CN110193329B - Device for preparing two-dimensional nano material by virtue of supergravity coupling - Google Patents
Device for preparing two-dimensional nano material by virtue of supergravity coupling Download PDFInfo
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- CN110193329B CN110193329B CN201910412425.6A CN201910412425A CN110193329B CN 110193329 B CN110193329 B CN 110193329B CN 201910412425 A CN201910412425 A CN 201910412425A CN 110193329 B CN110193329 B CN 110193329B
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- C01B32/00—Carbon; Compounds thereof
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Abstract
The invention relates to the technical field of nano material preparation, and provides a device for preparing a two-dimensional nano material by virtue of supergravity coupling, aiming at solving the problems of low efficiency energy consumption, low single-layer rate, wide sheet layer size distribution and low yield of the traditional two-dimensional nano material preparation process; the hypergravity circulating concentration system comprises a hypergravity coupling machine II, and the hypergravity coupling machine II is communicated with a second metering device, a second driving device and a conductivity measuring device through pipelines. The device has the advantages of simple structure, compact matching, high production efficiency, convenient installation and disassembly, and capability of realizing the large-scale low-cost production of various two-dimensional layered nano materials, and can realize the synchronous operation of three cycles.
Description
Technical Field
The invention relates to the technical field of nano material preparation, in particular to a device for preparing a two-dimensional nano material by supergravity coupling.
Background
The supergravity technology is a new technology for reinforcing the transmission and reaction process of multiphase flow, and has the advantages of small volume, light weight, low energy consumption, easy operation, easy maintenance, safety, reliability, flexibility, adaptability to environment and the like which are not possessed by the traditional equipment, so that the supergravity technology has wide commercial application prospect in the industrial fields of environmental protection, materials, biology, chemical industry and the like. The basic principle of the supergravity engineering technology is to utilize the unique flowing behavior of a multi-phase flow system under the condition of a supergravity field to strengthen the relative speed and mutual contact between phases, thereby realizing the high-efficiency momentum, mass and heat transfer process. The high gravity field is formed by rotating the whole or part of the equipment through a motor to form a centrifugal force field.
The Chinese patent discloses a method for stripping two-dimensional nano materials by high-efficiency supergravity, and the publication number is CN201811420442.6, the invention introduces a method for coupling primary rotation and secondary rotation together to couple positive energy flow and negative energy flow generated by the primary rotation and positive energy flow and negative energy flow generated by the secondary rotation into a whole to form a four-step mechanical energy driving system: primary rotation negative energy flow → primary rotation positive energy flow → secondary rotation negative energy flow → secondary rotation positive energy flow. The first step is that the negative energy flow generated by the primary rotation sucks the materials into the secondary rotation flow channel, and the second step to the fourth step are mechanical energy conversion processes which synchronously occur, namely: potential of supergravity → static pressure → kinetic energy of high speed rotation of dean vortex. The final result is that the potential of the hypergravity is almost completely converted into kinetic energy of high-speed rotation of the dean vortex, and the mechanical energy is basically not dissipated, so that the refrigeration power of a refrigerator in the stripping process is obviously reduced, and the method for efficiently stripping the two-dimensional nano material is realized. The method is characterized in that a dispersion liquid of a two-dimensional layered material enters a central inlet of a secondary rotating flow reactor rotating at a high speed through a pipeline, a feed liquid flowing out of an outlet of the reactor enters an inlet of a tubular heat exchanger through the pipeline, the feed liquid flowing out of the outlet of the tubular heat exchanger flows back to a circulating storage tank, and the two-dimensional nano material with less layers with the layer number below 3 is obtained after the circulation for many times. However, a great deal of experiments prove that the method still has the obvious defects that the dynamic high-speed rotating secondary rotating flow reactor generates a great amount of micro bubbles in the graphene stripping process, and the static secondary rotating flow reactor also generates micro bubbles in the graphene stripping process, but the amount of the micro bubbles is small. The more microbubbles are generated, the lower the stripping efficiency of the graphene is, because the friction of the graphite slurry in the process of strong friction with the inner wall of the reactor can generate bubbles more easily than the friction stripping of the graphene, the static secondary rotating flow reactor depends on the static pressure of more than 2 MPa to drive the graphite slurry to flow through the inner wall of the secondary rotating flow reactor, and the high static pressure obviously inhibits the generation of bubbles, so that a small amount of microbubbles are generated only at the position of the reactor close to the outlet due to the low static pressure. For the dynamic secondary rotating flow reactor rotating at high speed, the supergravity potential energy difference between the inlet and the outlet of the secondary rotating flow reactor exceeds 2 MPa, but the supergravity potential energy with high height is almost completely converted into kinetic energy required by high-speed rotation of dean vortex, so that the static pressure in the reactor is low, and the generation of a large amount of micro bubbles cannot be inhibited. The experimental results show that the stripping efficiency of the dynamic secondary rotating flow reactor is reduced by more than one order of magnitude compared with the stripping efficiency of the static secondary rotating flow reactor.
The invention discloses a method and a device for separating two-dimensional nano materials by continuous hypergravity, and the publication number is CN201810575493. X.The invention introduces a method and a device for separating two-dimensional nano materials by continuous hypergravity designed according to the principle of a U-shaped pipe. However, a large number of experimental results show that it is difficult to control the flow distribution of the continuous supergravity separator by using the conventional technology, because the pressure of the material sprayed from the upper nozzle exceeds 2 mpa, and the particle size distribution of graphite in the graphite slurry reaches the millimeter scale, which requires that the size of the nozzle also reaches the millimeter scale, and the nozzle of the millimeter scale is difficult to control the flow of the graphite slurry in a lower flow range under the pressure of 2 mpa.
Chinese patent discloses a device and a method for separating two-dimensional nano materials by continuous hypergravity percolation, and the publication number is CN201810752331.9, the invention introduces a stripping solvent which can be recycled and separated by gathering uniformly dispersed two-dimensional nano sheets on the inner surface of a rotating bed layer by utilizing a hypergravity rotating particle bed layer to form soft aggregates, then filling washing liquor in the rotating bed device, forming suspension under the action of low-speed forward rotation and reverse rotation of the rotating bed, stripping out the two-dimensional nano material soft aggregates, and gathering, concentrating and separating the soft aggregates by using a hypergravity centrifugal separation device. However, a large number of experimental results show that the graphene product separated by the method has high impurity content and is difficult to separate and remove.
Disclosure of Invention
In order to overcome the defects of the invention, the invention provides the device for preparing the two-dimensional nano material by supergravity coupling, which has the advantages of simple structure, compact matching, rapidness, high efficiency, energy conservation, low cost, large batch and high quality.
In order to achieve the purpose, the invention adopts the following technical scheme:
a device for preparing a two-dimensional nano material by virtue of supergravity coupling comprises a cooling circulation system, a supergravity circulation stripping system and a supergravity circulation concentration system, wherein the supergravity circulation stripping system comprises a supergravity coupling machine I, and the supergravity coupling machine I is communicated with a first metering device, a first driving device and the cooling circulation system through pipelines; the hypergravity circulating concentration system comprises a hypergravity coupling machine II, and the hypergravity coupling machine II is communicated with a second metering device, a second driving device and a conductivity measuring device through pipelines.
The device is applied to the supergravity coupling technology to prepare the two-dimensional nano material, and the two-dimensional layered material is a fourth to sixth main group semiconductor compound (such as GaSe and SnS) and a transition metal halide (such as PbI)2、MgBr2) Metal oxides (e.g. MnO)2、MoO3) Hexagonal boron nitride (graphene), graphite phase carbon nitride, transition metal carbide, carbon nitride, fourth main group graphene analogue (semimetal silylene, germanene), honeycomb binary compound of fourth main group element (such as SiC, SnGe), third to sixth main group compound (such as InSb, GaN), fifth main group element (such as phosphorus alkene, arsenic alkene and antimony alkene), silicate, charge balance membrane plate of aluminosilicate (such as mica, clay), layered hydrotalcite.
The core of the device is a supergravity coupling technology, the supergravity coupling refers to the fact that a supergravity separation process and a mixing process are coupled together, and a supergravity coupling machine can separate and mix the materials, but the separation and the mixing need to be separated. Therefore, the device of the invention divides the graphene preparation process into two slurry circulation processes: and (3) circulating stripping and circulating concentration processes. The invention adopts an overweight force coupling machine I for the circulating stripping process and adopts an overweight force coupling machine II for the circulating concentration process. The overweight coupling machine I takes stripping as a main part and separation as an auxiliary part, and the efficient stripping process cannot be separated from the efficient separation process from the thermodynamic angle. The overweight coupling machine II mainly separates and assists in mixing, and the efficient separation process cannot be separated from the efficient mixing process from the viewpoint of dynamics. The invention finally adopts a solution large circulation mode to unify two slurry circulation systems into one operation system, as shown in figure 5.
Preferably, the overweight force coupling machine I and the overweight force coupling machine I both have a turntable with a streamline structure, and the turntable comprises a hypergravity separation unit arranged inside and a hypergravity mixing unit arranged outside.
Preferably, the supergravity separation unit is a U-shaped pipe structure formed by buckling a double-sided symmetrical rotating impeller with an upper cover plate and a lower cover plate; the supergravity mixing unit is a secondary rotating flow channel structure formed by grooves formed in the upper cover plate and the lower cover plate in a relative mode.
Preferably, concentrated slurry discharge ports are formed in two sides of the bottom of the U-shaped pipe and communicated with the secondary rotating flow channel; a slurry feeding hole is formed in the center of the bottom of the U-shaped pipe; dilute solution discharge ports are formed in two sides of the opening end of the U-shaped pipe of the overweight coupling machine I; and stripping liquid discharge ports are formed in two sides of the opening end of the U-shaped pipe of the overweight coupling machine II. Taking the stripping of graphene as an example, graphene dilute solution flows out of dilute solution discharge ports on two sides of the opening end of a U-shaped pipe of the overweight coupling machine I; graphene stripping liquid flows out of stripping liquid discharge ports on two sides of the opening end of the U-shaped pipe of the overweight force coupling machine II.
The invention relates to a supergravity coupling machine which is disc-shaped equipment for coupling a continuous supergravity separation unit and a mixing unit together, wherein the supergravity separation unit is a supergravity U-shaped pipe structure formed by buckling a double-sided symmetrical rotating impeller with an upper cover plate and a lower cover plate, the supergravity mixing unit is a secondary rotating flow channel which is carved on the upper cover plate and the lower cover plate and rotates in an accelerating way, the separation unit is positioned in the center, and the mixing unit is positioned at the outer side, as shown in figure 2. The advantages of this coupling are: firstly, the separation unit provides static pressure enough for stripping the two-dimensional nano material for the mixing unit, and generation of a large number of micro bubbles in the stripping process is inhibited, so that the efficiency of stripping the two-dimensional layered material is improved; secondly, the secondary rotating flow channel of the mixing unit can stably control the flow distribution of the separating unit, and the slurry material can stably flow out, so that the slurry material cannot be blocked. The materials enter the overweight coupling machine in the sequence of separating and mixing, and the normal sequence can be returned only by circular flow, so that the device adopts a material circulation mode to prepare the two-dimensional nano material.
Preferably, the flow cross section of the secondary rotating flow channel is a circle with the diameter of 2-6 mm, and the radial length of the secondary rotating flow channel is 30-120 mm. Preferably, the radial dimension of the secondary rotating flow channel in the overweight coupling machine I is more than one time larger than that of the secondary rotating flow channel in the overweight coupling machine II. The difference determines the different effects of the two, namely the former is focused on stripping the two-dimensional nano-layered material, and the latter is focused on concentrating the two-dimensional nano-layered material. When the engine runs under the same power, the radial size of the engine is large, and the rotating speed is low; the latter has small radial dimension and high rotating speed.
The overweight coupling machine I and II have the same structure in that the separation units have the same structure, but the mixing units have similar but different structures, and the overweight coupling machine I and II have similar structures of the secondary rotating flow channels, but the radial dimension of the flow channels is more than one time of that of the secondary rotating flow channels.
Preferably, the front surface and the back surface of the double-surface symmetrical rotating impeller are provided with a plurality of impellers along the radial direction, and a feed liquid inlet is formed between the adjacent impellers.
Preferably, the maximum hypergravity field intensity of the overweight coupling machine I and the overweight coupling machine II during one rotation is lower than 6000 g.
More preferably, the maximum hypergravity field intensity of the overweight coupling machines I and II during one rotation is controlled to be 2500-5000 g.
Preferably, the rotating speed of the overweight coupling machine I is at least 1000 rpm lower than that of the overweight coupling machine II in the process of preparing the two-dimensional nano material. When the maximum output power of the motors of the overweight coupling machine I and the overweight coupling machine II is the same, the rotating speed of the overweight coupling machine II is at least 1000 rpm higher than that of the overweight coupling machine I, namely the separation capacity of the overweight coupling machine II is obviously higher than that of the overweight coupling machine I, but the mixing capacity is obviously weaker than that of the overweight coupling machine I.
Preferably, the scale amplification mode of the method for preparing the two-dimensional nano material by coupling the hypergravity is to scale up on the premise that the strength of the hypergravity field of the separation unit is kept unchanged.
Preferably, the cooling circulation system includes a cooling circulation pump and a heat exchanger.
Therefore, the invention has the following beneficial effects: the device for preparing the two-dimensional nano material by supergravity coupling has the advantages of simple structure, compact matching, high production efficiency, realization of three-cycle synchronous operation, convenient installation and disassembly, and realization of large-scale low-cost production of various two-dimensional layered nano materials.
Drawings
FIG. 1 is a schematic structural diagram of an apparatus for preparing two-dimensional nanomaterials by supergravity coupling.
Fig. 2 is a schematic structural diagram of a overweight coupling machine I and an overweight coupling machine II.
Fig. 3 is a schematic structural view of a secondary rotation flow passage inside the turntable.
Fig. 4 is a schematic perspective view of a double-sided symmetrical rotary impeller.
Fig. 5 is a schematic diagram of the three cycle principle.
Fig. 6 is an SEM scanning electron micrograph of graphene obtained by exfoliation using the apparatus of example 1.
Fig. 7 is a SEM scanning electron micrograph of graphene obtained by exfoliation using the apparatus of example 1 at a high magnification.
Fig. 8 is an AFM atomic force microscope photograph of graphene obtained by peeling using the apparatus of example 1.
Fig. 9 is a corresponding graphene thickness plot of fig. 8.
Fig. 10 is an XRD comparison pattern of graphene obtained by graphite raw material, ultrasonic exfoliation and exfoliation using the apparatus of example 1.
In the figure: the device comprises a double-sided symmetrical rotary impeller 1, a concentrated slurry discharge port 2, a secondary rotary flow channel 3, a stripping liquid (dilute solution) discharge port 4, a supergravity separation unit 5, a supergravity mixing unit 6, a refrigeration circulating pump 7, a tube type heat exchanger 8, a first magnetic pump 9, a first metering tank 10, a supergravity coupling machine I11, a supergravity coupling machine II 12, a second metering tank 13, a second magnetic pump 14, a conductivity meter 15, a motor 16, a liquid flowmeter 17, a rotary table 18, an upper cover plate 19, a lower cover plate 20, a feed liquid inlet 21 and a slurry feed port 22.
Detailed Description
The technical solution of the present invention is further specifically described below by using specific embodiments and with reference to the accompanying drawings.
In the present invention, all the equipment and materials are commercially available or commonly used in the art, and the methods in the following examples are conventional in the art unless otherwise specified.
Example 1
As shown in fig. 1, a device for preparing a two-dimensional nanomaterial by supergravity coupling comprises a cooling circulation system, a supergravity circulation stripping system and a supergravity circulation concentration system, wherein the cooling circulation system is composed of a refrigeration circulation pump 7 and a tube type heat exchanger 8, and the supergravity circulation stripping system comprises a supergravity coupling machine i 11 which is communicated with a first metering tank 10, a first magnetic pump 9 and the cooling circulation system through pipelines; the hypergravity circulation concentration system comprises a hypergravity coupling machine II 12 which is communicated with a second metering tank 13, a second magnetic pump 14 and a conductivity meter 15 through pipelines.
As shown in fig. 2, each of the overweight coupling machine i and the overweight coupling machine II has a rotating disc 18 of a streamline structure and a motor 16 for generating power, and the rotating disc includes a hypergravity separation unit 5 arranged inside and a hypergravity mixing unit 6 arranged outside. The supergravity separation unit is a U-shaped pipe formed by buckling a double-sided symmetrical rotating impeller 1 with an upper cover plate 19 and a lower cover plate 20; the supergravity mixing unit is a secondary rotating flow channel 3 (see fig. 3) formed by grooves oppositely formed on an upper cover plate 19 and a lower cover plate 20, the centers of the bottoms of U-shaped pipes of a supergravity coupling machine I and a supergravity coupling machine II are provided with slurry feeding holes 22, two sides of the bottom of each U-shaped pipe are provided with concentrated slurry discharging holes 2 communicated with the secondary rotating flow channel, wherein two sides of the opening end of the U-shaped pipe of the supergravity coupling machine I are provided with dilute solution discharging holes 4, and two sides of the opening end of the U-shaped pipe of the supergravity coupling machine I are provided with stripping solution discharging holes 4; the flow section of a secondary rotating flow channel of the overweight coupling machine I is a circular section with the diameter of 2.5 mm, and the radial length of the secondary rotating flow channel is 60 mm; the flow section corresponding to the overweight coupling machine II is a circular section with the diameter of 2.0 mm, and the radial length is 30 mm; the separation unit comprises a double-sided symmetrical rotating impeller and a supergravity separation cavity; as shown in fig. 4, 12 impellers are respectively arranged on the front and back sides of the double-sided symmetrical impeller, and a feed liquid inlet 21 is arranged between the adjacent impellers, and the total number is 12. The maximum hypergravity field intensity of the overweight force coupling machines I and II during one-time rotation is controlled to be 2500-5000 g. The rotating speed of the overweight coupling machine I is at least 1000 rpm lower than that of the overweight coupling machine II in the process of preparing the two-dimensional nano material.
The application method of the device for preparing the two-dimensional nano material by the supergravity coupling comprises the following steps:
(1) as shown in fig. 1, the freezing cycle step is started: dispersing flake graphite raw materials into dispersion liquid to obtain graphite slurry, pouring the slurry into a first metering tank 10, starting a refrigeration circulating pump 7 and a first magnetic pump 9 to enable the slurry to circularly cool and flow between a tubular heat exchanger 8 and the first metering tank 10, reducing the temperature of the slurry to-2 ℃, and controlling the concentration of the low-temperature graphene slurry to be 3.0 g/L.
(2) As shown in fig. 5, the three-cycle step is initiated:
the step comprises two small cycles, namely the cyclic stripping of the graphite slurry and the cyclic concentration of the graphene slurry, and one large cycle, namely the cycle between the stripping solution and the graphene solution, wherein the three cycles are synchronously performed.
The stripping balance between graphite and graphene exists in the circulating stripping process, the graphite slurry circularly flows among the first metering tank 10, the tubular heat exchanger 8 and the overweight force coupling machine I11, the graphite slurry enters the overweight force coupling machine I11 to be separated into low-concentration graphene solution and high-concentration graphite slurry, the flow rates of the low-concentration graphene solution and the high-concentration graphite slurry are close, and the separated low-concentration graphene solution flows into the overweight force coupling machine II 12 to be circularly concentrated.
High-concentration graphite slurry continuously flows through a secondary rotating flow channel in the overweight coupling machine I11 to strip out new graphene, then flows back to the first metering tank 10, is mixed and diluted to be close to the original concentration with stripping liquid flowing out of the overweight coupling machine II 12 in the first metering tank 10, and then is continuously stripped in a circulating manner, the stripping balance of feed liquid is updated twice in one circle every cycle, and because the graphite concentration can continuously go low, new high-concentration graphite slurry needs to be supplemented, and the feeding mode can be continuous feeding or intermittent feeding.
Meanwhile, the cyclic concentration process is also carried out rapidly, the graphene slurry is cyclically concentrated among the second metering tank 13, the liquid flowmeter, the conductivity meter 15 and the overweight coupling machine II 12, the adsorption balance between the monodisperse graphene and the graphene soft aggregate exists in the cyclic concentration process, the flow rate and the conductivity of the slurry are synchronously monitored, after the graphene slurry enters the overweight coupling machine II 12, the nearly colorless transparent stripping liquid and the high-concentration graphene slurry are separated firstly, the stripping liquid flows back to the cyclic stripping process, the high-concentration graphene slurry flows into a secondary rotating flow channel of the overweight coupling machine II to be dispersed into very small graphene clusters, the graphene clusters and the low-concentration graphene solution are mixed uniformly and then are converged into the second metering tank 13 together, and the dispersed graphene clusters in the process rapidly adsorb the free graphene, make the graphite alkene concentration of free state in the graphite alkene thick liquid reduce fast, then constantly carry out the circulation concentration, the feed liquid adsorbs the equilibrium and updates twice every circulation a week, in order to stabilize the concentration of graphite alkene thick liquid, need discharge some high concentration graphite alkene thick liquids (graphite alkene content about 1 g/L), and the continuous ejection of compact or intermittent type ejection of compact can be selected to the ejection of compact mode.
In the overweight coupling machine II, the flow rates of the concentrated graphene slurry and the stripping liquid are similar; the axial average linear velocity of the graphene slurry is 50 m/s. Controlling the temperature to be-2 to-4 ℃ in the stripping process; the temperature during concentration was controlled at 2 to 4 ℃.
As shown in fig. 2, in the preparation process, a concentrated graphite coarse slurry flows out of a concentrated slurry outlet 2 of a gravity coupler i, a graphite slurry flows in a slurry inlet 22 at the center of the bottom of a U-shaped pipe, and a graphene dilute solution flows out of a dilute solution outlet 4. Concentrated graphene fine slurry flows out of a concentrated slurry outlet 2 at the bottom of a U-shaped pipe of the overweight coupling machine II, graphene fine slurry enters from a slurry inlet 22 at the top of the U-shaped pipe, and graphene stripping liquid flows out of a stripping liquid outlet 4. In the process of preparing graphene, the rotating speeds of the overweight coupling machines I and II are 4500 rpm and 5500rpm respectively, and the highest hypergravity field levels in the separation units of the overweight coupling machines I and II are 3170 g and 4733 g respectively (g is normal gravitational field acceleration) at the rotating speeds.
The device for preparing the two-dimensional nano material by supergravity coupling of the embodiment is used for carrying out stripping to obtain few-layer graphene, and the method comprises the following steps:
fig. 6 and 7 are SEM electron micrographs of graphene.
Fig. 8 is an AFM (atomic force microscopy) photograph of graphene peeled off by the device, fig. 9 is a corresponding graph of thickness of graphene nanosheets, and it can be seen from fig. 9 that the thickness of the graphene nanosheets is less than 1 nm, the thickness of single-layer graphene is theoretically 0.34 nm, and if the number of layers of graphene in the interlayer distance map is calculated to be two. The atomic force microscope characterization can prove that few-layer graphene (mostly double-layer or three-layer graphene) with the transverse dimension larger than 2 microns can be obtained by a supergravity coupling method.
Fig. 10 is an XRD comparison graph of graphene from graphite raw material, ultrasonic exfoliation and exfoliation by the apparatus, from which it can be seen that the (004) plane of graphite in the 55-degree position of graphene almost disappears, indicating that the ordered structure in the longitudinal stacking dimension is disturbed, thus demonstrating that multi-layer graphite is exfoliated into few-layer or single-layer graphene, and XRD results of graphene exfoliated by the ultrasonic method and the supergravity coupling method are consistent.
Example 2
In the graphene preparation process, the highest hypergravity field level of each separation unit of the overweight coupling machine I and the overweight coupling machine II in one rotation is still 3170 g and 4733 g respectively. Example 2 differs from example 1 in that: the flow cross section of the secondary rotating flow channel in the overweight coupling machine I is circular with the diameter of 2mm, the radial length of the secondary rotating flow channel in the overweight coupling machine I is 120mm, and the radial size of the secondary rotating flow channel in the overweight coupling machine I is 1.5 times of that of the secondary rotating flow channel in the overweight coupling machine II. Controlling the flow ratio of the graphite concentrated slurry to the low-concentration graphene solution to be 0.5: 1; the axial average linear velocity of the graphite concentrated slurry reaches 65 m/s. Controlling the temperature to be 4 ℃ below zero in the stripping process; the temperature during concentration was controlled at 1 ℃. In the step (1), the concentration of the low-temperature graphene slurry is controlled to be 6.0g/L, and the rest process steps and parameters are completely the same.
Example 3
In the graphene preparation process, the highest hypergravity field level of each separation unit of the overweight coupling machine I and the overweight coupling machine II in one rotation is still 3170 g and 4733 g respectively. Example 3 differs from example 1 in that: the flow cross section of the secondary rotating flow channel in the overweight coupling machine I is circular with the diameter of 6mm, the radial length of the secondary rotating flow channel in the overweight coupling machine I is 120mm, and the radial size of the secondary rotating flow channel in the overweight coupling machine I is 2 times of that of the secondary rotating flow channel in the overweight coupling machine II; controlling the flow ratio of the graphite concentrated slurry to the low-concentration graphene solution to be 2: 1; the axial average linear velocity of the graphene slurry was 65 m/s. Controlling the temperature to be-3 ℃ in the stripping process; the temperature during concentration was controlled at 2 ℃. In the step (1), the concentration of the low-temperature graphene slurry is controlled to be 9.0g/L, and the rest process steps and parameters are completely the same. The performance of the few-layer graphene obtained by stripping in examples 2-3 is equivalent to that of example 1, and details are not repeated here.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way, and other variations and modifications may be made without departing from the spirit of the invention as set forth in the claims.
Claims (7)
1. The device for preparing the two-dimensional nano material by virtue of supergravity coupling is characterized by comprising a cooling circulation system, a supergravity circulation stripping system and a supergravity circulation concentration system, wherein the supergravity circulation stripping system comprises a supergravity coupling machine I, and the supergravity coupling machine I is communicated with a first metering device, a first driving device and the cooling circulation system through pipelines; the supergravity circulating concentration system comprises a supergravity coupling machine II, and the supergravity coupling machine II is communicated with a second metering device, a second driving device and a conductivity measuring device through pipelines;
the feed inlet of the overweight coupling machine II is communicated with the discharge outlet of the overweight coupling machine I;
the overweight coupling machine I and the overweight coupling machine II are respectively provided with a turntable with a streamline structure, and the turntable comprises an overweight separating unit arranged inside and an overweight mixing unit arranged outside; the supergravity separation unit is of a U-shaped pipe structure formed by buckling a double-sided symmetrical rotating impeller with an upper cover plate and a lower cover plate; the supergravity mixing unit is a secondary rotating flow channel structure formed by grooves oppositely formed in an upper cover plate and a lower cover plate; concentrated slurry discharge ports are formed in two sides of the bottom of the U-shaped pipe and communicated with the secondary rotating flow channel; a slurry feeding hole is formed in the center of the bottom of the U-shaped pipe; dilute solution discharge ports are formed in two sides of the opening end of the U-shaped pipe of the overweight coupling machine I; and stripping liquid discharge ports are formed in two sides of the opening end of the U-shaped pipe of the overweight coupling machine II.
2. The device for preparing the two-dimensional nanometer material through the supergravity coupling according to claim 1, wherein the flow cross section of the secondary rotating flow channel is a circle with a diameter of 2-6 mm, and the radial length of the secondary rotating flow channel is 30-120 mm.
3. The apparatus of claim 1, wherein the radial dimension of the secondary rotating flow channel in the overweight coupling machine I is more than one time larger than the radial dimension of the secondary rotating flow channel in the overweight coupling machine II.
4. The device for preparing the two-dimensional nano material through the supergravity coupling according to claim 3, wherein the front and back surfaces of the double-sided symmetrical rotating impeller are provided with a plurality of impellers along the radial direction, and a material liquid inlet is formed between the adjacent impellers.
5. The apparatus for preparing two-dimensional nano-materials by supergravity coupling according to claim 1, wherein the maximum supergravity field intensity of the supergravity coupling machine I and the supergravity coupling machine II is less than 6000 g.
6. The apparatus for preparing two-dimensional nanometer material by supergravity coupling according to claim 1, wherein the rotation speed of the supergravity coupling machine I is at least 1000 rpm lower than that of the supergravity coupling machine II during the process of preparing two-dimensional nanometer material.
7. The device for preparing the two-dimensional nanometer material by the supergravity coupling according to any one of claims 1 to 6, wherein the cooling circulation system comprises a cooling circulation pump and a heat exchanger.
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| CN102725226A (en) * | 2009-11-03 | 2012-10-10 | 法国国家科学研究中心 | Preparation of graphene by mechanically thinning graphite materials |
| CN107139573A (en) * | 2017-04-01 | 2017-09-08 | 浙江海洋大学 | A kind of efficient method and device for peeling off two-dimensional material |
| US10304937B2 (en) * | 2013-03-14 | 2019-05-28 | The Provost, Fellows, Foundation Scholars, And The Other Members Of Board, Of The College Of The Holy And Undivided Trinity Of Queen Elizabeth Near Dublin | Scalable process for producing exfoliated defect-free, non-oxidised 2-dimensional materials in large quantities |
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| WO2009155353A1 (en) * | 2008-06-17 | 2009-12-23 | The Regents Of The University Of California | Process and system for reducing sizes of emulsion droplets and emulsions having reduced droplet sizes |
| CN205462060U (en) * | 2016-03-11 | 2016-08-17 | 无锡职业技术学院 | System is peeled off in mixture of graphite alkene |
| US11103848B2 (en) * | 2016-08-15 | 2021-08-31 | Advanced Energy Materials, Llc | Flame based fluidized bed reactor for nanomaterials production |
| CN206715904U (en) * | 2017-05-19 | 2017-12-08 | 四川大学 | A kind of super gravity field microreactor for preparing nano material |
| CN108993784B (en) * | 2018-06-06 | 2020-08-18 | 浙江海洋大学 | Method and device for separating two-dimensional nano material by continuous supergravity |
| CN108926881B (en) * | 2018-07-10 | 2021-01-15 | 浙江海洋大学 | Device and method for separating two-dimensional nano material by continuous hypergravity percolation |
| CN109502576A (en) * | 2019-01-07 | 2019-03-22 | 江苏省特种设备安全监督检验研究院 | The sealed helical flow field graphene nanometer sheet preparation facilities of ultrahigh speed and preparation method |
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| CN102725226A (en) * | 2009-11-03 | 2012-10-10 | 法国国家科学研究中心 | Preparation of graphene by mechanically thinning graphite materials |
| US10304937B2 (en) * | 2013-03-14 | 2019-05-28 | The Provost, Fellows, Foundation Scholars, And The Other Members Of Board, Of The College Of The Holy And Undivided Trinity Of Queen Elizabeth Near Dublin | Scalable process for producing exfoliated defect-free, non-oxidised 2-dimensional materials in large quantities |
| CN107139573A (en) * | 2017-04-01 | 2017-09-08 | 浙江海洋大学 | A kind of efficient method and device for peeling off two-dimensional material |
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