Modified basement membrane material based on silane coupling agent, basement membrane and preparation method

Abstract

The invention discloses a modified basement membrane material based on a silane coupling agent, a basement membrane and a preparation method, and relates to the technical field of organic composite nanomaterials, the specific steps are as follows: (N, N-dimethylaminopropyl) trimethoxysilane and 1, 3-propane sultone react to prepare a solid A, and the solid A is mixed with KH560 to prepare a solid B; reacting the mixture with a glacial acetic acid solution of ethyl silicate to obtain ZSiO2 particles, dispersing the ZSiO2 particles and polyethyleneimine in water to prepare a modified base membrane material, and carrying out surface modification on a polyolefin base membrane by using the modified base membrane material to obtain a modified base membrane; the prepared modified polyolefin film has the advantages of being high in binding force and flexibility, stable in structure and not prone to damage, the preparation technology is simple, the preparation process is short, energy consumption is low, and compared with a common base film in the prior art, the modified polyolefin film has the advantages of being clean, long in service life and environmentally friendly.

Description

Technical Field

[0001] The invention relates to the technical field of organic composite nanomaterials, in particular to a modified base film material based on a silane coupling agent, a base film and a preparation method thereof. Background Art

[0002] Due to the impact of climate change, urbanization and industrialization, the world is facing water shortage problems, which has prompted the research and development of freshwater resource management. At present, water treatment technologies mainly include:

[0003] Biochemical methods: such as activated sludge method and mixed biological method, these methods use the biological metabolic process of microorganisms to purify water.

[0004] Physicochemical methods: including particle filtration, activated carbon adsorption, chemical precipitation and membrane separation technology, these methods remove pollutants from water by physical or chemical means.

[0005] Natural treatment methods: Such as constructed wetlands, this method uses the purification capacity of natural ecosystems to treat sewage.

[0006] Among these technologies, membrane separation technology is highly respected for its high efficiency, low energy consumption, small footprint and no pollution. In particular, polymer membranes play a vital role in large-scale applications in water purification, ion separation and wastewater treatment due to their excellent performance and high selectivity for ions.

[0007] Polyethylene (PE) and polypropylene (PP) are two thermoplastic polymer materials with excellent performance. Their molecular structure consists of carbon atoms connected by single bonds, which gives them excellent heat resistance and mechanical strength. Therefore, they are the preferred materials for making organic membranes. However, the hydrophobicity of polyolefins makes their surfaces easily adsorbed by non-polar substances, colloidal particles and microorganisms, which not only reduces the flux of the membrane, but also weakens its separation effect, thereby shortening the service life of the polyolefin membrane. In order to improve the efficiency of water resource treatment and membrane separation technology, it is particularly important to improve the hydrophilicity of these membrane materials. Summary of the invention

[0008] In view of this, the present invention provides a method for hydrophilically modifying a hydrophobic polyolefin membrane based on a silane coupling agent. The modified membrane has the characteristics of high water flux, long-term stability and environmental friendliness, and can effectively improve the treatment efficiency.

[0009] The invention discloses a method for preparing a modified base film material based on a silane coupling agent, comprising the following steps:

[0010] Step S1: (N,N-dimethylaminopropyl)trimethoxysilane and 1,3-propane sultone are stirred and dissolved in acetone, and the resulting solution is stirred and reacted at room temperature for 12 hours under nitrogen protection, and filtered, washed, and dried to obtain solid A;

[0011] Step S2: adding solid A and KH560 into deionized water and stirring to dissolve, adding ethyl silicate glacial acetic acid solution to the obtained solution, stirring at room temperature for 24 hours and then centrifugally drying to obtain ZSiO2 particles;

[0012] Step S3: Add ZSiO2 particles and polyethyleneimine into water and stir evenly.

[0013] An embodiment of the present invention is that, in parts by weight, the ratio of (N,N-dimethylaminopropyl)trimethoxysilane to 1,3-propane sultone is 1:0.2-4.

[0014] One embodiment of the present invention is that, in parts by weight, the ratio of the solid A to KH560 is 1:1-30.

[0015] One embodiment of the present invention is that, in parts by weight, the ratio of glacial acetic acid to ethyl silicate in the glacial acetic acid solution of ethyl silicate is 1:0.4-6.

[0016] One embodiment of the present invention is that the amount of ZSiO2 particles and polyethyleneimine added to water is: 1-6g of ZSiO2 particles and 0.1-10g of polyethyleneimine are added to every 100mL of water, wherein the Dalton value range of polyethyleneimine is Da=600-70000.

[0017] The invention also discloses a modified base film material based on a silane coupling agent prepared by the method.

[0018] In addition, the present invention discloses a method for preparing a modified base film based on a silane coupling agent by using the modified base film material, which mainly comprises the following steps:

[0019] Step 1): select a polyolefin-based film and soak it in a 10-80% isopropanol solution for 2-10 hours, then rinse it with deionized water until it is clean, and then soak it in deionized water for 48 hours to complete the pretreatment, wherein the polyolefin-based film is one of a polypropylene film or a polyethylene film;

[0020] Step 2): fix the pretreated basement membrane in a plate frame, draw 10-50 mL of the modified basement membrane material and inject it evenly along one corner of the plate frame, and let it stand for 5-30 minutes;

[0021] Step 3): Place the base film in an oven at 40-80°C and cure for 10-30 minutes.

[0022] In some embodiments, the operation method of step 2) is: fix the pretreated base film on a glass plate, dip the modified base film material into the base film surface and coat it in one direction at a uniform speed, and repeat the coating 5-10 times.

[0023] In some embodiments, the operation method of step 2) is: fix the pretreated basement membrane in a Buchner funnel, measure 10-50 mL of the modified basement membrane material and evenly pour it into the Buchner funnel, and vacuum filter.

[0024] Furthermore, the modified base film based on silane coupling agent disclosed in the present invention is prepared by the above method.

[0025] The technical effects of the present invention are:

[0026] The modified polyolefin membrane prepared by the present invention has the characteristics of strong bonding force, strong flexibility, stable structure and not easy to be damaged. The preparation process is simple and the preparation process is short. It has the characteristics of low energy consumption, cleanliness, long service life and environmental friendliness. Compared with the general base membrane in the prior art, it can significantly improve its water flux, thereby effectively improving the water treatment efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a scanning electron microscope photograph of ZSiO2 particles in Example 1 of the present invention;

[0028] Figure 2 This is a scanning electron microscope photograph of the unmodified polypropylene base film of Example 1 of the present invention;

[0029] Figure 3 This is a scanning electron microscope photograph of the modified polypropylene base film in Example 1 of the present invention;

[0030] Figure 4 This is a diagram showing the water contact state of the surface of the unmodified polypropylene base film in Example 1 of the present invention;

[0031] Figure 5 This is a diagram showing the water contact state of the surface of the modified polypropylene base film in Example 1 of the present invention;

[0032] Figure 6 This is a diagram showing the water contact state of the surface of the modified polypropylene base film in Example 2 of the present invention;

[0033] Figure 7 This is a diagram showing the water contact state of the surface of the modified polypropylene base film in Example 3 of the present invention. DETAILED DESCRIPTION

[0034] The present invention will be further described in detail below in conjunction with the examples, but the embodiments of the present invention are not limited thereto. The experimental methods used in the following examples are conventional methods unless otherwise specified; the materials, reagents, etc. used therein are all commercially available unless otherwise specified.

[0035] Example 1

[0036] Preparation of modified base membrane materials:

[0037] (1) 4 g of (N,N-dimethylaminopropyl)trimethoxysilane (DMASi) and 2.4 g of 1,3-propane sultone were added to 20 mL of acetone, and stirred for 12 h under nitrogen protection at room temperature. The mixture was filtered, and then repeatedly rinsed with acetone to obtain a white solid, which was then dried in a vacuum at 30° C. for 24 h to obtain solid A;

[0038] (2) 1.8 g KH560 and 0.3 g solid A were added to 50 mL deionized water, stirred and ultrasonicated until uniform, 1.2 g ethyl silicate was slowly dripped into 0.6 g glacial acetic acid to prepare a glacial acetic acid solution of ethyl silicate, and the solution was added to the above solution containing solid A, stirred at room temperature for 24 h, and centrifuged and dried to obtain ZSiO2 particles;

[0039] (3) Take 1 g of ZSiO2 particles and 10 g of polyethyleneimine (PEI, Da=600) and disperse them in 100 mL of aqueous solution to obtain a modified base membrane material.

[0040] Preparation of modified base film:

[0041] (4) Soak the polypropylene film in a 10% isopropanol solution for 10 h, then rinse with a large amount of deionized water and soak in deionized water for 48 h;

[0042] (5) Fix the soaked polypropylene film in a plate frame of matching size, use a syringe to draw 50 mL of the modified base film material obtained in step (3), and inject it along one corner of the plate frame at a uniform speed until it is evenly laid, and let it stand for 30 minutes;

[0043] (6) The base film after standing is placed in a 40° C. oven for curing for 10 minutes to obtain a modified base film.

[0044] Example 2

[0045] (1) 1 g of (N,N-dimethylaminopropyl)trimethoxysilane (DMASi) and 1 g of 1,3-propane sultone were added to 10 mL of acetone, and stirred for 12 h under nitrogen protection at room temperature. The mixture was filtered, and then repeatedly rinsed with acetone to obtain a white solid, which was then dried in a vacuum at 30° C. for 24 h to obtain solid A;

[0046] (2) 5 g of KH560 and 1 g of solid A were added to 200 mL of deionized water, stirred and ultrasonicated until uniform, 5 g of ethyl silicate was slowly dripped into 5 g of glacial acetic acid to prepare a glacial acetic acid solution of ethyl silicate, and the solution was added to the above solution containing solid A, stirred at room temperature for 24 h, and centrifuged and dried to obtain ZSiO2 particles;

[0047] (3) Take 6 g of ZSiO2 particles and 1 g of polyethyleneimine (PEI, Da=10000) and disperse them in 100 mL of aqueous solution to obtain a modified base membrane material.

[0048] Preparation of modified base film:

[0049] (4) Soak the polypropylene film in 80% isopropanol solution for 2 h, then rinse with a large amount of deionized water and soak in deionized water for 24 h;

[0050] (5) Fixing the soaked polypropylene film on a glass plate, using a brush to evenly dip the modified base film material obtained in step (3), and uniformly coating along the surface of the base film 10 times in one direction;

[0051] (6) The base film after standing is placed in a 60° C. oven for curing for 20 minutes to obtain a modified base film.

[0052] Example 3

[0053] (1) 5 g of (N,N-dimethylaminopropyl)trimethoxysilane (DMASi) and 4 g of 1,3-propane sultone were added to 30 mL of acetone, and stirred for 12 h under nitrogen protection at room temperature. The mixture was filtered, and then repeatedly rinsed with acetone to obtain a white solid, which was then dried in a vacuum at 30° C. for 24 h to obtain solid A;

[0054] (2) 3 g of KH560 and 0.5 g of solid A were added to 60 mL of deionized water, stirred and ultrasonicated until uniform, 3 g of ethyl silicate was slowly dripped into 2 g of glacial acetic acid to prepare a glacial acetic acid solution of ethyl silicate, and the solution was added to the above solution containing solid A, stirred at room temperature for 24 h, and centrifuged and dried to obtain ZSiO2 particles;

[0055] (3) Take 2 g of ZSiO2 particles and 0.1 g of polyethyleneimine (PEI, Da=70000) and disperse them in 100 mL of aqueous solution to obtain a modified base membrane material.

[0056] Preparation of modified base film:

[0057] (4) Soak the polypropylene film in a 40% isopropanol solution for 12 h, then rinse with a large amount of deionized water and soak in deionized water for 48 h;

[0058] (5) Fix the soaked polypropylene membrane in a Buchner funnel, take 50 mL of the modified base membrane material, and perform vacuum filtration;

[0059] (6) The base film after standing is placed in an oven at 80° C. for curing for 30 minutes to obtain a modified base film.

[0060] In order to better illustrate the technical effects of the present invention, performance evaluation is performed based on relevant embodiments below.

[0061] 1. Comparison of microscopic morphology:

[0062] See also Figures 1 to 3 The scanning electron microscope photo of ZSiO2 particles in Example 1 is as follows: Figure 1 As shown, the scanning electron microscope photo of commercially available polypropylene base film is as follows Figure 2 As shown in the scanning electron microscope photo of the polypropylene base film after hydrophilic modification by silane coupling agent, Figure 3 As shown by Figure 2 It can be seen that the unmodified polypropylene base film is wrinkled, with no particles deposited on the surface and is relatively smooth. Figure 3 It can be seen that after the deposition of the silane coupling agent, the surface of the base film presents an obvious synaptic structure, that is, the deposition of ZSiO2 particles prepared based on the silane coupling agent gives the modified base film a unique microstructure, proving that ZSiO2 particles can achieve surface modification of the polypropylene base film.

[0063] 2. Membrane surface contact angle test:

[0064] See also Figure 4 , Figure 5 The contact angle of unmodified polypropylene film with water is Figure 4 The contact angle of the modified base film in Example 1 is 113°, which proves that it is hydrophobic. Figure 5 The contact angle of the modified base film in Example 2 is shown as 58°. Figure 6 The contact angle of the modified base film in Example 3 is shown as 60°. Figure 7 It is shown as 78°, indicating that it has changed from its original hydrophobicity to hydrophilicity. It can be seen that the hydrophilicity and hydrophobicity of the polypropylene base film can be effectively improved after the surface of the base film is modified with ZSiO2 particles.

[0065] 3. Membrane separation performance test:

[0066] The membrane separation performance can be investigated from two aspects: membrane water flux performance and membrane adsorption performance. The calculation formula of membrane water flux performance is shown in formula (1):

[0067] J=V / (A×t) (1)

[0068] In formula (1): J is the flux (L / m2 / h), V is the permeate volume (L), A is the effective membrane area (m 2 ), t is the test time (h)

[0069] The present invention uses a cross-flow filtration device to perform cross-flow tests on each embodiment and a general basement membrane at 25°C. The test conditions are: the effective test area (A) is 18.5 cm 2 , pressure is 1MPa, test time is 1h.

[0070] The membrane adsorption performance test was conducted by soaking each embodiment and the general base membrane in a bovine serum albumin (BSA) solution, and the membrane adsorption capacity was calculated by the concentration change after soaking. In the test, the original membrane and the different modified polyolefin bases were cut into 2cm×2cm sizes and then soaked in 40ml of 1.0g / L BSA solution for 10h. Among them, the initial concentration of the bovine serum albumin (BSA) solution was 1.0g / L, V was the volume of the BSA solution 40mL, and the effective membrane area was 2cm×2cm.

[0071] The test result calculation formula can be expressed by formula (2):

[0072] F=(C0-C1)×V / A (2)

[0073] In formula (2), F is the membrane adsorption capacity (g / m 2 ), C0 is the initial concentration of bovine serum albumin (BSA) solution (g / L), C1 is the concentration of BSA solution after the polyolefin water treatment membrane is immersed (g / L), V is the volume of BSA solution (L), and A is the effective membrane area (m 2 )

[0074] In summary, the membrane water flux performance and membrane adsorption performance results are shown in Table 1:

[0075] Table 1 Cross-flow test results

[0076]

[0077]

[0078] It can be seen from the results in Table 1 that in the membrane water flux performance experiment, each embodiment has undergone hydrophilic modification relative to the general base membrane, which significantly improves the water flux, among which the water flux improvement rate of Embodiment 3 is the largest.

[0079] In the membrane separation performance test, the contact angle of the polyolefin-based membrane was significantly reduced by modification with a silane coupling agent, indicating that the hydrophilicity was enhanced, which led to an increase in its water flux. At the same time, through the membrane adsorption separation performance test, it can be found that the adsorption amount of the unmodified original membrane after being immersed in the BSA solution for 10 hours reached 25g / m2, and the anti-protein adsorption ability was poor. This is attributed to the strong hydrophobicity of the surface of the polyolefin-based membrane, which easily causes bovine serum albumin to adsorb on the membrane surface. Compared with the original membrane, the adsorption amount of the modified polyolefin-based membrane has significantly improved its anti-protein ability. This is mainly due to the improved hydrophilicity of the membrane surface after modification. The hydrophilic modified polyolefin membrane preferentially adsorbs water molecules to form a hydration layer on the membrane surface, weakening the hydrophobic interaction between the polyolefin membrane and bovine serum albumin, effectively reducing the adsorption of bovine serum albumin on the membrane surface, thereby improving the anti-protein adsorption ability of the membrane surface.

[0080] In summary, the modified polyolefin membrane prepared in the present invention has the characteristics of high water flux, high structural stability, greatly improved mechanical properties and hydrophilic properties, and can be effectively applied in the fields of water resource treatment and membrane separation technology.

[0081] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the embodiments of the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for preparing a modified base film material based on a silane coupling agent, characterized in that: The following steps are involved: Step S1: (N,N-dimethylaminopropyl)trimethoxysilane and 1,3-propane sultone are stirred and dissolved in acetone, and the resulting solution is stirred and reacted at room temperature for 12 hours under nitrogen protection, and filtered, washed, and dried to obtain solid A; Step S2: adding solid A and KH560 into deionized water and stirring to dissolve, adding ethyl silicate glacial acetic acid solution to the obtained solution, stirring at room temperature for 24 hours and then centrifugally drying to obtain ZSiO2 particles; Step S3: Add ZSiO2 particles and polyethyleneimine into water and stir evenly.

2. The method for preparing a modified base film material based on a silane coupling agent according to claim 1, characterized in that: In parts by weight, the ratio of the (N,N-dimethylaminopropyl)trimethoxysilane to 1,3-propane sultone is 1:0.2-4.

3. The method for preparing a modified base film material based on a silane coupling agent according to claim 1, characterized in that: In parts by weight, the ratio of the solid A to KH560 is 1:1-30.

4. The method for preparing a modified base film material based on a silane coupling agent according to claim 1, characterized in that: In parts by weight, the ratio of glacial acetic acid to ethyl silicate in the glacial acetic acid solution of ethyl silicate is 1:0.4-6.

5. The method for preparing a modified base film material based on a silane coupling agent according to claim 1, characterized in that: The amount of ZSiO2 particles and polyethyleneimine added to water is: 1-6g of ZSiO2 particles and 0.1-10g of polyethyleneimine are added to every 100mL of water, wherein the Dalton value range of polyethyleneimine is Da=600-70000.

6. A modified base film material based on a silane coupling agent, characterized in that: The method is prepared by any one of claims 1 to 5.

7. A method for preparing a modified base film based on a silane coupling agent, characterized in that: The modified base film material according to claim 6 is used for preparation, comprising the following steps: Step 1): select a polyolefin-based film and soak it in a 10-80% isopropanol solution for 2-10 hours, then rinse it with deionized water until it is clean, and then soak it in deionized water for 48 hours to complete the pretreatment, wherein the polyolefin-based film is one of a polypropylene film or a polyethylene film; Step 2): fix the pretreated basement membrane in a plate frame, draw 10-50 mL of the modified basement membrane material and inject it evenly along one corner of the plate frame, and let it stand for 5-30 minutes; Step 3): Place the base film in an oven at 40-80°C and cure for 10-30 minutes.

8. The method for preparing a modified base film based on a silane coupling agent according to claim 7, characterized in that: The operation method of step 2) is: fix the pretreated base film on a glass plate, dip the modified base film material and apply it on the surface of the base film in one direction at a uniform speed, and repeat the application 5-10 times.

9. The method for preparing a modified base film based on a silane coupling agent according to claim 7, characterized in that: The operation method of step 2) is: fix the pretreated basement membrane in a Buchner funnel, measure 10-50 mL of the modified basement membrane material and pour it evenly on the basement membrane, and perform vacuum filtration.

10. A modified base film based on a silane coupling agent, characterized in that: The method is prepared by any one of claims 7 to 9.

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