Highly oriented nanofiber membrane based on uniaxial drawing technique and method of manufacturing the same

Abstract

This invention discloses a highly oriented nanofiber membrane based on uniaxial drawing technology and its preparation method, belonging to the field of nanomaterials technology. The method involves mixing polyethylene oxide (PEO) as a filament-forming aid with a fiber-forming polymer and dissolving it in 2,2,2-trifluoroethanol (TFE) to obtain a precursor solution. A continuous filamentous liquid stream is smoothly drawn using a uniaxial needle and directionally collected using a rotating receiving device, thereby obtaining a highly oriented nanofiber membrane. This invention overcomes the dependence of traditional electrospinning technology on a high-voltage electric field, simplifies the equipment, and eliminates safety hazards. Through the synergistic design of uniaxial continuous drawing and directional rotating receiving, highly uniform and oriented fiber alignment is achieved. This method is adaptable to various fiber-forming polymer systems, and the prepared nanofiber membrane has a smooth surface and uniform structure, showing broad application prospects in biomedicine, filtration, and separation fields.

Description

Technical Field

[0001] This invention belongs to the field of nanomaterials technology, specifically relating to a method for preparing highly oriented nanofiber membranes using polyethylene oxide as a filamentation aid and a uniaxial continuous drawing-directional rotation receiving process, as well as the nanofiber membranes prepared by this method. Background Technology

[0002] Traditional fiber membrane preparation mainly relies on electrospinning technology. Its core principle is to apply a 10–30 kV high-voltage electric field to form a jet of polymer solution, which then deposits as a fiber membrane after solvent evaporation. To achieve fiber orientation, a high-speed rotating receiving device or an electric field-assisted orientation structure is required. However, there are still insurmountable drawbacks: reliance on a high-voltage electric field leads to complex equipment (requiring high-voltage power supplies and insulation devices), poses a risk of electric shock, and has stringent environmental requirements (requiring anti-static, humidity, and temperature control). The jet motion under the electric field is random; even with an orientation receiving device, the fiber orientation degree is still affected by electric field fluctuations, making it difficult to achieve highly uniform directional alignment. Furthermore, the high-voltage electric field easily causes excessively rapid solvent evaporation, resulting in fiber morphology defects (such as broken fibers and bead-like agglomerations), affecting product performance.

[0003] Meanwhile, existing non-electric field drawing technologies (such as melt drawing and solution casting drawing) are mostly applicable to the preparation of macroscopic fibers, and cannot achieve continuous drawing and directional arrangement of nanoscale fibers; moreover, existing solution drawing technologies lack effective filamentation aid systems, and single polymer solutions are difficult to form stable and continuous nanoscale liquid flows. The process is complex and costly, making it difficult to adapt to the large-scale production of fiber membranes. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing highly oriented nanofiber membranes based on uniaxial drawing technology, which breaks through the dependence on high-voltage electric fields in traditional preparation techniques, simplifies the process, and reduces costs. At the same time, the highly oriented nanofiber membranes prepared by this method have excellent directional structures and broad application prospects.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A method for preparing a highly oriented nanofiber membrane based on uniaxial drawing technology includes the following steps:

[0007] Step 1: Add TFE (2,2,2-trifluoroethanol) to a mixture of PEO (polyethylene oxide) and fiber-forming polymer to obtain a mixed solution. The mass percentage of the mixture of PEO and fiber-forming polymer in the mixed solution is 1-5%; the mass ratio of PEO to fiber-forming polymer is 1:5-3:1.

[0008] Step 2: Stir the mixed solution until fully dissolved to obtain a uniform fiber drawing precursor solution;

[0009] Step 3: Based on uniaxial drawing technology, a continuous filamentous liquid flow is smoothly drawn from the uniaxial needle tip;

[0010] Step 4: The continuous filamentous liquid flow is collected by a rotating receiving device, so that the filamentous liquid flow is oriented in the direction of the rolling of the receiving roller to obtain a highly oriented nanofiber membrane.

[0011] As a more preferred technical solution of the present invention, the mass percentage of solute in the mixed solution in step one is 2%.

[0012] As a more preferred technical solution of the present invention, the mass ratio of PEO to fiber-forming polymer in step one is 1:1.

[0013] As a more preferred technical solution of the present invention, the fiber-forming polymer in step one is one or a combination of PTMC (polytrimethylene carbonate), PCL (polycaprolactone), PLGA (polylactic-co-glycolic acid copolymer), PVB (polyvinylbutyral), and PLA (polylactic acid).

[0014] As a more preferred technical solution of the present invention, the single-axis drawing parameters in step three are: the feeding speed is 0.06-0.1 mL / h, the distance from the drawing port to the receiving roller is 15-25 cm, and the needle inner diameter is 30 G.

[0015] As a more preferred technical solution of the present invention, the single-axis drawing parameters in step three are: the feeding speed is 0.08 mL / h, the distance from the drawing port to the receiving roller is 20 cm, and the needle inner diameter is 30 G.

[0016] As a preferred technical solution of the present invention, the receiving roller speed in step four is 200 rpm.

[0017] Another object of the present invention is to provide a highly oriented nanofiber membrane prepared by the preparation method described above.

[0018] The beneficial effects of this invention are as follows:

[0019] This invention uses PEO as a filamentation aid to form a synergistic filamentation system with various fiber-forming polymers, solving the technical problem that it is difficult to form continuous nanofibers from a single polymer solution. It is compatible with various material systems such as PTMC, PCL, PLGA, PVB, and PLA, expanding the application range of uniaxial drawing technology.

[0020] This invention breaks through the dependence of traditional electrospinning technology on high-voltage electric fields, eliminating the need for high-voltage power supplies and insulation devices. The equipment structure is simplified (requiring only a liquid storage device, a single-axis needle, and a rotating receiving device), eliminating safety hazards, reducing production costs, and making operation simple.

[0021] This invention utilizes a synergistic design of uniaxial continuous drawing and directional rotation receiving, where the fiber alignment direction is precisely controlled by the rolling direction of the receiving roller, avoiding orientation disorder caused by electric field fluctuations and achieving highly uniform directional alignment.

[0022] This invention is adaptable to a variety of fiber-forming polymer systems. The nanofibers prepared have smooth surfaces, no obvious bead-like agglomeration, and excellent structural uniformity, and can be widely used in biomedicine, filtration and separation, flexible electronics and other fields. Attached Figure Description

[0023] Figure 1 This is a process diagram illustrating the preparation of the highly oriented nanofiber membrane based on uniaxial drawing technology according to the present invention;

[0024] Figure 2 This is a photograph of the nanofiber membrane prepared in Example 1 of the present invention.

[0025] Figure 3 This is a scanning electron microscope image of the nanofiber membrane prepared in Example 1 of the present invention. Detailed Implementation

[0026] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0027] All raw materials used in this invention are commercially available, and the experimental and testing methods not specifically described are conventional methods.

[0028] Example 1

[0029] like Figure 1 As shown, a method for preparing a highly oriented nanofiber membrane based on uniaxial drawing technology includes the following steps:

[0030] Step 1: Add 11.76g TFE to a mixture of 0.12g PEO and 0.12g PTMC to obtain a mixed solution, wherein the mass percentage of the solute is 2%.

[0031] Step 2: Stir the mixed solution until fully dissolved to obtain a uniform fiber drawing precursor solution.

[0032] Step 3: Smoothly draw a continuous filamentous liquid stream from the single-axis needle tip. The drawing parameters are: feed rate of 0.08 mL / h, distance from the drawing nozzle to the receiving roller of 20 cm, and needle tip inner diameter of 30 G.

[0033] Step 4: The continuous filamentous liquid flow is collected by a rotating receiving device, causing the liquid flow to align in the direction of the receiving roller, resulting in a highly oriented nanofiber membrane. The receiving roller rotates at 200 rpm.

[0034] Example 2

[0035] The difference between this embodiment and Embodiment 1 is that the mass percentage of the solute in step one is 1%, that is, the mass of TFE added is 11.88g, the mass of PEO is 0.06g, and the mass of PTMC is 0.06g. All other process conditions are the same as in Embodiment 1.

[0036] Example 3

[0037] The difference between this embodiment and Embodiment 1 is that the mass percentage of the solute in step one is 3%, that is, the mass of TFE added is 11.64g, the mass of PEO is 0.18g, and the mass of PTMC is 0.18g. All other process conditions are the same as in Embodiment 1.

[0038] Example 4

[0039] The difference between this embodiment and Embodiment 1 is that the mass percentage of the solute in step one is 4%, that is, the mass of TFE added is 11.52g, the mass of PEO is 0.24g, and the mass of PTMC is 0.24g. All other process conditions are the same as in Embodiment 1.

[0040] Example 5

[0041] The difference between this embodiment and Embodiment 1 is that the mass percentage of the solute in step one is 5%, that is, the mass of TFE added is 11.4g, the mass of PEO is 0.3g, and the mass of PTMC is 0.3g. All other process conditions are the same as in Embodiment 1.

[0042] Example 6

[0043] The difference between this embodiment and Embodiment 1 is that the mass of PEO added in step one is 0.06g, the mass of PTMC is 0.18g, and all other process conditions are the same as in Embodiment 1.

[0044] Example 7

[0045] The difference between this embodiment and Embodiment 1 is that the mass of PEO added in step one is 0.04g, the mass of PTMC is 0.2g, and all other process conditions are the same as in Embodiment 1.

[0046] Example 8

[0047] The difference between this embodiment and embodiment 1 is that the mass of PEO added in step one is 0.18g, the mass of PTMC is 0.06g, and all other process conditions are the same as in embodiment 1.

[0048] Example 9

[0049] The difference between this embodiment and Embodiment 1 is that the fiber drawing parameters in step three are as follows: the solution feed rate is 0.06 mL / h, and all other process conditions are the same as in Embodiment 1.

[0050] Example 10

[0051] The difference between this embodiment and Embodiment 1 is that the fiber drawing parameters in step three are as follows: the solution feed rate is 0.1 mL / h, and all other process conditions are the same as in Embodiment 1.

[0052] Example 11

[0053] The difference between this embodiment and embodiment 1 is that the wire drawing parameters in step 3, the distance from the wire drawing nozzle to the receiving roller is 15cm, and the other process conditions are the same as in embodiment 1.

[0054] Example 12

[0055] The difference between this embodiment and embodiment 1 is that the wire drawing parameters in step 3, the distance from the wire drawing nozzle to the receiving roller is 25cm, and the other process conditions are the same as in embodiment 1.

[0056] Example 13

[0057] The difference between this embodiment and Embodiment 1 is that in step one, 11.76g of TFE is added to a mixture consisting of 0.12g of PEO and 0.12g of PCL to obtain a mixed solution, wherein the mass percentage of the solute is 2%, and other process conditions are the same as in Embodiment 1.

[0058] Example 14

[0059] The difference between this embodiment and Embodiment 1 is that in step one, 11.76g of TFE is added to a mixture consisting of 0.12g of PEO and 0.12g of PLGA to obtain a mixed solution, wherein the mass percentage of the solute is 2%, and other process conditions are the same as in Embodiment 1.

[0060] Example 15

[0061] The difference between this embodiment and Embodiment 1 is that in step one, 11.76g of TFE is added to a mixture consisting of 0.12g of PEO and 0.12g of PVB to obtain a mixed solution, wherein the mass percentage of the solute is 2%, and other process conditions are the same as in Embodiment 1.

[0062] Example 16

[0063] The difference between this embodiment and Embodiment 1 is that in step one, 11.76g of TFE is added to a mixture consisting of 0.12g of PEO and 0.12g of PLA to obtain a mixed solution, wherein the mass percentage of the solute is 2%, and other process conditions are the same as in Embodiment 1.

[0064] The morphology of the nanofiber membranes prepared in Examples 1 to 16 was studied using cold field emission scanning electron microscopy. The results showed that all the obtained nanofibers were distributed parallel to each other in the same direction, without any random interweaving, and exhibited uniform orientation and high consistency. The fibers had a continuous filamentous structure, a relatively smooth surface, no obvious bead-like agglomeration, and excellent structural uniformity.

[0065] The nanofibers obtained in Example 1 exhibited optimal uniformity in their oriented arrangement structure, such as... Figure 2 and Figure 3 As shown.

[0066] The statistical results of the average diameter of the nanofibers prepared in Examples 1 to 16 under different preparation parameters of the present invention are shown in Table 1.

[0067] Table 1:

[0068]

[0069] As shown in Table 1, the solute mass percentage, the mass ratio of PEO to fiber-forming polymer, the feed rate, and the drawing distance all have a significant impact on the fiber diameter. By adjusting the above parameters, the fiber diameter can be precisely controlled.

[0070] The PEO filamentation aid system has good compatibility with various polymers such as PTMC, PCL, PLGA, PVB, and PLA, and can be used to prepare highly oriented nanofiber membranes with excellent morphology.

[0071] The above description is merely a preferred embodiment of the present invention, and the scope of protection of the present invention is not limited thereto. Any simple changes or equivalent substitutions of the technical solutions that can be obviously obtained by those skilled in the art within the scope of the technology disclosed in the present invention shall fall within the scope of protection of the present invention.

Claims

1. A method for preparing a highly oriented nanofiber membrane based on uniaxial drawing technology, characterized in that, The method includes the following steps: Step 1: Add TFE to the mixture of PEO and fiber-forming polymer to obtain a mixed solution. The mass percentage of the mixture of PEO and fiber-forming polymer in the mixed solution is 1-5%; the mass ratio of PEO to fiber-forming polymer is 1:5-3:

1. Step 2: Stir the mixed solution until fully dissolved to obtain a uniform fiber drawing precursor solution; Step 3: Based on uniaxial drawing technology, a continuous filamentous liquid flow is smoothly drawn from the uniaxial needle tip; Step 4: The continuous filamentous liquid flow is collected by a rotating receiving device, so that the filamentous liquid flow is oriented in the direction of the rolling of the receiving roller to obtain a highly oriented nanofiber membrane.

2. The method for preparing a highly oriented nanofiber membrane based on uniaxial drawing technology according to claim 1, characterized in that, The mass percentage of solute in the mixed solution in step one is 2%.

3. The method for preparing a highly oriented nanofiber membrane based on uniaxial drawing technology according to claim 1, characterized in that, In step one, the mass ratio of PEO to fiber-forming polymer is 1:

1.

4. The method for preparing a highly oriented nanofiber membrane based on uniaxial drawing technology according to claim 1, characterized in that, In step one, the fiber-forming polymer is one or more of PTMC, PCL, PLGA, PVB, and PLA.

5. The method for preparing a highly oriented nanofiber membrane based on uniaxial drawing technology according to claim 1, characterized in that, The parameters for single-axis drawing in step three are: feed rate of 0.06-0.1 mL / h, distance from drawing nozzle to receiving roller of 15-25 cm, and needle inner diameter of 30 G.

6. The method for preparing a highly oriented nanofiber membrane based on uniaxial drawing technology according to claim 5, characterized in that, The parameters for single-axis wire drawing in step three are: feed rate of 0.08 mL / h, distance from the wire drawing nozzle to the receiving roller of 20 cm, and needle inner diameter of 30 G.

7. The method for preparing a highly oriented nanofiber membrane based on uniaxial drawing technology according to claim 1, characterized in that, In step four, the receiving roller rotates at 200 rpm.

8. A highly oriented nanofiber membrane prepared by the preparation method according to any one of claims 1 to 7.

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