure 9 , Figure 10 As shown, the specific shape of the α-Fe2O3 magnetic micro / nanoparticles is ring-shaped.

[0055] Application Example 2 Using the preparation apparatus proposed in Example 1 and the preparation method proposed in Example 2, the following preparation was prepared: Figure 11 The dumbbell-shaped Fe2O3 magnetic micro / nano particles shown are different from those in Application Example 1 in that the preset output frequency range is 10Hz to 35Hz, and the support plate 31 is inserted into the fifth slot 2030.

[0056] Application Example 3 Using the preparation apparatus proposed in Example 1 and the preparation method proposed in Example 2, the following preparation was prepared: Figure 12 The trilobed Fe2O3 magnetic micro / nano particles shown are different from those in Application Example 1 in that the preset output frequency range is 30Hz to 50Hz, and the support plate 31 is inserted into the sixth slot 2030.

[0057] Application Example 4 Using the preparation apparatus proposed in Example 1 and the preparation method proposed in Example 2, the following preparation was prepared: Figure 13 The C-shaped Fe2O3 magnetic micro / nano particles shown are different from those in Application Example 1 in that: the working high voltage is set to 80kV, the preset output frequency range is 10Hz~35Hz, and the support plate 31 is inserted into the eighth slot 2030.

[0058] The specific models of the above electronic components are not specifically specified; any commercially available ordinary products can be selected, as long as they can meet the usage requirements of this invention.

[0059] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and do not limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the protection scope of the present invention.

Claims

1. A continuous fabrication apparatus for magnetic micro / nano structures, characterized in that, include: The particle emission assembly includes a gas source, a powder pump, and a charged acceleration assembly. The gas source is connected to the air inlet of the powder pump through a pipeline. The charged acceleration assembly includes a high-voltage electrode disposed around the nozzle of the powder pump. The high-voltage electrode forms a high-voltage ionization region at the nozzle, which is used to charge the magnetic micro-nano particles ejected by the powder pump when they pass through. The reaction assembly includes a reaction vessel, a conductive sheet, an electromagnetic spin actuator, and a laser emitter. The front end of the reaction vessel is positioned opposite the nozzle of the powder pump. The conductive sheet and the electromagnetic spin actuator are sequentially arranged on the reaction vessel along the flight path of the magnetic micro / nano particles. The conductive sheet is grounded and forms a potential difference with the high-voltage ionization region to accelerate the charged magnetic micro / nano particles using an electric field. The electromagnetic spin actuator generates a rotating magnetic field to drive the magnetic micro / nano particles to rotate. The laser emitter is fixed to the outside of the reaction vessel, and its laser beam path is aligned with the flight path of the magnetic micro / nano particles downstream of the electromagnetic spin actuator. The collection component, located at the rear end of the reaction vessel, is used to collect the magnetic micro / nano particles deformed by laser irradiation.

2. The continuous fabrication apparatus for magnetic micro / nano structures as described in claim 1, characterized in that, The reaction vessel, along the direction of travel of the magnetic micro / nano particles, comprises a front section, a middle section, and a rear section connected in series from front to back. The front section has a first through channel distributed along the length direction, and the inlet of the first through channel is set opposite to the nozzle of the powder pump as the front end of the reaction vessel. The middle section has a second through channel distributed along its length, the inlet of the second through channel being connected to the outlet of the first through channel; the side wall of the middle section near its inlet has a conductive plate groove connected to the second through channel, the conductive plate being embedded in the conductive plate groove; the side wall of the middle section near its outlet has a laser injection hole connected to the second through channel, the laser beam of the laser emitting element being injected into the second through channel through the laser injection hole; the electromagnetic spin actuator is sleeved on the side wall of the middle section and located between the conductive plate groove and the laser injection hole; The rear section has a third through channel distributed along its length, the inlet of the third through channel being connected to the outlet of the second through channel; the third through channel has multiple slots from front to back along the direction of travel of the magnetic micro-nano particles, and the collection component is fixed in any of the slots.

3. The continuous fabrication apparatus for magnetic micro / nano structures as described in claim 2, characterized in that, The conductive sheet includes a conductive sheet body and an aluminum foil covering the conductive sheet body. Both the conductive sheet body and the aluminum foil are provided with through holes corresponding to the second through channel, and the aluminum foil is grounded.

4. The continuous fabrication apparatus for magnetic micro / nano structures as described in claim 2, characterized in that, The electromagnetic spin actuator includes: The first base is fitted onto the outer side of the middle section; Four sets of coils are arranged in a cross shape on the first base; the two sets of coils in opposite positions are connected in sequence and then connected to the frequency converter through wires. The frequency converter is connected to an external power supply, and the external power supply is used to supply power to the coils through the frequency converter.

5. The continuous fabrication apparatus for magnetic micro / nano structures as described in claim 2, characterized in that, The laser emitting device includes a laser emitter, a beam splitter, and an energy meter. The beam splitter is disposed on the output optical path of the laser emitter and transmits the laser light into the second through-channel through which it enters from the laser injection hole. The energy meter is disposed on the reflected optical path of the beam splitter.

6. The continuous fabrication apparatus for magnetic micro / nano structures as described in claim 2, characterized in that, The collection component includes: The support piece is inserted into any of the slots; The collecting plate, fixed on the support plate, is made of silicon and is used to collect C-shaped / ring / trefoil / dumbbell-shaped magnetic micro / nano particles in the third through-channel.

7. The continuous fabrication apparatus for magnetic micro / nano structures as described in claim 2, characterized in that, It also includes a scrubbing assembly, on which a particle output hole is provided on the side wall of the front section. The scrubbing assembly has a cavity that is connected to the particle output hole. The cavity is used to hold water. The particle output hole discharges the magnetic micro-nano particles that diverge in the first through-channel into the water in the cavity. The diverging magnetic micro-nano particles are magnetic micro-nano particles whose running direction deviates from the channel direction of the first through-channel.

8. The continuous fabrication apparatus for magnetic micro / nano structures as described in claim 7, characterized in that, The air scrubbing assembly includes: The second base has a cavity inside and is fitted onto the front section. The cavity is connected to the particle output hole. A holding tank is formed on the second base and is connected to the cavity through a channel; the holding tank serves as a container for holding water.

9. A method for continuous fabrication of magnetic micro / nano structures, characterized in that, Includes the following steps: Magnetic micro / nano particles are emitted, causing them to carry an electric charge after passing through a high-voltage ionization region; The charged magnetic micro- and nano-particles are accelerated by an electric field using a potential difference and driven to rotate by a rotating magnetic field. Magnetic micro- and nano-particles in a rotating state are irradiated with lasers to melt them. The molten magnetic micro- and nano-particles then deform under the action of centrifugal force to overcome surface tension, resulting in deformed magnetic micro- and nano-particles, which are then collected.

10. The continuous fabrication method of a magnetic micro / nano structure as described in claim 9, characterized in that, The laser irradiation time is 2 min to 5 min.

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