Centrifugation- and continuous shearing exfoliation-based preparation method and device for NANO material

Abstract

Disclosed in the present invention are a centrifugation- and continuous shearing exfoliation-based preparation method and device for a nano material. The method comprises: materials entering circumferential flow channels under the centrifugal effect, and using shearing flows in the circumferential flow channels to apply a strong shearing exfoliation effect on the materials; and under the action of a centrifugal force, screening for the exfoliated materials through radial flow channels and enabling the exfoliated materials to enter the circumferential flow channels of the next layer, and enabling the unexfoliated materials to remain in the circumferential flow channels of the previous layer for continued exfoliation. The device comprises a high-speed motor, a material container, stationary toothed discs, rotating toothed discs, and a toothed disc rotating shaft; a material cavity is formed in the material container and the stationary toothed discs are fixed to the material container; the rotating toothed discs are provided in the material cavity; the toothed disc rotating shaft passes through the middles of the rotating toothed discs; the high-speed motor is connected to one end of the toothed disc rotating shaft; the rotating toothed discs and the stationary toothed discs are mutually embedded to form a multi-layer flow channel area; circumferential flow channels are distributed layer by layer from the center to the periphery; and radial flow channels are distributed in the same circumferential direction. The present invention facilitates formation of one-dimensional nanofibers having a large length-diameter ratio and / or two-dimensional nanosheets having a large specific surface area.

Description

Centrifugal shear continuous peeling preparation method and device for nanomaterials TECHNICAL FIELD

[0001] The present application relates to the technical field of nanomaterial preparation, in particular to a centrifugal shear continuous peeling preparation method and device for nanomaterials. BACKGROUND

[0002] Nanomaterials are materials with at least one dimension in the nanometer range (1-100 nm) in three-dimensional space. Based on their unique size effect and surface properties, nanomaterials have been widely used in structural reinforcement, surface adsorption, optical protection and other fields. Common nanomaterials include one-dimensional nanofibers (such as aramid nanofibers, cellulose nanofibers, etc.) and two-dimensional nanosheets (such as graphene, boron nitride nanosheets, etc.). The preparation method generally involves chemical or mechanical processing to decompose or peel the macroscopic raw materials, thereby obtaining the target nanomaterials. Existing research shows that nanofibers with large aspect ratios and nanosheets with large specific surface areas often exhibit stronger surface effects and better mechanical properties. Different processing methods based on different separation principles produce nanomaterials of different sizes. Therefore, in the preparation process of nanomaterials, using a more reasonable processing method is crucial to improving the performance of nanomaterial products.

[0003] Currently widely used mechanical peeling methods for nanomaterials include ball milling and high-speed mixing. In the ball milling method, the rotation of the drum of the ball mill causes the ball mill bodies and the materials in the drum to collide and rub with each other, thereby crushing the materials into nanomaterials. In the high-speed mixing method, the high-speed rotation of the mixer draws the materials into the shear head, where they are broken by the cutter head and then discharged, and this cycle is repeated until all the materials are nanometerized. However, using ball milling or high-speed mixing (homogenization) to prepare nanomaterials often has the following problems:

[0004] ①During ball milling or homogenization, the materials are subjected to not only peeling but also impact, which easily causes the nanomaterial products to be broken, resulting in a decrease in the aspect ratio of the fibers or the specific surface area of the sheets.

[0005] ②The peeling action is uneven, with the materials in the center of the container being more easily subjected to peeling than the materials at the edges, resulting in poor size consistency of the obtained nanomaterials.

[0006] ③The peeled materials cannot be separated from the unpeeled materials, and the materials that have been peeled for a long time stay in the high-force area, increasing the probability of impact damage.

[0007] ④The preparation process of ball milling and high-speed mixing is complex, with low yield, making it difficult to achieve large-scale production and commercial application.

[0008] In summary, if a suitable peeling method can be found to prepare nanomaterials with large aspect ratio and large specific surface area, and realize high-efficiency and continuous production, it will have great significance for the application and promotion of nanofunctional materials. SUMMARY

[0009] The present application aims to overcome the deficiencies of the prior art, and provides a centrifugal shear continuous peeling preparation method for nanomaterials, which can effectively overcome the problems that nanomaterials are easily damaged by impact during peeling, the peeling effect is random, and the peeled materials and unpeeled materials cannot be separated, and is conducive to forming one-dimensional nanofibers with large aspect ratio and / or two-dimensional nanosheets with large specific surface area.

[0010] Another object of the present application is to provide a centrifugal shear continuous peeling preparation device for nanomaterials for realizing the above preparation method.

[0011] The technical scheme of the present application is: a centrifugal shear continuous peeling preparation method for nanomaterials, first, the material at the center position enters the circumferential flow channel close to the center position under the centrifugal action of the preparation device, and the shear flow formed by the velocity difference of the two circumferential wall surfaces of the circumferential flow channel is used to apply strong shear peeling action to the material; then, under the pushing of the centrifugal force, the peeled material passes through the radial flow channel and is screened into the next layer of circumferential flow channel gradually away from the center position, and the unpeeled material stays in the previous layer of circumferential flow channel to continue peeling; finally, all the materials form nanomaterials after multiple shear peeling and multiple screening and are guided out for collection. In the whole process, the macroscopic material undergoes multiple processes of peeling, screening, re-peeling, and re-screening, so that the diameter of one-dimensional nanofiber or the thickness of two-dimensional nanosheet is continuously reduced and finally forms nanomaterials with target size.

[0012] The centrifugal action and the shear peeling action are both generated by the rotation of the preparation device. The relative rotation between the static tooth disc and the dynamic tooth disc in the preparation device generates rotation, and the centrifugal force generated by the rotation forces the material solution to flow continuously from the center to the periphery, which realizes the selective passage of the material in cooperation with the radial flow channel, and the shear force generated by the rotation realizes the shear peeling of the material in cooperation with the circumferential flow channel.

[0013] The centrifugal shear continuous peeling preparation device for nanomaterials can be used for realizing the centrifugal shear continuous peeling preparation method, and comprises a high-speed motor, a material container, a static gear plate, a dynamic gear plate and a gear plate rotating shaft. A cavity in the material container is a material cavity, the static gear plate is fixed in the material container, the dynamic gear plate is arranged in the material cavity and matched with the static gear plate, the gear plate rotating shaft is arranged in the middle of the dynamic gear plate, one end of the gear plate rotating shaft extends out of the material container and is connected with the high-speed motor. The dynamic gear plate and the static gear plate are embedded with each other to form a plurality of layer flow channel regions. In each layer flow channel region, circumferential flow channels are distributed layer by layer along the center to the outer peripheral direction, and radial flow channels are distributed along the same circumferential direction. The material cavity forms a closed working region, and the bottom of the material container is concentrically arranged on the base table with the high-speed motor.

[0014] The top of the material container is provided with a feeding port, the bottom of the material container is provided with a discharging port, the feeding port and the discharging port are communicated through a circulating pipeline, and a three-way valve is arranged on the circulating pipeline at the discharging port. In addition, the circulating pipeline is also connected to an external pipeline, and the circulation and discharge of the material solution can be realized by switching the opening and closing states of the three-way valve.

[0015] The circumferential flow channel is an annular slit arranged along the circumferential direction, and the annular slit is formed by two layers of circumferential wall surfaces with relative motion. One layer of circumferential wall surface is the disc tooth wall surface of the dynamic gear plate, and the other layer of circumferential wall surface is the disc tooth wall surface of the static gear plate. After the dynamic gear plate and the static gear plate are embedded, the disc tooth wall surfaces of the two are embedded to form the annular slit as the circumferential flow channel. The width of each annular slit can be designed according to actual needs, and the size of the shear peeling effect provided can be controlled by changing the width of the annular slit and the relative motion speed difference.

[0016] The radial flow channel is a radial slit between two adjacent circumferential flow channels, and the width of each layer of radial flow channel gradually decreases along the center to the outer peripheral direction. The radial flow channel is a slit with a certain shape and a screening function, and the width of each stage of radial flow channel has a gradient change relationship. The size of the screened material can be controlled by changing the width of the radial flow channel.

[0017] The radial flow channel has an included angle of 0°-80° between the axial direction and the diameter direction of the circumferential direction where the radial flow channel is located. The radial flow channels at different layers can have different sizes of the included angle.

[0018] The material cavity in the material container has one or more stages, and each stage of the material cavity is distributed in sequence from top to bottom, and each stage of the material cavity is respectively provided with a pair of static gear plates and dynamic gear plates.

[0019] The material container and the static toothed disc are in an integrated structure or a split structure, and the dynamic toothed disc and the toothed disc rotating shaft are in an integrated structure or a split structure. That is, the static toothed disc can be directly machined on the inner wall of the material container to form an integrated material container and static toothed disc, or the material container and the static toothed disc can be separately machined and then locked and installed in the material container. At the same time, a sealing rubber ring can be arranged between the material cavity and the static toothed disc, and the static toothed disc is installed and fixed through the corresponding sink. Similarly, the dynamic toothed disc and the toothed disc rotating shaft can be integrally machined or separately machined and then fixed and installed. When the material cavity has multiple levels, multiple dynamic toothed discs are required, and each dynamic toothed disc is distributed on the toothed disc rotating shaft from top to bottom. When the dynamic toothed disc and the toothed disc rotating shaft are in a split structure, a hexagonal embedded structure can be machined on the dynamic toothed disc, and adjusting shims are placed between the dynamic toothed discs during installation. Each dynamic toothed disc is fixed by bolts and the motor shaft.

[0020] The dynamic toothed disc comprises a first disc body and first disc teeth, and the side of the first disc body facing the static toothed disc is distributed with a plurality of first disc teeth. The static toothed disc comprises a second disc body and second disc teeth, and the side of the second disc body facing the dynamic toothed disc is distributed with a plurality of second disc teeth. The first disc teeth and the second disc teeth are staggered and embedded. The first disc teeth and the second disc teeth are both cylindrical disc teeth or block-shaped disc teeth. Among them, a plurality of layers of first disc teeth are annularly distributed on the first disc body, and a plurality of layers of second disc teeth are annularly distributed on the second disc body. There is a gap between adjacent two disc teeth (i.e. first disc teeth or second disc teeth) on the same layer to form a radial flow channel with a certain width. The edge of the disc teeth close to the gap has a special shape such as a straight line or a circular arc, which can form different types of radial flow channels. The width and number of radial flow channels on different tooth discs (i.e. static toothed disc or dynamic toothed disc) or different layers of the same tooth disc can be different.

[0021] In the above preparation device structure, the dynamic toothed disc and the static toothed disc in each material cavity can be designed in a modular manner, and can be combined and replaced according to different material requirements. By using different combinations of dynamic toothed discs and static toothed discs, a single-level multi-layer or multi-level multi-layer stripping structure can be formed. In the single-level multi-layer stripping structure, a set of dynamic and static toothed discs are used, and a plurality of layers of disc teeth are distributed on the dynamic and static toothed discs. Each layer of radial flow channels and circumferential flow channels extends in the span direction of the toothed disc. In the multi-level multi-layer stripping structure, multiple sets of dynamic and static toothed discs are used, and each set of dynamic and static toothed discs is axially stacked. A plurality of layers of disc teeth are independently distributed on each set of dynamic and static toothed discs. Each layer of radial and circumferential flow channels can extend in the span direction and the axial direction of the toothed disc.

[0022] The principle of the centrifugal shear continuous exfoliation preparation method and device for the nanomaterial is as follows: the high-speed relative rotation between the movable gear plate and the static gear plate can simultaneously provide centrifugal force and shear force to any point in the system, the two actions are decomposed by using the designed radial flow channel and the circumferential flow channel, the shear exfoliation action is exerted on the material in the circumferential flow channel based on the shear flow formed by the speed difference between the two walls, and the centrifugal force is used to push and couple with the flow channel width to realize the size selection of the material in the radial flow channel; the exfoliation and screening of the material are synchronized by the cooperation of the two flow channels, and therefore the nanomaterial with uniform size can be efficiently prepared.

[0023] Compared with the prior art, the centrifugal shear continuous exfoliation preparation method for the nanomaterial has the following beneficial effects:

[0024] The centrifugal shear continuous exfoliation preparation method for the nanomaterial is simple, convenient, high in production efficiency and good in product quality, and the preparation device for realizing the preparation method has a simple structure and wide applicability, and can be applied to the continuous mass production of various one-dimensional and two-dimensional nanomaterials.

[0025] The centrifugal shear continuous exfoliation preparation method and device for the nanomaterial are based on the strong shear action and centrifugal force provided by the rotation, the material solution only receives shear exfoliation force without impact force in the circumferential flow channel by using the strong shear action, which is beneficial to form one-dimensional nanofibers with large length-diameter ratio and two-dimensional nanosheets with large specific surface area; meanwhile, all the materials are forced to pass through each layer of circumferential flow channel by using the centrifugal force, and the exfoliated materials are separated from the unexfoliated materials by using the radial flow channel, so that all the materials receive equivalent shear exfoliation action, the obtained nanomaterial product is uniform in size, and subsequent centrifugal separation is not needed.

[0026] In the centrifugal shear continuous exfoliation preparation device for the nanomaterial, the movable gear plate and the static gear plate have various variable structures, and the width and shape of the radial flow channel and the circumferential flow channel can be realized. Among them, each gear plate can be modularized and replaced, and the exfoliation structure of single-stage multi-layer or multi-stage multi-layer can be realized by selecting different combinations of movable gear plates and static gear plates, the corresponding process adjustment can be made for different nanomaterials, the use is flexible, and the application range is wide.

[0027] The centrifugal shear continuous exfoliation preparation device for the nanomaterial is connected by using a circulating pipeline, the running state of the equipment can be switched by adjusting the three-way valve, and automatic and continuous production can be easily realized. BRIEF DESCRIPTION OF DRAWINGS

[0028] Fig. 1 is a multi-stage multi-layer exfoliation structure schematic diagram of the centrifugal shear continuous exfoliation preparation device for the nanomaterial.

[0029] Fig. 2 is a single-stage multi-layer exfoliation structure schematic diagram of the centrifugal shear continuous exfoliation preparation device for the nanomaterial.

[0030] Fig. 3 is a schematic diagram of the principle of the centrifugal shear continuous exfoliation method for the nanomaterials, showing the circumferential flow channel, the radial flow channel and the material exfoliation process.

[0031] Fig. 4 is a schematic diagram of the principle of the exfoliation process in the circumferential flow channel in the centrifugal shear continuous exfoliation method for the nanomaterials.

[0032] Fig. 5 is a schematic diagram of the structure of the movable gear plate with cylindrical gear teeth.

[0033] Fig. 6 is a schematic diagram of the structure of the movable gear plate with block gear teeth.

[0034] Fig. 7 is an atomic force microscope image of the aramid nanofiber prepared by the centrifugal shear continuous exfoliation method for the nanomaterials.

[0035] Fig. 8 is a schematic diagram of the fiber diameter measurement results of the aramid nanofiber prepared by the centrifugal shear continuous exfoliation method for the nanomaterials.

[0036] In the above figures, the components shown by the reference numerals are as follows: 1 is a high-speed motor, 2 is a material container, 3 is a stationary gear plate, 4 is a movable gear plate, 4-1 is a first plate body, 4-2 is a first gear tooth, 5 is a gear plate rotating shaft, 6 is a material cavity, 7 is a feeding port, 8 is a discharging port, 9 is a circulating pipeline, 10 is a three-way valve, 11 is a gear tooth in the inner layer of the movable gear plate, 12 is a gear tooth in the outer layer of the movable gear plate, 13 is a gear tooth in the inner layer of the stationary gear plate, 14 is a gear tooth in the outer layer of the stationary gear plate, 15 is a circumferential flow channel, 16 is a radial flow channel, and 17 is an aramid fiber. DETAILED DESCRIPTION

[0037] The application will be further described in detail below in conjunction with the examples, but the embodiments of the application are not limited thereto.

[0038] Example 1

[0039] The centrifugal shear continuous exfoliation method and device for the nanomaterials in this example are used to realize the efficient and continuous preparation of macroscopic aramid fibers to obtain aramid nanofibers with large aspect ratio.

[0040] In this embodiment, the centrifugal shear continuous exfoliation device for nanomaterials adopts a two-stage two-layer exfoliation structure, as shown in FIG. 1. The device includes a high-speed motor 1, a material container 2, a static gear plate 3, a dynamic gear plate 4, and a gear plate rotating shaft 5. The cavity in the material container is a material cavity 6. The static gear plate is fixed in the material container. The dynamic gear plate is arranged in the material cavity and cooperates with the static gear plate. The dynamic gear plate has a gear plate rotating shaft in the middle. One end of the gear plate rotating shaft extends out of the material container and is connected to the high-speed motor. The dynamic gear plate and the static gear plate are embedded with each other to form multiple layers of flow channel areas. In each layer of flow channel area, the circumferential flow channels are distributed layer by layer from the center to the outer periphery, and the radial flow channels are distributed along the same circumferential direction. The material cavity forms a closed working area. The bottom of the material container is concentrically installed with the high-speed motor on the base table. The static gear plate and the dynamic gear plate of the first stage are installed in the material cavity of the first stage. The material cavity of the second stage is arranged above the material cavity of the first stage. The static gear plate and the dynamic gear plate of the second stage are arranged in the material cavity of the second stage. The two-stage material cavities are connected to each other. The top of the material container is provided with a feeding port 7, and the bottom of the material container is provided with a discharging port 8. The feeding port and the discharging port are connected by a circulating pipeline 9, and a three-way valve 10 is arranged on the circulating pipeline at the discharging port. In addition, the circulating pipeline is also connected to an external pipeline. By switching the three-way valve, the circulation and discharge of the material solution can be realized.

[0041] In the above structure, as shown in FIG. 3, the teeth 11 of the inner layer of the dynamic gear plate, the teeth 12 of the outer layer of the dynamic gear plate, the teeth 13 of the inner layer of the static gear plate, and the teeth 14 of the outer layer of the static gear plate are embedded with each other to form corresponding layers of circumferential flow channels 15 and radial flow channels 16. The exfoliation principle of aramid fibers 17 in these flow channels is shown in FIGS. 4 and 5. The circumferential flow channel is an annular slit arranged along the circumferential direction. The annular slit is composed of two layers of circumferential wall surfaces with relative motion. One layer of circumferential wall surface is the tooth wall surface of the dynamic gear plate, and the other layer of circumferential wall surface is the tooth wall surface of the static gear plate. After the dynamic gear plate and the static gear plate are embedded, the tooth wall surfaces of the two form an annular slit as the circumferential flow channel. The width of each annular slit can be designed according to actual needs. By changing the width of the annular slit and the relative motion speed difference, the size of the shear exfoliation effect provided can be controlled. The radial flow channel is a radial slit between two adjacent circumferential flow channels. Along the center to the outer periphery direction, the width of each layer of radial flow channel gradually decreases. The radial flow channel is a slit with a certain shape and a screening function. The width of each stage of radial flow channel has a gradient change relationship. By changing the width of the radial flow channel, the size of the screened material can be controlled. The axial direction of the radial flow channel and the diameter direction of the circumference on which the radial flow channel is located form an included angle of 0°~80°. Among them, the radial flow channels located at different layers can have different sizes of included angles. In this embodiment, the radial flow channels in the static gear plate form an included angle of 0° with the diameter direction, and the radial flow channels in the dynamic gear plate form an included angle of 20° with the diameter direction.

[0042] The material container and the static tooth disc can be in an integrated structure or a split structure, and the movable tooth disc and the tooth disc rotating shaft can also be in an integrated structure or a split structure. That is, the tooth part of the static tooth disc can be directly machined on the inner wall of the material container to form an integrated material container and static tooth disc, or the material container and the static tooth disc can be separately machined and then the static tooth disc is locked and installed in the material container. At the same time, a sealing rubber ring can be arranged between the material cavity and the static tooth disc, and the static tooth disc is installed and fixed through the corresponding sink. Similarly, the movable tooth disc and the tooth disc rotating shaft can be integrally machined or separately machined and then fixed and installed. When the material cavity has multiple levels, multiple movable tooth discs are required, and each movable tooth disc is distributed on the tooth disc rotating shaft from top to bottom. When the movable tooth disc and the tooth disc rotating shaft are in a split structure, a hexagonal embedded structure (as shown in FIG. 5 or FIG. 6) can be machined on the movable tooth disc, and adjustment shims are placed between each level of movable tooth disc during installation, and each level of movable tooth disc is fixed by bolts and the motor main shaft.

[0043] The movable tooth disc includes a first disc body 4-1 and first disc teeth 4-2, and the side of the first disc body facing the static tooth disc is distributed with a plurality of first disc teeth. The static tooth disc includes a second disc body and second disc teeth, and the side of the second disc body facing the movable tooth disc is distributed with a plurality of second disc teeth. The first disc teeth and the second disc teeth are staggered and embedded. The first disc teeth and the second disc teeth are cylindrical disc teeth (as shown in FIG. 5) or block-shaped disc teeth (as shown in FIG. 6). Among them, a plurality of layers of first disc teeth are annularly distributed on the first disc body, and a plurality of layers of second disc teeth are annularly distributed on the second disc body. Adjacent two disc teeth (i.e. first disc teeth or second disc teeth) on the same layer have a gap to form a radial flow channel with a certain width. The edge of the disc tooth close to the gap has a special shape such as a straight line or a circular arc, which can form different types of radial flow channels. The width and number of radial flow channels on different tooth discs (i.e. static tooth disc or movable tooth disc) or different layers of the same tooth disc can be different.

[0044] In the above preparation device structure, the movable tooth disc and the static tooth disc in each level of material cavity can be modularly designed, and can be combined and replaced according to different material requirements. A single-level multi-layer stripping structure can be formed by using different combinations of movable tooth discs and static tooth discs. In the single-level multi-layer stripping structure, a set of movable and static tooth discs are used, and a plurality of layers of disc teeth are distributed on the movable and static tooth discs. Each layer of radial flow channel and circumferential flow channel extends in the span direction of the tooth disc. In the multi-level multi-layer stripping structure, a plurality of sets of movable and static tooth discs are used, and each level of movable and static tooth discs is axially stacked and installed. Each level of movable and static tooth discs independently has a plurality of layers of disc teeth, and each layer of radial and circumferential flow channel can extend in the span direction and the axial direction of the tooth disc.

[0045] The principle of the preparation device is as follows: the high-speed relative rotation between the movable gear plate and the static gear plate can simultaneously provide centrifugal force and shear force to any point in the system, and the two actions are separated by the designed radial flow channel and the circumferential flow channel. The shear flow formed by the speed difference between the two walls of the circumferential flow channel exerts a shear peeling action on the material, and the centrifugal force in the radial flow channel is coupled with the flow channel width to realize the size selection of the material. The cooperation of the two flow channels realizes the synchronization of material peeling and screening, so that nanomaterials with uniform size can be efficiently prepared.

[0046] The present embodiment realizes a centrifugal shear continuous peeling preparation method of aramid fiber by using the above preparation device. The solution used is a deprotonated system formed by adding DMSO / KOH to macroscopic aramid (PPTA), wherein the mass ratio of PPTA to KOH (potassium hydroxide) is 1:1-1:3, and the volume ratio of DMSO (dimethyl sulfoxide) to water is 25:1.

[0047] The process of preparing aramid nanofiber using the above preparation device with two-stage two-layer peeling structure is as follows: first, the prepared aramid fiber suspension is added to the material cavity, the main motor is adjusted to the predetermined speed and started, and the suspension is pushed by the centrifugal force in the material cavity to pass through the second-stage movable gear plate and static gear plate, the first-stage movable gear plate and static gear plate in turn, and the aramid fiber is subjected to continuous shear peeling action in each circumferential flow channel, and the fiber diameter gradually decreases; then the suspension passes through the discharge port on the first-stage cavity and enters the circulation pipeline, and under the action of centrifugal pressure, it returns to the material cavity through the inlet port for the next round of processing; finally, after a predetermined processing time, the three-way valve on the circulation pipeline is adjusted to guide the aramid nanofiber product out. In the whole process, the macroscopic aramid fiber undergoes a multi-stage process of peeling, screening, re-peeling, and re-screening, so that the diameter of the nanofiber continuously decreases and finally forms a nanomaterial with a target size. Among them, the centrifugal action and the shear peeling action are generated by the rotation of the preparation device, and the relative rotation between the static gear plate and the movable gear plate in the preparation device generates a centrifugal force that forces the material solution to flow from the center to the periphery, and cooperates with the radial flow channel to realize the selective passage of the material, while the shear force generated by the rotation cooperates with the circumferential flow channel to realize the shear peeling of the material.

[0048] The prepared aramid nanofiber sol with a concentration of 0.2-3wt% is detected, and the atomic force microscope image is shown in Figure 7, and the fiber diameter measurement result is shown in Figure 8. The obtained fiber diameter range is 2.12-11.30 nanometers, the average diameter is 4.27 nanometers, the fiber length is 6-12 microns, and the maximum aspect ratio can reach 3000.

[0049] Example 2

[0050] The centrifugal shearing continuous preparation device for nanomaterials of the embodiment is different from the embodiment 1 in that, as shown in Figure 2, a single-stage four-layer stripping structure is adopted, only one-stage material cavity is arranged in the material container, a matched movable gear plate and a static gear plate are arranged in the material cavity, four layers of gear plates are respectively arranged on the movable gear plate and the static gear plate, and the remaining component parts of the preparation device, the mounting method, the preparation method and the principle are the same as those of the embodiment 1.

[0051] As described above, the application can be better implemented, and the above-mentioned embodiments are only the preferred embodiments of the application, but not used to limit the implementation range of the application; that is, all equivalent changes and modifications made according to the content of the application are covered in the scope of the claims of the application.

Claims

1. A method for continuous exfoliation of nanomaterials by centrifugal shear, characterized in that, First, the material in the central position enters the circumferential flow channel close to the central position under the centrifugal action of the preparation device, and the shear flow formed by the velocity difference of the two circumferential wall surfaces of the circumferential flow channel is used to exert strong shear peeling action on the material; then, under the push of the centrifugal force, the peeled material passes through the radial flow channel and is screened into the next layer of circumferential flow channel gradually away from the central position, and the unpeeled material stays in the upper layer of circumferential flow channel to continue peeling; finally, all the materials form nanomaterials after multi-layer shear peeling and multi-layer screening and are guided out for collection.

2. The method according to claim 1, wherein the method is characterized by, The centrifugal action and the shear peeling action are both generated by the rotation of the preparation device.

3. A device for continuous exfoliation of nanomaterials by centrifugal shear, characterized in that, The preparation device comprises a high-speed motor, a material container, a static toothed disc, a dynamic toothed disc, and a toothed disc rotating shaft. The cavity in the material container is a material cavity. The static toothed disc is fixed in the material container. The dynamic toothed disc is arranged in the material cavity and cooperates with the static toothed disc. The toothed disc rotating shaft is arranged in the middle of the dynamic toothed disc. One end of the toothed disc rotating shaft extends out of the material container and is connected with the high-speed motor. The dynamic toothed disc and the static toothed disc are embedded with each other to form a plurality of flow channel regions. In each flow channel region, the circumferential flow channels are arranged layer by layer along the center to the outer circumferential direction, and the radial flow channels are arranged along the same circumferential direction.

4. The apparatus according to claim 3, wherein the apparatus is characterized by: The material container is provided with a feeding port at the top and a discharging port at the bottom. The feeding port and the discharging port are connected by a circulating pipeline, and a three-way valve is arranged on the circulating pipeline at the discharging port.

5. The apparatus according to claim 3, wherein the apparatus is characterized by: The circumferential flow channel is an annular slit arranged along the circumferential direction, and the annular slit is composed of two circumferential wall surfaces with relative motion.

6. The apparatus according to claim 3, wherein the apparatus is characterized by: The radial flow channel is a radial slit between two adjacent circumferential flow channels, and the width of each layer of radial flow channels gradually decreases along the center to the outer circumferential direction.

7. The apparatus according to claim 6, wherein the apparatus is characterized by: The radial flow channel forms an included angle of 0°-80° between the axial direction of the radial flow channel and the diameter direction of the circumferential direction where the radial flow channel is located.

8. The apparatus according to claim 3, wherein the apparatus is characterized by: The material cavity in the material container has one or more levels, and each level of the material cavity is arranged in sequence from top to bottom. Each level of the material cavity is respectively provided with a pair of static toothed discs and dynamic toothed discs.

9. The apparatus according to claim 3, wherein the apparatus is characterized by: The material container and the static toothed disc are in an integrated structure or a split structure, and the dynamic toothed disc and the toothed disc rotating shaft are in an integrated structure or a split structure.

10. The apparatus according to claim 3, wherein the apparatus is characterized by: The dynamic toothed disc comprises a first disc body and first disc teeth. The side of the first disc body facing the static toothed disc is provided with a plurality of first disc teeth. The static toothed disc comprises a second disc body and second disc teeth. The side of the second disc body facing the dynamic toothed disc is provided with a plurality of second disc teeth. The first disc teeth and the second disc teeth are staggered and embedded. The first disc teeth and the second disc teeth are cylindrical disc teeth or block disc teeth.

Images