A device and method for preparing graphene suspension

Abstract

The present invention discloses a device and method for preparing a graphene suspension. The device for preparing a graphene suspension comprises a rotating drum arranged in a box, a drum cover arranged on the top of the rotating drum, an isolation drum arranged on the bottom of the drum cover, a fixed sleeve arranged at the center of the drum cover, a connecting nozzle arranged in the middle of the fixed sleeve, a connecting frame fixedly connected to the bottom of the fixed sleeve, an ultrasonic vibration plate fixedly connected to the side of the connecting frame, a connecting sleeve fixedly connected to the bottom center of the rotating drum, a rotating shaft symmetrically arranged at the bottom of the inner wall of the rotating drum, and a stirring blade fixedly connected to the top of the rotating shaft. The present invention relates to the technical field of material preparation. The device and method for preparing a graphene suspension solve the problem of low efficiency of the existing graphene suspension in the preparation process. The entire preparation process is completed in one device, avoiding the transfer of the suspension and improving the preparation efficiency. At the same time, the suspension separated with impurities can be processed for secondary use.

Description

Technical Field

[0001] The invention relates to the technical field of material preparation, and in particular to a device and a method for preparing a graphene suspension. Background Art

[0002] Graphene is a two-dimensional carbon atom crystal with a single atom thickness. It is the thinnest material artificially produced so far. It is considered to be the basic structural unit of fullerenes, carbon nanotubes and graphite. Now, crystals with several atomic layers composed of carbon atoms can also be called graphene; graphene has excellent optical, electrical and mechanical properties, and has important application prospects in materials science, micro-nano processing, energy, biomedicine and drug delivery, and is considered to be a revolutionary material in the future.

[0003] Nowadays, most graphene suspensions need to go through multiple devices during the preparation process. If there is no centrifugal structure, the solvent needs to be centrifuged separately by a centrifuge. At the same time, the existing devices expose the solution directly to the air during the preparation process, resulting in low efficiency in the preparation. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the deficiencies in the prior art, the present invention provides a device and method for preparing a graphene suspension, which solves the problem of low efficiency in the preparation process of the existing graphene suspension.

[0006] (II) Technical solution

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: a device for preparing a graphene suspension, comprising a box body, a fixed seat is fixedly connected to the middle of the inner wall of the box body, a fixed ring is slidably connected to the top of the fixed seat, a rotating cylinder is fixedly connected to the center of the fixed ring, a cylinder cover is arranged on the top of the rotating cylinder, an isolation cylinder is arranged on the bottom of the cylinder cover, a fixed sleeve is arranged at the center of the cylinder cover, a fixed frame is fixedly connected to the top of the fixed sleeve, a lifting device for driving the fixed frame up and down is arranged on the top of the fixed frame, a first motor is fixedly connected to one side of the fixed frame, a first gear is fixedly connected to the output shaft end of the first motor, a first internal gear ring is also fixedly connected to the top of the cylinder cover, the first gear is meshedly connected to the first internal gear ring, the middle part of the fixed sleeve is hollow, a connecting nozzle is arranged in the middle of the fixed sleeve, a first feeding pipe is arranged on the top of the connecting nozzle, a second feeding pipe is also connected to one side of the first feeding pipe, a connecting frame is fixedly connected to the bottom of the fixed sleeve, an ultrasonic vibration plate is fixedly connected to the side of the connecting frame, A heater is fixedly connected to the bottom of the connecting frame, an ultrasonic generator is fixedly connected to one side of the top of the inner wall of the box, a connecting sleeve is fixedly connected to the bottom center of the rotating drum, a connecting pipe is arranged on the inner wall of the connecting sleeve, the bottom end of the connecting pipe passes through the bottom of the box and is connected to the first electromagnetic valve, a discharge pipe is arranged at one end of the first electromagnetic valve, a second motor is fixedly connected to one side of the bottom of the inner wall of the box, a second gear is fixedly connected to the output shaft end of the second motor, a third gear is fixedly connected to the surface of the connecting sleeve, the second gear is meshingly connected to the third gear, a rotating shaft is symmetrically arranged at the bottom of the inner wall of the rotating drum, a stirring blade is fixedly connected to the top of the rotating shaft, a fourth gear is fixedly connected to the surface of the rotating shaft and located at the bottom of the rotating drum, an annular support plate is fixedly connected to the bottom of the inner wall of the box, a second inner gear ring is fixedly connected to the inner wall of the annular support plate, the fourth gear is meshingly connected to the second inner gear ring, an annular plate is arranged at the bottom end of the rotating shaft, and a first electric telescopic rod is arranged between the bottom of the annular plate and the bottom of the inner wall of the box.

[0008] Preferably, a fixed cylinder is obliquely arranged on the side wall of the box body and located above the rotating cylinder, a sliding cylinder is slidably connected inside the fixed cylinder, one end of the sliding cylinder is fixedly connected to a hopper, one side of the fixed cylinder is fixedly connected to a second electric telescopic rod, one side of the sliding cylinder is fixedly connected to a fixed block, and the working end of the second electric telescopic rod is fixedly connected to one side of the fixed block.

[0009] Preferably, the lifting device includes a motor fixing frame and a screw nut, the motor fixing frame is fixed on one side of the top of the box, the screw nut is arranged in the top center of the box and is rotatably connected to the box, a third motor is fixedly connected to one side of the motor fixing frame, a fifth gear is fixedly connected to the output shaft end of the third motor, a sixth gear is fixedly connected to the surface of the screw nut, the fifth gear is meshingly connected to the sixth gear, a screw is arranged at the center of the screw nut, the bottom end of the screw is fixedly connected to the fixing frame, a guide rod is also vertically arranged on one side of the top of the fixing frame, and the guide rod is slidably connected to the box.

[0010] Preferably, a second solenoid valve is provided on the first feed pipe, a third solenoid valve is provided on the second feed pipe, one end of the first feed pipe extends to the outside of the box and is connected to the vacuum machine and the tank body, and one end of the second feed pipe extends to the outside of the box and is connected to the storage tank.

[0011] Preferably, the bottom of the isolation cylinder can be sealed and connected to the bottom of the inner wall of the drum, the bottom of the drum cover can be sealed and connected to the top of the drum, the isolation cylinder is coaxially arranged with the drum, and a controller is also arranged on the top side of the inner wall of the box body.

[0012] Preferably, a protective cover is provided on the top of the box body, and supporting legs are provided on the bottom of the box body.

[0013] A method for preparing a graphene suspension comprises the following steps:

[0014] S1, putting the crushed graphite oxide powder from the hopper into the drum, and then adding deionized water into the hopper;

[0015] S2, the first electric telescopic rod works, so that the fourth gear meshes with the second inner gear ring, the second motor is started, the drum is driven to rotate, and the stirring blade is driven to rotate and stir, the drum cover is controlled to descend by the lifting device, and after the ultrasonic vibration plate enters the solution, the ultrasonic generator is turned on to perform ultrasonic dispersion;

[0016] S3, the drum cover returns to the initial position, the first electric telescopic rod works to separate the fourth gear from the second inner gear ring, the second motor drives the drum to rotate for centrifugal treatment, after a period of time, the drum cover is controlled to descend by the lifting device, and then the first motor is started to drive the drum cover to rotate, and the drum cover and the drum rotate at the same speed, until the drum cover is sealed and connected to the drum, and the first motor and the second motor are turned off;

[0017] S4, using a heater to heat the solution, while the second electromagnetic valve is opened, the vacuum machine works to extract air using the first feed pipe, and then nitrogen is injected from the tank body. After the nitrogen is injected, the second electromagnetic valve is closed, the third electromagnetic valve is opened, and the reducing agent is added, and the third electromagnetic valve is closed after the addition;

[0018] S5, turning on the ultrasonic generator to perform ultrasonic dispersion;

[0019] S6, opening the first electromagnetic valve, obtaining the graphene suspension from the discharge pipe, and after the graphene suspension is collected, using the lifting device to control the cylinder cover to rise, obtaining the graphene suspension with impurities from the discharge pipe.

[0020] Preferably, in step S1, the particle size of the graphite oxide powder is 1-50 microns, and deionized water is added to prepare a suspension with a concentration of 0.3-5 mg / ml.

[0021] Preferably, in step S2, the ultrasonic frequency is 50-150 kHz, and the working time is 20 min-200 min; in step S5, the ultrasonic frequency is 30-200 kHz, and the working time is 60 min-400 min.

[0022] Preferably, in step S4, the heater heats the solution to 30-100°C.

[0023] (III) Beneficial effects

[0024] The present invention provides a device and method for preparing a graphene suspension, which has the following beneficial effects:

[0025] (1) The device for preparing a graphene suspension can quickly prepare a graphene oxide suspension through the stirring blades arranged in the drum and the ultrasonic vibration plate arranged on the connecting frame, and can separate impurities from the suspension after centrifugation through the isolation cylinder, and cooperate with the drum cover to seal the drum, fill nitrogen through the first feed pipe, and add a reducing agent through the second feed pipe, so that the graphene oxide suspension is reduced to a graphene suspension in a nitrogen environment. The entire preparation process is completed in one device, avoiding the transfer of the suspension and improving the preparation efficiency; at the same time, the suspension with impurities separated can be processed for secondary utilization.

[0026] (2) This method for preparing a graphene suspension uses ultrasonic radiation to suppress the clustering between graphene sheets, providing conditions for preparing a high-concentration and stable graphene suspension. In combination with a device for preparing a graphene suspension, the preparation process is simple and easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0028] Figure 2 This is a schematic diagram of the inner cylinder cover of the present invention in a raised state;

[0029] Figure 3 This is a schematic diagram of the sealing state between the inner drum cover and the rotating drum of the present invention;

[0030] Figure 4 For the present invention Figure 2 Enlarged view of point A in the middle;

[0031] Figure 5 For the present invention Figure 2 Enlarged view of point B in the middle;

[0032] Figure 6 For the present invention Figure 2 Enlarged view of point C in the middle;

[0033] Figure 7 It is a schematic diagram of the meshing of the second gear and the third gear of the present invention.

[0034] In the figure: 1-box, 2-fixed seat, 3-fixed ring, 4-rotating cylinder, 5-cylinder cover, 6-isolation cylinder, 7-fixed frame, 8-first motor, 9-first gear, 10-first internal gear ring, 11-connecting nozzle, 12-first feed pipe, 13-second feed pipe, 14-connecting frame, 15-ultrasonic vibration plate, 16-heater, 17-ultrasonic generator, 18-connecting sleeve, 19-connecting pipe, 20-first electromagnetic valve, 21-discharging pipe, 22-second motor, 23-second gear, 24-third gear, 25-rotating shaft, 26- Stirring blade, 27-fourth gear, 28-annular support plate, 29-second inner gear ring, 30-first electric telescopic rod, 31-annular plate, 32-fixed cylinder, 33-sliding cylinder, 34-hopper, 35-second electric telescopic rod, 36-fixed block, 37-motor fixing frame, 38-third motor, 39-fifth gear, 40-screw nut, 41-screw, 42-sixth gear, 43-guide rod, 44-second electromagnetic valve, 45-third electromagnetic valve, 46-protective cover, 47-support leg, 48-fixed sleeve, 49-controller. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] See also Figure 1-7 , the present invention provides a technical solution:

[0037] Embodiment 1:

[0038] A device for preparing a graphene suspension, comprising a box body 1, a fixing seat 2 is fixedly connected to the middle of the inner wall of the box body 1, a fixing ring 3 is slidably connected to the top of the fixing seat 2, a rotating drum 4 is fixedly connected to the center of the fixing ring 3, a drum cover 5 is arranged on the top of the rotating drum 4, an isolating drum 6 is arranged on the bottom of the drum cover 5, a fixing sleeve 48 is arranged at the center of the drum cover 5, a fixing frame 7 is fixedly connected to the top of the fixing sleeve 48, a lifting device for driving the fixing frame 7 up and down is arranged on the top of the fixing frame 7, and the lifting device can drive the fixing frame 7 to move up and down; when the fixing frame 7 moves to the lowest position, the bottom of the isolating drum 6 can be sealed and connected to the bottom of the inner wall of the rotating drum 4, the bottom of the drum cover 5 can be sealed and connected to the top of the rotating drum 4, and the isolating drum 6 is coaxially arranged with the rotating drum 4 to ensure that the isolating drum 6 is located in the middle of the rotating drum 4;

[0039] A first motor 8 is fixedly connected to one side of the fixing frame 7, and a first gear 9 is fixedly connected to the output shaft end of the first motor 8. A first internal gear ring 10 is also fixedly connected to the top of the cylinder cover 5. The first gear 9 is meshed and connected with the first internal gear ring 10. The first motor 8 can drive the cylinder cover 5 to rotate around the fixing sleeve 48 through gear transmission. The middle part of the fixing sleeve 48 is hollow, and a connecting nozzle 11 is provided in the middle part of the fixing sleeve 48. A first feeding pipe 12 is provided on the top of the connecting nozzle 11. One side of the first feeding pipe 12 is also connected to a second feeding pipe 13. The first feeding pipe 12 is provided with a second electromagnetic valve 44, and the second feed pipe 13 is provided with a third electromagnetic valve 45. One end of the first feed pipe 12 extends to the outside of the box body 1 and is connected to the vacuum machine and the tank body. Nitrogen is set in the tank body. Before the reduction reaction, the air in the drum 4 is extracted by the vacuum machine and filled with nitrogen, so that the reduction reaction is carried out in a nitrogen environment to improve the preparation efficiency. One end of the second feed pipe 13 extends to the outside of the box body 1 and is connected to the storage tank. The storage tank contains a reducing agent, which is generally one or more of ethylenediamine, p-phenylenediamine, and hydroquinone;

[0040] The bottom of the fixed sleeve 48 is fixedly connected to a connecting frame 14, the side of the connecting frame 14 is fixedly connected to an ultrasonic vibration plate 15, and the bottom of the connecting frame 14 is fixedly connected to a heater 16, which can heat the solution to increase the appropriate temperature for the reduction reaction; one side of the top of the inner wall of the box body 1 is fixedly connected to an ultrasonic generator 17, which is connected to the ultrasonic vibration plate 15 through a cable, and the ultrasonic dispersion weakens the van der Waals force between the graphene layers, inhibits the agglomeration of the graphene sheets, and provides conditions for preparing a high-concentration and stable graphene suspension;

[0041] A connecting sleeve 18 is fixedly connected to the center of the bottom of the rotating drum 4, and a connecting pipe 19 is provided on the inner wall of the connecting sleeve 18. The connecting pipe 19 is sealed with the connecting sleeve 18, and the bottom end of the connecting pipe 19 passes through the bottom of the box body 1 and is connected to the first electromagnetic valve 20. The surface of the connecting pipe 19 is fixedly connected to the box body 1. When the rotating drum 4 rotates, the connecting pipe 19 is fixed, thereby preventing the first electromagnetic valve 20 from rotating with the rotating drum 4; a discharge pipe 21 is provided at one end of the first electromagnetic valve 20, and the prepared graphene suspension can be discharged from the discharge pipe 21; at the same time, the suspension containing impurities separated by centrifugation can be discharged from the discharge pipe 21 after the graphene suspension is discharged, so that the suspension containing impurities can be reused;

[0042] A second motor 22 is fixedly connected to one side of the bottom of the inner wall of the casing 1, and a second gear 23 is fixedly connected to the output shaft end of the second motor 22. A third gear 24 is fixedly connected to the surface of the connecting sleeve 18, and the second gear 23 is meshingly connected with the third gear 24. The second motor 22 can drive the rotating drum 4 to rotate through gear transmission; a rotating shaft 25 is also symmetrically arranged at the bottom of the inner wall of the rotating drum 4, and a stirring blade 26 is fixedly connected to the top of the rotating shaft 25. A fourth gear 27 is fixedly connected to the surface of the rotating shaft 25 and located at the bottom of the rotating drum 4. An annular support plate 28 is fixedly connected to the bottom of the inner wall of the casing 1, and a second inner gear ring 29 is fixedly connected to the inner wall of the annular support plate 28. The fourth gear 27 is meshingly connected with the second inner gear ring 29, and the bottom end of the rotating shaft 25 is provided with The annular plate 31 and the bottom end of the rotating shaft 25 are set to a T-shaped structure, and a sliding groove is opened on the surface of the annular plate 31. A first electric telescopic rod 30 is arranged between the bottom of the annular plate 31 and the bottom of the inner wall of the box body 1. The first electric telescopic rod 30 drives the annular plate 31 to rise and fall, so as to realize the meshing and separation of the fourth gear 27 and the second inner gear ring 29. When the rotating drum 4 rotates at a low speed, the fourth gear 27 meshes with the second inner gear ring 29, and can drive the stirring blade 26 to stir the solution. When the rotating drum 4 rotates at a high speed, the fourth gear 27 separates from the second inner gear ring 29, and the rotation of the rotating drum 4 is used for centrifugal impurity removal. A controller 49 is also arranged on the top side of the inner wall of the box body 1. The controller 49 adopts a PLC controller to realize the control of various electrical appliances.

[0043] A fixed cylinder 32 is obliquely arranged on the side wall of the box body 1 and located above the rotating drum 4, a sliding cylinder 33 is slidably connected inside the fixed cylinder 32, one end of the sliding cylinder 33 is fixedly connected to a hopper 34, one side of the fixed cylinder 32 is fixedly connected to a second electric telescopic rod 35, one side of the sliding cylinder 33 is fixedly connected to a fixed block 36, a working end of the second electric telescopic rod 35 is fixedly connected to one side of the fixed block 36, and the movement of the sliding cylinder 33 can realize the dropping of materials into the rotating drum 4, which can facilitate the lifting and lowering of the drum cover 5.

[0044] The lifting device includes a motor fixing frame 37 and a screw nut 40. The motor fixing frame 37 is fixed on one side of the top of the box body 1. The screw nut 40 is arranged in the top center of the box body 1 and is rotatably connected to the box body 1. A third motor 38 is fixedly connected to one side of the motor fixing frame 37. A fifth gear 39 is fixedly connected to the output shaft end of the third motor 38. A sixth gear 42 is fixedly connected to the surface of the screw nut 40. The fifth gear 39 is meshed with the sixth gear 42. A screw 41 is arranged at the center of the screw nut 40. The bottom end of the screw nut 41 is fixedly connected to the fixing frame 7. The third motor 38 drives the screw nut 40 to rotate through gear transmission. Since the screw nut 40 is axially fixed on the box body 1, the screw 41 can move up and down through the rotation of the screw nut 40, thereby driving the fixing frame 7 to move up and down. A guide rod 43 is also vertically arranged on one side of the top of the fixing frame 7. The guide rod 43 is slidably connected to the box body 1. The guide rod 43 prevents the fixing frame 7 from rotating around the screw 41, thereby ensuring that the fixing frame 7 can move up and down smoothly.

[0045] A protective cover 46 is provided on the top of the box body 1 , and supporting legs 47 are provided on the bottom of the box body 1 .

[0046] A method for preparing a graphene suspension comprises the following steps:

[0047] S1, putting the crushed graphite oxide powder from the hopper into the drum, and then adding deionized water into the hopper;

[0048] S2, the first electric telescopic rod works, so that the fourth gear meshes with the second inner gear ring, the second motor is started, the drum is driven to rotate, and the stirring blade is driven to rotate and stir, the drum cover is controlled to descend by the lifting device, and after the ultrasonic vibration plate enters the solution, the ultrasonic generator is turned on to perform ultrasonic dispersion;

[0049] S3, the drum cover returns to the initial position, the first electric telescopic rod works to separate the fourth gear from the second inner gear ring, the second motor drives the drum to rotate for centrifugal treatment, after a period of time, the drum cover is controlled to descend by the lifting device, and then the first motor is started to drive the drum cover to rotate, and the drum cover and the drum rotate at the same speed, until the drum cover is sealed and connected to the drum, and the first motor and the second motor are turned off;

[0050] S4, using a heater to heat the solution, while the second electromagnetic valve is opened, the vacuum machine works to extract air using the first feed pipe, and then nitrogen is injected from the tank body. After the nitrogen is injected, the second electromagnetic valve is closed, the third electromagnetic valve is opened, and the reducing agent is added, and the third electromagnetic valve is closed after the addition;

[0051] S5, turning on the ultrasonic generator to perform ultrasonic dispersion;

[0052] S6, opening the first electromagnetic valve, obtaining the graphene suspension from the discharge pipe, and after the graphene suspension is collected, using the lifting device to control the cylinder cover to rise, obtaining the graphene suspension with impurities from the discharge pipe.

[0053] In the step S1, the particle size of graphite oxide powder is 1 micron, and deionized water is added to prepare a suspension with a concentration of 0.3 mg / ml.

[0054] In the step S2, the ultrasonic frequency is 50 kHz and the working time is 20 min. In the step S5, the ultrasonic frequency is 30 kHz and the working time is 60 min.

[0055] In step S4, the heater heats the solution to 30°C.

[0056] Embodiment 2:

[0057] Different from the first embodiment, in step S1, the particle size of the graphite oxide powder is 50 microns, and deionized water required for preparing a suspension with a concentration of 5 mg / ml is added.

[0058] In step S2, the ultrasonic frequency is 150 kHz and the working time is 200 min. In step S5, the ultrasonic frequency is 200 kHz and the working time is 400 min.

[0059] In step S4, the heater heats the solution to 100°C.

[0060] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0061] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A device for preparing a graphene suspension, comprising a housing (1), characterized in that: A fixing seat (2) is fixedly connected to the middle of the inner wall of the box body (1), a fixing ring (3) is slidably connected to the top of the fixing seat (2), a rotating drum (4) is fixedly connected to the center of the fixing ring (3), a drum cover (5) is provided on the top of the rotating drum (4), an isolation drum (6) is provided on the bottom of the drum cover (5), a fixing sleeve (48) is provided at the center of the drum cover (5), a fixing frame (7) is fixedly connected to the top of the fixing sleeve (48), a lifting device for driving the fixing frame (7) up and down is provided on the top of the fixing frame (7), a first motor (8) is fixedly connected to one side of the fixing frame (7), and a first gear (9) is fixedly connected to the output shaft end of the first motor (8). The top of the cylinder cover (5) is also fixedly connected to a first internal gear ring (10), the first gear (9) is meshingly connected to the first internal gear ring (10), the middle of the fixed sleeve (48) is hollow, the middle of the fixed sleeve (48) is provided with a connecting nozzle (11), the top of the connecting nozzle (11) is provided with a first feed pipe (12), one side of the first feed pipe (12) is also connected to a second feed pipe (13), the bottom of the fixed sleeve (48) is fixedly connected to a connecting frame (14), the side of the connecting frame (14) is fixedly connected to an ultrasonic vibration plate (15), the bottom of the connecting frame (14) is fixedly connected to a heater (16), and a portion of the top of the inner wall of the box body (1) is fixedly connected to a connecting frame (14). An ultrasonic generator (17) is fixedly connected to the side of the rotating drum (4); a connecting sleeve (18) is fixedly connected to the bottom center of the rotating drum (4); a connecting pipe (19) is provided on the inner wall of the connecting sleeve (18); the bottom end of the connecting pipe (19) passes through the bottom of the box body (1) and is connected to a first electromagnetic valve (20); one end of the first electromagnetic valve (20) is provided with a discharge pipe (21); a second motor (22) is fixedly connected to one side of the bottom of the inner wall of the box body (1); a second gear (23) is fixedly connected to the output shaft end of the second motor (22); a third gear (24) is fixedly connected to the surface of the connecting sleeve (18); the second gear (23) is meshingly connected to the third gear (24); A rotating shaft (25) is symmetrically arranged at the bottom of the inner wall of the rotating drum (4); a stirring blade (26) is fixedly connected to the top of the rotating shaft (25); a fourth gear (27) is fixedly connected to the surface of the rotating shaft (25) and located at the bottom of the rotating drum (4); an annular support plate (28) is fixedly connected to the bottom of the inner wall of the box body (1); a second inner gear ring (29) is fixedly connected to the inner wall of the annular support plate (28); the fourth gear (27) is meshingly connected to the second inner gear ring (29); an annular plate (31) is arranged at the bottom end of the rotating shaft (25); and a first electric telescopic rod (30) is arranged between the bottom of the annular plate (31) and the bottom of the inner wall of the box body (1).

2. A device for preparing a graphene suspension according to claim 1, characterized in that: A fixed cylinder (32) is obliquely arranged on the side wall of the box body (1) and located above the rotating cylinder (4); a sliding cylinder (33) is slidably connected inside the fixed cylinder (32); one end of the sliding cylinder (33) is fixedly connected to a hopper (34); one side of the fixed cylinder (32) is fixedly connected to a second electric telescopic rod (35); one side of the sliding cylinder (33) is fixedly connected to a fixed block (36); and a working end of the second electric telescopic rod (35) is fixedly connected to one side of the fixed block (36).

3. A device for preparing a graphene suspension according to claim 1, characterized in that: The lifting device comprises a motor fixing frame (37) and a screw nut (40), wherein the motor fixing frame (37) is fixed to one side of the top of the box body (1), the screw nut (40) is arranged at the center of the top of the box body (1) and is rotatably connected to the box body (1), a third motor (38) is fixedly connected to one side of the motor fixing frame (37), a fifth gear (39) is fixedly connected to the output shaft end of the third motor (38), a sixth gear (42) is fixedly connected to the surface of the screw nut (40), the fifth gear (39) is meshingly connected to the sixth gear (42), a screw (41) is arranged at the center of the screw nut (40), the bottom end of the screw (41) is fixedly connected to the fixing frame (7), a guide rod (43) is also vertically arranged on one side of the top of the fixing frame (7), and the guide rod (43) is slidably connected to the box body (1).

4. A device for preparing a graphene suspension according to claim 1, characterized in that: The first feed pipe (12) is provided with a second electromagnetic valve (44), and the second feed pipe (13) is provided with a third electromagnetic valve (45); one end of the first feed pipe (12) extends to the outside of the box (1) and is connected to the vacuum machine and the tank body, and one end of the second feed pipe (13) extends to the outside of the box (1) and is connected to the storage tank.

5. A device for preparing a graphene suspension according to claim 1, characterized in that: The bottom of the isolation cylinder (6) is sealedly connected to the bottom of the inner wall of the rotating cylinder (4), the bottom of the cylinder cover (5) is sealedly connected to the top of the rotating cylinder (4), the isolation cylinder (6) and the rotating cylinder (4) are coaxially arranged, and a controller (49) is also arranged on one side of the top of the inner wall of the box body (1).

6. A device for preparing a graphene suspension according to claim 1, characterized in that: A protective cover (46) is provided on the top of the box body (1), and supporting legs (47) are provided on the bottom of the box body (1).

7. A method for preparing a graphene suspension, applicable to a device for preparing a graphene suspension according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1, putting the crushed graphite oxide powder from the hopper into the drum, and then adding deionized water into the hopper; S2, the first electric telescopic rod works, so that the fourth gear meshes with the second inner gear ring, the second motor is started, the drum is driven to rotate, and the stirring blade is driven to rotate and stir, the drum cover is controlled to descend by the lifting device, and after the ultrasonic vibration plate enters the solution, the ultrasonic generator is turned on to perform ultrasonic dispersion; S3, the drum cover returns to the initial position, the first electric telescopic rod works to separate the fourth gear from the second inner gear ring, the second motor drives the drum to rotate for centrifugal treatment, after a period of time, the drum cover is controlled to descend by the lifting device, and then the first motor is started to drive the drum cover to rotate, and the drum cover and the drum rotate at the same speed, until the drum cover is sealed and connected to the drum, and the first motor and the second motor are turned off; S4, using a heater to heat the solution, while the second electromagnetic valve is opened, the vacuum machine works to extract air using the first feed pipe, and then nitrogen is injected from the tank body. After the nitrogen is injected, the second electromagnetic valve is closed, the third electromagnetic valve is opened, and the reducing agent is added, and the third electromagnetic valve is closed after the addition; S5, turning on the ultrasonic generator to perform ultrasonic dispersion; S6, opening the first electromagnetic valve, obtaining the graphene suspension from the discharge pipe, and after the graphene suspension is collected, using the lifting device to control the cylinder cover to rise, obtaining the graphene suspension with impurities from the discharge pipe.

8. A method for preparing a graphene suspension according to claim 7, characterized in that: In the step S1, the particle size of graphite oxide powder is 1-50 microns, and deionized water is added to prepare a suspension with a concentration of 0.3-5 mg / ml.

9. A method for preparing a graphene suspension according to claim 7, characterized in that: In the step S2, the ultrasonic frequency is 50-150kHz, and the working time is 20min-200min. In the step S5, the ultrasonic frequency is 30-200kHz, and the working time is 60min-400min.

10. A method for preparing a graphene suspension according to claim 7, characterized in that: In step S4, the heater heats the solution to 30-100°C.

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