Production equipment for preparing independent self-supporting ultrathin graphene oxide composite membrane

Abstract

The production equipment comprises a shell, an opening is formed in the left side of the shell, the inner bottom wall of the shell is fixedly connected with a stripping coagulating bath tank, the inner wall of the shell is fixedly connected with a drying water bath tank, and the drying water bath tank is fixedly connected with a water outlet of the shell. Avoiding grooves are formed in the two sides of the stripping coagulating bath and the two sides of the drying water bath, the inner wall of the shell is rotationally connected with a first circulating conveying system, the surface of the first circulating conveying system is in lap joint with a PET film, the inner wall of the shell is rotationally connected with a second circulating conveying system, and the surface of the second circulating conveying system is in lap joint with a filter screen. According to the invention, the rapid curing and forming capability of a polymer in water is utilized, stripping is assisted by virtue of water surface tension, and the interface affinity is reduced by replacing a volatile solvent with small surface tension and utilizing a porous rough substrate with small contact area, so that membrane separation is facilitated; the wrinkle-free ultrathin composite film is obtained on the basis of the simple cleaning method.

Description

Technical Field

[0001] The present application relates to the technical field of ultra-thin graphene oxide composite film production, and in particular to a production device for preparing an independent self-supporting ultra-thin graphene oxide composite film. Background Art

[0002] In recent years, with the continuous development of nanotechnology, the use of nanomaterials to prepare high-performance composite membranes has become a frontier research direction in the field of membrane technology. Nanocomposite materials have both the toughness and easy processing of polymer materials and the rigidity and special properties of nanomaterials. This is an important aspect of the development of organic polymer materials and an emerging functional material in the development of materials science. Among them, nanocomposite membranes play an important role in liquid separation membranes, gas separation membranes, proton exchange membranes, etc. As a precursor of graphene, graphene oxide has excellent hydrophilicity, electrical and mechanical properties, and is expected to give nanocomposite membranes excellent performance. However, due to the influence of defects, graphene oxide composite membranes with nanometer thickness can better reflect the characteristics of graphene oxide.

[0003] Common methods for preparing ultra-thin graphene oxide composite membranes include: suction filtration, scraping, spinning, spraying, spin coating, etc. Among them, as for the suction filtration method, the objects of the suction filtration are mostly two-dimensional sheets, and the objects of the suction filtration are limited. At the same time, the membranes prepared by the suction filtration method cannot be prepared on a large scale. The drying process of the membranes prepared by scraping, spraying, spin coating, etc. is relatively long and cannot be quickly separated from the substrate, and it is also difficult to ensure uniformity. Due to the precision of the flow channel size, the difficulty of the operation method and the effect of the surface tension of the solvent, the membrane prepared by the spinning method can be continuous but it is impossible to prepare nano-level films. For this reason, a production device for preparing an independent self-supporting ultra-thin graphene oxide composite membrane is proposed to solve the problems in the background technology. Summary of the invention

[0004] The object of the present invention is to provide a production device for preparing an independent self-supporting ultra-thin graphene oxide composite film to solve the problems raised in the above background technology.

[0005] The present application embodiment adopts the following technical solutions:

[0006] A production device for preparing an independent self-supporting ultra-thin graphene oxide composite film comprises a shell, wherein a first circulating conveying system composed of a PET film and a second circulating conveying system composed of a porous filter screen are arranged inside the shell; the first circulating conveying system and the second circulating conveying system are both rotatably mounted on the side wall of the shell, an opening is opened on the left side of the shell, a winding roller is rotatably mounted on the upper right side wall of the shell side wall, a peeling coagulation bath is fixedly connected to the inner bottom wall of the shell, a drying water tank bath is fixedly connected to the upper side wall of the shell, and a volatile solvent is contained in the drying water tank bath.

[0007] Furthermore, the first circulating conveying system is composed of five rollers, and PET films are wound around the surfaces of the five rollers at the ends, and the second circulating conveying system is composed of seven rollers, and porous filters are wound around the surfaces of the seven rollers at the ends.

[0008] Furthermore, a first infrared heating tube is fixedly connected to the side wall of the outer shell, and the first infrared heating tube irradiates the inner circle of the PET film; a hard plate is detachably connected to the side wall of the outer shell; a scraper is fixedly connected to the side wall of the outer shell, and a second infrared heating tube is fixedly connected to the side wall of the outer shell, and the second infrared heating tube irradiates the inner circle of the porous filter; a third infrared heating tube is fixedly connected to the side wall of the outer shell, and the third infrared heating tube is fixedly connected between the PET film and the porous filter; the bottom end of the scraper is arranged above the surface of the PET film, and the upper surface of the hard plate is in contact with the inner circle surface of the PET film.

[0009] Furthermore, avoidance grooves are provided on both sides of the stripping coagulation bath and the drying water bath to facilitate the passage of the PET film and the porous filter.

[0010] Furthermore, two first infrared heating tubes and two second infrared heating tubes are provided respectively.

[0011] A method for preparing an ultra-thin graphene oxide composite film comprises the following steps: dispersing graphene oxide and a polymer in a solvent X to form a coating liquid; applying the coating liquid on a PET film by a scraper to form a primary film; then, the PET film carrying the primary film is conveyed at a certain angle by a first circulation conveying system and inserted into a stripping and solidifying bath; the primary film is rapidly separated and formed and stripped from the PET film to obtain an ultra-thin composite film, which is suspended on the surface of the stripping and solidifying bath; then, a porous filter screen on a second circulation conveying system takes out the ultra-thin composite film, first conveys the ultra-thin composite film to a drying water tank bath filled with a volatile solvent, and then conveys the ultra-thin composite film to an infrared heating tube for drying; after drying, the film automatically separates from the porous filter screen and is collected by a winding roller to obtain an independently supported ultra-thin graphene oxide composite film.

[0012] Compared with the prior art, the present application can achieve the following beneficial effects: by further designing the continuous equipment for inserting and fishing the film, large-scale continuous production can be achieved. Among them, the present invention transmits the PET film carrying the primary film at a certain angle through the first circulation transmission system and inserts it into the peeling coagulation bath tank, utilizes the ability of polymer to quickly solidify and shape in water, and assists peeling with the help of water surface tension, and takes out the ultra-thin composite film through the porous filter screen on the second circulation transmission system, first transports the ultra-thin composite film to a drying water tank bath containing a volatile solvent, and then transports it to the infrared heating tube for drying, by replacing the volatile solvent with small surface tension and using the porous filter screen with a small porous rough contact area, the interface affinity is reduced, which is beneficial to membrane separation, and a wrinkle-free ultra-thin composite film is obtained based on these simple and clean methods. This method realizes the molding peeling of the liquid surface for the first time, and gets rid of the dependence on the type and properties of the substrate. The composite graphene oxide nanofilm prepared by the production equipment can be used on any flat surface substrate, without considering the interaction between the substrate and the film. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0014] Figure 1 This is the structural diagram of the production equipment;

[0015] Figure 2 This is a schematic diagram of the production equipment structure Figure I ;

[0016] Figure 3 This is a schematic diagram of the production equipment structure Figure II ;

[0017] Figure 4 It is the production process flow chart;

[0018] In the figure: 1. shell; 2. opening; 3. stripping coagulation bath; 4. drying water bath; 5. first circulation conveying system; 6. first infrared heating tube; 7. PET film; 8. hard plate; 9. scraper; 10. second circulation conveying system; 11. porous filter; 12. second infrared heating tube; 13. third infrared heating tube. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0020] The technical solutions provided by various embodiments of the present application are described in detail below in conjunction with the accompanying drawings.

[0021] See also Figure 1-3 The present invention provides a technical solution for preparing an independent self-supporting ultra-thin graphene oxide composite film production equipment:

[0022] A production device for preparing an independent self-supporting ultra-thin graphene oxide composite film comprises a shell 1, wherein a first circulating conveying system 5 composed of a PET film 7 and a second circulating conveying system 10 composed of a porous filter screen 11 are arranged inside the shell 1; the first circulating conveying system 5 and the second circulating conveying system 10 are both rotatably mounted on the side wall of the shell 1, an opening 2 is provided on the left side of the shell 1, a winding roller is rotatably mounted on the upper right side of the side wall of the shell 1, a stripping coagulation bath 3 is fixedly connected to the inner bottom wall of the shell 1, a drying water tank bath 4 is fixedly connected to the upper side wall of the shell 1, a volatile solvent is contained in the drying water tank bath 4, and the stripping coagulation bath 3 and the drying water tank bath 4 are respectively used to strip and dry the composite film.

[0023] Specifically, the first circulating conveying system 5 is composed of five rollers, and the surfaces of the five rollers are wound with PET films 7 at the head and tail. The second circulating conveying system 10 is composed of seven rollers, and the surfaces of the seven rollers are wound with porous filters 11 at the head and tail. The opening 2 is set on the left side of the housing 1 to facilitate observation of the internal situation.

[0024] Specifically, the side wall of the outer shell 1 is fixedly connected with a first infrared heating tube 6, which irradiates the inner circle of the PET film 7 to heat and dry the PET film 7. The side wall of the outer shell 1 is detachably connected with a hard plate 8. The side wall of the outer shell 1 is fixedly connected with a scraper 9. The side wall of the outer shell 1 is fixedly connected with a second infrared heating tube 12, which irradiates the inner circle of the porous filter screen to dry the final composite film. The side wall of the outer shell 1 is fixedly connected with a third infrared heating tube 13, which is fixedly connected between the PET film 7 and the porous filter screen 11 to preliminarily dry the primary film after peeling. The bottom end of the scraper 9 is arranged above the surface of the PET film 7, and the upper surface of the hard plate 8 is in contact with the inner circle surface of the PET film 7.

[0025] Specifically, avoidance grooves are provided on both sides of the stripping coagulation bath 3 and the drying water bath 4 to facilitate the passage of the PET film 7 and the porous filter screen 11 .

[0026] Specifically, two first infrared heating tubes 6 and two second infrared heating tubes 12 are provided respectively.

[0027] Working principle: graphene oxide and polymer are dispersed in solvent X to form a coating liquid, and the coating liquid is injected from the left opening (2) of the housing (1). A scraper 9 is used to apply the coating liquid on the PET film 7 to form a primary film, and then the PET film 7 carrying the primary film is conveyed at a certain angle (20-45°) through the first circulation conveying system 5 and inserted into the peeling coagulation bath 3. The primary film is rapidly separated and formed from the PET film 7 to obtain an ultra-thin composite film, which is suspended on the surface of the peeling coagulation bath 3. Then, the porous filter 11 on the second circulation conveying system 10 takes out the ultra-thin composite film, and first conveys the ultra-thin composite film to a drying water tank bath 4 filled with a volatile solvent, and then conveys it to the infrared heating tube 12 for drying. After drying, the film automatically separates from the porous filter 11 and is collected by a winding roller to obtain an independently supported ultra-thin graphene oxide composite film.

[0028] In order to ensure smooth stripping, the polymer is soluble in solvent X and insoluble in the aqueous coagulation bath, the aqueous coagulation bath is water or a mixed solution of water and solvent X; the volume fraction of water in the aqueous coagulation bath is above 70%; the polymer is polyacrylonitrile (PAN), high molecular weight lignin, polyether sulfone (PES), polysulfone (PS), polyvinylidene fluoride (PVDF), etc. The solvent X is dimethylformamide (DMF), dimethylacetamide (DMAC) or N-methylpyrrolidone (NMP). The solid content of the mixture is 1wt% to 2wt%.

[0029] The volatile solvent contained in the drying water tank bath 4 includes isopropyl alcohol, ethanol, ethyl acetate and other solvents with low surface tension.

[0030] The porous filter screen 11 preferably has a mesh size of less than 500.

[0031] The production equipment in the present application effectively solves the problem that the film drying process prepared by scraping, spraying, spin coating, etc. is relatively long and cannot be separated from the substrate quickly, and it is also difficult to ensure uniformity.

[0032] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0033] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A production device for preparing an independent self-supporting ultra-thin graphene oxide composite film, characterized in that: The production equipment comprises a shell (1), wherein a first circulating conveying system (5) composed of a PET film (7) and a second circulating conveying system (10) composed of a porous filter screen (11) are arranged inside the shell (1); the first circulating conveying system (5) and the second circulating conveying system (10) are both rotatably mounted on the side wall of the shell (1); an opening (2) is provided on the left side of the shell (1); the opening (2) is located above the PET film (7) and is used to inject a coating liquid into the PET film (7); the side wall of the shell (1) A winding roller is rotatably installed on the upper right side for winding the composite film; a peeling coagulation bath (3) is fixedly connected to the inner bottom wall of the outer shell (1), and a drying water tank bath (4) is fixedly connected to the upper side wall of the outer shell (1), and a volatile solvent is contained in the drying water tank bath (4); wherein the PET film (7) enters the peeling coagulation bath (3) at a downward inclination angle; the porous filter screen (11) at the lower part of the second circulating conveying system (10) is located on the surface of the peeling coagulation bath (3), and the upper part is located in the drying water tank bath (4).

2. The production equipment for preparing an independent self-supporting ultra-thin graphene oxide composite film according to claim 1, characterized in that: The first circulating conveying system (5) is composed of five rollers, and the surfaces of the five rollers are wound around the PET film (7) end to end. The position of the rollers is set so that the PET film (7) enters the stripping coagulation bath (3) at a downward inclination angle; the second circulating conveying system (10) is composed of seven rollers, and the surfaces of the seven rollers are wound around the porous filter screen (11) end to end. The position of the rollers is set so that the porous filter screen (11) at the lower part of the second circulating conveying system (10) is located on the surface of the stripping coagulation bath (3), and the upper part is located in the drying water tank bath (4).

3. The production equipment for preparing an independent self-supporting ultra-thin graphene oxide composite film according to claim 2, characterized in that: A first infrared heating tube (6) is fixedly connected to the side wall of the outer shell (1), and the surface of the first infrared heating tube (6) irradiates the inner circle of the PET film (7). A hard plate (8) is detachably connected to the side wall of the outer shell (1). A scraper (9) is fixedly connected to the side wall of the outer shell (1). A second infrared heating tube (12) is fixedly connected to the side wall of the outer shell (1), and the second infrared heating tube (12) irradiates the inner circle of the porous filter (11). A third infrared heating tube (13) is fixedly connected to the side wall of the outer shell (1), and the third infrared heating tube (13) is fixedly connected between the PET film (7) and the porous filter (11). The bottom end of the scraper (9) is arranged above the surface of the PET film (7), and the upper surface of the hard plate (8) is in contact with the inner circle surface of the PET film (7).

4. The production equipment for preparing an independent self-supporting ultra-thin graphene oxide composite film according to claim 3, characterized in that: Both sides of the stripping coagulation bath (3) and the drying water bath (4) are provided with avoidance grooves to facilitate the PET film (7) and the porous filter screen (11) to pass through.

5. The production equipment for preparing an independent self-supporting ultra-thin graphene oxide composite film according to claim 4, characterized in that: Two first infrared heating tubes (6) and two second infrared heating tubes (12) are provided respectively.

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