Method of depositing a film coating on the surface of a membrane tube and membrane tube having a film coating

Abstract

The application relates to the technical field of industrial membrane filtration, in particular to a method for depositing a membrane coating on the surface of a membrane tube and a membrane tube with a membrane coating, which comprises the following steps: fixing a plurality of membrane tubes in a deposition reaction chamber and discharging air in the deposition reaction chamber; introducing gaseous neopentyl glycol into the deposition reaction chamber to deposit and grow a layer of neopentyl glycol membrane on the membrane tube or the previous layer of methyl propylene glycol membrane; discharging the gaseous neopentyl glycol in the deposition reaction chamber; introducing methyl propylene glycol into the deposition reaction chamber to deposit and grow a layer of methyl propylene glycol membrane on the previous layer of neopentyl glycol membrane; discharging the gaseous methyl propylene glycol in the deposition reaction chamber; and repeating the deposition and growth of the neopentyl glycol membrane and the methyl propylene glycol membrane according to a predetermined cycle number to deposit and grow a membrane coating with a predetermined thickness on the surface of the membrane tube. The application forms a membrane coating with higher filtering precision on the surface of the membrane tube, greatly improves the precision of membrane filtration, improves the filtering efficiency and the application range, and reduces the operation energy consumption and investment.

Description

Technical Field

[0001] The present application relates to the technical field of industrial membrane filtration, and in particular to a method for depositing a membrane coating on the surface of a membrane tube and a membrane tube having the membrane coating. Background Art

[0002] Membrane filtration is a precision separation technology that can achieve molecular-level filtration. It utilizes the selective permeability of membrane pores to separate two phases. Using the pressure difference across the membrane as the driving force, solvents, inorganic ions, and small molecules pass through the membrane while retaining microparticles and macromolecules.

[0003] The filtration accuracy of membranes made of specific materials, under certain processing techniques and raw materials, is also stable within a certain range. How to improve the filtration accuracy of already formed membranes is the core issue in improving membrane filtration accuracy. Summary of the Invention

[0004] The present application provides a method for depositing a membrane coating on the surface of a membrane tube and a membrane tube with a membrane coating, which forms a membrane coating with higher filtration accuracy on the surface of the membrane tube, greatly improving the accuracy of membrane filtration, improving filtration efficiency and scope of application, and reducing operating energy consumption and investment.

[0005] To solve the above technical problems, this application provides the following technical solutions:

[0006] A method for depositing a film coating on a membrane tube surface comprises the following steps: step S110, fixing a plurality of membrane tubes into a deposition reaction chamber, and exhausting the air in the deposition reaction chamber, wherein the process of exhausting the air requires heating, and the temperature is 50-75°C; step S120, introducing gaseous neopentyl glycol into the deposition reaction chamber to deposit and grow a layer of neopentyl glycol film on the membrane tube / previous methylpropylene glycol film, and exhausting the gaseous neopentyl glycol in the deposition reaction chamber after the layer of neopentyl glycol film is deposited and grown, and the process of depositing and forming the neopentyl glycol film ...1, introducing gaseous neopentyl glycol into the deposition reaction chamber to deposit and grow the neopentyl glycol film Heating at a temperature of 60-85°C; step S130, introducing methylpropanediol into the deposition reaction chamber to deposit and grow a layer of methylpropanediol film on the previous layer of neopentyl glycol film, and after depositing and growing a layer of methylpropanediol film, discharging the gaseous methylpropanediol in the deposition reaction chamber. The process of depositing and growing the methylpropanediol film requires heating at a temperature of 30-60°C; step S140, cyclically depositing and growing the neopentyl glycol film and the methylpropanediol film according to a predetermined number of cycles, so as to deposit and grow a membrane coating of a predetermined thickness on the surface of the membrane tube.

[0007] In the method for depositing a membrane coating onto the surface of a membrane tube as described above, preferably, the membrane coating is deposited and grown onto the outer surface of the membrane tube.

[0008] In the method for depositing a membrane coating onto the surface of a membrane tube as described above, preferably, the thickness of the membrane coating is no more than 0.05 um.

[0009] In the method for depositing a membrane coating onto the surface of a membrane tube as described above, preferably, the membrane coating has uniform voids, and the void diameter is between 0.005um and 0.1um.

[0010] In the above method for depositing a membrane coating on the surface of a membrane tube, preferably, multiple membrane tubes are evenly fixed to the deposition reaction chamber to ensure that the thickness of the neopentyl glycol film and methylpropylene glycol film deposited on the surface of each membrane tube is uniform.

[0011] In the above-mentioned method for depositing a membrane coating on the surface of a membrane tube, preferably, both ends of the membrane tube are fixed to fixed supports in the deposition reaction chamber to prevent the fixed supports from blocking the outer surface of the membrane tube.

[0012] A membrane tube with a membrane coating comprises: a membrane tube and a membrane coating; wherein the membrane coating is a membrane deposited and grown on the surface of the membrane tube by any of the above methods for depositing a membrane coating on the surface of the membrane tube.

[0013] The membrane tube with the membrane coating as described above, wherein preferably, the membrane coating is deposited and grown to the outer surface of the membrane tube.

[0014] The membrane tube with the membrane coating as described above, wherein preferably, the thickness of the membrane coating is not greater than 0.05 um.

[0015] The membrane tube with the membrane coating as described above, wherein preferably, the membrane coating has uniform voids, and the void pore diameter is between 0.005um and 0.1um.

[0016] Compared with the above background technology, the method of depositing a membrane coating on the surface of a membrane tube and the membrane tube with a membrane coating provided by the present invention form a membrane coating with higher filtration accuracy on the surface of the membrane tube, greatly improving the accuracy of membrane filtration, improving filtration efficiency and scope of application, and reducing operating energy consumption and investment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments described in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0018] Figure 1 This is a flow chart of a method for depositing a membrane coating on a membrane tube surface provided in an embodiment of the present application. DETAILED DESCRIPTION

[0019] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and are not to be construed as limiting the present application.

[0020] See also Figure 1 , Figure 1 This is a flow chart of a method for depositing a membrane coating on a membrane tube surface provided in an embodiment of the present application.

[0021] The present application provides a method for depositing a membrane coating on the surface of a membrane tube, comprising the following steps:

[0022] Step S110, fixing multiple membrane tubes into a deposition reaction chamber, and exhausting the air in the deposition reaction chamber. The process of exhausting the air requires heating at a temperature of 50-75° C.;

[0023] The membrane tube is a tubular membrane filtration product. The liquid to be treated can flow into the inside of the membrane tube after being filtered from the outside of the membrane tube. Therefore, the liquid inside the membrane tube is the filtered liquid, and the filtered liquid flows out from the membrane tube port, thereby completing the membrane filtration.

[0024] In the present application, a membrane tube is secured within a deposition chamber to deposit a membrane coating on the outer surface of the membrane tube within the deposition chamber. Optionally, multiple membrane tubes are uniformly secured within the deposition chamber to ensure a uniform thickness of the membrane coating deposited on the outer surface of each membrane tube. Furthermore, the membrane tubes are secured at both ends to fixed brackets within the deposition chamber to prevent the brackets from obstructing the outer surface of the membrane tube.

[0025] After the multiple membrane tubes are secured within the deposition chamber, the air within the chamber is exhausted to prevent interference with the subsequent deposition of the neopentyl glycol film onto the membrane tubes. Furthermore, the exhaust process requires heating to a temperature of 50-75°C to preheat the neopentyl glycol film subsequently deposited onto the membrane tubes. Optionally, an inert gas can be introduced into the deposition chamber to purge the air within.

[0026] Step S120: introducing vaporous neopentyl glycol into the deposition reaction chamber to deposit and grow a neopentyl glycol film on the membrane tube / the previous methylpropylene glycol film. After the neopentyl glycol film is deposited and grown, the vaporous neopentyl glycol in the deposition reaction chamber is discharged. The deposition process of forming the neopentyl glycol film requires heating at a temperature of 60-85° C.

[0027] After the air in the deposition reaction chamber is exhausted, gaseous neopentyl glycol is introduced into the deposition reaction chamber and maintained in the deposition reaction chamber. During the process of maintaining the gaseous neopentyl glycol in the deposition reaction chamber, the temperature in the deposition reaction chamber has been heated to 60-85°C. In this way, the gaseous neopentyl glycol in the deposition reaction chamber and the surface of the membrane tube are chemically adsorbed in a self-controlled manner until the adsorption of the reactant neopentyl glycol reaches a saturated state, that is, all reactive sites on the surface of the membrane tube are filled with the reactant neopentyl glycol. When there are no more adsorbable reactive sites, the growth of the membrane stops, and the first layer of neopentyl glycol film is deposited and grown on the outer surface of the membrane tube.

[0028] After the gaseous methylpropylene glycol from the previous deposition reaction in the deposition reaction chamber is discharged, gaseous neopentyl glycol is introduced into the deposition reaction chamber and maintained in the deposition reaction chamber. During the process of maintaining the gaseous neopentyl glycol in the deposition reaction chamber, the temperature in the deposition reaction chamber has been heated to 60-85°C. In this way, the gaseous neopentyl glycol in the deposition reaction chamber and the surface of the previous methylpropylene glycol film are chemically adsorbed in a self-controlled manner until the adsorption of the reactant neopentyl glycol reaches a saturated state, that is, all reactive sites on the surface of the previous methylpropylene glycol film are filled with the reactant neopentyl glycol. When there are no more adsorbable reactive sites, the growth of the film stops, and the next neopentyl glycol film is deposited and grown on the outer surface of the previous methylpropylene glycol film.

[0029] The amount of film formed during each neopentyl glycol film deposition cycle is related to the chemical bonding between the vapor-phase neopentyl glycol molecules introduced into the deposition reaction chamber and the film molecules on the substrate surface. Because the substrate material for the first neopentyl glycol film being deposited is a membrane tube, while the substrate materials for the remaining neopentyl glycol films are methylpropylene glycol films, the amount of film formed on the first neopentyl glycol film differs from that on the remaining neopentyl glycol films. Therefore, changes in the concentration of vapor-phase neopentyl glycol within the deposition reaction chamber can be used to determine whether the amount of film formed on each neopentyl glycol film has reached a preset standard. If so, deposition growth of that neopentyl glycol film is complete.

[0030] After a layer of neopentyl glycol film is deposited and grown on the surface of the membrane tube or on the previous methylpropylene glycol film, the remaining vaporous neopentyl glycol in the deposition reaction chamber is discharged to prevent it from affecting the subsequent deposition of the methylpropylene glycol film on the surface of the neopentyl glycol film. Optionally, an inert gas is introduced into the deposition reaction chamber to purge the vaporous neopentyl glycol in the deposition reaction chamber, thereby discharging the vaporous neopentyl glycol in the deposition reaction chamber.

[0031] Step S130: introducing methylpropanediol into the deposition reaction chamber to deposit and grow a methylpropanediol film on the previous neopentyl glycol film. After the methylpropanediol film is deposited and grown, the vapor phase methylpropanediol in the deposition reaction chamber is discharged. The process of depositing the methylpropanediol film requires heating at a temperature of 30-60° C.

[0032] After the gaseous neopentyl glycol from the previous deposition reaction in the deposition reaction chamber is discharged, gaseous methylpropanediol is introduced into the deposition reaction chamber and maintained in the deposition reaction chamber. During the process of maintaining the gaseous methylpropanediol in the deposition reaction chamber, the temperature in the deposition reaction chamber has been heated to 30-60°C. In this way, the gaseous methylpropanediol in the deposition reaction chamber and the surface of the previous neopentyl glycol film are chemically adsorbed in a self-controlled manner until the adsorption of the reactant methylpropanediol reaches a saturated state, that is, all reactive sites on the surface of the previous neopentyl glycol film are filled with the reactant methylpropanediol, and when there are no adsorbable reactive sites, the growth of the film stops, and the next methylpropanediol film is deposited and grown on the outer surface of the previous neopentyl glycol film.

[0033] The amount of film formed during the deposition growth cycle of each layer of methylpropylene glycol film is related to the chemical bonding between the molecules of the vapor-phase methylpropylene glycol introduced into the deposition reaction chamber and the film molecules on the substrate surface. Since the substrate material of the first layer of methylpropylene glycol film grown by deposition is a neopentyl glycol film, the amount of film formed for each layer of methylpropylene glycol film is the same. Of course, it is also possible to determine whether the amount of film formed for each layer of methylpropylene glycol film has reached a preset standard based on the concentration change of the vapor-phase methylpropylene glycol in the deposition reaction chamber. If the preset standard is reached, the film deposition growth of that layer of methylpropylene glycol film is complete.

[0034] After a methylpropylene glycol film is deposited and grown on the previous neopentyl glycol film, the remaining vapor-phase methylpropylene glycol in the deposition reaction chamber is discharged to prevent it from affecting the subsequent deposition of the neopentyl glycol film on the surface of the methylpropylene glycol film. Optionally, an inert gas is introduced into the deposition reaction chamber to purge the vapor-phase methylpropylene glycol in the deposition reaction chamber, thereby discharging the vapor-phase methylpropylene glycol in the deposition reaction chamber.

[0035] Based on the above, we can use the formula The film formation amount of each layer of neopentyl glycol film or methyl propylene glycol film is calculated. AB is the amount of film formed by the gas phase A deposited on the surface of the substrate B, C A is the initial concentration of gas phase A, C A′ is the current concentration of gas phase A, V is the volume of the deposition reaction chamber, W A is the weight of the effect of gas phase A on the film formation amount of gas phase A on the surface of substrate B, A1 is the first deposition reaction bond of gas phase A molecule, A nis the nth deposition reaction bond of gas phase A molecule, is the bond energy of the i-th deposition reaction bond of gas phase A molecule, M B is the number of matrix molecules on the surface of matrix B, W B is the weight of the influence of substrate B on the film formation amount of gas phase A on the surface of substrate B, B1 is the first deposition reaction bond of the matrix molecule of substrate B, and B m is the mth deposition reaction bond of the matrix molecule of matrix B, is the bond energy of the jth deposition reaction bond of the matrix molecule of matrix B.

[0036] Step S140 , cyclically depositing and growing a neopentyl glycol film and a methylpropylene glycol film according to a predetermined number of cycles, so as to deposit and grow a film coating of a predetermined thickness on the surface of the membrane tube.

[0037] By alternately depositing neopentyl glycol and methylpropylene glycol on a membrane tube, a membrane coating is formed that conforms perfectly to the membrane tube surface, growing to a desired thickness. Optionally, the thickness of the deposited membrane coating is strictly controlled to within 0.05 μm. Furthermore, the resulting membrane coating exhibits uniform pores with a controllable pore size between 0.005 μm and 0.1 μm.

[0038] Based on the above, we can use the formula The predetermined number of cycles N for depositing and growing neopentyl glycol film and methylpropylene glycol film is calculated; where H is the predetermined thickness of the film coating, f A is the length of the neopentyl glycol molecule, f B is the length of the methylpropylene glycol molecule, μ AB is the loss correction parameter for the film formation of neopentyl glycol and methylpropylene glycol (μ AB =0.75).

[0039] The present application also provides a membrane tube with a membrane coating, comprising: a membrane tube and a membrane coating; wherein the membrane coating is deposited and grown on the surface of the membrane tube by the above-mentioned method of depositing the membrane coating on the surface of the membrane tube.

[0040] Optionally, the membrane coating is deposited and grown onto the outer surface of the membrane tube. Furthermore, the membrane coating has a thickness no greater than 0.05 μm. Furthermore, the membrane coating has uniform pores with a controllable pore size between 0.005 μm and 0.1 μm.

[0041] The method of depositing a membrane coating on the surface of a membrane tube according to the present application can form a membrane coating with high uniformity, high shape retention, high density, and a smooth surface (low friction coefficient) on the membrane tube, thereby enhancing the membrane processing capacity, so that the membrane tube has resistance to strong acids, strong alkalis, and free chlorine. It can also block and precipitate precipitates such as high calcium and magnesium while preventing the precipitates from blocking the membrane tube, thereby ensuring the operating flux of the membrane, simplifying the membrane cleaning method, and increasing the service life of the membrane. Therefore, the membrane tube manufactured by the method of depositing a membrane coating on the surface of a membrane tube according to the present application is used for filtration, simplifying the process flow, avoiding the addition of a pretreatment process before membrane filtration, and avoiding the increase of the circulation volume and kinetic energy for filtration by adding a high-pressure pump. It also avoids the introduction of new pollutants through the use of drugs, reducing energy consumption and investment.

[0042] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0043] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A method for depositing a membrane coating on a membrane tube surface, characterized in that: The steps include: Step S110, fixing multiple membrane tubes into a deposition reaction chamber, and exhausting the air in the deposition reaction chamber. The process of exhausting the air requires heating at a temperature of 50-75° C.; Step S120: introducing vaporous neopentyl glycol into the deposition reaction chamber to deposit and grow a neopentyl glycol film on the membrane tube / the previous methylpropylene glycol film. After the neopentyl glycol film is deposited and grown, the vaporous neopentyl glycol in the deposition reaction chamber is discharged. The deposition process of the neopentyl glycol film requires heating at a temperature of 60-85° C. Step S130: introducing methylpropanediol into the deposition reaction chamber to deposit and grow a methylpropanediol film on the previous neopentyl glycol film. After the methylpropanediol film is deposited and grown, the vapor phase methylpropanediol in the deposition reaction chamber is discharged. The process of depositing the methylpropanediol film requires heating at a temperature of 30-60° C. Step S140, cyclically depositing and growing a neopentyl glycol film and a methylpropylene glycol film according to a predetermined number of cycles to deposit and grow a film coating of a predetermined thickness on the surface of the film tube; the thickness of the film coating is not greater than 0.05 μm; The membrane coating has uniform voids with a pore size ranging from 0.005um to 0.1um.

2. The method for depositing a membrane coating onto a membrane tube surface according to claim 1, wherein: The membrane coating is deposited and grown to the outer surface of the membrane tube.

3. The method for depositing a membrane coating onto a membrane tube surface according to claim 1 or 2, characterized in that: The plurality of membrane tubes are uniformly fixed to the deposition reaction chamber to ensure that the thickness of the neopentyl glycol film and the methylpropylene glycol film deposited on the surface of each membrane tube is uniform.

4. The method for depositing a membrane coating onto a membrane tube surface according to claim 3, wherein: The two ends of the membrane tube are fixed to the fixing brackets in the deposition reaction chamber to prevent the fixing brackets from blocking the outer surface of the membrane tube.

5. A membrane tube having a membrane coating, characterized in that include: A membrane tube and a membrane coating; wherein the membrane coating is a membrane deposited and grown on the surface of the membrane tube by the method for depositing a membrane coating on the surface of a membrane tube according to any one of claims 1 to 4.

Images