CN213761851U

CN213761851U - High-efficiency filter membrane

Info

Publication number: CN213761851U
Application number: CN201921959574.6U
Authority: CN
Inventors: 不公告发明人
Original assignee: Shanghai Juna New Material Technology Co ltd
Current assignee: Shanghai Juna New Material Technology Co ltd
Priority date: 2019-11-12
Filing date: 2019-11-12
Publication date: 2021-07-23
Anticipated expiration: 2029-11-12

Abstract

The utility model provides a high-efficient filtration membrane, this filtration membrane includes: a carbon nanotube array; and an amino-rich modifier uniformly loaded on the carbon nanotubes in the carbon nanotube array. When gas or liquid passes through the carbon nano tube, effective filtration and adsorption can be realized; and an amino-rich modifier is matched to further improve the adsorption and filtration effects. Moreover, the vertical carbon nanotube array has good tropism, has a guiding effect on the flow direction of gas or liquid, and can be designed for different environments due to the fact that the height of the carbon nanotube array can be controlled according to growth conditions, and the adsorption effect and the capacity can be controlled.

Description

High-efficiency filter membrane

Technical Field

The utility model relates to a filter technical field, concretely relates to high-efficient filtration membrane.

Background

The great emission of greenhouse gases mainly comprising carbon dioxide accelerates the global warming trend and causes ecological damage. Therefore, materials for removing carbon dioxide have been studied in large quantities. There are several techniques for carbon dioxide removal, however, various problems remain.

Conventional carbon dioxide removal methods are: physical adsorption and chemical adsorption. Examples of the chemical adsorption include a metal compound absorption method, an alcohol amine solution absorption method, a molecular sieve pressure swing adsorption method, and a solid amine adsorption method. The metal compound absorption method utilizes the basic property of metal oxide to absorb acidic carbon dioxide and simultaneously generate bicarbonate, and then the regeneration is realized by reverse reaction at high temperature. Because of the need for synthesis and regeneration at high temperatures, the energy consumption is relatively high and the carbon dioxide absorption capacity is reduced at extremely low temperatures and high pressures. The alcohol amine solution absorption method belongs to chemical absorption, and absorbs carbon dioxide at low temperature and releases the carbon dioxide at high temperature. However, the alcohol amine solution absorption method has the problems of high toxicity, low efficiency, high regeneration energy consumption and the like, and is difficult to absorb when the concentration of carbon dioxide is lower than 0.5%, the existence of oxygen can also cause the degradation of a solvent in an absorption liquid, and the degradation product can easily cause the corrosion of a container. The molecular sieve pressure swing adsorption method realizes regeneration in a pressure swing or temperature swing mode, and still has the problems that the regeneration cycle time is long, the hydrophilicity of the molecular sieve is strong, the molecular sieve is easy to lose efficacy after moisture absorption, and a drying device needs to be added in front of an adsorption bed, so that the bed weight and the flow resistance are increased, and the equivalent weight and the energy consumption ratio of a cleaning system are increased; the adsorption capacity to oxygen and nitrogen is certain, so that a certain amount of sodium is brought to separation; since the adsorption capacity of the molecular sieve depends on the partial pressure of carbon dioxide, it is difficult to achieve low-concentration carbon dioxide adsorption. The solid amine adsorption method introduces organic amine on a porous material substrate through means of grafting, dipping and the like, the solid amine and carbon dioxide can be reversible to form carbamate or bicarbonate, reversible regeneration is realized through heating or vacuum, and the solid amine adsorption method has many advantages, such as low regeneration energy consumption, large adsorption capacity, high selectivity, easy operation and the like. Therefore, it has received extensive attention and research.

The existing solid amine adsorption material mainly comprises a carbon dioxide adsorption material which is prepared by modifying the surface of a silicon dioxide carrier by adopting aminosilane, and a solid amine material which takes a PMMS polymer as a substrate, and has the defects of high assembly cost and large volume due to small specific surface area of the polymer substrate, and meanwhile, the heat transfer of the adsorbent in the adsorption and desorption processes is limited due to low hot melting and heat conduction rates of the polymer substrate. In addition, the thickness of the existing silicon dioxide carrier or polymer carrier is limited by the material, and the thickness of the finally prepared device is not adjustable, so that the performance of the device is not adjustable.

Therefore, it is a new research direction to develop a new porous material with a large specific surface area, simple fabrication, and good thermal conductivity. Currently, there is much interest in porous material substrates such as zeolites, activated carbon, carbon nanotubes, mesoporous molecular sieves, fibers, polymers, silica gel, and the like. As a new generation of carbon functional material, carbon nanotubes have the advantages of uniform tube diameter, large specific surface area, good thermal conductivity, light weight, and the like, and are gradually a hot spot in current research. The carbon nano tube modified by the amino group has good adsorption selectivity and thermal conductivity when being used for carbon dioxide adsorption.

However, the main focus of the research on the application of the amino-modified carbon nanotube to carbon dioxide adsorption is to introduce an amino functional group on the surface of the carbon nanotube to improve the carbon dioxide adsorption effect, and neglect the influence of the structure and surface chemical properties of the carbon nanotube on the amino-modified effect and the carbon dioxide effect, so that the carbon dioxide filtration effect of the existing amino-modified carbon nanotube is not ideal, which is one of the problems to be solved urgently.

Moreover, the existing methods include an impregnation method and a grafting method, organic amine obtained by the impregnation method is not uniformly distributed, agglomeration can occur, the utilization rate is not high, even pore channels can be blocked, mass transfer of carbon dioxide is limited, the organic amine is adsorbed on the surface of a carrier through intermolecular force, the stability is not high, and the adsorption performance of the adsorbent is gradually reduced due to volatilization or decomposition of the organic amine along with increase of regeneration times. Although the grafting method has good thermal stability and can highly disperse on the surface of the carrier, the total amount of the introduced amino groups is limited due to the limited number of oxygen-containing functional groups on the surface of the carrier, so that the adsorption amount of the adsorption material obtained by the grafting method is reduced.

Therefore, how to effectively and firmly disperse the amino functional groups on the surface of the carbon nanotube without the limitation of the oxygen-containing functional groups, and to increase the adsorption amount is another problem that needs to be solved.

SUMMERY OF THE UTILITY MODEL

In order to overcome the problems, the utility model aims to provide a high-efficiency filtering membrane, which can flexibly adjust the thickness of the filtering membrane and improve the filtering effect; and the defect that the number of the traditional amino functional groups is limited by the number of the oxygen-containing functional groups is overcome.

In order to achieve the above object, the present invention provides a high efficiency filtering membrane, including: a carbon nanotube array; and an amino-rich modifier uniformly loaded on the carbon nanotubes in the carbon nanotube array.

In some embodiments, the array of carbon nanotubes is a vertical array of carbon nanotubes.

In some embodiments, the carbon nanotube array has a spacing between adjacent carbon nanotubes, and the top or bottom of the carbon nanotube array is fixed on a porous support; the holes of the porous support frame are aligned and communicated with the inner holes of the carbon nano tubes.

In some embodiments, the amino-rich modifier is uniformly distributed on the top of the carbon nanotubes and on the inner and outer walls of the carbon nanotubes.

In some embodiments, the amino-rich modifier is located on top of the carbon nanotubes and forms a ring attached to the top of the carbon nanotubes.

In some embodiments, the graphene nanotubes have an inner diameter greater than an inner diameter of the ring formed by the amino-rich modifier.

In some embodiments, the amino-rich modifier is also uniformly distributed at the bottom of the carbon nanotubes.

In some embodiments, the amino-rich modifier forms an annular inner diameter of no greater than 2nm, and the carbon nanotubes have an inner diameter of 0.5 to 60 nm; the height of the graphene nanotube array is 1-1000 microns.

The high-efficiency filtering membrane of the utility model is composed of the carbon nanotube array and the amino-rich modifier uniformly loaded on the carbon nanotube, and can realize effective filtering and adsorption when gas or liquid passes through the carbon nanotube; and an amino-rich modifier is matched to further improve the adsorption and filtration effects. Moreover, the vertical carbon nanotube array has good tropism, has a guiding effect on the flow direction of gas or liquid, and can be designed for different environments due to the fact that the height of the carbon nanotube array can be controlled according to growth conditions, and the adsorption effect and the capacity can be controlled. Furthermore, the top and/or the bottom of the carbon nano tube form an annular amino-rich modifier, and when gas or liquid enters the inner hole of the carbon nano tube, the annular amino-rich modifier can be fully adsorbed and grabbed, so that the adsorption and filtration effects are improved. The inner diameter of the ring formed by the amino-rich modifier is smaller than the inner diameter of the graphene carbon nanotube and also can be larger than the inner diameter of the graphene carbon nanotube, when the inner diameter of the ring is smaller than the inner diameter of the carbon nanotube, the adsorption effect of the amino-rich modifier can be improved, the inner hole of the carbon nanotube is further reduced on the basis of the aperture of the carbon nanotube, and therefore the superfine carbon nanotube filter membrane is formed. Because the grafting process is adopted to form the loaded amino-rich modifier on the inner wall and the outer wall of the carbon nano tube, the contact of the amino-rich modifier and the chemical bond of the carbon nano tube is improved, and the selective adsorption property and the thermal conductivity are improved. And moreover, atomic layer in-situ deposition is carried out on two ends of the carbon nano tube by adopting a monoatomic layer deposition process, the formed amino-rich modifier can form the thickness of a monoatomic layer or a polyatomic layer, the chemical bonding of the amino-rich modifier and the carbon nano tube is realized, the number of the amino-rich modifier loaded on the carbon nano tube is increased, and the adsorption and filtration effects are further improved. Furthermore, the adjacent carbon nano tubes are spaced, and the corresponding porous support frames are provided with holes corresponding to the inner holes of the carbon nano tubes, so that gas or liquid can pass through the gaps and the inner holes of the solid modified carbon nano tubes, and the filtering effect and the adsorption effect are further improved. Moreover, the porous support frame is formed at one end of the carbon nano tube in a vacuum evaporation mode, the damage degree to the end part of the carbon nano tube is reduced, and meanwhile, the porous support frame is tightly combined with the end part of the carbon nano tube, so that the carbon nano tube is really supported.

Furthermore, in the efficient filtering device based on the efficient filtering membrane, besides the advantages, the corresponding porous support frame is provided with the first holes corresponding to the inner holes of the carbon nanotubes and the second holes corresponding to the gaps between the carbon nanotubes aiming at the condition that the adjacent carbon nanotubes have the intervals, so that gas or liquid can pass through the gaps and the inner holes of the solid modified carbon nanotubes, and the filtering effect and the adsorption effect are further improved. Moreover, the porous support frame is formed at the two ends of the carbon nano tube in a vacuum evaporation mode, so that the damage degree to the end part of the carbon nano tube is reduced, and meanwhile, the porous support frame is tightly combined with the end part of the carbon nano tube, so that the carbon nano tube is really supported.

Drawings

FIG. 1 is a schematic structural diagram of a filtering membrane according to an embodiment of the present invention

FIG. 2 is a schematic view of the matching relationship between the carbon nanotube array and the porous support frame according to an embodiment of the present invention

FIG. 3 is a schematic flow chart of a method for preparing a filtration membrane according to an embodiment of the present invention

Detailed Description

In order to make the contents of the present invention clearer and easier to understand, the following description will further explain the contents of the present invention in conjunction with the specific embodiments. Of course, the invention is not limited to this specific embodiment, and general alternatives known to those skilled in the art are also within the scope of the invention.

The utility model discloses a high-efficient filtration membrane, including carbon nanotube array and the rich amino modifier of even load on the carbon nanotube in the carbon nanotube array.

The present invention will be described in further detail with reference to the following embodiments and accompanying drawings 1 to 3.

Referring to fig. 1, the carbon nanotube array is a vertical carbon nanotube array, and fig. 1 shows a carbon nanotube array arranged closely. Referring to fig. 2, the adjacent carbon nanotubes in the carbon nanotube array have a spacing therebetween, and the top or bottom of the carbon nanotube array is fixed on a porous support frame 00; the holes K of the porous support frame 00 are aligned and communicated with the inner holes of the carbon nano tubes.

Referring to fig. 1, the amino group-rich modifier (thick solid line) is uniformly distributed on the top and bottom of the carbon nanotube and on the inner and outer walls (black dots) of the carbon nanotube, where the amino group-rich modifier is located on the top of the carbon nanotube and forms a ring shape attached to the top of the carbon nanotube. It is noted that the amino group-rich modifier ring shape may be a dashed ring shape or a solid ring shape. Here, the amino-rich modifier is also located at the bottom of the carbon nanotube and forms a ring attached to the bottom of the carbon nanotube. Here, the inner diameter of the graphene nanotube is larger than that of the ring formed by the amino-rich modifier. Preferably, the inner diameter of the ring formed by the amino-rich modifier is not more than 2nm, and the inner diameter of the graphene nanotube is 0.5-60 nm.

The amino-rich modifier can be positioned on the top of the carbon nano tube, the bottom of the carbon nano tube and both the top and the bottom of the carbon nano tube besides being positioned on the inner wall and the outer wall of the carbon nano tube.

In addition, the filtering membranes with different thicknesses are obtained by controlling the height of the carbon nanotube array, so that the filtering adsorption characteristic which can be tuned according to different environments and different requirements is realized. Preferably, the height of the carbon nanotube array is 1 to 1000 μm.

Referring to fig. 3, the preparation method of the high efficiency filtration membrane of the present embodiment includes:

step 01: providing a carbon nanotube array;

specifically, the carbon nanotube array may be prepared by a conventional method, and it should be noted that the carbon nanotube array is grown on the basis of a substrate, and the grown carbon nanotube array may have a gap or no gap, and is not peeled off from the substrate after growth, and the substrate still exists during subsequent growth of the amino-rich modifier.

Step 02: forming evenly loaded amino-rich modifier on the inner wall and the outer wall of the carbon nano tube;

specifically, the grafting process is utilized to form the uniformly loaded amino-rich modifier on the inner wall and the outer wall of the carbon nanotube, and the conventional grafting process can be adopted to form the amino-rich modifier loaded on the inner wall and the outer wall of the carbon nanotube.

Step 03: an annular amino-rich modifier is formed at the top and bottom of the carbon nanotube.

Specifically, the carbon nanotube array with the substrate is placed in the forward direction, the substrate is placed below, the carbon nanotube array is placed above, and the amino-rich modifier is deposited on the top of the carbon nanotube by adopting a monoatomic layer deposition process. If the ring shape of the amino group-rich modifier is provided only on the top, then the substrate is removed, which may be by chemical etching or cutting.

If the top and bottom of the carbon nanotube have the ring shape of the amino-rich modifier, then a porous support is deposited on the top of the carbon nanotube array, and the porous support is made of alloy, and vacuum evaporation can be used here. Then, the substrate is removed, and the substrate can be removed by chemical etching or cutting. And then, placing the carbon nanotube array in a manner that the porous support frame is arranged below the carbon nanotube array, and depositing an amino-rich modifier on the upward surface of the carbon nanotube array by adopting a monoatomic layer deposition process, wherein the upward surface is the bottom. Thereby forming an amino-rich modifier on both the top and bottom of the carbon nanotubes.

It should be noted that the processes described in the above steps 01 to 03 are applicable to both the carbon nanotube array with gaps and the carbon nanotube array without gaps. However, for the carbon nanotube array without gaps, the substrate may be removed in step 01, and the amino-rich modifier on the top and bottom of the carbon nanotubes is formed subsequently without the substrate, because the non-spaced carbon nanotube array has a certain hardness and is self-supporting.

To sum up, the high-efficiency filtering membrane of the utility model is composed of the carbon nanotube array and the amino-rich modifier uniformly loaded on the carbon nanotube, and can realize effective filtering and adsorption when gas or liquid passes through the carbon nanotube; and an amino-rich modifier is matched to further improve the adsorption and filtration effects. Moreover, the vertical carbon nanotube array has good tropism, has a guiding effect on the flow direction of gas or liquid, and can be designed for different environments due to the fact that the height of the carbon nanotube array can be controlled according to growth conditions, and the adsorption effect and the capacity can be controlled. Furthermore, the top and/or the bottom of the carbon nano tube form an annular amino-rich modifier, and when gas or liquid enters the inner hole of the carbon nano tube, the annular amino-rich modifier can be fully adsorbed and grabbed, so that the adsorption and filtration effects are improved. The inner diameter of the ring formed by the amino-rich modifier is smaller than the inner diameter of the graphene carbon nanotube and also can be larger than the inner diameter of the graphene carbon nanotube, when the inner diameter of the ring is smaller than the inner diameter of the carbon nanotube, the adsorption effect of the amino-rich modifier can be improved, the inner hole of the carbon nanotube is further reduced on the basis of the aperture of the carbon nanotube, and therefore the superfine carbon nanotube filter membrane is formed. Because the grafting process is adopted to form the loaded amino-rich modifier on the inner wall and the outer wall of the carbon nano tube, the contact of the amino-rich modifier and the chemical bond of the carbon nano tube is improved, and the selective adsorption property and the thermal conductivity are improved. And moreover, atomic layer in-situ deposition is carried out on two ends of the carbon nano tube by adopting a monoatomic layer deposition process, the formed amino-rich modifier can form the thickness of a monoatomic layer or a polyatomic layer, the chemical bonding of the amino-rich modifier and the carbon nano tube is realized, the number of the amino-rich modifier loaded on the carbon nano tube is increased, and the adsorption and filtration effects are further improved.

Although the present invention has been described with reference to the preferred embodiments, which are given by way of illustration only, and not by way of limitation, it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A high efficiency filtration membrane, comprising: a carbon nanotube array; and an amino-rich modifier uniformly loaded on the carbon nanotubes in the carbon nanotube array; the amino-rich modifier is uniformly distributed on the top of the carbon nano tube and on the inner wall and the outer wall of the carbon nano tube; the amino-rich modifier is positioned on the top of the carbon nano tube and attached to the top of the carbon nano tube to form a ring.

2. The high efficiency filtration membrane according to claim 1, wherein said array of carbon nanotubes is an array of vertical carbon nanotubes.

3. The high efficiency filtration membrane according to claim 1, wherein the carbon nanotube array has a spacing between adjacent carbon nanotubes, and the top or bottom of the carbon nanotube array is fixed on a porous support; the holes of the porous support frame are aligned and communicated with the inner holes of the carbon nano tubes.

4. The high efficiency filtration membrane of claim 1, wherein the carbon nanotubes have an inner diameter that is greater than the inner diameter of the ring formed by the amino-rich modifier.

5. The high efficiency filtration membrane according to claim 1, wherein said amino group rich modifier is also homogeneously distributed at the bottom of said carbon nanotubes.

6. The high-efficiency filter membrane according to claim 1, wherein the amino-rich modifier forms a ring with an inner diameter of not more than 2nm, and the carbon nanotubes have an inner diameter of 0.5-60 nm; the height of the carbon nanotube array is 1-1000 microns.