Preparation method of oxygen-enriched composite membrane, oxygen-enriched composite membrane and its applications

Abstract

This disclosure presents a method for preparing an oxygen-enriched composite membrane, the membrane itself, and its applications. One specific embodiment of the method includes: mixing 1,1,3,3,5,5-hexamethyltrisiloxane and diallyl maleate, wherein the mass ratio of 1,1,3,3,5,5-hexamethyltrisiloxane to diallyl maleate is 1:(2-4); adding a first platinum catalyst to obtain an intermediate product, wherein the intermediate product has vinyl groups on its side chains; mixing a second mixture, n-hexane, and a second platinum catalyst, wherein the second mixture is a mixture of the intermediate product and 1,1,3,3-tetramethyldisiloxane, and the mass ratio of the intermediate product to 1,1,3,3-tetramethyldisiloxane is 1:(0.4-0.5); performing viscosity testing on the polymer solution; and coating the polymer solution onto the surface of a base membrane. This embodiment can improve the oxygen-enriching performance and service life of the oxygen-enriched composite membrane.

Description

Technical Field

[0001] The embodiments disclosed herein relate to the fields of membrane preparation and membrane separation technology, specifically to a method for preparing an oxygen-enriched composite membrane, the oxygen-enriched composite membrane, and its applications. Background Technology

[0002] Oxygen-enriched membranes selectively allow oxygen molecules to pass through while blocking other gas molecules, thereby achieving gas separation and enrichment. Oxygen-enriched membranes have wide applications in various fields such as industry and energy. For example, in the energy sector, oxygen-enriched membranes can be used to improve combustion efficiency and reduce fuel consumption and pollutant emissions; in industrial production, oxygen-enriched membranes can be used for air separation to extract high-purity oxygen for industrial production. Currently, the commonly used method for preparing oxygen-enriched membranes is to use polydimethylsiloxane (PDMS) or polyimide (PI) as the materials for manufacturing the membranes.

[0003] However, in practice, it has been found that when the above-mentioned method is used to prepare oxygen-enriched membranes, the following technical problems often occur: the characteristics of PDMS material itself limit its oxygen-enriched separation performance, and the mechanical strength of PDMS material is poor, resulting in a short service life of oxygen-enriched membranes; PI membranes are hydrophilic membranes, and under high humidity conditions, more water enters the oxygen-enriched membrane and blocks the oxygen permeation channels, thereby reducing the oxygen-enriched performance of the oxygen-enriched membrane.

[0004] The information disclosed in this background section is only intended to enhance the understanding of the background of the inventive concept, and therefore may contain information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The summary portion of this disclosure is intended to provide a brief overview of the concepts, which will be described in detail in the detailed description portion. This summary portion is not intended to identify key or essential features of the claimed technical solutions, nor is it intended to limit the scope of the claimed technical solutions.

[0006] Some embodiments of this disclosure provide a method for preparing oxygen-enriched composite membranes, oxygen-enriched composite membranes, and their applications, in order to solve the technical problems mentioned in the background section above.

[0007] In a first aspect, some embodiments of this disclosure provide a method for preparing an oxygen-enriched composite membrane. The method includes: mixing 1,1,3,3,5,5-hexamethyltrisiloxane and diallyl maleate to obtain a first mixture, wherein the mass ratio of 1,1,3,3,5,5-hexamethyltrisiloxane to diallyl maleate is 1:(2-4); adding a first platinum catalyst to the first mixture to perform a crosslinking reaction to obtain an intermediate product, wherein the side chain of the intermediate product contains vinyl groups; mixing a second mixture, n-hexane, and a second platinum catalyst to perform a crosslinking reaction to obtain a polymer solution, wherein the second mixture is a mixture of the intermediate product and 1,1,3,3-tetramethyldisiloxane, and the mass ratio of the intermediate product to 1,1,3,3-tetramethyldisiloxane is 1:(0.4-0.5); performing a viscosity test on the polymer solution to obtain the polymer solution viscosity; and coating the polymer solution onto the surface of a prepared base membrane according to the polymer solution viscosity to obtain an oxygen-enriched composite membrane.

[0008] Optionally, the mass ratio of the above-mentioned n-hexane to the above-mentioned second mixture is (10-12):1.

[0009] Optionally, the amount of the second platinum catalyst is 0.1% to 0.5% of the mass of the second mixture.

[0010] Optionally, the amount of the first platinum catalyst is 0.1% to 0.5% of the mass of the first mixture.

[0011] Optionally, the material of the base film includes at least one of the following: polyvinylidene fluoride, polyetherimide, polyacrylonitrile, and polysulfone.

[0012] Optionally, the first platinum catalyst and the second platinum catalyst are chloroplatinic acid-vinylsiloxane complexes.

[0013] Optionally, the above-mentioned mixing treatment of the second mixture, n-hexane, and the second platinum catalyst to carry out a crosslinking reaction to obtain a polymer solution includes: mixing the second mixture, n-hexane, and the second platinum catalyst to carry out a crosslinking reaction by a water bath method to obtain a polymer solution, wherein the water bath temperature range is 30°C to 60°C.

[0014] Optionally, the above-mentioned method of applying the polymer solution to the prepared base film surface according to the polymer solution viscosity to obtain an oxygen-enriched composite film includes: inputting the polymer solution viscosity into a preset coating speed generation model to obtain a coating speed; and applying the polymer solution to the prepared base film surface according to the coating speed to obtain an oxygen-enriched composite film.

[0015] Secondly, some embodiments of this disclosure provide an oxygen-enriched composite membrane, which is prepared by the oxygen-enriched composite membrane preparation method described in any implementation of the first aspect above.

[0016] Thirdly, some embodiments of this disclosure provide a use of the oxygen-enriched composite membrane as described in any implementation of the first aspect above, wherein the oxygen-enriched composite membrane is used in oxygen-enriched combustion systems and portable oxygen-enriched devices.

[0017] The above-described embodiments of this disclosure have the following beneficial effects: the oxygen-enriched composite membrane preparation method of some embodiments of this disclosure can improve the oxygen-enriched performance and service life of the oxygen-enriched composite membrane. Specifically, the reason for the short service life and reduced oxygen-enriched performance of the oxygen-enriched membrane is that the characteristics of the PDMS material itself limit its oxygen-enriched separation limit performance, and the mechanical strength of the PDMS material is poor, resulting in a short service life of the oxygen-enriched membrane; the PI membrane is a hydrophilic membrane, and under high humidity conditions, more water enters the oxygen-enriched membrane and blocks the oxygen permeation channels, thereby reducing the oxygen-enriched performance of the oxygen-enriched membrane. Based on this, the oxygen-enriched composite membrane preparation method of some embodiments of this disclosure firstly mixes 1,1,3,3,5,5-hexamethyltrisiloxane and diallyl maleate to obtain a first mixture, wherein the mass ratio of the above-mentioned 1,1,3,3,5,5-hexamethyltrisiloxane to the above-mentioned diallyl maleate is 1:(2-4); a first platinum catalyst is added to the above-mentioned first mixture to carry out a cross-linking reaction to obtain an intermediate product, wherein the side chain of the above-mentioned intermediate product contains vinyl groups. Therefore, an intermediate product containing vinyl groups can be obtained, which can be used to improve the adhesion between the polymer solution and the base film. Next, under preset temperature conditions, a second mixture, n-hexane, and a second platinum catalyst are mixed to undergo a crosslinking reaction, yielding a polymer solution. The second mixture is a mixture of the aforementioned intermediate product and 1,1,3,3-tetramethyldisiloxane, with a mass ratio of the intermediate product to 1,1,3,3-tetramethyldisiloxane of 1:(0.4-0.5). This yields a highly crosslinked polymer network structure, thereby improving the mechanical strength and durability of the oxygen-enriched composite membrane. The viscosity of the polymer solution is then measured; based on this viscosity, the polymer solution is coated onto the surface of a prepared base film to obtain an oxygen-enriched composite membrane. This results in an oxygen-enriched composite membrane with a relatively dense network structure and high mechanical properties, thereby improving its service life and oxygen-enriching performance. Because the intermediate product of hexamethyltrisiloxane and diallyl maleate contains vinyl groups on its side chain under the action of a catalyst, and the density of the cross-linked network structure is improved through a secondary cross-linking reaction, the oxygen permeability and structural stability of the oxygen-enriched composite membrane are improved. Thus, the service life and oxygen-enriching performance of the oxygen-enriched composite membrane can be improved. Attached Figure Description

[0018] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. Throughout the drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and elements are not necessarily drawn to scale.

[0019] Figure 1 This is a flowchart of some embodiments of the method for preparing oxygen-enriched composite membranes according to this disclosure;

[0020] Figure 2 These are test product images of oxygen-enriched composite membranes according to some embodiments of this disclosure. Detailed Implementation

[0021] Embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings. While some embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this disclosure. It should be understood that the accompanying drawings and embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of protection of this disclosure.

[0022] It should also be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings. Unless otherwise specified, the embodiments and features described in this disclosure can be combined with each other.

[0023] It should be noted that the concepts of "first" and "second" mentioned in this disclosure are used only to distinguish different devices, modules or units, and are not used to limit the order of functions performed by these devices, modules or units or their interdependencies.

[0024] It should be noted that the terms "a" and "a plurality of" used in this disclosure are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0025] The names of messages or information exchanged between multiple devices in the embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of such messages or information.

[0026] This disclosure will now be described in detail with reference to the accompanying drawings and embodiments.

[0027] Figure 1 A process 100 is shown illustrating some embodiments of a method for preparing an oxygen-enriched composite membrane according to the present disclosure. This method for preparing an oxygen-enriched composite membrane includes the following steps:

[0028] Step 101: Mix 1,1,3,3,5,5-hexamethyltrisiloxane with diallyl maleate to obtain a first mixture.

[0029] In some embodiments, 1,1,3,3,5,5-hexamethyltrisiloxane and diallyl maleate can be mixed to obtain a first mixture. The mass ratio of 1,1,3,3,5,5-hexamethyltrisiloxane to diallyl maleate is 1:(2-4).

[0030] Step 102: Add a first platinum catalyst to the first mixture to carry out a crosslinking reaction to obtain an intermediate product.

[0031] In some embodiments, a first platinum catalyst may be added to the first mixture to carry out a crosslinking reaction to obtain an intermediate product. The intermediate product has vinyl groups as side chains. The first platinum catalyst may be a catalyst made with platinum as the main active component. In practice, the first platinum catalyst may be added to the first mixture and stirred with a stirring rod to carry out a crosslinking reaction to obtain the intermediate product.

[0032] Optionally, the amount of the first platinum catalyst is 0.1% to 0.5% of the mass of the first mixture. Thus, by controlling the amount of catalyst, the efficient crosslinking reaction can be ensured while reducing the impact of catalyst residue on the performance of the oxygen-rich composite membrane.

[0033] Step 103: The second mixture, n-hexane, and the second platinum catalyst are mixed to carry out a crosslinking reaction to obtain a polymer solution.

[0034] In some embodiments, the second mixture, n-hexane, and a second platinum catalyst can be mixed to perform a crosslinking reaction to obtain a polymer solution. The second mixture can be a mixture of the intermediate product and 1,1,3,3-tetramethyldisiloxane. The mass ratio of the intermediate product to 1,1,3,3-tetramethyldisiloxane is 1:(0.4 to 0.5).

[0035] Optionally, the mass ratio of the above-mentioned n-hexane to the above-mentioned second mixture can be (10-12):1. This can improve the uniformity and stability of the secondary crosslinking reaction.

[0036] Optionally, the amount of the second platinum catalyst is 0.1% to 0.5% of the mass of the second mixture.

[0037] Optionally, the first platinum catalyst and the second platinum catalyst described above can be chloroplatinic acid-vinylsiloxane complexes.

[0038] In some optional implementations of certain embodiments, the second mixture, n-hexane, and the second platinum catalyst can be mixed and treated using a water bath method to carry out a crosslinking reaction, obtaining a polymer solution. The water bath temperature range can be 30°C to 60°C. This range can be considered as a specific temperature range for the water bath. The water bath temperature can be the temperature of the water bath. Therefore, the stability of the reaction can be improved while promoting the crosslinking reaction.

[0039] Step 104: Perform viscosity detection on the polymer solution to obtain the viscosity of the polymer solution.

[0040] In some embodiments, the polymer solution can be subjected to viscosity detection processing to obtain the viscosity of the polymer solution. The viscosity of the polymer solution can be the viscosity of the polymer solution itself. In practice, the viscosity of the polymer solution can be detected by a viscometer at first preset time intervals to obtain the viscosity of the polymer solution. The first preset time interval can be a pre-set duration. For example, the first preset time interval can be 10 minutes.

[0041] Step 105: Based on the viscosity of the polymer solution, apply the polymer solution to the prepared base film surface to obtain an oxygen-enriched composite film.

[0042] In some embodiments, the polymer solution can be coated onto the surface of a prepared base film according to its viscosity to obtain an oxygen-enriched composite film. The base film can be a multifunctional thin film material made of various polymer materials. In practice, firstly, when the viscosity of the polymer solution is determined to meet a preset viscosity condition, the polymer solution can be coated onto the surface of the prepared base film at a preset coating speed. The preset viscosity condition can be that the polymer solution viscosity is within a preset polymer solution viscosity range. The preset polymer solution viscosity range can be a pre-defined range characterizing the adhesion between the polymer solution and the base film. For example, the preset polymer solution viscosity range can be 50–60 mPa·s. The preset coating speed can be a pre-defined coating speed. For example, the preset coating speed can be 0.5 m / min. Then, the coated base film is placed in an oven for a second preset time to obtain the oxygen-enriched composite film. The second preset time can be a pre-defined duration. For example, the second preset time can be 4 hours or 5 hours. The temperature range of the oven mentioned above can be 100 to 120°C.

[0043] Optionally, the material of the base film may include, but is not limited to, at least one of the following: polyvinylidene fluoride (PVDF), polyetherimide (PEI), polyacrylonitrile (PAN), and polysulfone (PSF).

[0044] In some optional implementations of certain embodiments, the polymer solution can be coated onto the surface of a prepared base film according to the viscosity of the polymer solution to obtain an oxygen-enriched composite film: First, the viscosity of the polymer solution is input into a preset coating speed generation model to obtain the coating speed. The preset coating speed generation model can be a pre-trained coating speed generation model. This model can be a linear function with the polymer solution viscosity as input and the coating speed as output. It should be noted that the higher the polymer solution viscosity, the lower the coating speed. For example, when the polymer solution viscosity is 10 mPa·s, the coating speed can be 1 m / min. As another example, when the polymer solution viscosity is 8 mPa·s, the coating speed can be 1.5 m / min.

[0045] The second step involves applying the polymer solution onto the prepared base film surface at the aforementioned coating speed to obtain an oxygen-rich composite film.

[0046] Therefore, when the polymer solution viscosity is low, the coating speed can be increased, thereby reducing the phenomenon of dripping at the cutting edge. When the polymer solution viscosity is high, the coating speed can be reduced, thereby reducing the accumulation and cross-linking of the coating solution at the cutting edge and the contact area between the cutting edge and the base film, thus improving the uniformity of the oxygen-rich composite film surface.

[0047] This disclosure is further illustrated in the following examples. It should be understood that although these examples indicate certain aspects herein, they are given by way of illustration only. From the foregoing discussion and these examples, those skilled in the art can determine the essential features of the disclosed embodiments, and various changes and modifications can be made to adapt the disclosed embodiments to a variety of uses and conditions without departing from the spirit and scope of the disclosed embodiments.

[0048] Example 1

[0049] First, 1,1,3,3,5,5-hexamethyltrisiloxane and diallyl maleate are thoroughly mixed in a mass ratio of 1:2 to obtain the first mixture.

[0050] Then, a first platinum catalyst was added to the first mixture and stirred with a stir bar to carry out a crosslinking reaction, yielding an intermediate product with vinyl side chains. The amount of the first platinum catalyst added was 0.1% of the combined mass of 1,1,3,3,5,5'-hexamethyltrisiloxane and diallyl maleate.

[0051] Subsequently, the intermediate product was mixed with 1,1,3,3-tetramethyldisiloxane at a mass ratio of 1:0.4, and n-hexane was added as a solvent. A second platinum catalyst was then added, and a crosslinking reaction was carried out in a water bath at 30°C. The amount of n-hexane added was 10 times the mass of the second mixture, and the amount of the second platinum catalyst was 0.1% of the mass of the second mixture.

[0052] Next, the viscosity of the polymer solution was measured every 10 minutes using a viscometer to obtain the viscosity of the polymer solution.

[0053] Finally, when the viscosity of the polymer solution reaches 50 mPa·s, the membrane solution is coated on the surface of the PVDF base membrane and crosslinked in an oven at 100°C for 4 hours to obtain an oxygen-enriched composite membrane.

[0054] Example 2

[0055] First, 1,1,3,3,5,5-hexamethyltrisiloxane and diallyl maleate are thoroughly mixed in a mass ratio of 1:3 to obtain the first mixture.

[0056] Then, a first platinum catalyst was added to the first mixture and stirred with a stir bar to carry out a crosslinking reaction, yielding an intermediate product with vinyl side chains. The amount of the first platinum catalyst added was 0.3% of the combined mass of 1,1,3,3,5,5'-hexamethyltrisiloxane and diallyl maleate.

[0057] Subsequently, the intermediate product was mixed with 1,1,3,3-tetramethyldisiloxane at a mass ratio of 1:0.45, and n-hexane was added as a solvent. Then, a second platinum catalyst was added, and a crosslinking reaction was carried out at a water bath temperature of 40°C. The amount of n-hexane added was 11 times the mass of the second mixture, and the amount of the second platinum catalyst was 0.3% of the mass of the second mixture.

[0058] Next, the viscosity of the polymer solution was measured every 10 minutes using a viscometer to obtain the viscosity of the polymer solution.

[0059] Finally, when the viscosity of the polymer solution reaches 55 mPa·s, the membrane solution is coated on the surface of the PVDF base membrane and crosslinked in an oven at 110°C for 5 hours to obtain an oxygen-enriched composite membrane.

[0060] Example 3

[0061] First, 1,1,3,3,5,5-hexamethyltrisiloxane and diallyl maleate are thoroughly mixed in a mass ratio of 1:4 to obtain the first mixture.

[0062] Then, a first platinum catalyst was added to the first mixture and stirred with a stir bar to carry out a crosslinking reaction, yielding an intermediate product with vinyl side chains. The amount of the first platinum catalyst added was 0.5% of the combined mass of 1,1,3,3,5,5'-hexamethyltrisiloxane and diallyl maleate.

[0063] Subsequently, the intermediate product was mixed with 1,1,3,3-tetramethyldisiloxane at a mass ratio of 1:0.5, and n-hexane was added as a solvent. Then, a second platinum catalyst was added, and a crosslinking reaction was carried out at a water bath temperature of 40°C. The amount of n-hexane added was 12 times the mass of the second mixture, and the amount of the second platinum catalyst was 0.5% of the mass of the second mixture.

[0064] Next, the viscosity of the polymer solution was measured every 10 minutes using a viscometer to obtain the viscosity of the polymer solution.

[0065] Finally, when the viscosity of the polymer solution reaches 60 mPa·s, the membrane solution is coated on the surface of the PVDF base membrane and crosslinked in an oven at 120°C for 6 hours to obtain an oxygen-enriched composite membrane.

[0066] To demonstrate the effectiveness of the oxygen-enriched composite membrane prepared by the above-mentioned method, the following experimental methods and results are provided.

[0067] Experiment 1

[0068] The gas separation performance of each oxygen-enriched composite membrane, conventional PDMS membrane, and PI membrane corresponding to Examples 1, 2, and 3 was tested using a small-scale membrane testing device. The specific steps are as follows:

[0069] The first step involves introducing air into the membrane module and measuring the permeate-side flux of the oxygen-enriched composite membrane, conventional PDMS membrane, and PI membrane in the respective embodiments using a gas flow meter in a small-scale membrane testing device at 0.45 MPa.

[0070] The second step involves measuring the oxygen concentration on each permeation side of the oxygen-enriched composite membrane, conventional PDMS membrane, and PI membrane using an oxygen concentration analyzer in a small-scale membrane testing device.

[0071] It should be noted that the test areas of the oxygen-enriched composite membranes, conventional PDMS membranes, and PI membranes in Examples 1, 2, and 3 are the same.

[0072] The experimental results are shown in the table below. As can be seen from the table, the oxygen-enriched composite membranes of Examples 1, 2, and 3 have significantly improved oxygen-enrichment performance on the permeate side compared to conventional PDMS membranes. However, under normal air conditions, although the permeate flux of each oxygen-enriched composite membrane is more than 10 times higher than that of the PI membrane, and it has a higher flux advantage during use, its oxygen concentration is still lower than that of the PI membrane.

[0073]

[0074]

[0075] Experiment 2

[0076] A small-scale membrane device and a small humidifier were connected via a three-way valve to humidify the air, and the intake air humidity was measured using an air humidity meter. Then, the gas separation performance of the oxygen-enriched composite membrane and PI membrane corresponding to Example 3 was tested under different air humidity conditions. The test steps were the same as those in Experiment 1 and will not be repeated here.

[0077] The experimental results are shown in the table below. As can be seen from the table, because the PI membrane is a hydrophilic membrane, under high humidity conditions, its hydrophilicity blocks oxygen permeation channels, causing a rapid decrease in flux and a rapid decrease in its oxygen-enriching performance. However, Example 3, being a hydrophobic membrane, is less affected by air humidity, making it more promising for practical industrial applications and applicable to a wider range of regions.

[0078]

[0079] When employing technical solutions to address the technical problems in the background art, the following question often arises: how to improve the quality of oxygen-enriched composite membranes. A conventional solution to these problems is to acquire images of the prepared oxygen-enriched composite membrane and perform defect detection on these images. However, the above solution suffers from the following second technical problem: in fields such as medical equipment and aerospace, the quality requirements for oxygen-enriched composite membranes are very high. Since the surface of the oxygen-enriched composite membrane is transparent, directly acquiring images for defect detection results in low accuracy in bubble detection, thus leading to lower quality of the oxygen-enriched composite membrane.

[0080] Regarding technical problem two in the background section, by collaborating with university researchers and leveraging their existing image processing technologies, the following solution can be adopted:

[0081] The first step involves applying the polymer solution to the surface of a prepared base film using a coating device to obtain an oxygen-enriched composite film. The coating device can be an apparatus for applying the polymer solution to prepare the oxygen-enriched composite film. This coating device may include, but is not limited to, a coating assembly, a control chip and image acquisition device, a thickness detection assembly, and a sorting device. The coating assembly can be an assembly for applying the polymer solution. The coating assembly may include, but is not limited to, a scraper and a scraper robotic arm. The scraper may be fixedly mounted on the scraper robotic arm. The scraper robotic arm may be a robotic arm for performing the scraping operation. The scraping operation may be the operation of applying the polymer solution to the base film. The image acquisition device can be an apparatus for acquiring images. The image acquisition device may include, but is not limited to, a first laser device, a second laser device, and an image acquisition device. The first laser device and the second laser device can be devices for emitting a light curtain. The first laser device and the second laser device can emit a light curtain towards the base film surface at a counter-angle of 10° to 15°. The image acquisition device can be an apparatus for acquiring images. For example, the image acquisition device can be a camera. The image acquisition device can be positioned directly above the surface of the base film. The thickness detection component can include at least one thickness detection sensor. It should be noted that when the thickness detection component detects the thickness of the composite film, the thickness detection sensors are evenly distributed above the surface of the composite film. The sorting device can be a sorting robot. The coating component, the first laser device, the second laser device, the thickness detection component, the sorting device, and the image acquisition device are all communicatively connected to the control chip. The communication connection can be wired or wireless. The control chip is configured to perform the following sub-steps:

[0082] The first sub-step involves, in response to receiving the application scenario type and polymer solution viscosity information sent by the preparation user terminal, determining the preset oxygen-enriched composite membrane thickness corresponding to the aforementioned application scenario type as the oxygen-enriched composite membrane thickness, and determining the preset bubble condition corresponding to the aforementioned application scenario type as the bubble condition. The preparation user terminal can be the terminal of the preparation user. The preparation user can be the user preparing the oxygen-enriched composite membrane. The polymer solution viscosity information can include, but is not limited to, polymer solution viscosity. The application scenario type can be a type categorized according to the application scenario of the oxygen-enriched composite membrane. The application scenario type can be, but is not limited to, combustion systems, medical equipment, and industrial fields. The preset oxygen-enriched composite membrane thickness can be a pre-set thickness of the oxygen-enriched composite membrane used in the corresponding application scenario. The preset bubble condition can be a pre-set condition for the qualified bubbles in the oxygen-enriched composite membrane. As an example, when the application scenario is medical equipment, the preset oxygen-enriched composite membrane thickness can be 0.1 mm, and the preset bubble condition can be a bubble quantity of 0. Therefore, different preparation standards for oxygen-enriched composite membranes can be determined according to different application scenarios, thereby improving both the quality and preparation efficiency of the oxygen-enriched composite membrane.

[0083] The second sub-step involves inputting the polymer solution viscosity information and the oxygen-enriched composite film thickness into a preset coating pressure information generation model to obtain coating pressure information. This preset coating pressure information generation model can be a linear function that takes the polymer solution viscosity information and the oxygen-enriched composite film thickness as inputs and the coating pressure information as the output. The coating pressure information can be the pressure value of the doctor blade during the coating operation. This allows for the acquisition of a coating pressure more closely aligned with the application scenario and the currently prepared polymer solution, thereby improving the quality of the resulting oxygen-enriched composite film.

[0084] The third sub-step involves controlling the coating assembly to perform a coating operation on the polymer solution according to the aforementioned coating pressure information to generate a composite film. In practice, the blade included in the coating assembly can be controlled to apply the polymer solution onto a prepared base film according to the aforementioned coating pressure information to generate a composite film.

[0085] The fourth sub-step involves, in response to the detection of coating completion information corresponding to the aforementioned coating operation, controlling the first laser device and the second laser device to perform an activation operation, and controlling the image acquisition device to acquire an image of the composite film. The coating completion information can indicate the completion of the coating operation. For example, the coating completion information could be "finish". The activation operation could be the operation of activating the laser devices to emit a light curtain. Thus, the produced composite film can be illuminated by the two laser devices, generating alternating bright and dark stripes on the surface of the composite film to facilitate the detection of air bubbles in the composite film.

[0086] The fifth sub-step involves performing bubble detection processing on the composite film image to obtain bubble detection results. These results characterize the presence and size of bubbles in the composite film. In practice, a preset bubble detection algorithm can be used to perform bubble detection processing on the composite film image to obtain the results. This preset bubble detection algorithm can be a pre-defined algorithm for detecting bubbles. For example, it could be a deep learning-based bubble recognition algorithm.

[0087] The sixth sub-step involves, in response to determining that the bubble detection result meets the bubble condition, controlling the thickness detection component to perform thickness detection processing on the composite film, thereby obtaining a set of detected thicknesses corresponding to each thickness detection point. Here, a thickness detection point can be a point corresponding to a thickness detection sensor. The detected thickness can be the thickness value detected by the corresponding thickness detection sensor.

[0088] The seventh sub-step is to determine the variance of each detected thickness included in the above-mentioned detected thickness set as the thickness variance.

[0089] The eighth sub-step involves, in response to determining that the aforementioned thickness variance meets a preset thickness condition, controlling the sorting device to perform an oxygen-enriched composite film verification operation on the composite film, thereby obtaining an oxygen-enriched composite film. The preset thickness condition can be that the thickness variance is less than a preset thickness variance. The preset thickness variance can be a pre-set variance value characterizing the relatively uniform thickness of the composite film surface. The oxygen-enriched composite film verification operation can be an operation of sorting the composite film to the oxygen-enriched composite film location.

[0090] The above-described technical solution and related content, as an inventive point of this disclosure, solve the technical problem that "in fields such as medical equipment and aerospace, the quality requirements for oxygen-enriched composite membranes are very high. The surface of the oxygen-enriched composite membrane is transparent, and directly acquiring images for defect detection results in low accuracy in bubble detection, thus leading to low quality of the oxygen-enriched composite membrane." The factors leading to low quality of the oxygen-enriched composite membrane are often as follows: the surface of the oxygen-enriched composite membrane is transparent, and directly acquiring images for defect detection results in low accuracy in bubble detection, thus leading to low quality of the oxygen-enriched composite membrane. Solving these factors can improve the quality of the oxygen-enriched composite membrane. To achieve this effect, some embodiments of the oxygen-enriched composite membrane preparation method disclosed herein use two sets of laser devices to emit light curtains onto the surface of the composite membrane to generate alternating bright and dark stripes when detecting bubbles in the prepared oxygen-enriched composite membrane. Since the reflection and refraction characteristics of the laser to the bubbles and the composite membrane substrate are different, they will appear as areas of abnormal light intensity in the image, which facilitates the detection of bubbles in the composite membrane and improves the accuracy of bubble detection. Furthermore, during the preparation of the oxygen-enriched composite membrane, the thickness of the oxygen-enriched composite membrane and the coating pressure can be determined according to the viscosity of the polymer solution prepared in real time and the application scenario, thereby improving the applicability and quality of the oxygen-enriched composite membrane for the application scenario and thus improving the quality of the oxygen-enriched composite membrane.

[0091] The above-described embodiments of this disclosure have the following beneficial effects: the oxygen-enriched composite membrane preparation method of some embodiments of this disclosure can improve the oxygen-enriched performance and service life of the oxygen-enriched composite membrane. Specifically, the reason for the short service life and reduced oxygen-enriched performance of the oxygen-enriched membrane is that the characteristics of the PDMS material itself limit its oxygen-enriched separation limit performance, and the mechanical strength of the PDMS material is poor, resulting in a short service life of the oxygen-enriched membrane; the PI membrane is a hydrophilic membrane, and under high humidity conditions, more water enters the oxygen-enriched membrane and blocks the oxygen permeation channels, thereby reducing the oxygen-enriched performance of the oxygen-enriched membrane. Based on this, the oxygen-enriched composite membrane preparation method of some embodiments of this disclosure firstly mixes 1,1,3,3,5,5-hexamethyltrisiloxane and diallyl maleate to obtain a first mixture, wherein the mass ratio of the above-mentioned 1,1,3,3,5,5-hexamethyltrisiloxane to the above-mentioned diallyl maleate is 1:(2-4); a first platinum catalyst is added to the above-mentioned first mixture to carry out a cross-linking reaction to obtain an intermediate product, wherein the side chain of the above-mentioned intermediate product contains vinyl groups. Therefore, an intermediate product containing vinyl groups can be obtained, which can be used to improve the adhesion between the polymer solution and the base film. Next, under preset temperature conditions, a second mixture, n-hexane, and a second platinum catalyst are mixed to undergo a crosslinking reaction, yielding a polymer solution. The second mixture is a mixture of the aforementioned intermediate product and 1,1,3,3-tetramethyldisiloxane, with a mass ratio of the intermediate product to 1,1,3,3-tetramethyldisiloxane of 1:(0.4-0.5). This yields a highly crosslinked polymer network structure, thereby improving the mechanical strength and durability of the oxygen-enriched composite membrane. The viscosity of the polymer solution is then measured; based on this viscosity, the polymer solution is coated onto the surface of a prepared base film to obtain an oxygen-enriched composite membrane. This results in an oxygen-enriched composite membrane with a relatively dense network structure and high mechanical properties, thereby improving its service life and oxygen-enriching performance. Because the intermediate product of hexamethyltrisiloxane and diallyl maleate contains vinyl groups on its side chain under the action of a catalyst, and the density of the cross-linked network structure is improved through a secondary cross-linking reaction, the oxygen permeability and structural stability of the oxygen-enriched composite membrane are improved. Thus, the service life and oxygen-enriching performance of the oxygen-enriched composite membrane can be improved.

[0092] This disclosure also provides an oxygen-enriched composite membrane. This oxygen-enriched composite membrane is prepared through steps 101-105 described above.

[0093] This disclosure also provides an application of an oxygen-enriched composite membrane. The oxygen-enriched composite membrane can be used in oxygen-enriched combustion systems and portable oxygen-enriched devices. The portable oxygen-enriched device can be a vehicle-mounted oxygen-enriched air conditioner.

[0094] The above description is merely a selection of preferred embodiments of this disclosure and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in the embodiments of this disclosure is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in the embodiments of this disclosure.

Claims

1. A method for preparing an oxygen-enriched composite membrane, comprising: 1,1,3,3,5,5-hexamethyltrisiloxane and diallyl maleate are mixed to obtain a first mixture, wherein the mass ratio of 1,1,3,3,5,5-hexamethyltrisiloxane to diallyl maleate is 1:(2-4). A first platinum catalyst is added to the first mixture to carry out a crosslinking reaction to obtain an intermediate product, wherein the side chain of the intermediate product contains vinyl groups; The second mixture, n-hexane, and a second platinum catalyst are mixed to carry out a crosslinking reaction to obtain a polymer solution, wherein the second mixture is a mixture of the intermediate product and 1,1,3,3-tetramethyldisiloxane, and the mass ratio of the intermediate product to the 1,1,3,3-tetramethyldisiloxane is 1:(0.4-0.5). The viscosity of the polymer solution is obtained by performing viscosity detection processing on the polymer solution; Based on the viscosity of the polymer solution, the polymer solution is coated onto the surface of the prepared base film to obtain an oxygen-rich composite film.

2. The method according to claim 1, wherein, The mass ratio of n-hexane to the second mixture is (10-12):

1.

3. The method according to claim 1, wherein, The amount of the second platinum catalyst used is 0.1% to 0.5% of the mass of the second mixture.

4. The method according to claim 1, wherein, The amount of the first platinum catalyst is 0.1% to 0.5% of the mass of the first mixture.

5. The method according to claim 4, wherein, The base film is made of at least one of the following materials: polyvinylidene fluoride, polyetherimide, polyacrylonitrile, and polysulfone.

6. The method according to claim 1, wherein, The first platinum catalyst and the second platinum catalyst are chloroplatinic acid-vinylsiloxane complexes.

7. The method according to claim 6, wherein, The process of mixing the second mixture, n-hexane, and the second platinum catalyst to carry out a crosslinking reaction yields a polymer solution comprising: The second mixture, n-hexane, and the second platinum catalyst were mixed and treated by a water bath method to carry out a crosslinking reaction, thereby obtaining a polymer solution, wherein the water bath temperature range was 30℃~60℃.

8. The method according to claim 1, wherein, The step of coating the polymer solution onto the prepared base film surface according to the viscosity of the polymer solution to obtain an oxygen-rich composite film includes: The viscosity of the polymer solution is input into a preset coating speed generation model to obtain the coating speed; The polymer solution is applied to the prepared base film surface at the specified coating speed to obtain an oxygen-rich composite film.

9. An oxygen-enriched composite membrane, wherein, The oxygen-enriched composite membrane is prepared by the oxygen-enriched composite membrane preparation method as described in any one of claims 1-8.

10. The use of the oxygen-enriched composite membrane as described in claim 9, wherein, The oxygen-enriched composite membrane is used in oxygen-enriched combustion systems and portable oxygen-enriched devices.

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