CN115945023A - Application of Electrospun Nanofibrous Membranes in Gas Adsorption - Google Patents

Abstract

The invention discloses an application of an electrostatic spinning nanofiber membrane in gas adsorption, wherein the electrostatic spinning nanofiber membrane is used in carbon dioxide and/or nitrogen adsorption, and a preparation method of the electrostatic spinning nanofiber membrane is limited. The invention improves the spinnability of the silk fibroin, reduces the production cost and expands the application range of the silk fibroin membrane.

Description

Application of Electrospun Nanofibrous Membranes in Gas Adsorption

technical field

The invention relates to the technical field of polymer composite materials, in particular to the application of an electrospun nanofiber membrane in gas adsorption.

Background technique

Silk is a natural biological macromolecule composed of silk fibroin and sericin, among which silk fibroin accounts for about 70% of silk mass, and sericin accounts for about 25% of the total mass. There are various methods for separating sericin and silk fibroin, such as enzymatic hydrolysis, alkali hydrolysis, acid hydrolysis, high-temperature hydrolysis and organic solvent dissolution, among which high-temperature hydrolysis is the simplest. Silk fibroin (SF) in silkworm is composed of three subunits, namely heavy chain (H-chain), light chain (L-chain) and glycoprotein P25. The heavy chain and light chain are connected by disulfide bonds, and then combined with glycoprotein P25 by covalent bonds such as hydrophobic bonds. SF is composed of a variety of amino acids, the main amino acids are glycine, alanine and serine, accounting for about 85% of the amino acid composition. With good biocompatibility, biodegradability, and high tensile strength, SF has been used in various biomedical fields, including wound dressings, artificial blood vessels, and cell culture. The silk fibroin fiber is dissolved in different dissolution systems to obtain a regenerated silk fibroin solution, which is then regenerated into microspheres, membranes, fibers, gels, scaffolds, etc. and endowed with special properties for the recycled materials. Various properties of silk fibroin materials can be effectively controlled by regulating the secondary structure of silk fibroin, including the preparation of high-strength, high-orientation materials, etc. However, the spinnability of pure SF solution is poor, and the protein film prepared by it is hard and brittle , easy to break, and the mechanical properties of the film are poor, which greatly limits the practical application of the material.

Polyvinyl alcohol (PVA) is a semi-crystalline polymer formed by hydrolysis of polyvinyl acetate (PVAc). As we all know, polyvinyl alcohol is a water-soluble polymer with excellent hydrophilicity, good biocompatibility and degradability. It has a good linear structure, good flexibility, stable chemical properties, and good spinnability. It can be used in biomedical materials. Blending and spinning SF and PVA can improve the spinnability of SF, reduce the production cost, and expand the application range of silk fibroin film. Using electrospinning technology to process SF-PVA material, the obtained nanofiber material not only has biocompatibility, but also improves its excellent properties such as permeability and gas adsorption, which can further enhance its application potential in the field of gas adsorption.

To sum up, in order to solve the above problems, further in-depth research on the application field of silk fibroin/polyvinyl alcohol composite films is urgently needed.

Contents of the invention

In order to solve the above technical problems, the purpose of the present invention is to provide an application of electrospun nanofibrous membrane in gas adsorption, which improves the spinnability of silk fibroin, reduces production costs, and expands the use range of silk fibroin. .

The technical solution of the present invention to solve the above-mentioned technical problems is as follows: an application of an electrospun nanofiber membrane in gas adsorption is provided.

Specifically, the application of electrospun nanofibrous membranes in carbon dioxide and/or nitrogen adsorption.

Further, the electrospun nanofibrous membrane is prepared by the following method:

(1) adding silkworm cocoons to ultrapure water, performing high temperature and high pressure reaction to obtain solid silk fibroin; then washing and drying in sequence, and then performing microwave reaction to obtain silk fibroin solution;

(2) adding polyvinyl alcohol into the silk fibroin solution obtained in step (1), heating and stirring to dissolve, and obtaining a silk fibroin/polyvinyl alcohol blended spinning solution;

(3) Evenly inject the silk fibroin/polyvinyl alcohol blended spinning solution obtained in step (2) into a syringe, and perform electrospinning to obtain an electrospun nanofiber membrane.

Further, in step (1), react at 120-122° C. and 0.15-0.18 MPa for 10-15 min.

Further, in step (1), react at 121° C. and 0.17 MPa for 10 minutes.

Further, in step (1), the reaction is stirred at 210-230° C. and 500-1000 rpm for 1-2 h.

Further, in step (1), the reaction was stirred for 1 h at 220° C. and 600 rpm.

Further, in step (1), the mass ratio of silkworm cocoon to ultrapure water is 1:20-100, and the concentration of silk fibroin solution is 38-54 mg/mL.

Further, in step (2), the mass ratio of polyvinyl alcohol and silk fibroin solution is 1:8-15.

Further, in step (2), stirring is carried out at a temperature of 60-100° C. for 1-2 h.

Further, in step (3), electrospinning is performed under the conditions of 15-30kV voltage, 15-20cm receiving distance, 0.1-0.5mL/h injection rate, 50-60% humidity and 20-30°C temperature for 1-2h.

Further, in step (3), the injection volume is 10-15mL.

The present invention has the following beneficial effects:

1. The present invention utilizes electrospinning technology to obtain a silk fibroin/polyvinyl alcohol composite film, which solves the difficulty of spinning the silk fibroin solution and improves its spinnability. At the same time, the method of the present invention is simple and low in cost. The process is controllable, and the prepared material has a nanostructure, large specific surface area and high porosity, because silk fibroin contains a large number of amino groups, which will chemically react with _CO2 gas at 298K to produce carbamic acid. The silk fibroin/polyvinyl alcohol composite film provides a rich pore structure and large pore volume, providing channels and sites for physical adsorption of CO ₂ , and a large number of amino groups contained in silk fibroin will also react with CO ₂ gas to Chemical adsorption occurs, and the rich pore structure is equivalent to countless highway networks, which not only significantly increases the specific surface area of the hydrogel, but also has a large pore size that can fix or fill a large number of adsorbate molecules, and further improves the adsorption of CO ₂ . The spun composite film can be used to adsorb CO ₂ , N ₂ and other gases, showing excellent gas adsorption performance, because the composite film prepared by electrospinning has a large pore size, and silk fibroin can combine with CO ₂ in the air to achieve The dual adsorption of physics and chemistry provides the possibility for the application of silk fibroin/polyvinyl alcohol in _CO2 adsorption, making it possible for the electrospun silk fibroin nanofiber membrane to be applied in the fields of environmental protection and gas adsorption. and can be widely applied.

2. The present invention provides a preparation method of electrospinning nanofiber membrane and its application in gas adsorption. The method mixes silk fibroin (SF) and polyvinyl alcohol (PVA) to improve the spinnability of SF. sex. SF is partially biodegradable, and its degradation products not only have no toxic and side effects on tissues, but also have nutritional and repairing effects on skin and periodontal tissue. However, pure SF solution has poor spinnability, and the protein film prepared with it is hard and brittle. , easy to break, and the mechanical properties of the film are poor, which greatly limits the practical application of the material. Polyvinyl alcohol is a water-soluble polymer with excellent hydrophilicity, good biocompatibility and degradability. It has a good linear structure, good flexibility, stable chemical properties and good spinnability. SF and PVA Blending and spinning can improve the spinnability of SF, reduce the production cost, and expand the application range of silk fibroin film.

Description of drawings

Fig. 1 is the scanning electron micrograph of embodiment 1 gained electrospinning nanofiber film;

Fig. 2 is the nitrogen adsorption figure of polyvinyl alcohol and the electrospun nanofiber membrane of the gained electrospinning of embodiment 1;

Fig. 3 is the carbon dioxide adsorption figure of polyvinyl alcohol and the electrospun nanofiber membrane of embodiment 1 gained;

FIG. 4 is the carbon dioxide adsorption graph of the electrospun nanofiber membrane obtained in Example 1 at different times.

Detailed ways

The principles and features of the present invention are described below, and the examples given are only used to explain the present invention, and are not intended to limit the scope of the present invention. Those who do not indicate the specific conditions in the examples are carried out according to the conventional conditions or the conditions suggested by the manufacturer. The reagents or instruments used were not indicated by the manufacturer, and they were all conventional products that could be purchased from the market.

Example 1

The application of the electrospun nanofiber membrane in gas adsorption, specifically the application of the electrospun nanofiber membrane in the adsorption of carbon dioxide and/or nitrogen.

Wherein, the electrospun nanofiber membrane is prepared by the following method:

(1) Add silkworm cocoons to ultrapure water at a mass ratio of 1:50, and react at 121°C and 0.17MPa for 10 minutes to obtain solid silk fibroin; Stir and react for 1 hour to obtain a silk fibroin solution with a concentration of 45 mg/mL;

(2) Add polyvinyl alcohol into the silk fibroin solution obtained in step (1) at a mass ratio of 1:8, and stir at 90° C. for 2 hours to obtain a silk fibroin/polyvinyl alcohol blended spinning solution;

(3) The silk fibroin/polyvinyl alcohol blended spinning solution obtained in step (2) is evenly injected into the syringe, and electrostatically charged under the conditions of 20kV voltage, 17cm receiving distance, 0.15mL/h injection rate, 50% humidity and 25°C temperature conditions. Spin for 1 hour to obtain an electrospun nanofiber membrane.

The scanning electron microscope image of the electrospun nanofiber membrane obtained in Example 1 is obtained, as shown in FIG. 1 .

It can be seen from Figure 1 that the obtained electrospun nanofibrous membrane has an obvious fiber structure, and the fiber structure is relatively uniform, forming an interlaced interpenetrating network structure, no beaded structure, high porosity, and an interwoven network between fibers , the connectivity between the pores is good, these pores provide a path for gas molecules to enter and exit, which is conducive to the diffusion of gas molecules, and also provides a channel for the adsorption and release of other molecules. Scanning electron microscopy shows that an ideal electrospinning composite film.

The polyvinyl alcohol and the electrospun nanofiber membrane obtained in Example 1 were used for nitrogen adsorption, and the results are shown in FIG. 2 . Among them, in Fig. 2 from top to bottom are electrospun nanofiber membranes and polyvinyl alcohol.

It can be seen from Fig. 2 that the adsorption amount of nitrogen by electrospun nanofiber film is significantly increased (2.6067cc/g-320.3144cc/g) at 77.35K compared with pure polyvinyl alcohol film. At the same time, the type of N ₂ adsorption-desorption curve was Type IV, and H3 type hysteresis loop was produced when the silk fibroin content was 540mg. This type of hysteresis loop indicates that the material contains a large number of fracture pores or stacked pores. This is due to the compounding of silk fibroin, which produces a rich mesoporous and macroporous structure, which is equivalent to countless highway networks, which not only significantly improves the specific surface area of the composite film, but also has a large pore size that can fix or load a large amount of adsorbents. Molecules, providing a possibility for the application of silk fibroin/polyvinyl alcohol in _N2 adsorption.

The polyvinyl alcohol and the electrospun nanofiber membrane obtained in Example 1 were used for carbon dioxide adsorption, and the results are shown in FIG. 3 . Wherein, in Fig. 3 from top to bottom are electrospun nanofibrous membranes and polyvinyl alcohol.

It can be seen from Figure 3 that because silk fibroin contains a large number of amino groups, it will react with _CO2 gas at 298K to produce carbamic acid. However, polyvinyl alcohol (PVA) has no amino structure in its structural composition, and the adsorption capacity of _CO2 is 7.3345cc/g, which is significantly lower than that of electrospun nanofibrous membrane (silk fibroin/polyvinyl alcohol composite (SF/PVA) ) adsorption capacity (146.6907cc/g), the electrospun nanofibrous membrane provides a rich pore structure and large pore volume, providing channels and sites for the physical adsorption of CO ₂ , and a large number of amino groups contained in silk fibroin are also It will react with CO ₂ gas to cause chemical adsorption, which greatly improves the adsorption of CO ₂ , making the composite film applied in the field of CO ₂ adsorption.

The electrospun nanofiber membrane obtained in Example 1 was subjected to carbon dioxide adsorption (silk fibroin 540 mg, 298K) at different times, and the results are shown in FIG. 4 .

It can be seen from Figure 4 that the adsorption capacity of the electrospun nanofiber membrane for CO ₂ gas increases rapidly (0cc/g-43.1cc/g) at 0-60min; at 70-90min, the adsorption of _CO2 by the hydrogel is basically saturated, The adsorption capacity increased only slightly (43.1cc/g-52.8cc/g). This shows that the hydrogel has a fast adsorption capacity for CO ₂ and can reach its saturated adsorption capacity (52.8cc/g) within 90min.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within range.

Claims (10)

1. Application of electrospun nanofibrous membranes in gas adsorption. 2. Application of electrospun nanofibrous membranes in carbon dioxide and/or nitrogen adsorption. 3. The application according to claim 1 or 2, wherein the electrospun nanofiber membrane is prepared by the following method: (1) adding silkworm cocoons to ultrapure water, performing high temperature and high pressure reaction to obtain solid silk fibroin; then washing and drying in sequence, and then performing microwave reaction to obtain silk fibroin solution; (2) adding polyvinyl alcohol into the silk fibroin solution obtained in step (1), heating and stirring to dissolve, and obtaining a silk fibroin/polyvinyl alcohol blended spinning solution; (3) Evenly inject the silk fibroin/polyvinyl alcohol blended spinning solution obtained in step (2) into a syringe, and perform electrospinning to obtain an electrospun nanofiber membrane. 4. The application according to claim 3, characterized in that, in step (1), the reaction is carried out at 120-122° C. and 0.15-0.18 MPa for 10-15 minutes. 5. The application according to claim 3, characterized in that, in step (1), the stirring reaction is carried out at 210-230°C and 500-1000rpm for 1-2h. 6. The application according to claim 3, characterized in that, in step (1), the mass ratio of silkworm cocoon to ultrapure water is 1:20-100, and the concentration of silk fibroin solution is 38-54 mg/mL. 7. The application according to claim 3, characterized in that, in step (2), the mass ratio of polyvinyl alcohol and silk fibroin solution is 1:8-15. 8. The application according to claim 3, characterized in that, in step (2), stirring is carried out at a temperature of 60-100°C for 1-2h. 9. The application according to claim 3, characterized in that, in step (3), at 15-30kV voltage, 15-20cm receiving distance, 0.1-0.5mL/h injection rate, 50-60% humidity and 20- Electrospinning at 30°C for 1-2h. 10. The application according to claim 3, characterized in that, in step (3), the injection volume is 10-15mL.

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