阅读说明：本技术 一种复合分离薄膜及其制备方法和用途 (Composite separation film and preparation method and application thereof ) 是由 苏力宏 王锡桐 郝羽翀 杨凤霞 李越飞 葛岩 锁永永 王波 于 2021-08-30 设计创作，主要内容包括：本发明提供了一种复合分离薄膜及其制备方法和用途,解决现有物理薄膜过滤加离心分离方式,薄膜厚度较大,过滤阻力大,导致过滤时间长、过滤效率低的问题。该复合分离薄膜包括自下而上设置的沉积衬底层、分离层以及固定保护层；沉积衬底层和固定保护层均采用具有微米孔洞的多孔载体材料；分离层采用具有纳米孔洞的多孔二维材料,厚度为0.3～50nm；多孔二维材料由利用氧化物半导体纳米粉体剥离层状材料制备获得,且多孔二维材料的面积大于多孔载体材料中微米孔洞的面积。(The invention provides a composite separation membrane and a preparation method and application thereof, and solves the problems of long filtration time and low filtration efficiency caused by large membrane thickness and large filtration resistance in the existing physical membrane filtration and centrifugal separation mode. The composite separation film comprises a deposition substrate layer, a separation layer and a fixed protective layer which are arranged from bottom to top; the deposition substrate layer and the fixed protective layer both adopt porous carrier materials with micron holes; the separating layer is made of a porous two-dimensional material with nano holes, and the thickness of the separating layer is 0.3-50 nm; the porous two-dimensional material is prepared by stripping the layered material by using oxide semiconductor nano powder, and the area of the porous two-dimensional material is larger than that of the micron hole in the porous carrier material.)

1. A composite separation membrane characterized by: comprises a deposition substrate layer, a separation layer and a fixed protective layer which are arranged from bottom to top;

the deposition substrate layer and the fixed protective layer are both made of porous carrier materials with micron holes;

the separation layer is made of a porous two-dimensional material with nano holes, and the thickness of the separation layer is 0.3-50 nm;

the porous two-dimensional material is prepared by stripping a layered material by using oxide semiconductor nano powder, and the area of the porous two-dimensional material is larger than that of a micron hole in a porous carrier material.

2. The composite separation membrane of claim 1, wherein:

the porous two-dimensional material is two-dimensional monolayer molybdenum disulfide, two-dimensional monolayer graphene, two-dimensional monolayer MXene, two-dimensional monolayer tungsten disulfide, two-dimensional monolayer metal organic frame material, two-dimensional monolayer mica sheet or two-dimensional monolayer black phosphorus.

3. The composite separation membrane of claim 2, wherein:

the porous carrier material is a metal alloy porous net, a copper net, a plastic net or a polymer film net.

4. The composite separation membrane of claim 3, wherein:

the pore diameter of the pores of the porous carrier material is 1-200 μm.

5. The composite separation membrane of claim 4, wherein:

the pore diameter of the pores of the porous two-dimensional material is less than 150 nm.

6. The composite separation membrane of claim 5, wherein:

the separation layer comprises a single layer or a plurality of layers of porous two-dimensional materials with nano holes, the thickness of the single layer is 0.3-2nm, and the thickness of the plurality of layers is not higher than 50 nm.

7. A method for preparing a composite separation membrane according to any one of claims 1 to 6, comprising the steps of:

1) stripping the layered material by using oxide semiconductor nano powder to prepare a porous two-dimensional material with nano holes;

2) dispersing the porous two-dimensional material prepared in the step 1) in a solvent, and uniformly stirring to obtain a suspension solution; the content of the porous two-dimensional material in the suspension solution is 0.5-30%;

3) depositing the suspension solution obtained in the step 2) on a deposition substrate layer in a suspension manner to form a separation layer;

4) covering a fixed protective layer on the separation layer formed in the step 3), and drying after the solvent is volatilized to obtain the composite separation film.

8. The method for producing a composite separation membrane according to claim 7, characterized in that:

in the step 2), the solvent is water or ethanol.

9. Use of the composite separation membrane of any one of claims 1 to 6 for separating and purifying nanoparticles, polymers, proteins or viruses of different particle sizes.

Technical Field

The invention belongs to the technical field of separation films of proteins or viruses and the like, and particularly relates to a composite separation film and a preparation method and application thereof.

Background

Protein is an important component in the life cycle of organisms, and the research on the protein per se is an important link for the research and exploration of life science. With the technical development of biological science, the technical field of separating and preparing natural macromolecular compounds tends to mature, and the separation and purification of the active substances on the premise of not destroying the molecular activity also forms a field of biological pharmacy. Protein separation is based primarily on five principles: solubility, molecular size, charge, adsorption properties, biological affinity for ligand molecules, and the like. The basic principle includes two aspects: firstly, the separation aim is achieved by utilizing the distribution rate difference of each component in a phase, such as salting out, organic solvent extraction, chromatography, crystallization and the like; and the second is to achieve the separation purpose through the action of a physical force field, such as electrophoresis, ultrafiltration, ultracentrifugation and the like. Others such as many viruses, etc., including coronaviruses, etc., also have dimensions of tens of nanometers. How to rapidly separate and identify the components in the actual medical and sanitary protection without damaging the components also has great application value.

At present, the separation method according to the difference of the molecular size of the protein comprises: 1. dialyzing and ultrafiltering; dialysis (dialysis) uses the property of protein molecules that cannot pass through a semi-permeable membrane, commonly used as cellophane or cellophane paper, pyroxylin paper, and other modified cellulose materials, to separate proteins from other small molecules; 2. performing ultracentrifugation; 3. the porous gel filtration method is also called as size exclusion chromatography or molecular sieve chromatography.

The method for separation depending on the solubility of the protein includes salting out of the protein, isoelectric precipitation, low-temperature organic solvent precipitation, crystallization, and the like. Methods for separation according to the charged nature of proteins include electrophoresis or ion exchange chromatography. Methods for separating proteins using selective adsorption include hydroxyapatite chromatography, hydrophobic interaction chromatography, or the like. Methods for separation based on ligand specificity include affinity chromatography. In addition, there are various protein purification methods such as rapid protein liquid chromatography and high performance liquid chromatography.

However, since proteins exist in a complex mixture in tissues or cells, each type of cell contains thousands of different proteins, and therefore, the separation, purification and identification of proteins are an important part of biochemistry, a single method or a set of existing methods which have not been available up to now can be used to extract any one protein from the complex mixture, and thus several methods are often used in combination. For example: xupengwei scholars and other scholars take degreased fructus cannabis powder as a raw material, extraction and separation of fructus cannabis protein are carried out by two methods, alkali extraction/acid precipitation is carried out to obtain alkali extraction protein, and salt dissolution/salting-out is carried out to obtain salt extraction protein. The content of the salt extracted protein is higher than that of the alkali extracted protein, and the appearance color is brighter and whiter. Or filtering with positive charge molecular sieve to obtain filtrate, purifying protein by size exclusion chromatography, or purifying protein by anion exchange chromatography to obtain purified solution; wherein, a physical membrane filtration and centrifugal separation mode is also a common separation mode, but the thickness of a general filtering porous membrane is 100nm-100 mu m, the filtration resistance is large, and the filtration efficiency is low due to long filtration time.

Therefore, in order to improve the filtration efficiency, it is necessary to design a thinner separation membrane.

Disclosure of Invention

The invention aims to solve the problems of long filtering time and low filtering efficiency caused by large film thickness and large filtering resistance in the existing physical film filtering and centrifugal separation mode, and provides a composite separation film and a preparation method and application thereof.

In order to achieve the purpose, the technical solution provided by the invention is as follows:

a composite separation membrane is characterized in that: comprises a deposition substrate layer, a separation layer and a fixed protective layer which are arranged from bottom to top;

the deposition substrate layer and the fixed protective layer are both made of porous carrier materials with micron holes;

the separation layer is made of a porous two-dimensional material with nano holes, and the thickness of the separation layer is 0.3-50 nm;

the porous two-dimensional material is prepared by stripping a layered material by using oxide semiconductor nano powder, and the area of the porous two-dimensional material is larger than that of a micron hole in a porous carrier material.

Further, the porous two-dimensional material is two-dimensional monolayer molybdenum disulfide, two-dimensional monolayer graphene, two-dimensional monolayer MXene, two-dimensional monolayer tungsten disulfide, two-dimensional monolayer metal organic framework material, two-dimensional monolayer mica sheet or two-dimensional monolayer black phosphorus.

Further, the porous carrier material is a metal alloy porous net, a copper net, a plastic net or a polymer film net, and other carrier materials which do not damage the separated substances can be adopted;

further, the pore diameter of the pores of the porous support material is 1-200 μm, preferably 1-10 μm.

Further, the pore diameter of the porous two-dimensional material is less than 150nm, and the specific pore size range can be adjusted between 5nm and 150 nm.

Further, the separation layer comprises a single layer or multiple layers of porous two-dimensional material with nano-pores, the thickness of the single layer is 0.3-2nm, the thickness of the multiple layers is generally not more than 50nm, and the separation layer is obtained by deposition of a porous two-dimensional material suspension solution, and preferably not more than 10 nm.

The preparation method of the composite separation film is characterized by comprising the following steps:

1) the oxide semiconductor nano powder is used for stripping the layered material to prepare the porous two-dimensional material with nano holes, namely the method disclosed in Chinese patent application ZL 2020109766223;

2) dispersing the porous two-dimensional material prepared in the step 1) in a solvent, and uniformly stirring to obtain a suspension solution; the content of the porous two-dimensional material in the suspension solution is 0.5-30%;

3) depositing the suspension solution obtained in the step 2) on a deposition substrate layer in a suspension manner to form a separation layer, wherein the separation layer may be a single-layer material or a multi-layer material when being deposited, but in order to obtain the separation layer with uniform thickness, the suspension solution needs to be uniformly stirred in the step 2) so as to obtain a thin film with balanced separation effect;

4) covering a fixed protective layer on the separation layer formed in the step 3), and drying after the solvent is volatilized to obtain the composite separation film.

Further, in the step 2), the solvent is water or ethanol.

The invention also provides the application of the composite separation film in separating and purifying nano particles, macromolecules, proteins or viruses with different particle sizes.

The invention has the advantages that:

1. according to the peeling preparation characteristics of the two-dimensional material, the micron-sized two-dimensional single-layer porous material peeled and prepared by the technical scheme of Chinese patent application ZL2020109766223 is used as a filtering film, the filtering film is compounded with a porous carrier material with micron-sized holes to prepare a composite separation film with micron-sized thickness, the two-dimensional material is prepared by utilizing the nano-sized holes (generally below 100nm and also between 100 and 150 nm) randomly formed on the two-dimensional single-layer material, the two-dimensional material is further obtained by utilizing the thermosensitive semiconductor nano-powder to adsorb and assist peeling, and then the adsorbed saturated nano-particles and the two-dimensional material complex are subjected to heating or ultrasonic separation, the two-dimensional material is obtained, the nano-particles form randomly distributed holes on the surface in the separation process of the two-dimensional material, so that the porous two-dimensional material naturally formed on the surface of the two-dimensional material) for the biological macromolecular solution such as protein or virus, or the nano particles and the macromolecules can realize high-efficiency physical separation without destroying the properties of the nano particles and the macromolecules.

2. Because the separation layer adopts a porous membrane with the nanometer thickness, the filtration resistance is smaller than that of other membranes with thicker thickness, and the auxiliary efficiency of the centrifuge is higher. In addition, the composition or structure of filtering macromolecules, nano particles, proteins or viruses cannot be damaged in the physical separation process; after the membrane is filtered for a period of time and blocked, the membrane can be recovered by back flushing with water or solvent, and because the thickness of the membrane is generally below 10nm, the resistance of the membrane recovered by the back washing agent is also very small, the membrane can be recycled, the regeneration method is simple and convenient, and the effects of energy conservation and high efficiency are achieved.

3. Due to the common hydrophobicity or oil repellency of the two-dimensional material, the ultra-thin two-dimensional material can cause the advantage of reduced filtration resistance, high-efficiency physical separation of macromolecular solutions such as water or organic solvent protein and viruses is realized, the two-dimensional materials such as two-dimensional single-layer material graphene and TMDS have hydrophobicity, and meanwhile, the two-dimensional material has a large stripping size, holes are formed in the two-dimensional material, and the resistance of the ultra-thin two-dimensional material for filtering protein water solution is extremely low. The two-dimensional MXene material has hydrophilicity, and has better advantage in filtering protein organic solvent solution (ethanol, acetone or grease and the like).

4. The invention essentially utilizes a purification and separation method with different molecular sizes, but compared with the application of the traditional separation method in crude separation production, the composite separation film adopted by the invention has simple and convenient operation and can more effectively protect the molecular activity in the separation process, and has clear development direction in the future development.

5. The invention adopts a two-dimensional material solution suspension deposition mode to deposit on a carrier material with 1-200 mu m-level holes (the material of the carrier material is not limited as long as the filter protein is not damaged), the size of the protein is generally below 200nm, so the carrier material can not have the separation effect on the protein, but the size of the holes on the two-dimensional material peeled off by ZL2020109766223 is only dozens of nanometers, and the protein with the size of more than dozens of nanometers can be effectively blocked and can be used as a protein separation film.

Drawings

FIG. 1 is an atomic force microscope image of two-dimensional material surface nano-pores

FIG. 2 is a schematic view of a novel protein filtration membrane

The reference numerals in fig. 2 are:

1-a porous support material with micron-sized pores; 2-porous two-dimensional material with nano-pores;

FIG. 3 is a diagram showing an example of the distribution of chromatographic columns as a result of two-dimensional thin-film protein separation.

Detailed Description

The invention is described in further detail below with reference to the following figures and specific examples:

as shown in fig. 1 and fig. 2, fig. 1 is an atomic force microscope image of a two-dimensional material surface nano-pore, fig. 2 is a schematic view of a novel protein filtration membrane, wherein a deposition substrate layer, a separation layer and a fixed protective layer are arranged from bottom to top; the deposition substrate layer and the fixed protective layer both adopt porous carrier materials 1 with micron holes, the separation layer adopts porous two-dimensional materials 2 with nanometer holes, and the porous two-dimensional materials are prepared by stripping layered materials by using oxide semiconductor nanometer powder, namely the method disclosed in Chinese patent application ZL 2020109766223; the area of the porous two-dimensional material is larger than the area of the micron pores in the porous carrier material.

Example 1

The two-dimensional single-layer molybdenum disulfide material film peeled by the method of patent ZL2020109766223 has the size of 2-15 μm, nanometer holes with the size of 30-50nm are arranged on the film, the single-layer molybdenum disulfide solid content 15% water suspension solution is settled on a plastic net with holes of 1-5 μm, and the upper layer is covered with a layer of polymer film with holes of 1-5 μm. The three-layer composite separation membrane can be used for filtering protein aqueous solution, protein with the size less than 30nm can be filtered into filtrate, and protein with the size more than the size can be blocked and deposited on the membrane. Due to the hydrophobic property of the molybdenum disulfide, the filtration resistance of the protein water solution is smaller, and the separation process is quicker. Meanwhile, the membrane is used for a period of time after filtration, distilled water can be adopted for back flushing, and protein deposited on the surface of the membrane blocks the membrane pores of the filtration membrane, but the thickness of the membrane with the filtration nanometer thickness is very thin, and the hydrophobic property of molybdenum disulfide per se can enable the distilled water to be easier to clean and remove the deposition blocking layer.

Example 2

The single-layer graphene stripped by the method disclosed in patent ZL2020109766223 has the size of 10-200 μm generally, nanometer holes with the size of 30-50nm are arranged on the single-layer graphene, an aqueous suspension solution with the solid content of 20% of the single-layer graphene is settled on a copper net with holes of 1-3 μm, and a high polymer film with a mesh of holes of 1-3 μm is covered on the upper layer. The three-layer composite separation membrane can be used for filtering protein aqueous solution, protein with the size less than 30nm can be filtered into filtrate, and protein with the size more than the size can be blocked and deposited on the membrane. Due to the hydrophobic property of graphene, the filtration resistance of the protein water solution is smaller, and the separation process is quicker.

Example 3

The size of the single-layer MXene peeled by the method disclosed by the patent ZL2020109766223 is generally 10-50 μm, nanometer holes with the size of 10-30nm are formed on the single-layer MXene, an ethanol suspension solution with the solid content of 10% is allowed to settle on a copper net with holes of 3-5 μm, and a copper net with meshes with holes of 2-5 μm is covered on the upper layer. The three-layer composite separation membrane can be used for filtering protein ether solution, protein with the size less than 30nm can be filtered into filtrate, and protein with the size more than the size can be blocked and deposited on the membrane. MXene has the property of being oleophobic, so that the filtration resistance of the protein ether solution is smaller, and the separation process is quicker.

Example 4

The size of the single-layer MXene peeled by the method disclosed by the patent ZL2020109766223 is generally 3-60 mu m, nanometer holes with the size of 10nm are arranged on the single-layer MXene, an ethanol suspension solution with the solid content of 3% is allowed to settle on a copper net with holes of 3-5 mu m, and the upper layer is covered with a copper net with meshes with holes of 2-5 mu m. The three-layer composite separation membrane can be used for filtering ether solution of viruses, viruses with the size of more than 10nm can be blocked by the filtration membrane and cannot enter filtrate, and viruses with the size of more than 10nm can be blocked and deposited on the membrane, so that separation and blocking of the viruses are realized. MXene has the property of being oleophobic, so that the ether solvent in the virus ether solution has smaller filtration resistance, and the separation process is quicker.

Example 5

The size of the single-layer MXene peeled by the method disclosed in patent ZL2020109766223 is generally 10-50 μm, nanometer holes with the size of 50nm are arranged on the single-layer MXene, ethanol suspension with the solid content of 1% is deposited on a copper net with holes of 3-5 μm, and the upper layer is covered with a copper net with meshes of 2-5 μm. The three-layer composite separation membrane can be used for filtering acetone solution with suspended nano particles, nano particles with the size less than 50nm can be filtered into filtrate, and nano particles with the size more than the size can be blocked and deposited on the membrane. MXene has the property of being oleophobic, so that the filtration resistance of an acetone solution is smaller, and the separation process is quicker. Meanwhile, after the filtering is used for a period of time, acetone solvent can be adopted for back flushing, the nano particles deposited on the surface of the membrane block the pores of the filtering membrane, but the thickness of the filtering membrane with the nano thickness is very thin, MXene has the oil-repellent property, and acetone can be cleaned more easily to remove the deposited blocking layer.

Example 6

The black phosphorus stripped by the method disclosed in patent ZL2020109766223 (air isolation and oxidation prevention) is generally 5-10 μm in size, and is provided with 50-80nm nanometer holes, a single layer or a few layers of ethanol suspension with 25% solid content of black phosphorus are stripped and settled on a copper net with 1-3 μm holes, and a plastic net with 1-3 μm hole grids is covered on the upper layer. The three-layer composite separation membrane can be used for filtering protein aqueous solution, protein with the size less than 50nm can be filtered into filtrate, and protein with the size more than the size can be blocked and deposited on the membrane. Due to the hydrophobic property of the black phosphorus, the filtering resistance of the protein water solution is smaller, and the separation process is quicker.

Example 7

The size of the single-layer tungsten disulfide peeled by the method disclosed in patent ZL2020109766223 is 5-50 μm generally, nanometer holes with the size of 40-50nm are arranged on the single-layer tungsten disulfide, ethanol suspension solution with the solid content of 10% is deposited on a plastic net with holes of 3-5 μm, and a copper net with meshes of holes of 2-5 μm is covered on the upper layer. The three-layer composite separation membrane can be used for filtering protein aqueous solution, protein with the size less than 30nm can be filtered into filtrate, and protein with the size more than the size can be blocked and deposited on the membrane. The oil-repellent property of the tungsten disulfide is self, so that the filtration resistance of the protein aqueous solution is smaller, and the separation process is quicker.

Example 8

The single-layer Metal Organic Framework (MOF) stripped by the method disclosed in patent ZL2020109766223 has a size of 50-100 μm, nanometer holes with a size of 50-150nm are formed on the single-layer or few-layer MOF, an ethanol suspension solution with a solid content of 10% is deposited on a copper net with holes of 3-5 μm, and the upper layer is covered with a copper net with meshes with holes of 1-6 μm. The three-layer composite separation membrane can be used for filtering protein ether solution, protein with the size less than 30nm can be filtered into filtrate, and protein with the size more than the size can be blocked and deposited on the membrane. The thickness of the single-layer metal organic framework material is very thin, so the filtering resistance of the protein ether solution is small, and the separation process is rapid.

Example 9

The size of the single-layer nanometer-thickness mica sheet peeled by the method disclosed in patent ZL2020109766223 is generally 50-300 μm, nanometer holes with the size of 30-100nm are arranged on the single-layer nanometer-thickness mica sheet, an aqueous suspension solution with the solid content of 10% of the single-layer nanometer-thickness mica sheet is settled on a copper net with holes of 3-5 μm, and a plastic net with a mesh with holes of 1-10 μm is covered on the upper layer. The three-layer composite separation membrane can be used for filtering a mixed solution of protein water and ether, protein with the size less than 30nm can be filtered into filtrate, and protein with the size more than the size can be blocked and deposited on the membrane. The single-layer mica sheet is very thin, so that the filtering resistance of protein water and ether solution is small, and the separation process is quick.

FIG. 3 is a diagram showing an example of the results of the distribution of the chromatographic column as a result of the two-dimensional thin-film protein separation in this example; wherein, the size marker is a chromatographic column position mark of protein molecules with different sizes, only two layers of porous carrier materials with micron-sized holes are provided, a single-layer or multi-layer porous film with nanometer thickness and nanometer-sized holes is not provided in the middle, and the chromatographic distribution effect of the filtered protein molecule solution is achieved. Before filtration is the protein chromatographic column profile in the mother liquor Before filtration; the after filtration is a porous carrier material with micron-sized pores, a single-layer or multi-layer porous nano-scale pore membrane with the thickness of 0.5-10nm is clamped in the middle of the porous carrier material, and the chromatographic distribution test effect of the filtered protein molecules shows that the content of more than 25nm in the protein solution after the filtration and separation of the nano-scale membrane is obviously reduced, which indicates that the protein with the protein molecular size of more than 25nm is separated and blocked and is retained in the filtration mother solution, and the protein molecules with the size of less than 25nm pass through the filtration membrane.

While the invention has been described with reference to specific embodiments, the invention is not limited thereto, and various equivalent modifications or substitutions can be easily made by those skilled in the art within the technical scope of the present disclosure.