A speek filled ptf porous membrane and its preparation process

Abstract

The present application relates to the technical field of PTFE porous membrane, in particular to a kind of SPEEK filled PTFE porous membrane and its preparation process, the present application selects PTFE porous membrane as base film material, selects SPEEK as filler, with non-ionic surfactant polyoxyethylene laurate as hydrophilic layer element, induces dopamine to be self-polymerized on the surface of PTFE porous membrane and constructs mussel biomimetic coating;Then PEEK is treated with concentrated sulfuric acid, prepares SPEEK, and grafted gallic acid modified chitosan after activation;Carboxylated fiber nanocrystal, polycarboxyl group conjugated microporous polymer and composite SPEEK are introduced as filler;By controlling the ratio of carboxylated fiber nanocrystal, polycarboxyl group conjugated microporous polymer and composite SPEEK in mixed solution, introducing auxiliary agent in mixed solution, complex crosslinking network is constructed, PTFE porous membrane is endowed with durable antibacterial, corrosion resistance and high stability, the use range of PTFE porous membrane is widened, and the service life of PTFE porous membrane is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of PTFE porous membranes, in particular to a SPEEK-filled PTFE porous membrane and a preparation process thereof. Background Art

[0002] PTFE (polytetrafluoroethylene) porous membranes, which have good chemical stability, are widely used in filtration and separation fields. With the development of society, single PTFE porous membranes cannot meet the needs of filtration and separation fields. In the existing market, different fillers are often used to improve the various properties of PTFE porous membranes. Among them, SPEEK (sulfonated polyetheretherketone) is one of the commonly used fillers. However, directly filling PTFE porous membranes with SPEEK also has problems such as easy shedding, limited corrosion resistance, and poor antibacterial properties.

[0003] How to construct a SPEEK-filled PTFE porous membrane that has high strength, antibacterial properties, corrosion resistance, high temperature resistance and other properties, and expand its application in air purification filtration, medical food filtration, clean room filtration, industrial dust removal filtration, electronic waterproof and breathable, and clothing fabrics, has practical significance and economic value. Summary of the Invention

[0004] The object of the present invention is to provide a SPEEK-filled PTFE porous membrane and a preparation process thereof, so as to solve the problems in the prior art.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] A preparation process of a SPEEK-filled PTFE porous membrane comprises the following steps:

[0007] S1: The PTFE porous membrane is cleaned, dried, transferred to an ethanol solution of polyoxyethylene laurate for immersion treatment, then transferred to a Tris buffer solution of dopamine hydrochloride for immersion treatment, and washed with water to obtain a pretreated PTFE porous membrane;

[0008] S2: mixing polyethylene glycol, composite SPEEK, carboxylated fiber nanocrystals, multi-carboxyl conjugated microporous polymer, additives, and solvent to obtain a mixed solution;

[0009] S3: coating the mixed material solution on the surface of the pretreated PTFE porous membrane, performing hot pressing, washing and drying to obtain a SPEEK-filled PTFE porous membrane.

[0010] Furthermore, in step S1, the working conditions of the immersion treatment are: time is 18-20 hours, temperature is 18-25° C., and the mass concentration of polyoxyethylene laurate in the ethanol solution of polyoxyethylene laurate is 15-20%.

[0011] Furthermore, in step S1, the working conditions of the infiltration treatment are: time is 16-18 hours, temperature is 30-40° C., pH of the Tris buffer solution is 8.5, and the mass concentration of dopamine hydrochloride in the Tris buffer solution of dopamine hydrochloride is 5 g / L.

[0012] Furthermore, in the mixed material solution, the auxiliary agent is 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysulfosuccinimide in a mass ratio of 3:1.

[0013] Furthermore, the mass ratio of polyethylene glycol, composite SPEEK, carboxylated fiber nanocrystals, and multi-carboxyl conjugated microporous polymer is 1:4:2:1.

[0014] Furthermore, the preparation of composite SPEEK includes the following steps:

[0015] 1) Mix concentrated sulfuric acid and PEEK, keep warm at 48-52°C for 23-24 hours, cool, pour into ice water with stirring, wash with ice deionized water until neutral, and dry to obtain SPEEK;

[0016] 2) SPEEK, dimethyl sulfoxide, and N,N'-carbonyldiimidazole are heated to 58-62°C and kept warm for 2-3 hours, gallic acid-modified chitosan is added, and the temperature is raised to 78-82°C and kept warm for 2-3 hours, washed, and dried to obtain composite SPEEK.

[0017] Furthermore, the mass ratio of SPEEK and gallic acid-modified chitosan is 1:5.

[0018] Furthermore, the preparation of gallic acid modified chitosan comprises the following steps:

[0019] Under a nitrogen atmosphere, gallic acid and ethanol were mixed, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysulfosuccinimide were added, the pH was adjusted to 5.4-5.6, and the mixture was placed in an ice-water bath and stirred for 2-3 hours. Chitosan was added, the pH was adjusted to 5.5, the temperature was raised to 18-25°C and kept warm for 22-24 hours, dialyzed, and freeze-dried to obtain gallic acid-modified chitosan.

[0020] Furthermore, the preparation of the polycarboxyl conjugated microporous polymer comprises the following steps:

[0021] Under nitrogen protection, 1,4-phenylenediboronic acid, 2,5-dibromothiophene-3-carboxylic acid, 1,3,6,8-tetrabromocarbazole and N,N-dimethylformamide are mixed, potassium carbonate solution and tetrakis(triphenylphosphine)palladium(0) are added, stirred at 148-152°C for 47-48h, cooled, poured into 50mL methanol, filtered, washed with deionized water, chloroform, tetrahydrofuran and acetone 3-5 times in sequence, purified with tetrahydrofuran by Soxhlet extraction, and dried to obtain a polycarboxyl conjugated microporous polymer.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The invention provides a SPEEK-filled PTFE porous membrane and a preparation process thereof. By optimizing the components and the process, a high-strength, antibacterial, corrosion-resistant and highly stable PTFE porous membrane is prepared.

[0024] The present invention selects a PTFE porous membrane as a base membrane material and SPEEK as a filler. In order to improve the bonding strength between the SPEEK and the PTFE porous membrane, a non-ionic surfactant polyoxyethylene laurate is used as a hydrophilic layer unit to induce dopamine to self-polymerize on the surface of the PTFE porous membrane to construct a mussel biomimetic coating. The PEEK is then treated with concentrated sulfuric acid to prepare the SPEEK, and the SPEEK is activated with N,N'-carbonyldiimidazole. Gallic acid-modified chitosan containing multiple functional groups such as amino groups and carboxyl groups is grafted onto the SPEEK. The gallic acid-modified chitosan is prepared by grafting gallic acid, a plant extract with excellent antibacterial and antifungal properties, using chitosan, a non-toxic, biocompatible and biodegradable cationic polymer, as a raw material. The composite SPEEK is introduced to enrich the hydrogen bond network in the membrane, improve the proton conductivity and ion selectivity of the membrane, and simultaneously impart excellent antibacterial properties to the membrane.

[0025] To further improve the mechanical strength, filtration properties and corrosion resistance of SPEEK-filled PTFE porous membranes, carboxylated fiber nanocrystals, multi-carboxyl conjugated microporous polymers and composite SPEEK are introduced as fillers. The multi-carboxyl conjugated microporous polymer is made of 1,4-phenylenediboronic acid, 2,5-dibromothiophene-3-carboxylic acid and 1,3,6,8-tetrabromocarbazole. By controlling the raw material ratio, a multi-carboxyl conjugated microporous polymer with high specific surface area, high porosity and high stability is generated through copolymerization. By controlling the ratio of polyethylene glycol, carboxylated fiber nanocrystals, multi-carboxyl conjugated microporous polymer and composite SPEEK in the mixed solution and introducing an additive into the mixed solution, the bonding strength between each filler and the surface of the polydopamine layer is enhanced, a complex cross-linked network is constructed, and the PTFE porous membrane is endowed with long-lasting antibacterial, corrosion resistance and high stability, thereby broadening the application range of the PTFE porous membrane and extending the service life of the PTFE porous membrane. DETAILED DESCRIPTION

[0026] The following will provide a clear and complete description of the technical solutions of the present invention in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0027] It should be noted that if the embodiments of the present invention involve directional indications such as up, down, left, right, front, and back, such directional indications are only used to explain a specific posture, such as the relative position relationship between components, the movement status, etc. If the specific posture changes, the directional indication will also change accordingly. In addition, the technical solutions between the various embodiments may be combined with each other, but they must be based on the premise that they can be implemented by ordinary technicians in this field. If the combination of technical solutions is mutually inconsistent or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0028] The technical solutions of the present invention are further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely used to explain the present invention and are not intended to limit the present invention.

[0029] Example 1: A process for preparing a SPEEK-filled PTFE porous membrane, comprising the following steps:

[0030] S1: The PTFE porous membrane is cleaned with anhydrous ethanol, dried, transferred to an ethanol solution of polyoxyethylene laurate for immersion treatment, and then transferred to a Tris buffer solution of dopamine hydrochloride for immersion treatment, washed with water, and dried to obtain a pretreated PTFE porous membrane;

[0031] In step S1, the working conditions of the immersion treatment are: time is 18 hours, temperature is 25° C., and the mass concentration of polyoxyethylene laurate in the ethanol solution of polyoxyethylene laurate is 15%;

[0032] In step S1, the working conditions of the immersion treatment are: time 16 h, temperature 40° C., pH of the Tris buffer solution 8.5, and the mass concentration of dopamine hydrochloride in the Tris buffer solution of dopamine hydrochloride 5 g / L;

[0033] S2: polyethylene glycol, composite SPEEK, carboxylated fiber nanocrystals, polycarboxyl conjugated microporous polymer, additives, and tetrahydrofuran are mixed to obtain a mixed solution;

[0034] In the mixed material solution, the additives are 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysulfosuccinimide in a mass ratio of 3:1; the mass ratio of polyethylene glycol, composite SPEEK, carboxylated fiber nanocrystals, and multi-carboxyl conjugated microporous polymer is 1:4:2:1;

[0035] The dosage ratio of composite SPEEK, additive, and tetrahydrofuran is 4g:0.5g:20mL;

[0036] The preparation of composite SPEEK includes the following steps:

[0037] 1) Mix 50 mL of concentrated sulfuric acid and 5 g of PEEK, keep warm at 48°C for 24 h, cool, pour into ice water with stirring, wash with ice deionized water until neutral, and dry to obtain SPEEK;

[0038] 2) 1 g of SPEEK, 10 mL of dimethyl sulfoxide, and 0.6 g of N,N'-carbonyldiimidazole were heated to 58°C and kept warm for 3 h, 5 g of gallic acid-modified chitosan was added, and the temperature was raised to 78°C and kept warm for 3 h, washed, and dried to obtain composite SPEEK;

[0039] The preparation of gallic acid modified chitosan comprises the following steps:

[0040] Under nitrogen atmosphere, 1 mmol of gallic acid and 20 mL of ethanol were mixed, 1 mmol of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 1 mmol of N-hydroxysulfosuccinimide were added, the pH was adjusted to 5.4, and the mixture was placed in an ice-water bath and stirred for 2 h. 1.5 g of chitosan was added, the pH was adjusted to 5.5, the mixture was heated to 18°C ​​and kept warm for 24 h, dialyzed, and freeze-dried to obtain gallic acid-modified chitosan.

[0041] The preparation of polycarboxyl conjugated microporous polymer comprises the following steps:

[0042] Under nitrogen protection, 4mmol 1,4-phenylenediboronic acid, 1.6mmol 2,5-dibromothiophene-3-carboxylic acid, 1.2mmol 1,3,6,8-tetrabromocarbazole, and 40mL N,N-dimethylformamide were mixed, 3mL 2mol / L potassium carbonate solution and 50mg tetrakis(triphenylphosphine)palladium(0) were added, stirred at 148°C for 48h, cooled, poured into 100mL methanol, filtered, washed three times with deionized water, chloroform, tetrahydrofuran, and acetone in sequence, purified with tetrahydrofuran by Soxhlet extraction, and dried to obtain a conjugated microporous polymer with multiple carboxyl groups;

[0043] S3: coating the mixed material solution on the surface of the pretreated PTFE porous membrane, performing hot pressing, washing and drying to obtain a SPEEK-filled PTFE porous membrane.

[0044] Embodiment 2: A preparation process of a SPEEK filled PTFE porous membrane, comprising the following steps:

[0045] S1: washing the PTFE porous membrane with anhydrous ethanol, drying, transferring to a lauryl acid polyoxyethylene ester ethanol solution for impregnation treatment, then transferring to a dopamine hydrochloride Tris buffer solution for infiltration treatment, washing with water, drying, to obtain a pretreated PTFE porous membrane;

[0046] In step S1, the working conditions for impregnation treatment are: time of 19 h, temperature of 20℃, and lauryl acid polyoxyethylene ester mass concentration of 18% in the lauryl acid polyoxyethylene ester ethanol solution;

[0047] In step S1, the working conditions for infiltration treatment are: time of 17 h, temperature of 35℃, pH of 8.5 of the Tris buffer solution, and hydrochloric acid dopamine mass concentration of 5 g / L in the dopamine hydrochloride Tris buffer solution;

[0048] S2: mixing polyethylene glycol, composite SPEEK, carboxylated fiber nanocrystals, polycarboxylate conjugated microporous polymer, auxiliary agent, and tetrahydrofuran to obtain a mixed solution;

[0049] In the mixed solution, the auxiliary agent is a 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide compound obtained in a mass ratio of 3:1; in the mixed solution, the mass ratio of polyethylene glycol, composite SPEEK, carboxylated fiber nanocrystals, and polycarboxylate conjugated microporous polymer is 1:4:2:1;

[0050] The amount ratio of composite SPEEK, auxiliary agent, and tetrahydrofuran is 4 g:0.5 g:20 mL;

[0051] The preparation of the composite SPEEK comprises the following steps:

[0052] 1) mixing 50 mL of concentrated sulfuric acid and 5 g of PEEK, keeping at 50℃ for 23.5 h, cooling, pouring into ice water and stirring, washing with ice deionized water until neutral, drying, to obtain SPEEK;

[0053] 2) mixing 1 g of SPEEK, 10 mL of dimethyl sulfoxide, and 0.6 g of N,N'-carbonyl diimidazole, heating to 60℃ for 2.5 h, adding 5 g of gallic acid modified chitosan, heating to 80℃ for 2.5 h, washing, drying, to obtain the composite SPEEK;

[0054] The preparation of the gallic acid modified chitosan comprises the following steps:

[0055] Mix 1 mmol of gallic acid, 20 mL of ethanol under nitrogen atmosphere, add 1 mmol of 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride, 1 mmol of N-hydroxysuccinimide, adjust pH to 5.5, stir in an ice water bath for 2.5 h, add 1.5 g of chitosan, adjust pH to 5.5, warm to 20℃ for 23 h, dialysis, freeze-drying to obtain gallic acid modified chitosan;

[0056] The preparation of the polycarboxyl conjugated microporous polymer comprises the following steps:

[0057] Mix 4 mmol of 1,4-benzenediboronic acid, 1.6 mmol of 2,5-dibromothiophene-3-carboxylic acid, 1.2 mmol of 1,3,6,8-tetrabromocarbazole, 40 mL of N,N-dimethylformamide under nitrogen protection, add 3 mL of 2 mol / L potassium carbonate solution, 50 mg of tetrakis(triphenylphosphine)palladium(0), stir at 150℃ for 47.5 h, cool, pour into 100 mL of methanol, suction filtration, sequentially wash with deionized water, chloroform, tetrahydrofuran, acetone 4 times, purify with tetrahydrofuran by Soxhlet extraction, dry to obtain the polycarboxyl conjugated microporous polymer;

[0058] S3: coat the mixed solution on the surface of the pretreated PTFE porous membrane, hot-press treatment, washing, drying to obtain a SPEEK filled PTFE porous membrane.

[0059] Embodiment 3: a preparation process of a SPEEK filled PTFE porous membrane, comprising the following steps:

[0060] S1: clean the PTFE porous membrane with anhydrous ethanol, dry, transfer to a lauryl polyoxyethylene ester ethanol solution for immersion treatment, then transfer to a dopamine hydrochloride Tris buffer solution for infiltration treatment, water washing, drying to obtain a pretreated PTFE porous membrane;

[0061] In step S1, the working conditions of the immersion treatment are: time of 20 h, temperature of 18℃, mass concentration of lauryl polyoxyethylene ester in the lauryl polyoxyethylene ester ethanol solution of 20%;

[0062] In step S1, the working conditions of the infiltration treatment are: time of 18 h, temperature of 30℃, pH of the Tris buffer solution of 8.5, mass concentration of dopamine hydrochloride in the dopamine hydrochloride Tris buffer solution of 5 g / L;

[0063] S2: mix polyethylene glycol, composite SPEEK, carboxylated fiber nanocrystal, polycarboxyl conjugated microporous polymer, auxiliary agent, tetrahydrofuran to obtain a mixed solution;

[0064] The auxiliary agent is 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide with a mass ratio of 3:1 in the mixed solution; the mass ratio of polyethylene glycol, composite SPEEK, carboxylated nanocrystalline cellulose and the conjugated microporous polymer with multiple carboxyl groups is 1:4:2:1 in the mixed solution;

[0065] The dosage ratio of the composite SPEEK, the auxiliary agent and tetrahydrofuran is 4g:0.5g:20mL;

[0066] The preparation of the composite SPEEK comprises the following steps:

[0067] 1) 50mL concentrated sulfuric acid and 5g PEEK are mixed, and then the mixture is kept at 52℃ for 23h, cooled, poured into ice water and stirred, washed with ice deionized water until neutral, and dried to obtain SPEEK;

[0068] 2) 1g SPEEK, 10mL dimethyl sulfoxide and 0.6g N,N'-carbonyldiimidazole are mixed, and then the mixture is kept at 62℃ for 2h, 5g gallic acid modified chitosan is added, and then the mixture is kept at 82℃ for 2h, and then the mixture is washed and dried to obtain the composite SPEEK;

[0069] The preparation of the gallic acid modified chitosan comprises the following steps:

[0070] 1mmol gallic acid and 20mL ethanol are mixed under a nitrogen atmosphere, 1mmol 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and 1mmol N-hydroxysuccinimide are added, the pH is adjusted to 5.6, the mixture is stirred in an ice water bath for 3h, 1.5g chitosan is added, the pH is adjusted to 5.5, the mixture is kept at 25℃ for 22h, and then the mixture is dialyzed and freeze-dried to obtain the gallic acid modified chitosan;

[0071] The preparation of the conjugated microporous polymer with multiple carboxyl groups comprises the following steps:

[0072] 4mmol 1,4-benzenediboronic acid, 1.6mmol 2,5-dibromothiophene-3-carboxylic acid, 1.2mmol 1,3,6,8-tetrabromocarbazole and 40mL N,N-dimethylformamide are mixed under nitrogen protection, 3mL 2mol / L potassium carbonate solution and 50mg tetrakis(triphenylphosphine)palladium(0) are added, the mixture is stirred at 152℃ for 47h, the mixture is cooled, poured into 100mL methanol, suction filtered, sequentially washed with deionized water, chloroform, tetrahydrofuran and acetone for 3-5 times, purified by Soxhlet extraction with tetrahydrofuran, and dried to obtain the conjugated microporous polymer with multiple carboxyl groups;

[0073] S3: The mixed solution is coated on the surface of the pretreated PTFE porous membrane, hot-pressed, washed and dried to obtain a SPEEK filled PTFE porous membrane.

[0074] Comparative Example 1: Using Example 3 as the control group, SPEEK was used to replace the composite SPEEK, and the other processes were normal.

[0075] Comparative Example 2: Taking Example 3 as the control group, the mass ratio of polyethylene glycol, composite SPEEK, carboxylated fiber nanocrystals, and multi-carboxyl conjugated microporous polymer is 1:4:1:1, and other processes are normal.

[0076] The coating thickness of the mixed solution in the embodiment and the comparative example is 5 μm.

[0077] Sources of raw materials used (for demonstration purposes only):

[0078] PTFE porous membrane (air permeability 400 L / ㎡ / s@127pa, detected particle size 0.3-0.5μm, filtration efficiency 85%, breaking strength 38MPa, thickness 22μm): Suzhou Youkefa New Material Technology Co., Ltd.; carboxylated fiber nanocrystals I0007-200: Nanjing Dulai Biotechnology Co., Ltd.; polyoxyethylene laurate LAE-4: Linyi Guoli Chemical Co., Ltd.; N-hydroxysulfosuccinimide S30615: Shanghai Yuanye Biotechnology Co., Ltd.; PEEK (industrial grade, 0.1μm): Hubei Xinrunde Chemical Co., Ltd.; polyethylene glycol P103719, dopamine hydrochloride D103111, 1-ethyl 3-Dimethylaminopropylcarbodiimide hydrochloride E106172, N,N'-carbonyldiimidazole C109315, gallic acid G131992, chitosan C105801, 1,4-phenylenediboronic acid B100863, 2,5-dibromothiophene-3-carboxylic acid D155672, 1,3,6,8-tetrabromocarbazole T161599, tetrakis(triphenylphosphine)palladium(0) T359229: Aladdin reagent; Tris buffer solution (pH 8.5), dimethyl sulfoxide, N,N-dimethylformamide, dimethylacetamide, ethanol, concentrated sulfuric acid, potassium carbonate, methanol, chloroform, tetrahydrofuran, acetone, analytical grade, commercially available.

[0079] Performance test: The performance test of the SPEEK-filled PTFE porous membranes prepared in the examples and comparative examples was performed:

[0080] Fracture strength: The fracture strength was measured using an electronic strength tester. Samples were cut into 50 mm wide and 250 mm long sections, stretched at a speed of 100 mm / min, and held at a clamping length of 200 mm. Antibacterial properties: The samples were washed 20 times with standard water and then tested for antibacterial properties using a plate method using Escherichia coli as the test strain. Corrosion resistance: The samples were immersed in a 2 g / L sodium chloride solution at 50°C for 24 hours, dried, and then tested again for fracture strength. A change of 2% or less compared to the initial fracture strength was considered acceptable; otherwise, it was considered unqualified. The results are shown in Table 1.

[0081] Table 1

[0082] Breaking strength (MPa) Antibacterial rate (%) Corrosion resistance Example 1 45.6 99.3 qualified Example 2 45.7 99.3 qualified Example 3 45.9 99.4 qualified Comparative Example 1 41.8 / Unqualified Comparative Example 2 42.5 / Unqualified

[0083] The application provides a SPEEK-filled PTFE porous membrane and a preparation process thereof, and the PTFE porous membrane with high strength, antibiosis, corrosion resistance and high stability is prepared by optimizing components and processes, and / in table 1 represents not tested.

[0084] The application selects PTFE porous membrane as a base film material and selects SPEEK as a filler, in order to improve the bonding strength of the SPEEK and the PTFE porous membrane, a non-ionic surfactant polyoxyethylene laurate is selected as a hydrophilic layer element to induce dopamine to self-polymerize on the surface of the PTFE porous membrane and construct a mussel-biomimetic coating.

[0085] It can be known by comparing example 3 with comparative example 1 that the PEEK is treated by concentrated sulfuric acid, the SPEEK is activated by N, N'-carbonyl diimidazole, and the grafted gallic acid modified chitosan containing amino and carboxyl and other multifunctional groups is prepared, wherein the gallic acid modified chitosan is prepared from the non-toxic, biocompatible and biodegradable cationic polymer chitosan, and the gallic acid modified chitosan is prepared from the plant extract gallic acid with excellent antibacterial and antifungal properties, the introduction of the composite SPEEK enriches the hydrogen bond network in the membrane, improves the proton conductivity and ion selectivity of the membrane, and simultaneously endows the membrane with excellent antibacterial properties.

[0086] It can be known by comparing example 3 with comparative example 2 that, in order to further improve the mechanical strength, filtration property and corrosion resistance of the SPEEK-filled PTFE porous membrane, the carboxylated fiber nanocrystals and the polycarboxyl conjugated microporous polymer are introduced into the filler as the filler together with the composite SPEEK, wherein the polycarboxyl conjugated microporous polymer is prepared from 1, 4-benzenediol, 2, 5-dibromothiophene-3-carboxylic acid and 1, 3, 6, 8-tetrabromocarbazole, the polycarboxyl conjugated microporous polymer with high specific surface area, high porosity and high stability is copolymerized by controlling the proportion of raw materials, the proportion of the carboxylated fiber nanocrystals, the polycarboxyl conjugated microporous polymer and the composite SPEEK in the mixed solution is controlled, and the auxiliary agent is introduced into the mixed solution, so that the fillers are grafted on the surface of the polydopamine layer, a complex crosslinking network is constructed, the PTFE porous membrane is endowed with durable antibacterial property, corrosion resistance and high stability, the use range of the PTFE porous membrane is widened, and the service life of the PTFE porous membrane is prolonged.

[0087] The above only describes the embodiments of the application, and does not limit the patent range of the application, and any equivalent structural transformation made according to the application or direct / indirect application in other related technical fields within the inventive concept of the application is included in the patent protection range of the application.

Claims

1. A preparation process for a SPEEK-filled PTFE porous membrane, characterized in that: The following steps are involved: S1: The PTFE porous membrane is cleaned, dried, transferred to an ethanol solution of polyoxyethylene laurate for immersion treatment, then transferred to a Tris buffer solution of dopamine hydrochloride for immersion treatment, and washed with water to obtain a pretreated PTFE porous membrane; S2: mixing polyethylene glycol, composite SPEEK, carboxylated fiber nanocrystals, multi-carboxyl conjugated microporous polymer, additives and solvent to obtain a mixed solution; S3: coating the mixed solution on the surface of the pretreated PTFE porous membrane, hot pressing, washing, and drying to obtain a SPEEK-filled PTFE porous membrane; The preparation of composite SPEEK includes the following steps: 1) Mix concentrated sulfuric acid and PEEK, keep warm at 48-52℃ for 23-24h, cool, pour into ice water and stir, wash with ice deionized water until neutral, and dry to obtain SPEEK; 2) SPEEK, dimethyl sulfoxide and N,N'-carbonyldiimidazole are heated to 58-62°C and kept warm for 2-3 hours, gallic acid-modified chitosan is added, and the temperature is raised to 78-82°C and kept warm for 2-3 hours, washed and dried to obtain composite SPEEK; The preparation of gallic acid modified chitosan comprises the following steps: Under a nitrogen atmosphere, gallic acid and ethanol were mixed, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysulfosuccinimide were added, the pH was adjusted to 5.4-5.6, and the mixture was placed in an ice-water bath and stirred for 2-3 hours. Chitosan was added, the pH was adjusted to 5.5, the temperature was raised to 18-25°C and kept warm for 22-24 hours, dialyzed, and freeze-dried to obtain gallic acid-modified chitosan.

2. The preparation process of a PTFE porous membrane filled with SPEEK according to claim 1, wherein In step S1, the working conditions of the immersion treatment are: time is 18-20 hours, temperature is 18-25° C., and the mass concentration of polyoxyethylene laurate in the ethanol solution of polyoxyethylene laurate is 15-20%.

3. The preparation process of the PTFE porous membrane filled with SPEEK according to claim 1, wherein In step S1, the working conditions of the immersion treatment are: time of 16-18 hours, temperature of 30-40° C., and a mass concentration of dopamine hydrochloride in the Tris buffer solution of dopamine hydrochloride of 5 g / L.

4. The preparation process of a SPEEK-filled PTFE porous membrane according to claim 1, wherein In the mixed material solution, the auxiliary agent is 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysulfosuccinimide, which are compounded in a mass ratio of 3:

1.

5. The preparation process of a SPEEK-filled PTFE porous membrane according to claim 1, wherein In the mixed solution, the mass ratio of polyethylene glycol, composite SPEEK, carboxylated fiber nanocrystals, and multi-carboxyl conjugated microporous polymer is 1:4:2:

1.

6. The preparation process of a SPEEK-filled PTFE porous membrane according to claim 1, wherein In the preparation of composite SPEEK, the mass ratio of SPEEK to gallic acid-modified chitosan was 1:

5.

7. The preparation process of a SPEEK-filled PTFE porous membrane according to claim 1, wherein The preparation of polycarboxyl conjugated microporous polymer comprises the following steps: Under nitrogen protection, 1,4-phenylenediboronic acid, 2,5-dibromothiophene-3-carboxylic acid, 1,3,6,8-tetrabromocarbazole and N,N-dimethylformamide are mixed, potassium carbonate solution and tetrakis(triphenylphosphine)palladium(0) are added, stirred at 148-152°C for 47-48h, cooled, poured into 50mL methanol, filtered, washed with deionized water, chloroform, tetrahydrofuran and acetone 3-5 times in sequence, purified with tetrahydrofuran by Soxhlet extraction, and dried to obtain a polycarboxyl conjugated microporous polymer.

8. A SPEEK-filled PTFE porous membrane, characterized in that: Prepared according to the preparation process according to any one of claims 1 to 7.