A continuous preparation method for high-strength and tough ion-conducting hydrogel fibers

Abstract

This invention discloses a continuous preparation method for high-strength and tough ion-conductive hydrogel fibers. Highly oriented polyvinyl alcohol / sodium alginate / borax composite hydrogel fibers are prepared on a continuous, large-scale basis using wet spinning. These hydrogel fibers possess an interlocking dual-network structure. A rigid borax-crosslinked sodium alginate forms the first network, while physically crosslinked polyvinyl alcohol, constructed through freeze-thaw cycles, forms the second network. The two networks are further crosslinked by borax, significantly improving the mechanical properties of the hydrogel. Simultaneously, the negatively charged sodium alginate promotes ion transport. The hydrogel fibers prepared by this invention exhibit excellent mechanical properties, high ion conductivity, and good biocompatibility, showing promising application prospects in the field of flexible wearable devices.

Description

Technical Field

[0001] This invention relates to the field of hydrogel fiber materials technology, and in particular to a continuous preparation method for high-strength and tough ion-conducting hydrogel fibers. Background Technology

[0002] Flexible wearable electronic devices, with their unique flexibility and extensibility, have broad application prospects in fields such as information, medicine, and energy. Because they will be in close contact with the skin, directly or indirectly, flexible electronic devices must not only adapt to irregular surfaces but also possess excellent breathability and moisture permeability—achievable in thin-film electronic devices. Stretchable conductive fibers are a crucial component of next-generation flexible wearable electronic devices. Compared to traditional thin-film materials, fiber- or textile-based wearable electronic devices can be integrated into clothing using modern weaving techniques such as weaving, knitting, and embroidery. This not only overcomes the poor breathability and moisture permeability issues of thin-film materials but also better meets the requirements of wearable devices.

[0003] Most existing conductive fibers conduct electricity electronically, which has limitations such as poor ductility, opacity, and poor biocompatibility, and their conductivity decreases rapidly when stretched. Ion-conductive hydrogel fibers, on the other hand, possess excellent biocompatibility, softness, and high ionic conductivity and ductility, and are expected to play an important role in the field of flexible wearable electronic devices.

[0004] However, the poor spinnability of hydrogels and their precursor solutions makes it difficult to achieve large-scale preparation of ion-conductive hydrogel fibers through continuous spinning. Wet spinning is an efficient fiber preparation method, but traditional wet spinning is a non-solvent-induced phase separation process for thermoplastic polymers, which is unsuitable for the preparation of covalently cross-linked fibers. This is because the cross-linking reaction usually occurs under stress-free conditions and is a time-consuming process, while spinning is a dynamic process under stretching force. Therefore, most previously reported covalently cross-linked hydrogel fibers were prepared using tubular molds. Some studies have used wet or dry spinning to prepare hydrogel fibers, but the prepared hydrogel fibers have a single-network physical cross-linked structure, resulting in poor mechanical properties, low fatigue stability, and insufficient functionality. Therefore, a continuous, large-scale preparation method for high-strength, high-elongation-deformation, and highly conductive hydrogel fibers is needed.

[0005] Currently, the main methods for preparing one-dimensional hydrogel fibers include wet spinning and wet-dry spinning. For example, Chinese invention patent (CN105040153B) describes a smart hydrogel fiber with dual temperature responses prepared by combining wet spinning with ultraviolet light-initiated free radical polymerization. Ma et al.'s article in *Nature Communications*, "Bioinspired ultra-stretchable and anti-freezing conductive hydrogel fibers with ordered and reversible polymer chain alignment," reports a high-performance and low-cost elastic stretchable conductive hydrogel fiber that can be used to develop stretchable electronic devices based on textile materials. Yun et al.'s article in *Advanced Materials*, "Highly stretchable, strain sensing hydrogel optical fibers," describes a method where an aqueous solution of crosslinking agent, initiator, and monomer is filled into a silicone tube mold and crosslinked under ultraviolet radiation at 50°C in a nitrogen atmosphere to obtain covalently crosslinked hydrogel fibers. Ran et al., in their article "High-strength, highly conductive and woven organic hydrogel fibers for flexible electronics" published in the Chemical Engineering Journal, prepared high-strength, highly conductive, and woven organic hydrogel fibers by injecting a defoamed solution of polyvinyl alcohol and temperature-sensitive particles into PVC pipes and repeating the freeze-thaw cycle three times. However, none of these methods can effectively produce hydrogel fibers continuously.

[0006] Zhang et al. published an article in ACS Applied Materials & Interfaces entitled "Wearable and robust polyimide hydrogel fiber textiles for strain sensors," which describes the preparation of polyimide hydrogel fibers via continuous wet spinning using calcium chloride aqueous solution as the coagulation bath. These hydrogel fibers exhibit excellent chemical stability. Chinese Invention Patent (CN104652119A) describes the preparation of a double-network hydrogel fiber by combining natural polysaccharides and acrylamide polymers through wet spinning, dry-wet spinning, or gel spinning combined with radiation crosslinking. Chinese Invention Patent (CN115287777A) describes a high-strength, self-healing, conductive hydrogel fiber modified with polydopamine and polypyrrole polyvinyl alcohol using a wet spinning method with chemical and physical crosslinking. This fiber has a maximum tensile strength of 2.54 MPa, an elongation at break of 500%, and an electrical conductivity of 0.71 Sm. -1 It also possesses good water retention and freeze resistance. Wang et al., in their article "Stretchable, self-healing, conductive hydrogel fibers for strainsensing and triboelectric energy-harvesting smart textiles" published in the journal *Nano Energy*, utilized the thermally reversible sol-gel transition properties of physically crosslinked poly(N-acryloylglycine-acrylamide) (PNA) hydrogels to prepare a stretchable, conductive, and self-healing hydrogel fiber using continuous wet-dry spinning. The fiber exhibits a maximum tensile strength of 2.27 MPa, an elongation at break of 900%, and an electrical conductivity of 0.69 Sm. -1 It also has good self-healing capabilities. Summary of the Invention

[0007] Purpose of the invention: This invention aims to overcome the problems of poor mechanical properties and difficulty in large-scale preparation of hydrogel fibers through continuous spinning. It provides a continuous preparation method for high-strength and tough ion-conductive hydrogel fibers, enabling the continuous large-scale preparation of high-strength, high-elongation, and highly conductive hydrogel fibers. This results in polyvinyl alcohol / sodium alginate / borax composite hydrogel fibers with excellent mechanical properties and ion conductivity, which can be widely used in the field of intelligent sensing.

[0008] Technical solution: A continuous preparation method for high-strength and tough ion-conducting hydrogel fibers, comprising the following steps:

[0009] 1) Raw material preparation: Take a certain amount of polyvinyl alcohol granules, add deionized water, and dissolve at 90℃ for 2 hours to obtain a polyvinyl alcohol solution; while stirring, add sodium alginate powder to deionized water, let stand for 3 hours, and after the sodium alginate has fully swollen, continue stirring for 2 hours to obtain a sodium alginate solution.

[0010] 2) Preparation of spinning solution: Add the sodium alginate solution obtained in step 1) to the polyvinyl alcohol solution obtained in step 1), and then add a certain amount of borax while stirring. Stir at 90°C for 2 hours. After complete dissolution, a mixed solution is obtained. Centrifuge the mixed solution at low speed and degas to obtain the spinning solution.

[0011] 3) Spinning and forming: The spinning solution obtained in step 2) is extruded through the needle of a syringe, and the resulting filaments are solidified and formed in a coagulation bath under the drive of the spinning roller to obtain hydrogel fiber semi-finished product.

[0012] 4) Post-processing: The hydrogel fiber semi-finished product obtained in step 3) is subjected to freeze-thaw treatment to obtain polyvinyl alcohol / sodium alginate / borax composite hydrogel fiber.

[0013] It should be noted that in step 3), the borate ester bond formed by the reaction of borax with the hydroxyl groups of sodium alginate / polyvinyl alcohol exhibits a pH-reversible response; the cross-linking reaction occurs at high pH, ​​while the reaction is reversed at low pH, resulting in de-cross-linking. The prepared sodium alginate / polyvinyl alcohol / borax spinning solution has a neutral pH value. At this pH, the reaction between borax and sodium alginate and polyvinyl alcohol is relatively slow, resulting in excellent fluidity of the spinning solution, which is suitable for spinning.

[0014] Further, in step 1), the degree of polymerization of the polyvinyl alcohol particles is 1700, and the degree of alcoholysis is 99 (mol)%.

[0015] Further, in step 1), the concentration of the polyvinyl alcohol solution is 25 wt%.

[0016] Further, in step 1), the concentration of the sodium alginate solution is 1wt%-6wt%.

[0017] Further, in step 2), the mass ratio of the sodium alginate solution to the polyvinyl alcohol solution is 1:1.

[0018] Further, in step 2), the polyvinyl alcohol concentration in the spinning solution is 12.5 wt%.

[0019] Furthermore, in step 2), the concentration of borax in the spinning solution is 0.25 wt%.

[0020] Further, in step 2), the concentration of sodium alginate in the spinning solution is 0.5wt%-3wt%.

[0021] Further, in step 3), the coagulation bath is a sodium hydroxide solution with a mass percentage concentration of 5 wt%. When the spun fibers pass through the coagulation bath with 5 wt% sodium hydroxide, the high pH value induces borax crosslinking, forming interlocked double-crosslinked hydrogel fibers. If the sodium hydroxide concentration is too low, the spun fibers will not coagulate well, and the hydrogel fibers will easily break.

[0022] Furthermore, in step 4), the freeze-thaw process involves freezing at -20°C for 24 hours and then thawing at room temperature for 2 hours.

[0023] Beneficial effects:

[0024] 1) This invention utilizes the reversible pH response characteristics of dynamic borate ester bonds to prepare highly oriented polyvinyl alcohol / sodium alginate / borax composite hydrogel fibers by wet spinning, thereby achieving continuous large-scale preparation of hydrogel fibers and overcoming the problem of low preparation efficiency of covalently cross-linked hydrogel fibers using tubular molds.

[0025] 2) The polyvinyl alcohol / sodium alginate / borax composite hydrogel fiber prepared by this invention has an interlocking double network structure. Rigid borax-crosslinked sodium alginate serves as the first network, and physically crosslinked polyvinyl alcohol constructed through freeze-thaw cycles serves as the second network. The two networks are further crosslinked through borax, which significantly improves the mechanical properties of the hydrogel. At the same time, the negatively charged sodium alginate promotes ion transport. The polyvinyl alcohol / sodium alginate / borax composite hydrogel fiber prepared by this invention has excellent mechanical properties and ionic conductivity, overcoming the problems of poor mechanical properties and low fatigue stability of single-network hydrogel fibers.

[0026] 3) The spinning process of this invention does not involve the use of any organic solvents, making it more environmentally friendly; the raw materials used in this invention, polyvinyl alcohol and sodium alginate, both have good biocompatibility, and the prepared interlocked double network ion-conductive hydrogel fiber has good biocompatibility and excellent strain response performance, and has good application prospects in the field of flexible wearable devices (such as flexible sensors and smart fabrics). Attached Figure Description

[0027] Figure 1 This is a schematic diagram illustrating the preparation of the interlocked dual-network structure hydrogel fiber of the present invention;

[0028] Figure 2 Fourier transform infrared (FTIR) spectra of polyvinyl alcohol, sodium alginate, borax, sodium alginate / borax hydrogel, polyvinyl alcohol / borax hydrogel fiber and polyvinyl alcohol / borax / sodium alginate hydrogel fiber;

[0029] Figure 3The graph shows a comparison of (a) mechanical properties and (b) electrical conductivity of hydrogel fibers prepared by spinning solutions with different sodium alginate contents in Examples 1-4. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] It should be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and / or processing steps closely related to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0032] In the following embodiments, unless otherwise specified, the raw materials or processing techniques used are conventional commercially available raw materials or conventional processing techniques in the art.

[0033] Example 1

[0034] (1) Raw material preparation

[0035] Take a certain amount of polyvinyl alcohol particles with a degree of polymerization of 1700 and a degree of alcoholysis of 99 (mol)%, add deionized water, dissolve at 90℃ for 2 hours, and prepare a homogeneous and transparent solution with a concentration of 25wt% for later use.

[0036] While stirring, add sodium alginate powder to deionized water, let stand for 3 hours, and after the sodium alginate has fully swollen, continue stirring for 2 hours. The sodium alginate content is 1 wt%.

[0037] (2) Preparation of spinning solution

[0038] Add sodium alginate solution to polyvinyl alcohol solution at a mass ratio of 1:1, then add the required amount of borax while stirring. Stir at 90°C for 2 hours until completely dissolved to obtain a polyvinyl alcohol / sodium alginate / borax mixed solution, wherein the borax content is 0.25wt%.

[0039] Then, the polyvinyl alcohol / sodium alginate / borax mixed solution was centrifuged at low speed and degassed to obtain the spinning solution;

[0040] The polyvinyl alcohol concentration in the above spinning solution is 12.5 wt%, the borax concentration is 0.25 wt%, and the sodium alginate concentration is 0.5 wt%.

[0041] (3) Spinning and forming

[0042] The obtained spinning solution is extruded through the needle of a syringe, and the resulting filaments are solidified in a coagulation bath under the drive of the spinning rollers to obtain a semi-finished product of polyvinyl alcohol / sodium alginate / borax composite hydrogel fiber.

[0043] The coagulation bath described above is a sodium hydroxide solution with a mass percentage concentration of 5 wt%.

[0044] (4) Post-processing

[0045] The above-mentioned fiber semi-finished product was further frozen at -20℃ for 24 hours, and then thawed at room temperature for 2 hours to finally obtain polyvinyl alcohol / sodium alginate / borax composite hydrogel fiber.

[0046] The polyvinyl alcohol / sodium alginate / borax composite hydrogel fiber prepared in Example 1 has a tensile strength of 2.63 MPa, an elongation at break of 2073%, and an electrical conductivity of 8.02 Sm. -1 .

[0047] Example 2

[0048] (1) Raw material preparation

[0049] Take a certain amount of polyvinyl alcohol particles with a degree of polymerization of 1700 and a degree of alcoholysis of 99 (mol)%, add deionized water, dissolve at 90℃ for 2 hours, and prepare a homogeneous and transparent solution with a concentration of 25wt% for later use.

[0050] Add sodium alginate powder to deionized water while stirring, let stand for 3 hours, and after the sodium alginate has fully swollen, continue stirring for 2 hours. The sodium alginate content is 2wt%. Set aside for later use.

[0051] (2) Preparation of spinning solution

[0052] Add sodium alginate solution to polyvinyl alcohol solution at a mass ratio of 1:1, then add the required amount of borax while stirring. Stir at 90°C for 2 hours until completely dissolved to obtain a polyvinyl alcohol / sodium alginate / borax mixed solution, wherein the borax content is 0.25wt%.

[0053] Then, the polyvinyl alcohol / sodium alginate / borax mixed solution was centrifuged at low speed and degassed to obtain the spinning solution;

[0054] The polyvinyl alcohol concentration in the above spinning solution is 12.5 wt%, the borax concentration is 0.25 wt%, and the sodium alginate concentration is 1 wt%.

[0055] (3) Spinning and forming

[0056] The obtained spinning solution is extruded through the needle of a syringe, and the resulting filaments are solidified in a coagulation bath under the drive of the spinning rollers to obtain a semi-finished product of polyvinyl alcohol / sodium alginate / borax composite hydrogel fiber.

[0057] The coagulation bath described above is a sodium hydroxide solution with a mass percentage concentration of 5 wt%.

[0058] (4) Post-processing

[0059] The above-mentioned fiber semi-finished product was further frozen at -20℃ for 24 hours, and then thawed at room temperature for 2 hours to finally obtain polyvinyl alcohol / sodium alginate / borax composite hydrogel fiber.

[0060] The polyvinyl alcohol / sodium alginate / borax composite hydrogel fiber prepared in Example 2 has a tensile strength of 2.90 MPa, an elongation at break of 1921%, and an electrical conductivity of 10.51 S m. -1 .

[0061] Example 3

[0062] (1) Raw material preparation

[0063] Take a certain amount of polyvinyl alcohol particles with a degree of polymerization of 1700 and a degree of alcoholysis of 99 (mol)%, add deionized water, dissolve at 90℃ for 2 hours, and prepare a homogeneous and transparent solution with a concentration of 25wt% for later use.

[0064] Add sodium alginate powder to deionized water while stirring, let stand for 3 hours, and after the sodium alginate has fully swollen, continue stirring for 2 hours. The sodium alginate content is 4 wt%. Set aside for later use.

[0065] (2) Preparation of spinning solution

[0066] Add sodium alginate solution to polyvinyl alcohol solution at a mass ratio of 1:1, then add the required amount of borax while stirring. Stir at 90°C for 2 hours until completely dissolved to obtain a polyvinyl alcohol / sodium alginate / borax mixed solution, wherein the borax content is 0.25wt%.

[0067] Then, the polyvinyl alcohol / sodium alginate / borax mixed solution was centrifuged at low speed and degassed to obtain the spinning solution;

[0068] The polyvinyl alcohol concentration in the above spinning solution is 12.5 wt%, the borax concentration is 0.25 wt%, and the sodium alginate concentration is 2 wt%.

[0069] (3) Spinning and forming

[0070] The obtained spinning solution is extruded through the needle of a syringe, and the resulting filaments are solidified in a coagulation bath under the drive of the spinning rollers to obtain a semi-finished product of polyvinyl alcohol / sodium alginate / borax composite hydrogel fiber.

[0071] The coagulation bath described above is a sodium hydroxide solution with a mass percentage concentration of 5 wt%.

[0072] (4) Post-processing

[0073] The above-mentioned fiber semi-finished product was further frozen at -20℃ for 24 hours, and then thawed at room temperature for 2 hours to finally obtain polyvinyl alcohol / sodium alginate / borax composite hydrogel fiber.

[0074] The polyvinyl alcohol / sodium alginate / borax composite hydrogel fiber prepared in Example 3 has a tensile strength of 3.83 MPa, an elongation at break of 1701%, and an electrical conductivity of 14.67 Sm. -1 .

[0075] Example 4

[0076] (1) Raw material preparation

[0077] Take a certain amount of polyvinyl alcohol particles with a degree of polymerization of 1700 and a degree of alcoholysis of 99 (mol)%, add deionized water, dissolve at 90℃ for 2 hours, and prepare a homogeneous and transparent solution with a concentration of 25wt% for later use.

[0078] While stirring, add sodium alginate powder to deionized water, let stand for 3 hours, and after the sodium alginate has fully swollen, continue stirring for 2 hours. The sodium alginate content is 6 wt%. Set aside for later use.

[0079] (2) Preparation of spinning solution

[0080] Add sodium alginate solution to polyvinyl alcohol solution at a mass ratio of 1:1, then add the required amount of borax while stirring. Stir at 90°C for 2 hours until completely dissolved to obtain a polyvinyl alcohol / sodium alginate / borax mixed solution, wherein the borax content is 0.25wt%.

[0081] Then, the polyvinyl alcohol / sodium alginate / borax mixed solution was centrifuged at low speed and degassed to obtain the spinning solution; the polyvinyl alcohol concentration in the above spinning solution was 12.5wt%, the borax concentration was 0.25wt%, and the sodium alginate concentration was 3wt%.

[0082] (3) Spinning and forming

[0083] The obtained spinning solution is extruded through the needle of a syringe, and the resulting filaments are solidified in a coagulation bath under the drive of the spinning rollers to obtain a semi-finished product of polyvinyl alcohol / sodium alginate / borax composite hydrogel fiber.

[0084] The coagulation bath described above is a sodium hydroxide solution with a mass percentage concentration of 5 wt%.

[0085] (4) Post-processing

[0086] The above-mentioned fiber semi-finished product was further frozen at -20℃ for 24 hours, and then thawed at room temperature for 2 hours to finally obtain polyvinyl alcohol / sodium alginate / borax composite hydrogel fiber.

[0087] The polyvinyl alcohol / sodium alginate / borax composite hydrogel fiber prepared in Example 4 has a tensile strength of 4.39 MPa, an elongation at break of 1488%, and an electrical conductivity of 17.98 S / m. -1 .

[0088] like Figure 1 As shown, Figure 1 This is a schematic diagram of the preparation of the interlocked dual-network structure hydrogel fiber of the present invention. (1), (2), and (3) show the evolution of the polymer crosslinking network structure at different stages during the preparation of the hydrogel fiber, including: (1) spinning solution, (2) borax-crosslinked fiber, and (3) interlocked dual-network fiber. During spinning, through the reversible pH response characteristics of the dynamic borax ester bond, under the shear force during extrusion, polyvinyl alcohol and sodium alginate molecules are oriented along the hydrogel fiber axis, preparing highly oriented polyvinyl alcohol / algae composite hydrogel fibers. This hydrogel fiber has an interlocked dual-network structure, with rigid borax-crosslinked sodium alginate (SA) as the first network and physically crosslinked polyvinyl alcohol (PVA) constructed through freeze-thaw cycles as the second network. The two networks are further crosslinked through borax, significantly improving the mechanical properties of the hydrogel; simultaneously, the negatively charged sodium alginate promotes ion transport.

[0089] like Figure 2 As shown, Figure 2 Fourier transform infrared (FTIR) spectra of polyvinyl alcohol (PVA), sodium alginate (SA), borax, sodium alginate / borax hydrogel (BS), polyvinyl alcohol / borax hydrogel fiber (PB), and polyvinyl alcohol / borax / sodium alginate hydrogel fiber (PBS) are shown. It can be seen that 1451 cm⁻¹ was found in borax, borax / sodium alginate hydrogel, polyvinyl alcohol / borax hydrogel fiber, and polyvinyl alcohol / borax / sodium alginate hydrogel fiber. -1 and 1346cm -1 The two characteristic peaks, attributed to the asymmetric stretching and relaxation peaks of BOC, indicate that borate ester bonds have been successfully introduced into the hydrogel system, and that borax can form covalent cross-linked structures with sodium alginate and polyvinyl alcohol. These results verify that the polyvinyl alcohol / sodium alginate / borax composite hydrogel fibers form an interlocking double-network structure cross-linked by borate ester bonds.

[0090] like Figure 3 As shown, Figure 3 Example 1 (PBS) is shown. 0.5Examples 1, 2 (PBS1), 3 (PBS2), and 4 (PBS3) are described below. The mechanical properties and electrical conductivity (a) of hydrogel fibers prepared using spinning solutions with different sodium alginate contents (0.5 wt%, 1 wt%, 2 wt%, and 3 wt%) are presented. It can be seen that with increasing sodium alginate content, the tensile strength of the hydrogel fibers gradually increases, the elongation at break gradually decreases, and the electrical conductivity gradually increases. Comparison shows that when the sodium alginate concentration is 3 wt%, the polyvinyl alcohol / sodium alginate / borax composite hydrogel fiber prepared exhibits the best overall electromechanical properties, with a tensile strength reaching 4.31 MPa, an elongation at break reaching 1487%, and an electrical conductivity reaching 17.98 S / m. -1 .

[0091] The above-described specific embodiments have the following beneficial effects compared to the prior art:

[0092] 1) This invention utilizes the reversible pH response characteristics of dynamic borate ester bonds to prepare highly oriented polyvinyl alcohol / sodium alginate / borax composite hydrogel fibers by wet spinning, thereby achieving continuous large-scale preparation of hydrogel fibers and overcoming the problem of low preparation efficiency of covalently cross-linked hydrogel fibers using tubular molds.

[0093] 2) The polyvinyl alcohol / sodium alginate / borax composite hydrogel fiber prepared by this invention has an interlocking double network structure. Rigid borax-crosslinked sodium alginate serves as the first network, and physically crosslinked polyvinyl alcohol constructed through freeze-thaw cycles serves as the second network. The two networks are further crosslinked through borax, which significantly improves the mechanical properties of the hydrogel. At the same time, the negatively charged sodium alginate promotes ion transport. The polyvinyl alcohol / sodium alginate / borax composite hydrogel fiber prepared by this invention has excellent mechanical properties and ionic conductivity, overcoming the problems of poor mechanical properties and low fatigue stability of single-network hydrogel fibers.

[0094] 3) The spinning process of this invention does not involve the use of any organic solvents, making it more environmentally friendly; the raw materials used in this invention, polyvinyl alcohol and sodium alginate, both have good biocompatibility, and the prepared interlocked double network ion-conductive hydrogel fiber has good biocompatibility and excellent strain response performance, and has good application prospects in the field of flexible wearable devices (such as flexible sensors and smart fabrics).

[0095] Although the present invention has been illustrated and described with reference to preferred embodiments, those skilled in the art should understand that various changes and modifications can be made to the present invention without departing from the scope defined by the claims.

Claims

1. A continuous preparation method for high-strength and tough ion-conducting hydrogel fibers, characterized in that, Includes the following steps: 1) Raw material preparation: Take a certain amount of polyvinyl alcohol granules, add deionized water, and dissolve at 90℃ for 2 hours to obtain a polyvinyl alcohol solution; while stirring, add sodium alginate powder to deionized water, let stand for 3 hours, and after the sodium alginate has fully swollen, continue stirring for 2 hours to obtain a sodium alginate solution. 2) Preparation of spinning solution: Add the sodium alginate solution obtained in step 1) to the polyvinyl alcohol solution obtained in step 1), and then add a certain amount of borax while stirring. Stir at 90°C for 2 hours. After complete dissolution, a mixed solution is obtained. Centrifuge the mixed solution at low speed and degas to obtain the spinning solution. 3) Spinning and forming: The spinning solution obtained in step 2) is extruded through the needle of a syringe, and the resulting filaments are solidified and formed in a coagulation bath under the drive of the spinning roller to obtain hydrogel fiber semi-finished product. 4) Post-processing: The hydrogel fiber semi-finished product obtained in step 3) is subjected to freeze-thaw treatment to obtain polyvinyl alcohol / sodium alginate / borax composite hydrogel fiber.

2. The method according to claim 1, characterized in that, In step 1), the degree of polymerization of the polyvinyl alcohol particles is 1700, and the degree of alcoholysis is 99 (mol)%.

3. The method according to claim 1, characterized in that, In step 1), the concentration of the polyvinyl alcohol solution is 25 wt%.

4. The method according to claim 1, characterized in that, In step 1), the concentration of the sodium alginate solution is 1wt%-6wt%.

5. The method according to claim 1, characterized in that, In step 2), the mass ratio of the sodium alginate solution to the polyvinyl alcohol solution is 1:

1.

6. The method according to claim 1, characterized in that, In step 2), the polyvinyl alcohol concentration in the spinning solution is 12.5 wt%.

7. The method according to claim 1, characterized in that, In step 2), the concentration of borax in the spinning solution is 0.25 wt%.

8. The method according to claim 1, characterized in that, In step 2), the concentration of sodium alginate in the spinning solution is 0.5wt%-3wt%.

9. The method according to claim 1, characterized in that, In step 3), the coagulation bath is a sodium hydroxide solution with a mass percentage concentration of 5 wt%.

10. The method according to claim 1, characterized in that, In step 4), the freeze-thaw process involves freezing at -20°C for 24 hours and then thawing at room temperature for 2 hours.

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