An acid-resistant nanofiltration membrane and a method for manufacturing the same

Abstract

The application provides an acid-resistant nanofiltration membrane and a manufacturing method thereof, and relates to the technical field of membrane separation. The manufacturing method of the acid-resistant nanofiltration membrane comprises the following steps: forming a support membrane; sequentially immersing the support membrane in a first water-phase solution and a first oil-phase solution to form a first functional layer on the surface of the support membrane; and sequentially immersing the first functional layer in a second water-phase solution and a second oil-phase solution to form a second functional layer on the surface of the first functional layer. The manufacturing method of the acid-resistant nanofiltration membrane can be used to manufacture the acid-resistant nanofiltration membrane which has good environmental tolerance and stability.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of membrane separation technology, in particular to an acid-resistant nanofiltration membrane and a manufacturing method thereof. BACKGROUND

[0002] Membrane separation technology is a technology that uses a separation membrane as the core to separate, concentrate and purify substances. Due to the advantages of high selectivity, simple operation process, low energy consumption and the like, the membrane separation technology is widely used in the fields of food, medicine, biology, environmental protection, chemical industry, metallurgy, energy, petroleum, water treatment, electronics, and bionics.

[0003] As a research hotspot in the field of membrane separation, acid-resistant nanofiltration membrane technology is a method for separating, classifying, purifying and enriching a binary or multi-component mixed gas / liquid by using the difference in the selective permeation performance of the membrane to each component in the mixture and using external energy or chemical potential difference as the driving force. The acid-resistant nanofiltration membrane used in the acid-resistant nanofiltration membrane technology should have good selectivity and strong acid resistance to maintain long-term stability under strong acid conditions. However, the existing acid-resistant nanofiltration membrane has poor performance and is difficult to meet the industrial demand. SUMMARY

[0004] The present application relates to the field of membrane separation technology, in particular to an acid-resistant nanofiltration membrane and a manufacturing method thereof.

[0005] Another object of the present application is to provide an acid-resistant nanofiltration membrane.

[0006] The technical problem of the present application is solved by adopting the following technical solutions:

[0007] A manufacturing method of an acid-resistant nanofiltration membrane, comprising:

[0008] forming a support membrane;

[0009] immersing the support membrane in a first aqueous solution and a first oil solution in sequence to form a first functional layer on the surface of the support membrane; wherein the first aqueous solution is a solution formed by mixing inorganic oxides and sulfonamide monomers in a solution system containing acid, and the first oil solution is a solution whose raw material includes polyacyl chloride monomers;

[0010] immersing the first functional layer in a second aqueous solution and a second oil solution in sequence to form a second functional layer on the surface of the first functional layer; wherein the second aqueous solution is a solution whose raw material includes sulfonamide monomers, and the second oil solution is a solution whose raw material includes polyacyl chloride monomers.

[0011] Optionally, in some embodiments, the inorganic oxides are selected from one or more of titanium dioxide, silicon dioxide and zirconium dioxide.

[0012] Optionally, in some embodiments, the mass percentage of the sulfonamide monomer in the first aqueous solution is 0.1-3%.

[0013] Optionally, in some embodiments, the mass ratio of the acid, the inorganic oxide, and the sulfonamide monomer in the first aqueous solution is 0.5-8:0.5-12:1-30.

[0014] Optionally, in some embodiments, the acid is selected from one or more of hydrochloric acid and phosphoric acid.

[0015] Optionally, in some embodiments, the sulfonamide monomer is selected from one or more of sulfonamidopyridine and 3-aminobenzenesulfonamide.

[0016] Optionally, in some embodiments, the polybasic acid chloride monomer is selected from one or more of 1,3,5-benzene tricarbonyl chloride, phthaloyl chloride, terephthaloyl chloride, and isophthaloyl chloride.

[0017] Optionally, in some embodiments, the support membrane is a polymeric fiber membrane, and the polymer is one or more of polypropylene, polyethersulfone, polysulfone, and polyacrylonitrile.

[0018] Optionally, in some embodiments, the method of impregnation is selected from one or more of coating and soaking.

[0019] In addition, an acid-resistant nanofiltration membrane is prepared by the above method for manufacturing an acid-resistant nanofiltration membrane.

[0020] Compared with the prior art, the present application has the following advantages: the first functional layer is formed by using a first aqueous solution, which includes an acid, an inorganic oxide, and a sulfonamide monomer. The S=O bond angle in the sulfonamide is small, and based on the steric hindrance effect, the S=O bond in the polysulfonamide formed by polymerization of the monomer is not easily attacked by hydrogen ions. Moreover, because a small amount of acid is added to the solution system at the monomer stage, the hydrogen ions brought by the acid can promote the formation of a more stable resonance hybrid at the beginning of the monomer polymerization stage, thereby enhancing the acid-resistant nanofiltration membrane formed in the acid environment and improving its stability. In addition, the addition of the inorganic oxide can enhance the chemical stability, thermal stability, and mechanical strength of the acid-resistant nanofiltration membrane formed. Furthermore, because the first functional layer including the inorganic oxide is formed between the support membrane and the second functional layer, the material transition between the layers is also good. In summary, the method for manufacturing an acid-resistant nanofiltration membrane provided by the present application can produce an acid-resistant nanofiltration membrane with good environmental tolerance and stability, which is suitable for wide promotion. DETAILED DESCRIPTION

[0021] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below. If specific conditions are not specified in the embodiments, the conventional conditions or the conditions recommended by the manufacturers are adopted. If the manufacturers of the reagents or instruments are not specified, the conventional products that can be purchased in the market are adopted.

[0022] The acid-resistant nanofiltration membrane and the manufacturing method thereof according to the embodiments of the present application will be described in detail below.

[0023] The manufacturing method of the acid-resistant nanofiltration membrane provided by the present application comprises the following steps.

[0024] forming a support membrane;

[0025] sequentially immersing the support membrane in a first aqueous solution and a first oil solution to form a first functional layer on the surface of the support membrane; wherein the first aqueous solution is a solution formed by mixing inorganic oxides and sulfonamide monomers in a solution system containing acid, and the first oil solution is a solution whose raw material contains polyacyl chloride monomers;

[0026] sequentially immersing the first functional layer in a second aqueous solution and a second oil solution to form a second functional layer on the surface of the first functional layer; wherein the second aqueous solution is a solution whose raw material contains sulfonamide monomers, and the second oil solution is a solution whose raw material contains polyacyl chloride monomers.

[0027] It should be noted that the first aqueous solution, the first oil solution, the second aqueous solution and the second oil solution can contain other raw materials known to those skilled in the art in addition to the above-mentioned materials. For example, the first aqueous solution can also contain a catalyst, and the first oil solution can also contain an organic solvent. The specific materials of the above-mentioned substances (such as organic solvents) can be selected conventionally based on the industry knowledge of those skilled in the art, and therefore will not be described one by one here.

[0028] Of course, a small amount of acid can also be added to the second aqueous solution to promote the polymerization of the monomers to form a more stable resonance hybrid structure.

[0029] In some embodiments, the inorganic oxide is selected from one or more of titanium dioxide, silicon dioxide and zirconium dioxide. The selection of the inorganic oxide helps to improve the selectivity of the prepared acid-resistant nanofiltration membrane in the separation process.

[0030] In some embodiments, the mass fraction of the sulfonamide monomers in the first aqueous solution is 0.1-3%. Further, the mass fraction of the sulfonamide monomers can be, for example, 0.5%, 1.1%, 1.7% or 2.5%.

[0031] In some embodiments, the mass ratio of the acid, the inorganic oxide, and the sulfonamide monomer in the first aqueous solution is 0.5-8:0.5-12:1-30. An appropriate ratio among the substances can ensure a complementary effect. Further, the mass ratio of the acid, the inorganic oxide, and the sulfonamide monomer may, for example, be 0.7:5:10, 3:8:17, or 6.5:10:25.

[0032] In some embodiments, the acid is selected from one or more of hydrochloric acid and phosphoric acid. Hydrochloric acid and phosphoric acid are relatively easy to dissociate into hydrogen ions, which helps to provide hydrogen ions during the polymerization of the monomers.

[0033] In some embodiments, the sulfonamide monomer is selected from one or more of sulfonamidopyridine and 3-aminobenzenesulfonamide, and the polybasic acid chloride monomer is selected from one or more of 1,3,5-benzene tricarbonyl chloride, phthaloyl dichloride, terephthaloyl dichloride, and isophthaloyl dichloride.

[0034] In some embodiments, the support membrane is a polymeric fiber membrane, and the polymer is one or more of polypropylene, polyethersulfone, polysulfone, and polyacrylonitrile. The method of forming the support membrane can include: infiltrating the fiber membrane with a solution of the polymer, and then drying.

[0035] In some embodiments, the method of infiltrating is selected from one or more of coating and soaking. The coating can be selected from one or more of spraying and doctor blading.

[0036] In addition, the application also provides an acid-resistant nanofiltration membrane prepared by the method of manufacturing an acid-resistant nanofiltration membrane described above.

[0037] The features and properties of the application are described in further detail below in conjunction with the embodiments:

[0038] Embodiment One

[0039] The method of manufacturing an acid-resistant nanofiltration membrane provided in this embodiment includes:

[0040] Step S1: infiltrating a fiber membrane with a solution of polyacrylonitrile, and then drying to obtain a support membrane;

[0041] Step S2: sequentially coating a first aqueous solution and a first oil-phase solution on the surface of the support membrane, and drying to obtain a first functional layer; the first aqueous solution includes, by mass, 5 parts of phosphoric acid, 10 parts of titanium dioxide, and 18 parts of 3-aminobenzenesulfonamide monomer, and the first oil-phase solution includes 1,3,5-benzene tricarbonyl chloride monomer;

[0042] Step S3: sequentially coating a second aqueous solution and a second oil-phase solution on the surface of the first functional layer, and drying to obtain a second functional layer; the second aqueous solution includes 3-aminobenzenesulfonamide monomer, and the second oil-phase solution includes 1,3,5-benzene tricarbonyl chloride monomer.

[0043] The acid-resistant nanofiltration membrane provided by the embodiment further includes the acid-resistant nanofiltration membrane prepared by the method.

[0044] Embodiment two

[0045] The acid-resistant nanofiltration membrane provided by the embodiment further includes the acid-resistant nanofiltration membrane prepared by the method.

[0046] Step S1: a solution of polypropylene is used to infiltrate a fiber membrane, and then dried to obtain a support membrane;

[0047] Step S2: a first aqueous solution and a first oil-phase solution are sequentially coated on the surface of the support membrane, and a first functional layer is obtained after drying; the first aqueous solution includes hydrochloric acid, silicon dioxide and sulfapyridine monomers in a mass ratio of 1:4:10, and the first oil-phase solution includes terephthaloyl chloride monomers;

[0048] Step S3: a second aqueous solution and a second oil-phase solution are sequentially coated on the surface of the first functional layer, and a second functional layer is obtained after drying; the second aqueous solution includes sulfapyridine monomers, and the second oil-phase solution includes terephthaloyl chloride monomers.

[0049] The acid-resistant nanofiltration membrane provided by the embodiment further includes the acid-resistant nanofiltration membrane prepared by the method.

[0050] Embodiment three

[0051] The acid-resistant nanofiltration membrane provided by the embodiment further includes the acid-resistant nanofiltration membrane prepared by the method.

[0052] Step S1: a solution of polyether sulfone is used to infiltrate a fiber membrane, and then dried to obtain a support membrane;

[0053] Step S2: a first aqueous solution and a first oil-phase solution are sequentially coated on the surface of the support membrane, and a first functional layer is obtained after drying; the first aqueous solution includes phosphoric acid, inorganic oxides (a mixture of titanium dioxide and zirconium dioxide in a mass ratio of 1:1) and sulfapyridine monomers in a mass ratio of 7:12:25, and the first oil-phase solution includes 1,3,5-benzene triformyl chloride monomers;

[0054] Step S3: a second aqueous solution and a second oil-phase solution are sequentially coated on the surface of the first functional layer, and a second functional layer is obtained after drying; the second aqueous solution includes sulfapyridine monomers, and the second oil-phase solution includes 1,3,5-benzene triformyl chloride monomers.

[0055] The acid-resistant nanofiltration membrane provided by the embodiment further includes the acid-resistant nanofiltration membrane prepared by the method.

[0056] The above merely provides the preferred embodiments of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the principles and technical scope of the present application shall fall into the scope of the present application.

Claims

1. A method for producing an acid-resistant nanofiltration membrane sheet, characterized by comprising: The application relates to a method for manufacturing an acid-resistant nanofiltration membrane. forming a support membrane; immersing the support membrane in a first aqueous phase solution and a first oil phase solution in sequence to form a first functional layer on the surface of the support membrane; wherein the first aqueous phase solution is a solution formed by mixing inorganic oxide and sulfonamide monomers in a solution system containing acid selected from one or more of hydrochloric acid and phosphoric acid; and the first oil phase solution is a solution containing polyacyl chloride monomers as raw materials; immersing the first functional layer in a second aqueous phase solution and a second oil phase solution in sequence to form a second functional layer on the surface of the first functional layer; wherein the second aqueous phase solution is a solution containing sulfonamide monomers as raw materials, and the second oil phase solution is a solution containing polyacyl chloride monomers as raw materials.

2. The method for producing an acid-resistant nanofiltration membrane sheet according to claim 1, characterized by: The inorganic oxide is selected from one or more of titanium dioxide, silicon dioxide and zirconium dioxide.

3. The method of producing an acid-resistant nanofiltration membrane sheet according to claim 1, characterized by: The mass percentage of the sulfonamide monomers in the first aqueous phase solution is 0.1-3%.

4. The method of producing an acid-resistant nanofiltration membrane sheet according to claim 1, characterized by: In the first aqueous phase solution, the mass ratio of the acid, the inorganic oxide and the sulfonamide monomers is 0.5-8:0.5-12:1-30.

5. The method of producing an acid-resistant nanofiltration membrane sheet according to claim 1, characterized by: The sulfonamide monomers are selected from one or more of sulfonamidopyridine and 3-aminobenzenesulfonamide.

6. The method of producing an acid-resistant nanofiltration membrane sheet according to claim 1, characterized by: The polyacyl chloride monomers are selected from one or more of 1,3,5-benzene triformyl chloride, phthaloyl dichloride, terephthaloyl dichloride and isophthaloyl dichloride.

7. The method of producing an acid-resistant nanofiltration membrane sheet according to claim 1, characterized by: The support membrane is a polymer fiber membrane, and the polymer is one or more of polypropylene, polyether sulfone, polysulfone and polyacrylonitrile.

8. The method of producing an acid-resistant nanofiltration membrane sheet according to claim 1, characterized by: The immersing mode is selected from one or more of coating and soaking.

9. An acid-resistant nanofiltration membrane, characterized in that, The acid-resistant nanofiltration membrane is prepared by the method. The application relates to a method for manufacturing an acid-resistant nanofiltration membrane.