Needleless electrode electrospun water-based micro-nano functional fabric and preparation method thereof

Abstract

The application discloses a needle-free electrode electrospun water-based micro-nano functional fabric and a preparation method thereof, and belongs to the field of textile technology. The application uses water-soluble TPU, PEO / PVA and other spinning assistants, and water-soluble functional assistants to prepare a spinning solution with pure water, thereby eliminating the use of organic solvents. An infrared lamp is additionally arranged on the spinning equipment to control the ambient temperature, accelerate water evaporation, and avoid the fusion and adhesion of nascent fibers. In addition, a needle-free electrode filament is used to replace the spinning needle, thereby eliminating the disadvantage of filament blocking. Finally, the needle-free electrostatic spinning is followed by high-temperature hot pressing treatment, so that the fiber string bead structure is anchored on the surface of the base material. The process is green and low in energy consumption. The prepared fabric has complete fiber morphology, uniformly dispersed functional components, and excellent washing resistance, and the functional layer is not easy to fall off after washing. The application can be widely applied to the fields of medical protection, intelligent wearing and other textile products.

Description

Technical Field

[0001] This invention belongs to the field of textile technology, specifically relating to needleless electrode electrospun water-based micro-nano functional fabrics and their preparation methods. Background Technology

[0002] Electrospinning is a mainstream technology for preparing micro- and nano-functional textile fabrics. It relies on a high-voltage electric field to stretch the spinning solution to form nanofibers, and it is widely used in antibacterial, UV-resistant, and protective textiles. Traditional needle-type electrospinning is prone to defects such as needle clogging, uneven fabric coating, and low mass production efficiency. To address this, the industry has developed a needleless electrode electrospinning solution. Patent CN120401030 A discloses a needleless electrospinning device with a liquid storage stirring bottle and a bottom moving spray brush structure. By replacing the injection needle with a metal electrode wire, it solves the industry pain points of needle clogging and large particle filler deposition clogging the needle. At the same time, the continuous stirring of the liquid storage bottle ensures that large particle antibacterial agents are uniformly dispersed in the organic solvent spinning solution, which improves the processing stability of spinning solutions containing solid phase fillers to a certain extent.

[0003] However, this patented technology still has shortcomings: First, patent CN120401030A uses organic solvents such as acetone, DMF, and dimethylacetamide to prepare the spinning solution. Organic solvents are highly volatile and have biological toxicity. It is difficult to completely remove residual solvents from the finished spinning product. Subsequent residue removal processes are energy-intensive and have long processing cycles. They are also prone to damaging the microstructure of nanofibers, which does not meet the needs of green production development. Second, this patent only relies on the natural evaporation of solvents in the environment and does not have a temperature-controlled drying auxiliary structure. If the spinning system is replaced with an environmentally friendly water-based spinning solution, the vaporization rate of water is much lower than that of conventional organic solvents. Relying solely on natural drying will result in slow evaporation of water during the spinning process. The nascent nanofibers and beaded microspheres deposited on the surface of the base fabric will re-dissolve and adhere when exposed to residual water, failing to form a complete and regular micro-nano morphology. Functional components will agglomerate and have uneven loads, resulting in a significant decrease in the fabric's washability.

[0004] In addition, common methods for removing residual organic solvents include: 1) vacuum drying, which involves heating under vacuum conditions to lower the boiling point of the solvent and accelerate its evaporation; 2) freeze-drying, which involves freezing the membrane first and then sublimating it under vacuum to remove ice crystals, thus indirectly removing the solvent; and 3) solvent replacement, which involves replacing the high-boiling-point organic solvent in the membrane with a low-boiling-point, volatile solvent, and then removing the replaced solvent through evaporation or drying. However, none of these methods can completely eliminate residual organic solvents, and the processing is energy-intensive, time-consuming, and prone to damaging the fiber structure.

[0005] Therefore, aqueous needleless electrospinning is currently an important development direction for green spinning. However, existing needleless spinning technologies are difficult to adapt to all-aqueous spinning systems. Furthermore, traditional aqueous spinning suffers from poor spinnability, weak fiber-fabric bonding, and insufficient wash resistance. Therefore, there is an urgent need to improve the process and equipment based on existing needleless electrode spinning to achieve large-scale preparation of micro / nano functional fabrics with no organic solvents, regular fiber morphology, and excellent adhesion. Summary of the Invention

[0006] Technical issues Existing needleless electrospinning uses organic solvents that pollute the environment, while water-based spinning results in poor fiber adhesion, poor shaping, and poor washability.

[0007] Technical solution To address the aforementioned issues, this invention proposes a technique for electrospinning aqueous micro / nano functional fabrics using needle-free electrodes. This technique employs an aqueous polyurethane (TPU) solution as the spinning solution, avoiding the use of toxic organic solvents and fundamentally eliminating the risk of solvent residue. Simultaneously, polyvinyl alcohol (PVA), polyacrylic acid (PAA), polyethylene oxide (PEO), and polyvinylpyrrolidone (PVP) are added as auxiliary spinning agents to enhance the chain entanglement and conductivity of the solution, effectively improving the spinnability of the aqueous system. During the spinning process, suitable microspheres or bead structures are generated, which not only facilitates the uniform loading of functional materials but also serves as anchor points to enhance the bonding force between the micro / nano structure and the fabric, significantly improving wash resistance. The needle-free electrode design replaces the traditional multi-needle structure, eliminating the risk of needle clogging and achieving a large-area uniform electric field distribution, significantly improving spinning efficiency and fiber membrane consistency.

[0008] This invention provides a needleless electrospinning device for preparing water-based micro / nano functional fabrics. The needleless electrospinning device includes components: electrode wire, brushing liquid tank, DC high voltage power supply, winding roller, metal plate, and infrared lamp strip. The electrode wire is connected in series with the brushing liquid tank and is connected to the positive terminal of the DC high voltage power supply. The metal plate is placed directly above the electrode wire and is connected to the negative terminal of the DC high voltage power supply or grounded. The infrared lamp strip is placed on both sides of the spinning chamber, and the winding roller moves between the electrode wire and the metal plate.

[0009] Furthermore, the water-based micro-nano functional fabric refers to a functional textile fabric obtained by using water as a solvent, preparing a spinning solution with water-soluble TPU and water-soluble polymer, depositing a functional layer containing micro-nano fibers and bead structures on the surface of the base fabric through electrospinning, and then hot-pressing composite.

[0010] Furthermore, the electrode wire is a smooth metal wire and serves as the emitter of the spinning solution. The needleless electrospinning device can be equipped with multiple electrode wires arranged in parallel, with a spacing of 300-500 mm between adjacent electrode wires. The length of each electrode wire is set according to the required fiber membrane size.

[0011] Furthermore, the brush bath is used to hold the spinning precursor solution and can reciprocate on the electrode wire.

[0012] Furthermore, the distance between the electrode wire and the metal plate is 10-40 cm.

[0013] Furthermore, the infrared LED strip power is adjustable from 150 to 600 W.

[0014] This invention also provides a method for preparing needle-free electrode electrospun water-based micro / nano functional fabric, comprising the following steps: S1. Dissolve the spinning aid and water-based functional material in water to obtain the spinning solution; S2. Dissolve the water-soluble TPU emulsion in water to obtain a TPU solution, mix the TPU solution with the spinning solution and stir evenly to obtain an aqueous spinning solution; S3. The aqueous spinning solution is loaded into the brush liquid tank of the needleless electrospinning device, and then the aqueous micro-nano functional fabric is obtained by electrospinning. S4. The water-based micro-nano functional fabric is hot-pressed to obtain a needle-free electrode electrospun water-based micro-nano functional fabric.

[0015] Furthermore, the spinning aid is a water-soluble polymer PEO or PVA; the molecular weight of PEO is 400,000 to 800,000, and the molecular weight of PVA is 50,000 to 100,000.

[0016] Furthermore, the concentration of the spinning aid in the spinning solution is 1-3 wt%.

[0017] Furthermore, water-based functional materials are water-soluble nanomaterials, such as water-based antibacterial agents, UV stabilizers, or conductive polymer emulsions, including nano-silver ions and tobertidine (Tinosorb S).

[0018] Furthermore, the concentration of aqueous functional materials in the spinning solution is 0.5-5 wt%.

[0019] Furthermore, the concentration of the TPU solution is 15-25 wt%.

[0020] Furthermore, the mass ratio of TPU solution to spinning solution is 1:0.5~2.

[0021] Furthermore, the reciprocating speed of the brush bath during electrospinning is 100-300 mm / s.

[0022] Furthermore, the spinning voltage during electrospinning is 25-35 kV.

[0023] Furthermore, the rotation speed of the winding roller during electrospinning is 1-20 m / min.

[0024] Furthermore, the infrared lamp strip remains on during the electrospinning process, with a power of 150-600 W, preferably 250-400 W.

[0025] Furthermore, the hot-pressing temperature is 140-200 ℃, the pressure is 30-80 MPa, and the time is 1-3 min.

[0026] Finally, this invention provides a needleless electrode electrospun aqueous micro / nano functional fabric prepared according to the above preparation method.

[0027] The needleless electrode electrospun water-based micro-nano functional fabric can be applied to the fields of smart wearables, medical protection, and environmentally friendly textiles.

[0028] Beneficial effects 1. This invention uses a water-soluble TPU solution as the spinning solution, avoiding the use of toxic organic solvents and fundamentally eliminating the risk of solvent residue. Simultaneously, water-soluble polymers such as PEO are added as auxiliary spinning agents to enhance the chain entanglement ability and conductivity of the solution, effectively improving the spinnability of the aqueous system.

[0029] 2. This invention further optimizes the spinning environment by introducing an infrared light strip. Precise temperature control promotes rapid solvent evaporation, effectively preventing fiber adhesion and ensuring continuous and uniform deposition of micro / nano fibers on the fabric surface. After hot-pressing, the functional layers are firmly bonded, significantly improving washability. The resulting functional fiber membrane possesses excellent breathability and flexibility. Attached Figure Description

[0030] Figure 1 This is a structural diagram of a needleless electrode electrospinning device; in the diagram: 1. Electrode wire; 2. Brush liquid tank; 3. DC high voltage power supply; 4. Winding roller; 5. Metal plate; 6. Infrared light strip; 7. Fabric.

[0031] Figure 2 This is a scanning electron microscope (SEM) image of the microstructure of the spun fabric from Example 1.

[0032] Figure 3 This is a SEM image of the microstructure of the fabric after hot pressing in Example 1.

[0033] Figure 4 This is a SEM image of the microstructure of the fabric after washing in Example 1.

[0034] Figure 5 This is a comparison diagram of the color change of the fabric before and after spinning in Example 1. Detailed Implementation

[0035] The needleless electrospinning equipment used in the embodiments and comparative examples includes the following components: electrode wire 1, brushing liquid tank 2, DC high voltage power supply 3, winding roller 4, metal plate 5, and infrared lamp strip 6. The electrode wire 1 is a smooth metal wire, and two electrode wires 1 are arranged in parallel with a length set according to the required fiber membrane width, generally 40 cm. The electrode wire 1 is connected in series with the brushing liquid tank 2, which can reciprocate on the needleless electrode 1. The electrode wire 1 is connected to the positive terminal of the DC high voltage power supply 3, and the metal plate 5 is placed directly above the electrode wire 1. The metal plate 5 is connected to the negative terminal of the DC high voltage power supply 3 or grounded. The infrared lamp strip 6 is set on both sides of the spinning chamber, and the winding roller 4 drives the fabric 7 to move between the electrode wire 1 and the metal plate 5.

[0036] The PEO (molecular weight 600,000) used in the examples and comparative examples was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., the PVA (molecular weight 86,000) was purchased from Shanghai Maclean Biochemical Technology Co., Ltd., the bis(ethyl ethoxyphenol) methoxyphenyl triazine (Tinosorb S) was purchased from Sinopharm Chemical Reagent Co., Ltd., and the infrared lamp (model SW-I, power 300 W) was purchased from Taizhou Junqian Electric Heating Equipment Co., Ltd.

[0037] Example 1 A method for preparing a needle-free electrode electrospun aqueous micro / nano functional fabric includes the following steps: S1. Dissolve 2 g of PEO (molecular weight 600,000) and 0.5 g of nano silver ions in 98 g of deionized water and stir until completely dissolved to obtain PEO spinning solution.

[0038] S2. Dissolve 15 g of water-soluble TPU in 85 g of deionized water and stir until completely dissolved to obtain a TPU solution. Mix the TPU solution with the PEO spinning solution at a mass ratio of 1:1 and continue to stir magnetically for 1 hour to ensure that the system is uniform and transparent, thus obtaining an aqueous spinning solution that can be directly used for electrospinning.

[0039] S3. Place the aqueous spinning solution into the brush bath 2. The distance between the electrode wire 1 and the metal plate 5 is 25 cm. The spinning voltage is 25-30 kV. The reciprocating speed of the brush bath 2 is 100-300 mm / s. The rotation speed of the winding roller 4 is 1.0-1.5 m / min. The infrared lamp strip is kept on with a power of 300 W to obtain the aqueous micro-nano functional fabric.

[0040] S4. Hot-press the water-based micro-nano functional fabric at a temperature of 180℃, a pressure of 50 MPa, and a time of 2 min to obtain a needle-free electrode electrospun water-based micro-nano functional fabric.

[0041] The voltage and liquid feeding speed can be adjusted according to the spinning effect. If the spinning efficiency is low or spinning is impossible, the voltage should be increased. If the filaments fly around randomly, the voltage should be decreased. The liquid feeding speed is judged by the amount of residual steel wire during the reciprocating process. If there is a lot of residual solution on the steel wire after one round trip, it means that the liquid feeding speed is too fast and will waste solution.

[0042] Figure 2 The image shown is a scanning electron microscope (SEM) image of the microstructure of the fabric after yarn spinning in Example 1, indicating that the surface of the yarn-spun fabric is uniformly loaded with a layer of micro-nanospheres or beads.

[0043] Figure 3 The image shows the microstructure of the fabric after hot pressing in Example 1, which demonstrates that micro-nanospheres or beads were successfully cross-linked onto the fabric after hot pressing.

[0044] Figure 4 The image shows the microstructure of the fabric after washing in Example 1 using SEM. The morphology did not change significantly after washing, and the micro-nanospheres or bead structures (containing functional components) on the fiber surface still existed, proving that it has wash resistance.

[0045] Figure 5 The image shows a comparison of the fabric color changes before and after spinning in Example 1, demonstrating that the final fabric showed no color change after hot pressing. Although the spinning time was relatively long, a white fiber film could be observed forming on the fabric surface, but it returned to its original color after hot pressing, leaving no white residue.

[0046] Example 2 A method for preparing a needle-free electrode electrospun aqueous micro / nano functional fabric includes the following steps: S1. Dissolve 2 g of PEO (molecular weight 600,000) and 0.5 g of Tinosorb S in 98 g of deionized water and stir until completely dissolved to obtain PEO spinning solution.

[0047] S2. Dissolve 15 g of water-soluble TPU in 85 g of deionized water and stir until completely dissolved to obtain a TPU solution. Mix the TPU solution with the PEO spinning solution at a mass ratio of 1:1 and continue to stir magnetically for 1 hour to ensure that the system is uniform and transparent, thus obtaining an aqueous spinning solution that can be directly used for electrospinning.

[0048] S3. Place the aqueous spinning solution into the brush bath 2. The distance between the electrode wire 1 and the metal plate 5 is 30 cm. The spinning voltage is 27-32 kV. The reciprocating speed of the brush bath 2 is 100-300 mm / s. The rotation speed of the winding roller 4 is 1.5-2.0 m / min. The infrared lamp strip is kept on with a power of 300 W to obtain the aqueous micro-nano functional fabric.

[0049] S4. The water-based micro-nano functional fabric is hot-pressed at a temperature of 175℃, a pressure of 60 MPa, and a time of 2 min to obtain a needle-free electrode electrospun water-based micro-nano functional fabric.

[0050] Example 3 A method for preparing a needle-free electrode electrospun aqueous micro / nano functional fabric includes the following steps: S1. Dissolve 7.5 g PVA (molecular weight 86,000) and 0.5 g nano silver ions in 92 g deionized water and stir until completely dissolved to obtain PVA spinning solution.

[0051] S2. Dissolve 15 g of water-soluble TPU in 85 g of deionized water and stir until completely dissolved to obtain a TPU solution. Mix the TPU solution with the PVA spinning solution at a mass ratio of 1:1 and continue to stir magnetically for 1 hour to ensure that the system is uniform and transparent, thus obtaining an aqueous spinning solution that can be directly used for electrospinning.

[0052] S3. Place the aqueous spinning solution into the brush bath 2. The distance between the electrode wire 1 and the metal plate 5 is 25 cm. The spinning voltage is 25-30 kV. The reciprocating speed of the brush bath 2 is 100-300 mm / s. The rotation speed of the winding roller 4 is 1.0-1.5 m / min. The infrared lamp strip is kept on with a power of 300 W to obtain the aqueous micro-nano functional fabric.

[0053] S4. Hot-press the water-based micro-nano functional fabric at a temperature of 180℃, a pressure of 50 MPa, and a time of 2 min to obtain a needle-free electrode electrospun water-based micro-nano functional fabric.

[0054] Example 4 A method for preparing a needle-free electrode electrospun aqueous micro / nano functional fabric includes the following steps: S1. Dissolve 7.5 g PVA (molecular weight 86,000) and 0.5 g topotidine (Tinosorb S) in 92 g deionized water and stir until completely dissolved to obtain PVA spinning solution.

[0055] S2. Dissolve 15 g of water-soluble TPU in 85 g of deionized water and stir until completely dissolved to obtain a TPU solution. Mix the TPU solution with the PVA spinning solution at a mass ratio of 1:1 and continue to stir magnetically for 1 hour to ensure that the system is uniform and transparent, thus obtaining an aqueous spinning solution that can be directly used for electrospinning.

[0056] S3. Place the aqueous spinning solution into the brush bath 2. The distance between the electrode wire 1 and the metal plate 5 is 30 cm. The spinning voltage is 27-32 kV. The reciprocating speed of the brush bath 2 is 100-300 mm / s. The rotation speed of the winding roller 4 is 1.5-2.0 m / min. The infrared lamp strip is kept on with a power of 300 W to obtain the aqueous micro-nano functional fabric.

[0057] S4. The water-based micro-nano functional fabric is hot-pressed at a temperature of 175℃, a pressure of 60 MPa, and a time of 2 min to obtain a needle-free electrode electrospun water-based micro-nano functional fabric.

[0058] Comparative Example 1 The steps of Example 1 are followed, except that only the infrared light strip in step S3 is turned off, to obtain a needleless electrode electrospun water-based micro-nano functional fabric.

[0059] The resulting fabric fiber surface does not show clear nanofiber or micro / nano bead structures. Since water evaporates relatively slowly as a solvent, the electrospun structures deposited on the fabric fiber surface are not yet dry and will dissolve into each other, which is not conducive to the uniform distribution and fixation of the electrospun structures on the fabric fibers.

[0060] Comparative Example 2 The steps of Example 1 are followed, except that the power of the infrared lamp strip in step S3 is adjusted to 150 W to obtain a needleless electrode electrospun water-based micro-nano functional fabric.

[0061] The resulting fabric fiber surface shows relatively clear nanofiber or micro / nano bead structures. Due to the incomplete evaporation of some electrospinning jets, the electrospinning structures agglomerate in some places on the fabric, which locally affects the uniformity of the distribution of the electrospinning structures on the fabric fibers.

[0062] The embodiments provided above are not intended to limit the scope of the invention, nor are the described steps intended to limit the order of execution. Any obvious modifications made to the invention by those skilled in the art based on existing common knowledge also fall within the scope of protection defined by the claims.

Claims

1. A needleless electrospinning device for preparing water-based micro / nano functional fabrics, characterized in that, The needleless electrospinning device includes the following components: electrode wire, brush liquid tank, DC high voltage power supply, winding roller, metal plate, and infrared lamp strip. The electrode wire is connected in series with the liquid bath, the electrode wire is connected to the positive terminal of the DC high voltage power supply, a metal plate is placed directly above the electrode wire, the metal plate is connected to the negative terminal of the DC high voltage power supply or grounded, infrared lamps are set on both sides of the spinning chamber, and the winding roller moves between the electrode wire and the metal plate.

2. The needleless electrospinning apparatus according to claim 1, characterized in that, The needleless electrospinning device is equipped with multiple parallel electrode wires, with a spacing of 300-500 mm between two adjacent electrode wires; the distance between the electrode wires and the metal plate is 10-40 cm.

3. A method for preparing a needle-free electrode electrospun aqueous micro / nano functional fabric, characterized in that, Includes the following steps: S1. Dissolve the spinning aid and water-based functional materials in water to obtain a spinning solution; the spinning aid is a water-soluble polymer PEO or PVA, and the water-based functional materials include nano-silver ions and topetidine. S2. Dissolve the water-soluble TPU emulsion in water to obtain a TPU solution, mix the TPU solution with the spinning solution and stir evenly to obtain an aqueous spinning solution; S3. The aqueous spinning solution is loaded into the brushing tank of the needleless electrospinning device described in claim 1 or 2, and then the aqueous micro-nano functional fabric is obtained by electrospinning. The power of the infrared lamp strip during the electrospinning process is 250~400 W. S4. The water-based micro-nano functional fabric is hot-pressed to obtain a needle-free electrode electrospun water-based micro-nano functional fabric.

4. The preparation method according to claim 3, characterized in that, PEO has a molecular weight of 400,000 to 800,000, while PVA has a molecular weight of 50,000 to 100,000.

5. The preparation method according to claim 3, characterized in that, The concentration of the spinning aid in the spinning solution is 1-3 wt%; the concentration of the aqueous functional material in the spinning solution is 0.5-5 wt%.

6. The preparation method according to claim 3, characterized in that, The concentration of the TPU solution is 15-25 wt%; the mass ratio of the TPU solution to the spinning solution is 1:0.5~2.

7. The preparation method according to claim 3, characterized in that, During electrospinning, the reciprocating speed of the brush bath is 100-300 mm / s, and the spinning voltage is 25-35 kV.

8. The preparation method according to claim 3, characterized in that, The hot pressing temperature is 140-200 ℃, the pressure is 30-80 MPa, and the time is 1-3 min.

9. A needle-free electrode electrospun water-based micro / nano functional fabric, characterized in that, The needleless electrode electrospun water-based micro-nano functional fabric is obtained by the preparation method according to any one of claims 3 to 8.

10. The application of the needleless electrode electrospun aqueous micro-nano functional fabric as described in claim 9 in the fields of smart wearables, medical protection and environmentally friendly textiles.

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