Graphene oxide flow stripping and closed-loop regulation and control system and method driven by ultrasonic phased array

Abstract

The invention discloses an ultrasonic phased array driven graphene oxide flow stripping and closed-loop regulation and control system and method, and the system comprises an ultrasonic phased array module, and a piezoelectric transducer array element in the ultrasonic phased array module controls sound beam focusing and energy distribution through a phase delay controller, and carries out the stripping of graphite oxide flowing in a flow channel; a micro-Raman spectrometer in the micro-fluidic-Raman detection module collects characteristic peak data of a graphene oxide sheet layer in a micro-fluidic chip in real time and sends the characteristic peak data to a signal analysis unit; and the feedback control module is used for receiving the layer number distribution data output by the signal analysis unit, dynamically adjusting ultrasonic parameters of the phase delay controller, and controlling the diverter valve to guide substandard products into a secondary treatment channel and finally return the substandard products to the flow channel for stripping again. The system and the method for stripping the graphene oxide based on coupling of the ultrasonic phased array and the micro-fluidic chip have the advantages of efficient stripping, accurate detection, closed-loop optimization and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of material preparation and detection, and in particular to a graphene oxide flow exfoliation and closed-loop control system and method driven by an ultrasonic phased array. Background Art

[0002] Efficient exfoliation of graphene oxide and precise layer control are key processes for preparing high-quality graphene-based materials. Traditional exfoliation technologies mainly rely on mechanical shearing, chemical intercalation or ultrasonic cavitation effects, among which the ultrasonic method is widely used due to its simple operation and low cost. However, the existing ultrasonic exfoliation process has technical bottlenecks such as thermal damage, detection lag, and inefficient sorting: when conventional ultrasonic probes generate high-intensity sound fields in liquids, they are prone to cause local overheating (thermal aggregation effect), leading to oxidation of graphene sheets or structural defects. At the same time, the static batch processing mode is difficult to achieve continuous production, and the ultrasonic energy distribution is uneven, making it difficult to balance exfoliation efficiency and product uniformity. Current layer number detection mainly relies on atomic force microscopy (AFM), transmission electron microscopy (TEM) or offline Raman spectroscopy, which requires interrupting the production process for sampling, drying and fixation. This type of offline detection cannot provide real-time feedback on the layer number distribution, resulting in delayed adjustment of process parameters and difficulty in dynamically optimizing the exfoliation process. Traditional processes lack an effective sorting mechanism for incompletely exfoliated multilayer graphene, and usually require post-processing by centrifugation or filtration. However, such methods have problems such as large yield loss and high energy consumption, and cannot achieve in-situ re-exfoliation.

[0003] Currently, patent number CN117949428A discloses a technology that uses microfluidic chips and Raman detection technology for multi-factor SERS detection of lung cancer autoantibodies, while ultrasonic phased arrays are mainly used in cleaning (CN119793986A) and detection (CN119846067A) and other fields, and are less used in graphene oxide exfoliation.

[0004] The present invention integrates ultrasonic phased array multi-focus scanning technology, microfluidic-Raman in-situ detection technology and closed-loop feedback control algorithm to construct an integrated "stripping-detection-reprocessing" system, overcoming the problems of thermal aggregation, detection lag and inefficient sorting in traditional processes, and providing innovative technical support for the continuous preparation of highly consistent graphene. Summary of the Invention

[0005] In view of the above-mentioned shortcomings, the present invention provides an ultrasonic phased array-driven graphene oxide flow exfoliation and closed-loop control system and method. The ultrasonic phased array-driven graphene oxide flow exfoliation and closed-loop control system and method of the present invention have the advantages of efficient exfoliation, precise detection, closed-loop optimization, etc.

[0006] In order to achieve the above-mentioned object, the present invention provides an ultrasonic phased array driven graphene oxide flow exfoliation and closed-loop control system, comprising an ultrasonic phased array module, a microfluidic-Raman detection module and a feedback control module, a flow channel, a diverter valve, and a secondary processing channel;

[0007] An ultrasonic phased array module includes a piezoelectric transducer array element and a phase delay controller; a graphite oxide dispersion is built into the flow channel; the piezoelectric transducer array element controls the focusing and energy distribution of the acoustic beam through the phase delay controller and exfoliates the graphite oxide flowing in the flow channel;

[0008] A microfluidic-Raman detection module comprises a microfluidic chip, a Raman spectrometer, and a signal analysis unit; the microfluidic chip is provided with a serpentine sorting channel, and the microfluidic chip is provided with a detection window; the optical path of the Raman spectrometer is aligned with the detection window; the Raman spectrometer collects characteristic peak data of the graphene oxide layer in the serpentine sorting channel in real time and sends it to the signal analysis unit; wherein the flow channel is connected to the serpentine sorting channel of the microfluidic chip;

[0009] A feedback control module receives the layer distribution data output by the signal analysis unit, dynamically adjusts the ultrasonic parameters of the phase delay controller, and controls the diverter valve to direct substandard products into the secondary processing channel and finally return them to the flow channel for re-stripping; wherein one end of the secondary processing channel is connected to the diverter valve, and the other end is connected to the flow channel.

[0010] It should be noted that the function of the flow channel of the present invention is to allow the dispersion containing graphite oxide to flow, thereby taking away heat and preventing the heat accumulation effect during the stripping process.

[0011] It should be noted that the serpentine sorting channel of the microfluidic chip of the present application provides a laminar flow effect to guide the graphene sheets to pass through the laser focusing area in a directional manner, collect Raman signals in real time and invert the layer number distribution.

[0012] It should be noted that the microfluidic-Raman detection module of this application is a sampling module, while the flow channel + ultrasonic phased array module is a production module. When the microfluidic-Raman detection module detects that the batch of products is qualified, the batch of products is discharged from the outlet through the diverter valve. When the microfluidic-Raman detection module detects that the batch of products is unqualified, the batch of products enters the secondary processing channel through the diverter valve and then re-enters the flow channel. At the same time, the piezoelectric transducer array elements are adjusted to change the number of focal spots and pulse width for re-stripping.

[0013] Based on the same inventive concept, the present invention also provides a method for graphene oxide flow exfoliation and closed-loop control based on an ultrasonic phased array driven graphene oxide flow exfoliation and closed-loop control system, comprising the following steps:

[0014] S1. Injecting a graphite oxide dispersion into a flow channel, and starting an ultrasonic phased array module to apply shear force to the graphite oxide flowing in the flow channel for exfoliation, thereby obtaining an exfoliated dispersion;

[0015] S2, the dispersion after stripping flows into the microfluidic chip, forming a laminar flow in the serpentine sorting channel, and the characteristic peak data of the Raman spectrometer is collected through the detection window to collect the G peak and 2D peak intensity ratio of the graphene oxide sheet; the signal analysis unit calculates the layer number distribution based on the G peak and 2D peak intensity ratio of the graphene oxide sheet;

[0016] S3. The feedback control module outputs qualified products or re-introduces unqualified products into the flow channel according to the single-layer rate of the layer distribution.

[0017] According to one aspect of the present invention, the piezoelectric transducer array element controls the focusing of the acoustic beam through the phase delay controller to perform multi-focus acoustic field shear force exfoliation of graphite oxide.

[0018] According to one aspect of the present invention, if the single-layer rate of the layer distribution is lower than the threshold, the number of focal points or pulse width of the phase delay controller is adjusted, and the diverter valve is opened to re-introduce the substandard products into the flow channel; otherwise, the qualified products are output from the outlet.

[0019] According to one aspect of the present invention, the piezoelectric transducer array element is matched with the flow channel; the number of the piezoelectric transducer array elements is multiple, the element spacing is 0.01-200mm, the operating frequency is 0.01-100MHz, and the sound pressure amplitude is 0.01-100MPa; the inner diameter of the flow channel is 0.5-200mm, and the length is 0.01-20m.

[0020] According to one aspect of the present invention, the array element spacing is 0.5-2 mm, the operating frequency is 0.1-3 MHz, and the sound pressure amplitude is 0.5-10 MPa; the inner diameter of the flow channel is 5-20 mm, and the length is 0.5-2 m.

[0021] According to one aspect of the present invention, the width of the serpentine sorting channel of the microfluidic chip is 0.1-2000 μm.

[0022] According to one aspect of the present invention, the width of the serpentine sorting channel of the microfluidic chip is 50-200 μm.

[0023] According to one aspect of the present invention, the surface of the detection window is coated with an anti-reflection film, and the laser focus spot diameter of the Raman spectrometer is ≤5 μm.

[0024] According to one aspect of the present invention, the feedback control module adopts a fuzzy proportional-integral-differential control algorithm to calculate the ultrasonic energy adjustment amount in real time according to the single layer rate deviation value, and its control period is ≤1s.

[0025] According to one aspect of the present invention, the threshold of the monolayer rate is 85%. When it is detected that the monolayer rate is lower than the threshold, the number of focal points of the ultrasonic phased array module is increased by 10%-80%, and the pulse width is shortened to 20%-80% of the initial pulse width, and the initial pulse width is 20-100 μs.

[0026] Beneficial effects of the present invention:

[0027] The present invention uses the dynamic phase delay of the multi-element transducer array of an ultrasonic phased array module to control the acoustic beam focus and energy distribution, combined with flow channels to achieve efficient and uniform exfoliation of graphene sheets. A Raman spectroscopy detection window is integrated within the microfluidic chip, leveraging the laminar flow effect to guide the graphene sheets through the laser focus area. Raman signals (G peak to 2D peak intensity ratio, peak shift) are collected in real time and the layer distribution is inverted. Ultrasonic parameters (frequency, number of focal spots, pulse width) are dynamically adjusted based on the detection results, and a diverter valve is used to direct substandard products back to the secondary ultrasonic enhancement zone for cyclic processing. This approach achieves efficient exfoliation, precise detection, and closed-loop optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of the structure of the ultrasonic phased array driven graphene oxide flow exfoliation and closed-loop control system of the present invention;

[0029] Figure 2 Schematic diagram of the flow chart of the ultrasonic phased array driven graphene oxide flow exfoliation and closed-loop control method of the present invention;

[0030] Description of reference numerals:

[0031] 100. Ultrasonic phased array module; 101. Piezoelectric transducer array element; 102. Phase delay controller; 200. Microfluidic-Raman detection module; 201. Raman spectrometer; 202. Signal analysis unit; 300. Feedback control module; 400. Flow channel; 500. Diverter valve; 600. Secondary processing channel; 601. Outlet; 700. Microfluidic chip; 701. Serpentine sorting channel; 702. Detection window. DETAILED DESCRIPTION

[0032] To make the present invention easier to understand, the present invention is further described below with reference to specific examples. It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Unless otherwise defined, the professional terms used below are consistent with the meanings understood by professional and technical personnel in this field; unless otherwise specified, the raw materials and reagents involved in this article can be purchased from the market or prepared by known methods.

[0033] It should be noted that the function of the serpentine sorting channel of the present application is to achieve a laminar flow effect so as to guide the graphene sheets to pass through the laser focusing area in a directional manner, collect Raman signals in real time and invert the layer number distribution. Therefore, only the broadband of the serpentine sorting channel is limited, and there are no special requirements for other characteristics of the serpentine sorting channel, as long as the above-mentioned functions of the present invention are met.

[0034] In order to solve the problems of thermal aggregation effect, layer number detection hysteresis and inability to dynamically sort defective products in the existing graphene oxide exfoliation process, the inventors provide an ultrasonic phased array driven graphene oxide flow exfoliation and closed-loop control system, such as Figure 1 As shown, it includes an ultrasonic phased array module 100, a microfluidic-Raman detection module 200 and a feedback control module 300, a flow channel 400, a diverter valve 500, a secondary processing channel 600, one end of the serpentine sorting channel 701 is connected to the flow channel 400, and the other end is connected to the secondary processing channel 600; one end of the secondary processing channel 600 is connected to the serpentine sorting channel 701, and the other end is connected to the flow channel 401; wherein,

[0035] The ultrasonic phased array module 100 includes a piezoelectric transducer element 101 and a phase delay controller 102. The flow channel 400 contains a graphite oxide dispersion. The piezoelectric transducer element 101 controls the focusing and energy distribution of the acoustic beam through the phase delay controller 102 and exfoliates the graphite oxide flowing in the flow channel 400.

[0036] The microfluidic-Raman detection module 200 includes a microfluidic chip 700, a Raman spectrometer 201, and a signal analysis unit 202. The microfluidic chip 700 is provided with a serpentine sorting channel 701. The microfluidic chip 700 is provided with a detection window 702. The optical path of the Raman spectrometer 202 is aligned with the detection window 702. The Raman spectrometer 202 collects characteristic peak data of the graphene oxide sheets in the serpentine sorting channel 701 in real time and transmits it to the signal analysis unit. The flow channel 400 is connected to the serpentine sorting channel 701.

[0037] The feedback control module 300 receives the layer distribution data output by the signal analysis unit 202, dynamically adjusts the ultrasonic parameters of the phase delay controller 102, and controls the diverter valve 500 to introduce the substandard products into the secondary processing channel 600 and finally return them to the flow channel for re-stripping; wherein, one end of the secondary processing channel 600 is connected to the diverter valve 500, and the other end is connected to the flow channel 400.

[0038] Based on the same inventive concept, the present invention also provides a method for graphene oxide flow exfoliation and closed-loop control based on a graphene oxide flow exfoliation and closed-loop control system driven by an ultrasonic phased array, such as Figure 1-2 As shown, the following steps are included:

[0039] S1. Injecting a graphite oxide dispersion into the flow channel 400, and starting the ultrasonic phased array module 100 to apply shear force to the graphite oxide flowing in the flow channel 400 to exfoliate the graphite oxide, thereby obtaining an exfoliated dispersion. Preferably, the piezoelectric transducer array element 101 matches the flow channel 400. The number of the piezoelectric transducer array elements 101 is multiple, the array element spacing is 0.01-200 mm, the operating frequency is 0.01-100 MHz, the inner diameter of the flow channel 400 is 0.5-200 mm, and the length is 0.01-20 m. More preferably, the array element spacing is 0.5-2 mm, the operating frequency is 0.1-3 MHz, and the inner diameter of the flow channel 400 is 5-20 mm, and the length is 0.5-2 m.

[0040] S2. The stripped dispersion flows into the microfluidic chip 700, forming a laminar flow in the serpentine sorting channel 701. The characteristic peak data of the Raman spectrometer 201 is collected through the detection window 702 to collect the G peak and 2D peak intensity ratio of the graphene oxide sheet; the signal analysis unit 202 calculates the layer number distribution based on the G peak and 2D peak intensity ratio of the graphene oxide sheet; preferably, the width of the serpentine sorting channel 701 of the microfluidic chip 700 is 0.1-2000 μm; more preferably, the width of the serpentine sorting channel 701 of the microfluidic chip 700 is 50-200 μm. The surface of the detection window 702 is coated with an anti-reflection film, and the laser focus spot diameter of the Raman spectrometer is ≤5 μm.

[0041] S3. The feedback control module 300 outputs the qualified product to the outlet 601 or redirects the substandard product to the flow channel 400 based on the monolayer rate of the layer distribution. Preferably, if the monolayer rate of the layer distribution is lower than the threshold, the number of focal points or pulse width of the phase delay controller 102 is adjusted, and the diverter valve 500 is opened to redirect the substandard product to the flow channel 400. Otherwise, the monolayer rate of the layer distribution is output and the product is collected at the product outlet. Preferably, the feedback control module 300 uses a fuzzy proportional-integral-differential control algorithm to calculate the ultrasonic energy adjustment amount in real time based on the monolayer rate deviation value, and its control period is ≤1s. The threshold value of the monolayer rate is 85%. When the monolayer rate is detected to be lower than the threshold, the number of focal points of the ultrasonic phased array module is increased by 10%-80%, and the pulse width is shortened to 20%-80% of the initial pulse width, and the initial pulse width is 20-100μs. Preferably, the initial pulse width is 320-60μs.

[0042] In a specific embodiment, the method for preparing the graphite oxide dispersion comprises the following steps:

[0043] Raw material pretreatment: Graphite flakes are crushed in a ball mill to a particle size of 20-50 μm and then graded using a vibrating screen. Graphite powder is then obtained by soaking in a mixture of hydrochloric acid and hydrofluoric acid (3:1 by volume) to remove metallic impurities.

[0044] Preparation of graphite oxide dispersion: First, place the above-mentioned graphite powder, concentrated sulfuric acid (98%), and sodium nitrate in a mass ratio of 1:20-50:0.5 into a corrosion-resistant reactor. Slowly add potassium permanganate (the mass ratio of potassium permanganate to the total mass of graphite powder, concentrated sulfuric acid, and sodium nitrate is 1:3-6) at a temperature controlled at 0-5°C. Mechanically stir for 4-6 hours. Then, raise the temperature to 35-40°C and continue the reaction for 12-18 hours until the system turns brown. Finally, add water in a gradient (≤5mL / min) and raise the temperature to 90-95°C, maintaining it for 2-3 hours.

[0045] The following is further described with reference to specific embodiments and comparative examples.

[0046] Example 1

[0047] A method for graphene oxide flow exfoliation and closed-loop control based on a graphene oxide flow exfoliation and closed-loop control system driven by an ultrasonic phased array comprises the following steps:

[0048] (1) Raw material pretreatment: Graphite flakes were crushed to a particle size of 30 μm using a ball mill and classified using a vibrating screen. Graphite powder was then obtained by soaking in a mixture of hydrochloric acid and hydrofluoric acid (volume ratio 3:1) to remove metallic impurities.

[0049] (2) Preparation of graphite oxide dispersion: First, the above-mentioned graphite powder, concentrated sulfuric acid (98%), and sodium nitrate (mass ratio of 1:35:0.5) were placed in a corrosion-resistant reactor. Potassium permanganate (the mass ratio of potassium permanganate to the total mass of graphite powder, concentrated sulfuric acid, and sodium nitrate was 1:4) was slowly added at 0°C and mechanically stirred for 4 hours. Then, the temperature was raised to 35°C and the reaction was continued for 15 hours until the system turned brown. Finally, water was added gradually (3 mL / min) and the temperature was raised to 90°C and maintained for 3 hours to obtain.

[0050] (3) Injecting a graphite oxide dispersion into the flow channel 400, starting the ultrasonic phased array module 100 to apply shear force to the graphite oxide flowing in the flow channel 400 for exfoliation, and obtaining an exfoliated dispersion; wherein the piezoelectric transducer array element 101 is matched with the flow channel 400; the number of the piezoelectric transducer array elements 101 is 17, the array element spacing is 100 mm, the operating frequency is 2 MHz, and the sound field amplitude is 6 MPa; the inner diameter of the flow channel 400 is 20 mm, and the length is 0.5 m.

[0051] (4) The stripped dispersion flows into the microfluidic chip 700, forming a laminar flow in the serpentine sorting channel 701, and the characteristic peak data of the Raman spectrometer 201 is collected through the detection window 702, and the G peak to 2D peak intensity ratio of the graphene oxide sheet is 2.8; the signal analysis unit 202 calculates the mass ratio percentage of the single-layer graphene oxide to the graphene oxide sheet based on the G peak to 2D peak intensity ratio of the graphene oxide sheet, which is 95%.

[0052] (5) The feedback control module 300 outputs the qualified single-layer graphene oxide at the outlet 601 according to the result of the layer number distribution data.

[0053] Example 2

[0054] The difference between this embodiment and embodiment 1 is that the operating frequency of step (3) is 1 MHz and the acoustic field amplitude is 6 MPa. The other steps and parameters are the same as those in embodiment 1. The final output of the single-layer graphene oxide accounts for 80%.

[0055] Example 3

[0056] The difference between this embodiment and embodiment 1 is that the operating frequency of step (3) is 3 MHz and the acoustic field amplitude is 6 MPa. The other steps and parameters are the same as those in embodiment 1. The final output of the single-layer graphene oxide accounts for 90%.

[0057] Example 4

[0058] The difference between this embodiment and embodiment 1 is that the operating frequency of step (3) is 2 MHz and the acoustic field amplitude is 4 MPa. The other steps and parameters are the same as those in embodiment 1. The final output of the single-layer graphene oxide accounts for 83%.

[0059] Example 5

[0060] The difference between this embodiment and embodiment 1 is that the operating frequency of step (3) is 2 MHz and the acoustic field amplitude is 9 MPa. The other steps and parameters are the same as those in embodiment 1. The final output of the single-layer graphene oxide accounts for 89%.

[0061] Comparative Example 1

[0062] The difference between this comparative example and Example 1 is that steps (3) to (5) are different, specifically:

[0063] (3) The graphene oxide dispersion was placed in a high-pressure homogenizer and circulated 6 times at 160 MPa, followed by ultrasonic treatment at a frequency of 1 MHz for 5 hours to exfoliate the graphene oxide.

[0064] (4) None.

[0065] (5) None.

[0066] The graphene oxide sheets obtained above were detected by Raman spectroscopy, and the mass ratio of the monolayer graphene oxide to the graphene oxide sheets was deduced to be 56%.

[0067] Comparative Example 2

[0068] The difference between this comparative example and comparative example 1 is that steps (3) to (5) are different, specifically:

[0069] (3) The ultrasonic phased array module of the present application is used to perform flow stripping on the graphite oxide in the flow channel, wherein the piezoelectric transducer array element 101 is matched with the flow channel 400; the number of the piezoelectric transducer array elements 101 is 17, the array element spacing is 100 mm, the operating frequency is 3 MHz, and the sound field amplitude is 6 MPa; the inner diameter of the flow channel 400 is 20 mm and the length is 0.5 m.

[0070] (4) None.

[0071] (5) None.

[0072] The graphene oxide sheets obtained above were detected by Raman spectroscopy, and the mass ratio of the monolayer graphene oxide to the graphene oxide sheets was deduced to be 82%.

[0073] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. An ultrasonic phased array driven graphene oxide flow exfoliation and closed-loop control system, characterized in that: It includes ultrasonic phased array module, microfluidics-Raman detection module and feedback control module, flow channel, diverter valve and secondary processing channel; An ultrasonic phased array module includes a piezoelectric transducer array element and a phase delay controller; a graphite oxide dispersion is built into the flow channel; the piezoelectric transducer array element controls the focusing and energy distribution of the acoustic beam through the phase delay controller and exfoliates the graphite oxide flowing in the flow channel; A microfluidic-Raman detection module comprises a microfluidic chip, a Raman spectrometer, and a signal analysis unit; the microfluidic chip is provided with a serpentine sorting channel, and the microfluidic chip is provided with a detection window; the optical path of the Raman spectrometer is aligned with the detection window; the Raman spectrometer collects characteristic peak data of the graphene oxide layer in the serpentine sorting channel in real time and sends it to the signal analysis unit; wherein the flow channel is connected to the serpentine sorting channel of the microfluidic chip; A feedback control module receives the layer distribution data output by the signal analysis unit, dynamically adjusts the ultrasonic parameters of the phase delay controller, and controls the diverter valve to direct substandard products into the secondary processing channel and finally return them to the flow channel for re-stripping; wherein one end of the secondary processing channel is connected to the diverter valve, and the other end is connected to the flow channel.

2. The method for graphene oxide flow exfoliation and closed-loop control based on the graphene oxide flow exfoliation and closed-loop control system driven by ultrasonic phased array according to claim 1 is characterized in that: The following steps are involved: S1. Injecting a graphite oxide dispersion into a flow channel, and starting an ultrasonic phased array module to apply shear force to the graphite oxide flowing in the flow channel for exfoliation, thereby obtaining an exfoliated dispersion; S2, the dispersion after stripping flows into the microfluidic chip, forming a laminar flow in the serpentine sorting channel, and the characteristic peak data of the Raman spectrometer is collected through the detection window to collect the G peak and 2D peak intensity ratio of the graphene oxide sheet; the signal analysis unit calculates the layer number distribution based on the G peak and 2D peak intensity ratio of the graphene oxide sheet; S3. The feedback control module outputs qualified products or re-introduces unqualified products into the flow channel according to the single-layer rate of the layer distribution.

3. The method for flow exfoliation and closed-loop control of graphene oxide according to claim 2, characterized in that: The piezoelectric transducer array element controls the focusing of the acoustic beam through the phase delay controller to perform multi-focus acoustic field shear force exfoliation of graphite oxide.

4. The method for flow exfoliation and closed-loop control of graphene oxide according to claim 2, characterized in that: If the single layer rate of the layer distribution is lower than the threshold, the number of focal points or the pulse width of the phase delay controller is adjusted, and the diverter valve is opened to re-introduce the substandard products into the flow channel; otherwise, the qualified products are output from the outlet.

5. The method for flow exfoliation and closed-loop control of graphene oxide according to claim 2, characterized in that: The piezoelectric transducer array element is matched with the flow channel; the number of the piezoelectric transducer array elements is multiple, the array element spacing is 0.01-200mm, the operating frequency is 0.01-100MHz, and the sound pressure amplitude is 0.01-100MPa; the inner diameter of the flow channel is 0.5-200mm, and the length is 0.01-20m.

6. The method for flow exfoliation and closed-loop control of graphene oxide according to claim 2, characterized in that: The width of the serpentine sorting channel of the microfluidic chip is 0.1-2000 μm.

7. The method for flow exfoliation and closed-loop control of graphene oxide according to claim 2, characterized in that: The surface of the detection window is coated with an anti-reflection film, and the laser focus spot diameter of the Raman spectrometer is ≤5 μm.

8. The method for flow exfoliation and closed-loop control of graphene oxide according to claim 4, characterized in that: The feedback control module adopts a fuzzy proportional-integral-differential control algorithm to calculate the ultrasonic energy adjustment amount in real time according to the single layer rate deviation value, and its control period is ≤1s.

9. The method for flow exfoliation and closed-loop control of graphene oxide according to claim 4, characterized in that: The threshold of the monolayer rate is 85%. When the monolayer rate is detected to be lower than the threshold, the number of focal points of the ultrasonic phased array module increases by 10%-80%, and the pulse width is shortened to 20%-80% of the initial pulse width, and the initial pulse width is 20-100μs.

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