Biodegradable nano-fiber membrane for integrally eliminating multi-phase pollutants in precision manufacturing industry as well as preparation method and application of biodegradable nano-fiber membrane

Abstract

The invention provides a biodegradable nano-fiber membrane for integrated elimination of multiphase pollutants in the precision manufacturing industry and a preparation method and application thereof, the preparation method comprises the following steps: step S1, dissolving metal salt and an organic ligand in a mixed solvent, and synthesizing MOF (Metal Organic Framework) nano-crystals by microwave-assisted functional modification; s2, dissolving polylactic acid in a solvent A to prepare a spinning solution; s3, dispersing the MOF nanocrystals obtained in the step S1 in a solvent B to prepare a uniformly dispersed suspension; s4, the spinning solution obtained in the step S2 and the dispersed suspension liquid obtained in the step S3 are subjected to a technology combining high-speed airflow spinning, ultrasonic-assisted spraying and online rolling, and the biodegradable nano-fiber membrane is obtained. The biodegradable nano-fiber membrane prepared by the method has the remarkable advantages of high porosity, superfine fiber diameter, ultrahigh PM filtering efficiency, toxic gas adsorption capacity and the like, meets the requirements of low resistance energy consumption and flexible processability, and can realize integrated elimination of multiphase pollutants in the semiconductor precision manufacturing industry.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated elimination materials for multiphase pollutants in precision manufacturing industries such as semiconductor integrated circuits, new energy, and biomedicine, and specifically relates to a biodegradable nanofiber membrane and a preparation method thereof. Background Art

[0002] In the process of semiconductor manufacturing, the generation of dust and toxic gases is inevitable. These pollutants will not only seriously affect the yield and performance of products, but also pose a serious threat to the health of production equipment and operators. With the continuous reduction of semiconductor device size and the improvement of process complexity, the requirements for a clean environment are becoming increasingly strict. Dust particles even at the nanometer level can cause device short circuits or open circuits, while the accumulation of toxic gases (such as volatile organic compounds, acidic gases, and alkaline gases) will cause equipment corrosion and environmental pollution. Therefore, developing efficient and reliable dust and toxic gas removal technologies is not only the key to ensuring the stability of semiconductor manufacturing processes and product quality, but also an important link in achieving green manufacturing and sustainable development. In recent years, in response to this challenge, researchers have been continuously exploring new filter materials, adsorbents, and purification technologies to meet the extreme requirements of the semiconductor industry for a clean environment.

[0003] Spun fiber membranes have shown significant advantages in removing dust and toxic gases. Their high specific surface area, adjustable pore structure, and excellent mechanical properties enable them to efficiently capture nanoscale dust particles, and at the same time, through functional modification (such as loading active components or introducing specific functional groups), selective adsorption and sequestration of toxic gases can be achieved. In addition, spun fiber membranes have the characteristics of light weight, flexibility, and easy processing, and can adapt to a variety of complex application scenarios. However, existing spun fiber membranes still have limitations in terms of long-term stability, flux-efficiency balance, and multifunctional integration. Therefore, current research mainly focuses on further improving their filtration performance, durability, and environmental adaptability through means such as material compounding (such as introducing nanoparticles or metal-organic frameworks), structural optimization (such as hierarchical pore design), and surface modification (such as plasma treatment or chemical grafting) to meet the increasingly stringent industrial requirements.

[0004] Spraying metal-organic framework (MOF) materials on the surface of ultrafine spun fiber membranes provides an innovative solution for the removal of dust and toxic gases in the semiconductor industry. Due to its high specific surface area, tunable pore structure, and abundant active sites, MOF materials can efficiently adsorb nanoscale dust particles and exhibit excellent selective capture and adsorption-sequestration performance for toxic gases. Combining the high permeability, flexibility, and mechanical strength of ultrafine spun fiber membranes, the MOF-coated fiber membranes not only achieve a balance between high filtration efficiency and low pressure drop but also demonstrate good durability and environmental adaptability. However, to further improve their performance in practical applications, current research focuses on optimizing the loading uniformity of MOF, enhancing the stability of membrane materials, and developing multifunctional integrated systems to meet the extreme requirements for a clean environment in semiconductor manufacturing and the goal of green sustainable development. Summary of the Invention

[0005] The object of the present invention is to prepare a biodegradable nanofiber membrane for the integrated elimination of multiphase pollutants in precision manufacturing (multifunctional ultrafine spun fiber membrane) to meet the demand for the integrated elimination of multiphase pollutants such as ultrafine dust and toxic gases in precision manufacturing industries such as semiconductor integrated circuits, new energy, and biomedicine.

[0006] To achieve the above object, the present invention provides a biodegradable nanofiber membrane for the integrated elimination of multiphase pollutants in precision manufacturing, its preparation method, and application. The present invention uses microwave-assisted functionalization modification to synthesize MOF nanocrystals, and then disperses them in a solvent to prepare a uniformly dispersed suspension; then, through a technology combining high-speed air spinning, ultrasonic-assisted spraying, and online roll pressing, the MOF nanocrystals are uniformly and densely loaded on the surface of polylactic acid nanofibers to prepare a biodegradable nanofiber membrane.

[0007] According to the first aspect of the present invention, a method for preparing a biodegradable nanofiber membrane for the integrated elimination of multiphase pollutants in precision manufacturing is provided, including the following steps: Step S1, preparing MOF nanocrystals: dissolving metal salts and organic ligands in a mixed solvent, and synthesizing MOF nanocrystals by microwave-assisted functionalization modification; Step S2, preparing a spinning solution: dissolving polylactic acid in solvent A to prepare a homogeneous and stable spinning solution; Step S3, preparing a dispersed suspension: dispersing the MOF nanocrystals obtained in Step S1 in solvent B to prepare a uniformly dispersed suspension; Step S4, preparing a biodegradable nanofiber membrane: obtaining a biodegradable nanofiber membrane for the integrated elimination of multiphase pollutants in precision manufacturing through a technology combining the spinning solution obtained in Step S2 and the dispersed suspension obtained in Step S3, high-speed air spinning, ultrasonic-assisted spraying, and online roll pressing.

[0008] Preferably, in step S1, the metal salt is one or more of tetrabutyl titanate, isopropyl titanate, titanium tetrachloride, and titanium sulfate, the organic ligand is one or more of 2-aminoterephthalic acid, terephthalic acid, 3-aminoterephthalic acid, and 4-aminoisophthalic acid, and the molar ratio of the metal salt to the organic ligand is 1:1 to 1:4.

[0009] Preferably, in step S1, the mixed solvent is obtained by mixing one or more of methanol, ethanol, water, acetonitrile, isopropanol, acetone, tetrahydrofuran, dimethyl sulfoxide with N,N-dimethylformamide, and the volume ratio of the solvents listed above to N,N-dimethylformamide in the mixed solvent is 1:1 to 1:10.

[0010] Preferably, in step S1, the reaction conditions for microwave-assisted functionalization modification are as follows: the microwave power is 100 - 500 W, the reaction temperature is 100 - 200 °C, the reaction time is 3 - 60 min, and the stirring speed is 20 - 1000 rpm / min; the particle size of the obtained MOF nanocrystals is 50 - 300 nm, and the average pore size is 0.6 - 1.0 nm.

[0011] Preferably, in step S2, the solvent A is one or more of dichloromethane, N,N-dimethylformamide, chloroform, tetrahydrofuran, acetone, ethyl acetate, dimethyl sulfoxide, N,N-dimethylacetamide, methanol, ethanol, N-methylpyrrolidone, and hexafluoroisopropanol, and the mass fraction of polylactic acid in solvent A is 5% - 25%.

[0012] Preferably, in step S3, the solvent B is one or more of water, methanol, ethanol, isopropanol, N,N-dimethylformamide, N,N-dimethylacetamide, acetone, butanone, dichloromethane, chloroform, acetonitrile, ethyl acetate, tetrahydrofuran, and dimethyl sulfoxide, and the mass fraction of MOF nanocrystals in solvent B is 1% - 20%.

[0013] Preferably, in step S4, the high-speed air spinning technology is one or more of solution air spinning, solution blow-spinning, centrifugal air spinning, and microfluidic air spinning technologies.

[0014] Preferably, in step S4, the spinning process is solution air spinning, and the spinning parameters are set as follows: the gas pressure is 0.1 - 10 MPa, the air flow rate is 200 - 800 m / s, the solution supply rate is 0.1 - 5 mL / h, the receiving distance is 10 - 50 cm, the temperature is 20 - 40 °C, and the humidity is 10% - 50% RH.

[0015] Preferably, in step S4, the spinning process is solution blow-spinning, and the spinning parameters are set as follows: the gas pressure is 0.2 - 5.0 MPa, the gas temperature is 5 - 80 °C, the gas flow rate is 10 - 50 L / min, the solution supply rate is 0.5 - 5 mL / h, the receiving distance is 10 - 50 cm, the temperature is 20 - 40 °C, and the humidity is 20% - 60% RH.

[0016] Preferably, in step S4, the spinning process is centrifugal air spinning, and the spinning parameters are set as follows: the centrifugal speed is 5000 - 30000 rpm, the diameter of the centrifugal disk is 5 - 20 cm, the gas pressure is 0.1 - 0.8 MPa, the gas injection angle is 15 - 90°, the collection distance is 20 - 200 cm, the temperature is 25 - 60 °C, and the humidity is 10% - 50% RH.

[0017] Preferably, in step S4, the spinning process is microfluidic air spinning, and the spinning parameters are set as follows: the microchannel size is 50 - 500 μm (width) × 20 - 200 μm (depth), the channel geometry is one of Y-shaped, coaxial or multi-stage branched structures, the gas pressure is 0.05 - 2.0 MPa, the gas flow rate is 5 - 200 L / min, the solution supply rate is 0.1 - 50 μL / min, and the receiving distance is 5 - 100 cm.

[0018] Preferably, the technical parameters of the ultrasonic-assisted spraying in step S4 are as follows: the ultrasonic frequency is 15 - 250 kHz, the ultrasonic power is 100 - 3000 W, the spraying flow rate is 0.1 - 50 mL / min, the gas pressure drop is 0.1 - 10 MPa, and the spraying distance is 10 - 200 mm; the technical parameters of the on-line roll pressing are as follows: the roll pressing speed is 0.1 - 20 m / min, the roll pressure is 1 - 20 MPa, and the roll gap spacing is 0.05 - 5 mm; the thickness of the biodegradable nanofiber membrane for the integrated elimination of multiphase pollutants in precision manufacturing is 20 - 150 μm, and the fiber diameter is 50 - 120 nm.

[0019] To achieve the above object, according to the second aspect of the present invention, the present invention also provides a biodegradable nanofiber membrane obtained by the foregoing preparation method.

[0020] Preferably, the specific surface area of the biodegradable nanofiber membrane for the integrated elimination of multiphase pollutants in precision manufacturing is 398 m 2 / g - 863 m 2 / g, and the filtration efficiency for PM 3 is 99.80% - 99.999% at a gas flow rate of 0.1 - 1.0 m 0.1 / min, and the filtration efficiency for PM 0.3The filtration efficiency is 99.90% - 99.99999%, the pressure loss is 10 - 140 Pa, SO 2 The adsorption capacity is 5.1 - 7.2 mmol / g, H 2 The S adsorption capacity is 3.8 - 5.6 mmol / g.

[0021] To achieve the above object, according to the third aspect of the present invention, the present invention also provides an application of the aforementioned biodegradable nanofiber membrane in the integrated elimination of multiphase pollutants in semiconductor integrated circuits, new energy, and precision manufacturing of biomedicine.

[0022] Applying the technical solution of the present invention, the beneficial effects of the present invention are as follows: (1) MOF nanocrystals have a high specific surface area and narrow pore size. The ultrasonic-assisted spraying technology is used to uniformly attach them to the surface of the spun fibers, endowing the membrane material with better physical and chemical properties and functions; (2) Using the air-jet spinning technology, biodegradable nanofiber membranes with ultra-fine fiber diameters are prepared by regulating the spinning process parameters, significantly improving the filtration efficiency of the material for ultra-fine dust and improving the air filtration resistance; (3) The surface of the sprayed MOF nanocrystals is reinforced by the online roll pressing process, promoting a stronger binding force and a faster industrialization process between the nanocrystals and the spun fibers; (4) The combined action of various reaction methods and preparation processes results in materials with significant advantages such as high porosity, ultra-fine fiber diameter, high surface activity, high-efficiency dust filtration efficiency, and excellent toxic gas adsorption capacity, meeting the requirements of low resistance energy consumption and flexible processability, and enabling the integrated removal of multiphase pollutants in precision manufacturing industries such as semiconductor integrated circuits, new energy, and biomedicine.

[0023] The technical solution proposed by the present invention enables the biodegradable nanofiber membrane to have high porosity, ultra-fine fiber diameter, high surface activity, high-efficiency dust filtration efficiency, and excellent toxic gas adsorption capacity. The design of this material aims to meet the needs of integrated removal of multiphase pollutants in precision manufacturing industries such as semiconductor integrated circuits, new energy, and biomedicine, and has broad application potential and market prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0025] Figure 1 It is a scanning electron microscope image of the biodegradable nanofiber membrane in Example 1.

[0026] Figure 2It is the Fourier transform infrared spectrum of the biodegradable nanofiber membrane in Example 1.

[0027] Figure 3 It is the scanning electron microscope image of the biodegradable nanofiber membrane in Example 2.

[0028] Figure 4 It is the scanning electron microscope image of the biodegradable nanofiber membrane in Example 3.

[0029] Figure 5 It is the scanning electron microscope image of the biodegradable nanofiber membrane in Example 4.

[0030] Figure 6 It is the schematic diagram of the method flow of the present invention. Detailed implementation manners

[0031] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation manners obtained by those of ordinary skill in the art without creative efforts belong to the scope protected by the present invention. The present invention will be described in detail below in conjunction with the embodiments.

[0032] As Figure 6 shown, Example 1 of the present invention provides a method for preparing a biodegradable nanofiber membrane for integrated elimination of multiphase pollutants in precision manufacturing, including the following steps.

[0033] Step S11, preparing MOF nanocrystals: Dissolve tetrabutyl titanate and 2-aminoterephthalic acid (molar ratio 1:2) in a mixed solvent composed of methanol and N,N-dimethylformamide (volume ratio 1:4), and use microwave-assisted functionalization modification (microwave power 300 W, reaction temperature 150 °C, reaction time 20 min, stirring speed 400 rpm) to prepare MOF nanocrystals. The average particle size of the obtained MOF nanocrystals is 50 nm, and the average pore size is 0.6 nm.

[0034] Step S12, preparing a spinning solution: Dissolve polylactic acid in N,N-dimethylformamide (the mass fraction of polylactic acid in the solvent is 15%) to prepare a spinning solution.

[0035] Step S13, preparing a dispersed suspension: Disperse the MOF nanocrystals obtained in step S11 in water (the mass fraction of MOF nanocrystals in water is 10%) to prepare a uniformly dispersed suspension.

[0036] Step S14, preparing the biodegradable nanofiber membrane: The spinning solution obtained in step S12 and the dispersion suspension obtained in step S13 are combined with the technologies of microfluidic air spinning (the microchannel size is 50 μm (width) × 20 μm (depth), the channel geometric configuration is a multi-stage branching structure, the gas pressure is 0.05 MPa, the gas flow rate is 10 L / min, the solution supply rate is 0.5 μL / min, and the receiving distance is 10 cm), ultrasonic-assisted spraying (the ultrasonic frequency is 100 kHz, the ultrasonic power is 1000 W, the spraying flow rate is 2 mL / min, the gas pressure drop is 0.5 MPa, and the spraying distance is 20 mm), and on-line roll pressing (the roll pressing speed is 0.5 m / min, the roll pressure is 5 MPa, and the roll gap spacing is 0.5 mm) to prepare the biodegradable nanofiber membrane. The obtained biodegradable nanofiber membrane has a thickness of 20 μm and a fiber diameter of 50 nm.

[0037] As Figure 1 shown, the scanning electron microscope image of the biodegradable nanofiber membrane obtained in Example 1 of the present invention shows that the MOF nanocrystals are uniformly and densely loaded on the surface of the ultrafine nanofibers.

[0038] As Figure 2 shown, the Fourier transform infrared spectrum of the biodegradable nanofiber membrane obtained in Example 1 of the present invention shows that there are stretching vibration peaks of amino groups (−NH 2 ), coordination stretching vibration peaks of carboxylic acids (−COOH), and stretching vibration peaks of benzene ring skeletons in the structure of the biodegradable nanofiber membrane.

[0039] Example 2 of the present invention provides a method for preparing a biodegradable nanofiber membrane for integrated elimination of multiphase pollutants in precision manufacturing, including the following steps.

[0040] Step S21, preparing MOF nanocrystals: Isopropyl titanate and terephthalic acid (molar ratio 1:1) are dissolved in a mixed solvent composed of ethanol and N,N-dimethylformamide (volume ratio 1:2), and microwave-assisted functional modification is used (microwave power 100 W, reaction temperature 120 °C, reaction time 60 min, stirring speed 200 rpm) to prepare MOF nanocrystals. The obtained MOF nanocrystals have an average particle size of 140 nm and an average pore size of 0.7 nm.

[0041] Step S22, preparing the spinning solution: Poly(lactic acid) is dissolved in dichloromethane (the mass fraction of poly(lactic acid) in the solvent is 10%) to prepare the spinning solution.

[0042] Step S23, preparing the dispersion suspension: The MOF nanocrystals obtained in step S21 are dispersed in ethanol (the mass fraction of MOF nanocrystals in ethanol is 5%) to prepare a uniformly dispersed suspension.

[0043] Step S24, preparing the biodegradable nanofiber membrane: The spinning solution obtained in step S22 and the dispersed suspension obtained in step S23 are combined with solution air spinning (gas pressure is 0.5 MPa, air flow velocity is 200 m / s, solution supply rate is 1 mL / h, receiving distance is 15 cm, temperature is 25°C, humidity is 20% RH), ultrasonic-assisted spraying (ultrasonic frequency is 50 kHz, ultrasonic power is 500 W, spraying flow rate is 0.5 mL / min, gas pressure drop is 0.2 MPa, spraying distance is 10 mm), and in-line rolling (rolling speed is 0.2 m / min, rolling pressure is 2 MPa, roll gap spacing is 0.3 mm) to prepare the biodegradable nanofiber membrane. The obtained biodegradable nanofiber membrane has a thickness of 60 μm and a fiber diameter of 70 nm.

[0044] As Figure 3 shown, the scanning electron microscope image of the biodegradable nanofiber membrane obtained in Example 2 of the present invention shows that the MOF nanocrystals are uniformly and densely loaded on the surface of the ultrafine nanofibers.

[0045] Example 3 of the present invention provides a method for preparing a biodegradable nanofiber membrane for integrated elimination of multiphase pollutants in precision manufacturing, including the following steps.

[0046] Step S31, preparing MOF nanocrystals: Titanium tetrachloride and 3-aminoterephthalic acid (molar ratio is 1:3) are dissolved in a mixed solvent composed of water and N,N-dimethylformamide (volume ratio is 1:6), and microwave-assisted functionalization modification is used (microwave power is 200 W, reaction temperature is 130°C, reaction time is 40 min, stirring speed is 600 rpm) to prepare MOF nanocrystals. The obtained MOF nanocrystals have an average particle size of 220 nm and an average pore size of 0.8 nm.

[0047] Step S32, preparing the spinning solution: Poly(lactic acid) is dissolved in chloroform (the mass fraction of poly(lactic acid) in the solvent is 12%) to prepare the spinning solution.

[0048] Step S33, preparing the dispersed suspension: The MOF nanocrystals obtained in step S31 are dispersed in methanol (the mass fraction of MOF nanocrystals in methanol is 13%) to prepare a uniformly dispersed suspension.

[0049] Step S34, preparing the biodegradable nanofiber membrane: The spinning solution obtained in step S32 and the dispersed suspension obtained in step S33 are combined with solution blowspinning (gas pressure is 0.5 MPa, gas temperature is 40 °C, gas flow rate is 10 L / min, solution supply rate is 1 mL / h, receiving distance is 10 cm, temperature is 20 °C, humidity is 30% RH), ultrasonic-assisted spraying (ultrasonic frequency is 150 kHz, ultrasonic power is 1500 W, spraying flow rate is 5 mL / min, gas pressure drop is 1 MPa, spraying distance is 15 mm), and in-line rolling (rolling speed is 1 m / min, rolling pressure is 8 MPa, roll gap spacing is 1 mm) to prepare the biodegradable nanofiber membrane. The obtained biodegradable nanofiber membrane has a thickness of 110 μm and a fiber diameter of 100 nm.

[0050] As Figure 4 shown, the scanning electron microscope image of the biodegradable nanofiber membrane obtained in Example 3 of the present invention shows that MOF nanocrystals are uniformly and densely loaded on the surface of ultrafine nanofibers.

[0051] Example 4 of the present invention provides a method for preparing a biodegradable nanofiber membrane for integrated elimination of multiphase pollutants in precision manufacturing, including the following steps.

[0052] Step S41, preparing MOF nanocrystals: Titanium sulfate and 4-aminoterephthalic acid (molar ratio of 1:4) are dissolved in a mixed solvent composed of acetonitrile and N,N-dimethylformamide (volume ratio of 1:8), and microwave-assisted functionalization modification is used (microwave power is 500 W, reaction temperature is 180 °C, reaction time is 10 min, stirring speed is 800 rpm) to prepare MOF nanocrystals. The obtained MOF nanocrystals have an average particle size of 300 nm and an average pore size of 1.0 nm.

[0053] Step S42, preparing the spinning solution: Poly(lactic acid) is dissolved in ethyl acetate (the mass fraction of poly(lactic acid) in the solvent is 18%) to prepare the spinning solution.

[0054] Step S43, preparing the dispersed suspension: The MOF nanocrystals obtained in step S41 are dispersed in N,N-dimethylformamide (the mass fraction of MOF nanocrystals in N,N-dimethylformamide is 20%) to prepare a uniformly dispersed suspension.

[0055] Step S44, preparing a multifunctional biodegradable nanofiber membrane: The spinning solution obtained in step S42 and the dispersion suspension obtained in step S43 are combined with centrifugal air spinning (centrifugal speed is 30000 rpm, centrifugal disk diameter is 20 cm, gas pressure is 0.1 MPa, gas injection angle is 90°, collection distance is 20 cm, temperature is 30 °C, humidity is 10% RH), ultrasonic-assisted spraying (ultrasonic frequency is 200 kHz, ultrasonic power is 2000 W, spraying flow rate is 10 mL / min, gas pressure drop is 5 MPa, spraying distance is 30 mm), and in-line roll pressing (roll pressing speed is 5 m / min, roll pressure is 12 MPa, roll gap spacing is 3 mm) to prepare a biodegradable nanofiber membrane. The obtained biodegradable nanofiber membrane has a thickness of 150 μm and a fiber diameter of 120 nm.

[0056] As Figure 5 shown, the scanning electron microscope image of the biodegradable nanofiber membrane obtained in Example 4 of the present invention shows that the MOF nanocrystals are uniformly and densely loaded on the surface of the ultrafine nanofibers.

[0057] Comparative Example 1 of the present invention provides a method for preparing a biodegradable nanofiber membrane, which basically uses the method of Example 1 to prepare a biodegradable nanofiber membrane. The difference is that in this example, the solvothermal method is used to prepare MOF nanocrystals.

[0058] Specifically, tetrabutyl titanate and 2-aminoterephthalic acid (molar ratio of 1:2) are dissolved in a mixed solvent composed of methanol and N,N-dimethylformamide (volume ratio of 1:4), and placed in a polytetrafluoroethylene-lined reaction kettle at 150 °C for 12 hours to prepare MOF nanocrystals; polylactic acid is dissolved in N,N-dimethylformamide (the mass fraction of polylactic acid in the solvent is 15%) to prepare a spinning solution; the obtained MOF nanocrystals are dispersed in water (the mass fraction of MOF nanocrystals in water is 10%) to prepare a dispersion suspension; the obtained spinning solution and dispersion suspension are combined with microfluidic air spinning technology (microchannel size is 50μm (width) × 20 μm (depth), channel geometric configuration is a multi-stage branched structure, gas pressure is 0.05 MPa, gas flow rate is 10 L / min, solution supply rate is 0.5 μL / min, receiving distance is 10 cm), ultrasonic-assisted spraying (ultrasonic frequency is 100 kHz, ultrasonic power is 1000 W, spraying flow rate is 2 mL / min, gas pressure drop is 0.5 MPa, spraying distance is 20 mm), and in-line roll pressing (roll pressing speed is 0.5 m / min, roll pressure is 5 MPa, roll gap spacing is 0.5 mm) to prepare a biodegradable nanofiber membrane.

[0059] Comparative Example 2 of the present invention provides a method for preparing a biodegradable nanofiber membrane, and basically uses the method of Example 2 to prepare the biodegradable nanofiber membrane. The difference is that in this example, electrospinning technology is used for preparation.

[0060] Specifically, isopropyl titanate and terephthalic acid (molar ratio 1:1) are dissolved in a mixed solvent composed of ethanol and N,N-dimethylformamide (volume ratio 1:2), and microwave-assisted functionalization modification (microwave power 100 W, reaction temperature 120 °C, reaction time 60 min, stirring speed 200 rpm) method is used to prepare MOF nanocrystals; polylactic acid is dissolved in dichloromethane (mass fraction of polylactic acid in the solvent is 10%) to prepare a spinning solution; the obtained MOF nanocrystals are dispersed in ethanol (mass fraction of MOF nanocrystals in ethanol is 5%) to prepare a dispersed suspension; the obtained spinning solution and dispersed suspension are combined with electrospinning technology (working voltage 6.5 kV, spraying speed 1 mL / h, receiving distance 15 cm, temperature 25 °C, relative humidity 30%, reciprocating speed 3 cm / min), ultrasonic-assisted spraying (ultrasonic frequency 50 kHz, ultrasonic power 500 W, spraying flow rate 0.5 mL / min, gas pressure drop 0.2 MPa, spraying distance 10 mm), and online roll pressing (roll pressing speed 0.2 m / min, roll pressure 2 MPa, roll gap spacing 0.3 mm) technology to prepare the biodegradable nanofiber membrane.

[0061] Comparative Example 3 of the present invention provides a method for preparing a biodegradable nanofiber membrane, and basically uses the method of Example 3 to prepare the biodegradable nanofiber membrane. The difference is that in this example, MOF nanocrystals are loaded on the biodegradable nanofiber membrane by natural sedimentation.

[0062] Specifically, titanium tetrachloride and 3-aminoterephthalic acid (molar ratio 1:3) are dissolved in a mixed solvent composed of water and N,N-dimethylformamide (volume ratio 1:6), and microwave-assisted functionalization (microwave power 200 W, reaction temperature 130 °C, reaction time 40 min, stirring speed 600 rpm) method is used to prepare MOF nanocrystals; polylactic acid is dissolved in chloroform (mass fraction of polylactic acid in the solvent is 12%) to prepare a spinning solution; the obtained MOF nanocrystals are dispersed in methanol (mass fraction of MOF nanocrystals in methanol is 13%) to prepare a dispersed suspension; the obtained spinning solution and dispersed suspension are prepared into a biodegradable nanofiber membrane through solution blow-spinning (gas pressure 0.5 MPa, gas temperature 40 °C, gas flow rate 10 L / min, solution supply rate 1 mL / h, receiving distance 10 cm, temperature 20 °C, humidity 30% RH) and natural sedimentation (placing the spun fiber membrane in the MOF dispersed suspension for 12 h).

[0063] The structural characterization and performance tests are as follows.

[0064] Scanning electron microscopy observation: The microstructure of the biodegradable nanofiber membrane was observed by a field emission scanning electron microscope (model JSM-7900F, JEOL, Japan) ( Figure 1 , Figure 3 , Figure 4 , Figure 5 ).

[0065] Functional group structure test: The functional groups of the biodegradable nanofiber membrane were recorded using an infrared spectrometer (model VERTEX 70, Bruker, USA) ( Figure 2 ).

[0066] Filtration performance test: The air filtration performance of the fiber membrane (with an area of 25 cm 2 ) was tested using a CLJ-3016 laser dust particle counter (Shenzhen Huashengchang Machinery Experiment Co., Ltd.). The gas flow rate was set at 50 L / min. Each group of filter membranes was tested at least at 3 different positions, and the results were averaged.

[0067] Gas adsorption performance test: A gas sorption analyzer (ASAP 2020, Micromeritics, USA) was used to adsorb SO 2 and H 2 S. High-purity dilution gases SO 2 and H 2 S were used for adsorption measurements, while the free space was measured using helium (99.999%). Isothermal adsorption was carried out at 273 K (ice-water bath).

[0068] Experimental results: As shown in Figure 1 , Figure 3 , Figure 4 and Figure 5 , in addition to significantly reducing the preparation time and energy consumption, the MOF nanocrystals synthesized by microwave-assisted functionalization modification have excellent properties such as high purity, good crystallinity, functionalization modification ability, controllable particle size and morphology, and can fully exert the physicochemical properties of the MOF nanocrystals. The technology combining high-speed air spinning, ultrasonic-assisted spraying, and online roll pressing can uniformly and densely load the MOF nanocrystals on the surface of the spun fibers. At the same time, the prepared fiber membrane has an ultra-fine diameter, which can effectively improve the dust filtration efficiency and reduce the resistance energy consumption.

[0069] As shown in Figure 2 , it can be observed that the amino groups (−NH 2The presence of characteristic peaks such as stretching vibration, carboxyl (-COOH) coordination stretching vibration, and benzene ring skeleton stretching vibration indicates the successful loading of MOF nanocrystals on the surface of the electrospun fiber membrane, thereby endowing the biodegradable nanofiber membrane with characteristics such as high porosity and high activity, and improving the purification ability of the material for dust and toxic gases.

[0070] Table 1 compares the specific surface area, dust filtration efficiency, filtration resistance, and SO 2 and H 2 adsorption capacity results of the biodegradable nanofiber membranes obtained in the examples and comparative examples.

[0071] Table 1

[0072] Examples 1-4 have a relatively high specific surface area (398 m 2 / g - 863 m 2 / g). This is because the MOF nanocrystals prepared by microwave-assisted functionalization are uniformly and densely loaded on the surface of the biodegradable nanofiber membrane, thereby improving the filtration efficiency of the material for ultrafine dust and gas permeability. The specific surface areas of Comparative Examples 1-3 are only 177-252 m 2 / g. This is due to the adverse effects of the microscopic morphology of the synthesized biodegradable nanofiber membrane, such as the physical and chemical properties of MOF, fiber diameter, and binding mode, resulting in a decrease in dust filtration efficiency and an increase in air resistance. Example 1 with the highest specific surface area has a filtration efficiency of 99.999% for PM 3 / min at a gas flow rate of 0.1-1.0 m 0.1 , a filtration efficiency of 99.99999% for PM 0.3 , and a minimum pressure drop of 10 Pa, which is much higher than that of Comparative Example 3 with a low specific surface area (filtration efficiency of 88.974% for PM 3 / min at a gas flow rate of 0.1-1.0 m 0.1 , a filtration efficiency of 92.38258% for PM 0.3 , and a pressure drop of 508 Pa).

[0073] The ability of the biodegradable nanofiber membrane to adsorb toxic gases is closely related to its specific surface area, MOF loading amount, and degree of binding. In Examples 1-4 with a large specific surface area and uniformly dense loading of MOF nanocrystals, the sulfur dioxide adsorption amount is above 5.1 mmol / g, and the hydrogen sulfide adsorption amount is above 3.8 mmol / g, showing good toxic gas adsorption ability. Among them, Example 1 with the highest specific surface area, optimal MOF loading amount, and degree of binding showed the best performance in the sulfur dioxide and hydrogen sulfide adsorption capacity tests. The sulfur dioxide adsorption amount was 7.2 mmol / g, and the hydrogen sulfide adsorption amount was 5.6 mmol / g, far higher than that of Comparative Example 3 with a low specific surface area, poor MOF loading amount, and degree of binding (sulfur dioxide adsorption amount of 1.6 mmol / g and hydrogen sulfide adsorption amount of 1.2 mmol / g).

[0074] The present invention provides a biodegradable nanofiber membrane for integrated elimination of multiphase pollutants in precision manufacturing, its preparation method and application. There are many methods and ways to specifically implement this technical solution. The above description is only the preferred implementation mode of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention. Each component not clearly defined in this embodiment can be realized by existing technologies.

Claims

1. A method for preparing a biodegradable nanofiber membrane for integrated elimination of multiphase pollutants in precision manufacturing, characterized in that: The following steps are involved: Step S1, dissolving a metal salt and an organic ligand in a mixed solvent, performing functional modification using microwave-assisted technology, and synthesizing MOF nanocrystals; Step S2, dissolving polylactic acid in solvent A to prepare a spinning solution; Step S3, dispersing the MOF nanocrystals obtained in step S1 in solvent B to prepare a dispersed suspension; Step S4, combining the spinning solution obtained in step S2 and the dispersed suspension obtained in step S3 through high-speed airflow spinning technology, ultrasonic-assisted spraying technology and online rolling process to prepare a multi-phase pollutant integrated biodegradable nanofiber membrane for precision manufacturing industry.

2. The method for preparing a biodegradable nanofiber membrane for integrated elimination of multiphase pollutants in the precision manufacturing industry according to claim 1, characterized in that: The metal salt in step S1 is one or more of tetrabutyl titanate, isopropyl titanate, titanium tetrachloride, and titanium sulfate; the organic ligand is one or more of 2-aminoterephthalic acid, terephthalic acid, 3-aminoterephthalic acid, and 4-aminoisophthalic acid, and the molar ratio of the metal salt to the organic ligand is 1:1 to 1:

4.

3. The method for preparing a biodegradable nanofiber membrane for integrated elimination of multiphase pollutants in the precision manufacturing industry according to claim 1, characterized in that: The mixed solvent in step S1 is a mixture of one or more solvents selected from methanol, ethanol, water, acetonitrile, isopropanol, acetone, tetrahydrofuran, and dimethyl sulfoxide and N,N-dimethylformamide, and the volume ratio of the listed solvent to N,N-dimethylformamide is 1:1 to 1:

10.

4. The method for preparing a biodegradable nanofiber membrane for integrated elimination of multiphase pollutants in the precision manufacturing industry according to claim 1, characterized in that: The conditions of the microwave-assisted technology in step S1 are: microwave power of 100-500 W, reaction temperature of 100-200° C., reaction time of 3-60 min, stirring speed of 20-1000 rpm / min; the average particle size of the obtained MOF nanocrystals is 50-300 nm, and the average pore size is 0.6-1.0 nm.

5. The method for preparing a biodegradable nanofiber membrane for integrated elimination of multiphase pollutants in the precision manufacturing industry according to claim 1, characterized in that: In step S2, solvent A is one or more of dichloromethane, N,N-dimethylformamide, chloroform, tetrahydrofuran, acetone, ethyl acetate, dimethyl sulfoxide, N,N-dimethylacetamide, methanol, ethanol, N-methylpyrrolidone, and hexafluoroisopropanol, and the mass fraction of polylactic acid in solvent A is 5% to 25%.

6. The method for preparing a biodegradable nanofiber membrane for integrated elimination of multiphase pollutants in the precision manufacturing industry according to claim 1, characterized in that: In step S3, solvent B is one or more of water, methanol, ethanol, isopropanol, N,N-dimethylformamide, N,N-dimethylacetamide, acetone, butanone, dichloromethane, chloroform, acetonitrile, ethyl acetate, tetrahydrofuran, and dimethyl sulfoxide, and the mass fraction of MOF nanocrystals in solvent B is 1% to 20%.

7. The method for preparing a biodegradable nanofiber membrane for integrated elimination of multiphase pollutants in the precision manufacturing industry according to claim 1, characterized in that: The high-speed air-spinning technology in step S4 is one or more of solution air-spinning, solution blow-jet spinning, centrifugal air-spinning, and microfluidic air-spinning technologies.

8. The method for preparing a biodegradable nanofiber membrane for integrated elimination of multiphase pollutants in the precision manufacturing industry according to claim 1, characterized in that: The conditions of the ultrasonic-assisted spraying technology in step S4 are as follows: the ultrasonic frequency is 15-250 kHz, the ultrasonic power is 100-3000 W, the spray flow rate is 0.1-50 mL / min, the gas pressure drop is 0.1-10 MPa, and the spray distance is 10-200 mm; the conditions of the online rolling process are as follows: the rolling speed is 0.1-20 m / min, the roller pressure is 1-20 MPa, and the roller gap distance is 0.05-5 mm; the obtained precision manufacturing multiphase pollutant integrated elimination biodegradable nanofiber membrane has a thickness of 20-150 μm and a fiber diameter of 50-120 nm.

9. A biodegradable nanofiber membrane prepared by the method for preparing a biodegradable nanofiber membrane for integrated elimination of multiphase pollutants in the precision manufacturing industry as described in any one of claims 1 to 8.

10. Application of the biodegradable nanofiber membrane according to claim 9 in the integrated elimination of multiphase pollutants in semiconductor integrated circuits, new energy, and biomedical precision manufacturing industries.

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