A multilayer film material and a method for producing the same

Abstract

The application discloses a kind of multilayer film materials and preparation method thereof, and the preparation method comprises: two-dimensional material is dispersed in solvent, and two-dimensional material dispersion liquid is prepared;The raw material of each layer film is dispersed in each solvent respectively, and several film material dispersion liquids are prepared;Two-dimensional material dispersion liquid is subjected to suction filtration;When two-dimensional material dispersion liquid is about to be suction filtered, the film material dispersion liquid of the adjacent film layer of two-dimensional material layer is added to the two-dimensional material layer formed, and suction filtration is continued until the film material dispersion liquid of each layer film is suction filtered;After suction filtration is completed, the suction filtration membrane attached with multilayer film is dried and peeled, and multilayer film is prepared.The application can finely control the number of layers and the thickness of each layer film material of film material, and the operation is simple, convenient and fast.

Description

Technical Field

[0001] This invention belongs to the field of thin film materials technology, and relates to a multilayer film material and its preparation method. Background Technology

[0002] With the development of technology, membrane materials are increasingly used in electromagnetic protection, semiconductors, medicine, batteries, and other fields. Meanwhile, modern industry places greater emphasis on the refined structural design of membranes. Traditional homogeneous membrane materials made from a single substance are gradually disappearing, and emerging multilayer structured membrane materials are gradually gaining popularity. Vacuum filtration, as a method that can effectively control the refined structure of membranes, is an excellent preparation method for designing the number and thickness of membrane layers.

[0003] Chinese invention patent CN113060734A discloses an infrared low emissivity MXene thin film and its preparation method. A uniform single-layer MXene thin film is obtained by vacuum filtration, but it does not provide a method for preparing multi-layer composite films of different materials, and cannot be further adjusted to meet the application under various conditions.

[0004] Chinese invention patent CN105336551B discloses a method for preparing a carbon-based bilayer film. The method involves first filtering two films separately, then processing them and applying pressure to naturally bond the two films together, followed by drying to obtain the bilayer film. However, this method essentially involves forcibly bonding the two films through external forces, making the process cumbersome and lacking in versatility. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a multilayer membrane material and its preparation method, which can finely control the number of membrane layers and the thickness of each membrane layer, and is simple, convenient and quick to operate.

[0006] To achieve the above objectives, the present invention is implemented using the following technical solution:

[0007] A method for preparing a multilayer film material includes the following steps:

[0008] Two-dimensional materials are dispersed in a solvent to prepare a two-dimensional material dispersion.

[0009] The raw materials for each membrane layer are dispersed in different solvents to prepare several membrane material dispersions.

[0010] The two-dimensional material dispersion was filtered.

[0011] When the two-dimensional material dispersion is about to be completely filtered, the membrane material dispersion of the adjacent membrane layer is added to the formed two-dimensional material layer and the filtration continues until the membrane material dispersion of each membrane layer is completely filtered.

[0012] After filtration is completed, the filtration membrane with multiple layers attached is dried and peeled off to produce a multilayer membrane.

[0013] Optionally, before adding the membrane material dispersion of the adjacent membrane layer, a solvent may be added dropwise for wetting.

[0014] Optionally, the two-dimensional material includes graphene, graphene oxide, reduced graphene oxide, or MXene.

[0015] Optionally, the solvent may include water, alcohols, metal salt solutions, or acid / base solutions.

[0016] Optionally, the solvent has the characteristics of low viscosity, easy filtration, and easy evaporation.

[0017] Optionally, the solvent contains metal ions to improve filtration efficiency.

[0018] Optionally, the solvent used to disperse the two-dimensional material is the same as the solvent used to disperse the raw materials for each layer of the film.

[0019] Optionally, each layer of the film is a solid material that is insoluble in solvents but easily dispersed in solvents.

[0020] Optionally, each membrane layer has a two-dimensional material layer on both sides to improve the overall mechanical properties of the multilayer membrane.

[0021] A multilayer film material is prepared by the above-mentioned technical preparation method.

[0022] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0023] This invention provides a multilayer membrane material and its preparation method. The method is simple to operate. The number of membrane material layers can be precisely controlled by the number of times the membrane material dispersion is filtered, and the thickness of each membrane material layer can be precisely controlled by the amount of membrane material dispersion filtered, thereby obtaining multilayer membranes with various structures to meet the higher requirements of modern processes for membrane materials.

[0024] This application requires no high temperature or external electric field as a whole, and the design of each layer is solved in one step by vacuum filtration, which greatly improves the preparation efficiency. Attached Figure Description

[0025] Figure 1 The figures shown are schematic diagrams of the rGO side (a) and the ZIF-67 side of the rGO / ZIF-67 bilayer membrane prepared according to an embodiment of the present invention (b).

[0026] Figure 2 The diagram shown is a schematic diagram of the GO / PS / GO three-layer film prepared according to an embodiment of the present invention;

[0027] Figure 3The diagram shown is a schematic diagram of the five-layer membrane with alternating rGO / CNTs structure prepared according to an embodiment of the present invention. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0029] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and should be understood to include values ​​close to those ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0030] For the purposes of this specification and the appended claims, unless otherwise stated, all expressions, percentages, or proportions, and other numerical values ​​used in this specification and the appended claims, are to be understood to be modified by the term "about" in all cases. Furthermore, all scopes disclosed herein include their endpoints and can be combined independently.

[0031] Example 1

[0032] like Figure 1 As shown, a method for preparing a multilayer film material includes the following steps:

[0033] S1. Add 40 mg of copper chloride and 40 mg of graphene oxide to 40 mL of methanol solution and ultrasonically disperse for 60 min until uniformly dispersed to obtain graphene oxide dispersion. Then add 400 mg of ascorbic acid to the graphene oxide dispersion and reduce at 60℃ for 30 min to obtain reduced graphene oxide dispersion.

[0034] S2, 160 mg of cobalt nitrate hexahydrate, 640 mg of 2-methylimidazole and 160 mg of polyvinylpyrrolidone were added to 40 mL of methanol, stirred for 1 h and aged for 24 h to obtain a purple ZIF-67 dispersion.

[0035] S3, place the filtration membrane on the sand core of the filtration flask, set up the filtration device, and pour the reduced graphene oxide dispersion from S1 into the filtration device for filtration.

[0036] S4. When the liquid is about to be completely filtered, add a few drops of methanol to wet and reduce the graphene oxide layer, and immediately add the ZIF-67 dispersion from S2 slowly along the container wall until the filtration is complete.

[0037] S5. After filtration is completed, remove the filtration membrane with the attached rGO / ZIF-67 bilayer membrane and dry it in the air for 10 minutes. After drying, the rGO / ZIF-67 bilayer membrane can be easily peeled off from the edge of the filtration membrane. One side of the bilayer membrane is purple, representing ZIF-67, while the other side is dark brown, representing graphene oxide. Its flexibility can be seen from the surface wrinkles.

[0038] A multilayer film material is prepared by the above-mentioned technical preparation method.

[0039] Example 2

[0040] like Figure 2 As shown, a method for preparing a multilayer film material includes the following steps:

[0041] S1, 20 mg of copper chloride and 20 mg of graphene oxide were added to 20 mL of aqueous solution and ultrasonically dispersed for 30 min until uniformly dispersed to obtain graphene oxide dispersion. Two of the above solutions were prepared.

[0042] S2, add 5 mg of PS microspheres to 5 mL of water and ultrasonically disperse for 30 min to obtain a light white PS dispersion;

[0043] S3, place the filtration membrane on the sand core of the filtration flask, set up the filtration device, and pour one portion of the graphene oxide dispersion from S1 into the filtration device for filtration.

[0044] S4. When the liquid is about to be completely filtered, add a few drops of water to wet the layer. Immediately add the PS microsphere dispersion from S2 slowly along the container wall. When the liquid is about to be completely filtered, add a few drops of water to wet the layer. Immediately add the other part of the graphene oxide dispersion from S1 slowly along the container wall until the filtration is complete.

[0045] S5. After filtration is completed, remove the filtration membrane with the three-layer membrane attached and dry it in the air for 10 minutes. After drying, the GO / PS / GO three-layer membrane can be easily peeled off from the edge of the filtration membrane. The three-layer membrane clearly shows that there is a sandwich core structure between the two layers of graphene oxide on the top and bottom, which is the added PS microsphere layer.

[0046] A multilayer film material is prepared by the above-mentioned technical preparation method.

[0047] Example 3

[0048] A method for preparing a multilayer film material includes the following steps:

[0049] S1, 10 mg of copper chloride and 10 mg of graphene oxide were added to 10 mL of ethanol solution and ultrasonically dispersed for 30 min until uniform dispersion was obtained to obtain graphene oxide dispersion; then 100 mg of ascorbic acid was added to the graphene oxide dispersion and reduced for 60 min to obtain reduced graphene oxide dispersion. Three of the above solutions were prepared in total.

[0050] S2, 10 mg CNTs and 3 mg polyvinylpyrrolidone were added to 10 mL of ethanol and ultrasonically dispersed for 10 min to obtain CNTs dispersion. Two of the above solutions were prepared.

[0051] S3, place the filtration membrane on the sand core of the filtration flask, set up the filtration device, and pour one portion of the reduced graphene oxide dispersion from S1 into the filtration device for filtration.

[0052] S4, when the liquid is about to be completely filtered, add a few drops of ethanol to wet the layer, and immediately slowly add one part of the CNTs dispersion from S2 along the container wall; when the liquid is about to be completely filtered, add a few drops of ethanol to wet the layer, and immediately slowly add another part of the reduced graphene oxide dispersion from S1 along the container wall; when the liquid is about to be completely filtered, add a few drops of ethanol to wet the layer, and immediately slowly add another part of the CNTs dispersion from S2 along the container wall; when the liquid is about to be completely filtered, add a few drops of ethanol to wet the layer, and immediately slowly add the third part of the reduced graphene oxide dispersion from S1 along the container wall, until filtration is complete;

[0053] S5. After vacuum filtration is completed, remove the five-layer membrane with alternating rGO / CNTs structure attached and dry it in air for 20 minutes. After drying, the five-layer membrane with alternating rGO / CNTs structure can be easily peeled off from the edge of the vacuum filtration membrane.

[0054] A multilayer film material is prepared by the above-mentioned technical preparation method.

[0055] Example 4

[0056] like Figure 3 As shown, a method for preparing a multilayer film material includes the following steps:

[0057] S1, 10 mg of copper chloride and 10 mg of graphene oxide were added to 10 mL of ethanol solution and ultrasonically dispersed for 30 min until uniform dispersion was obtained to obtain graphene oxide dispersion; then 100 mg of ascorbic acid was added to the graphene oxide dispersion and reduced for 60 min to obtain reduced graphene oxide dispersion. Three of the above solutions were prepared in total.

[0058] S2, 10 mg CNTs and 3 mg polyvinylpyrrolidone were added to 10 mL of ethanol and ultrasonically dispersed for 10 min to obtain CNTs dispersion. Two of the above solutions were prepared.

[0059] S3, place the filtration membrane on the sand core of the filtration flask, set up the filtration device, and pour one portion of the reduced graphene oxide dispersion from S1 into the filtration device for filtration.

[0060] S4, when the liquid is about to be completely filtered, add a few drops of ethanol to wet the layer, move the filtration flask on the sand core to one side by 2 mm, and immediately slowly add one portion of the CNTs dispersion from S2 along the container wall; when the liquid is about to be completely filtered, add a few drops of ethanol to wet the layer, move the filtration flask on the sand core to the same side by 2 mm, and immediately slowly add another portion of the reduced graphene oxide dispersion from S1 along the container wall; when the liquid is about to be completely filtered, add a few drops of ethanol to wet the layer, move the filtration flask on the sand core to the same side by 2 mm, and immediately slowly add another portion of the CNTs dispersion from S2 along the container wall; when the liquid is about to be completely filtered, add a few drops of ethanol to wet the layer, move the filtration flask on the sand core to the same side by 2 mm, and immediately slowly add the third portion of the reduced graphene oxide dispersion from S1 along the container wall, until filtration is complete;

[0061] S5, after vacuum filtration, remove the five-layer membrane with alternating rGO / CNTs structure and dry it in air for 20 minutes. After drying, the five-layer membrane with alternating rGO / CNTs structure can be easily peeled off from the edge of the vacuum filtration membrane. Figure 3 As shown, it is clear that the film has a five-layer structure, namely smooth and reflective rGO layers 1, 3, and 5, and coarse and granular CNTs layers 2 and 4.

[0062] A multilayer film material is prepared by the above-mentioned technical preparation method.

[0063] Example 5

[0064] A method for preparing a multilayer film material includes the following steps:

[0065] S1, 10 mg of copper chloride and 10 mg of graphene oxide were added to 10 mL of ethanol solution and ultrasonically dispersed for 30 min until uniform dispersion was obtained to obtain graphene oxide dispersion; then 100 mg of ascorbic acid was added to the graphene oxide dispersion and reduced for 60 min to obtain reduced graphene oxide dispersion. A total of six of the above solutions were prepared.

[0066] S2, add 10 mg CNTs and 3 mg polyvinylpyrrolidone to 10 mL of ethanol, and ultrasonically disperse for 10 min to obtain CNTs dispersion. Five of the above solutions were prepared in total.

[0067] S3, place the filtration membrane on the sand core of the filtration flask, set up the filtration device, and pour the first portion of reduced graphene oxide dispersion from S1 into the filtration device for filtration.

[0068] S4, when the liquid is almost completely filtered, add a few drops of ethanol to wet the layer, and immediately slowly add the first portion of the CNT dispersion from S2 along the container wall; when the liquid is almost completely filtered, add a few drops of ethanol to wet the layer, and immediately slowly add the second portion of the reduced graphene oxide dispersion from S1 along the container wall; when the liquid is almost completely filtered, add a few drops of ethanol to wet the layer, and immediately slowly add the second portion of the CNT dispersion from S2 along the container wall; when the liquid is almost completely filtered, add a few drops of ethanol to wet the layer, and immediately slowly add the third portion of the reduced graphene oxide dispersion from S1 along the container wall; when the liquid is almost completely filtered, add a few drops of ethanol to wet the layer, and immediately slowly add the third portion of the CNT dispersion from S2 ... When the filtration is almost complete, add a few drops of ethanol to wet the layer, and immediately add the fourth part of the reduced graphene oxide dispersion from S1 slowly along the container wall; when the liquid is almost completely filtered, add a few drops of ethanol to wet the layer, and immediately add the fourth part of the CNTs dispersion from S2 slowly along the container wall; when the liquid is almost completely filtered, add a few drops of ethanol to wet the layer, and immediately add the fifth part of the reduced graphene oxide dispersion from S1 slowly along the container wall; when the liquid is almost completely filtered, add a few drops of ethanol to wet the layer, and immediately add the fifth part of the CNTs dispersion from S2 slowly along the container wall; when the liquid is almost completely filtered, add a few drops of ethanol to wet the layer, and immediately add the sixth part of the reduced graphene oxide dispersion from S1 slowly along the container wall, until the filtration is complete;

[0069] S5. After filtration is completed, remove the eleven-layer membrane with alternating rGO / CNTs structure attached and dry it in air for 60 min. After drying, the eleven-layer membrane with alternating rGO / CNTs structure can be easily peeled off from the edge of the filtration membrane.

[0070] A multilayer film material is prepared by the above-mentioned technical preparation method.

[0071] A comparison of the preparation processes in each embodiment reveals that various porous two-dimensional carriers serve as the bottom of the film, supporting other layers to form an overall multilayer membrane structure. This approach has wide applicability; however, as the number of layers increases, the filtration time for each layer also gradually increases, requiring the selection of the structure based on actual needs.

[0072] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a multilayer film material, characterized in that, Includes the following steps: A two-dimensional material is dispersed in a solvent to prepare a two-dimensional material dispersion; the two-dimensional material is graphene oxide. The raw materials for each membrane layer are dispersed in different solvents to prepare several membrane material dispersions. The two-dimensional material dispersion was filtered. When the two-dimensional material dispersion is about to be completely filtered, the membrane material dispersion of the adjacent membrane layer is added to the formed two-dimensional material layer and the filtration continues until the membrane material dispersion of each membrane layer is completely filtered. Before adding the membrane material dispersion of the adjacent membrane layer, solvent is added dropwise for wetting. After filtration is completed, the filtration membrane with multiple layers attached is dried and peeled off to produce a multilayer membrane. The solvent is water or an alcohol; the solvent used to disperse the two-dimensional material contains metal ions to improve the filtration efficiency; the metal ions are copper ions; the solvent used to disperse the two-dimensional material is the same as the solvent used to disperse the raw materials of each membrane layer; each membrane layer is a solid material that is insoluble in the solvent but easily dispersed in the solvent; the solid material is ZIF-67, PS, or CNTs.

2. The method for preparing a multilayer film material according to claim 1, characterized in that: The solvent has the characteristics of low viscosity, easy filtration, and easy evaporation.

3. The method for preparing a multilayer film material according to claim 1, characterized in that: Two-dimensional material layers are provided on both sides of each membrane layer to improve the overall mechanical properties of the multilayer membrane.

4. A multilayer film material, characterized in that: Prepared by the preparation method according to any one of claims 1-3.

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