Heterogeneous segmented fiber and preparation method thereof

Abstract

This invention provides a heterogeneous segmented fiber that successfully integrates multiple materials into a single fiber. This fiber differs from traditional homogeneous fibers by enabling the independent integration of multiple materials with different or even opposing functions into a single fiber while maintaining fiber continuity, creating a series of heterogeneous structural fibers and novel multifunctional fibers. The multi-material heterogeneous segmented fibers prepared by this invention possess functions encompassing mechanical, electrical, magnetic, optical, and thermal properties, significantly enriching the variety and performance of multifunctional fibers, promoting their development, and providing new insights into the design and development of smart fabrics and fiber-based electronic devices.

Description

Technical Field

[0001] The present invention belongs to the field of material technology, and in particular relates to a heterogeneous segmented fiber and a preparation method thereof. Background Art

[0002] With the advancement of science and technology and the development of the times, people's demand for fiber materials is increasing to achieve more functions. Compared with traditional fibers with only a single function, functional fibers can often integrate multiple functions and are a more ideal carrier for realizing people's demand for smart fabrics. Usually, functional fibers need to integrate multiple functional layers with different performances into a single fiber to achieve a combination of performances. For example, fiber electronic devices need to composite electrodes and electrical functional layers to prepare corresponding electronic devices. Since fiber materials usually undergo certain loads and deformations during use, the composite multifunctional structure needs to ensure the continuity of the fiber. At the same time, considering the development trend of high array and integration of fiber electronic devices, the importance of improving the functional layer integration process is self-evident. Limited by the above two points, the design of fiber axial heterogeneous block structure is often ignored.

[0003] Because fibers have a large aspect ratio (typically greater than 300), their radial design is limited by size, but they offer extensive freedom along their length to enable multifunctional integration. However, effective methods for large-scale design of fiber functionality along its length remain lacking, primarily due to the continuity and complexity of the fiber spinning process.

[0004] Currently, there is still a lack of a universal method for accurately producing fibers with segmented structures. While post-processing homogeneous fibers can achieve segmented structures, these methods are complex, time-consuming, and labor-intensive, making them impractical for large-scale production. Therefore, the large-scale production of heterogeneous fibers with continuous segmented structures using existing spinning technologies remains a challenge.

[0005] Existing technologies enable microfluidic chip technology to control the convergence and outflow of fluids. Because the Reynolds number of fluids in microscale channels is low, the flow tends to be laminar. Therefore, if microfluidics can effectively design the selective flow of spinning solutions, combined with a universal wet spinning system compatible with a wide range of material options, the design and large-scale production of segmented fibers is possible. Summary of the Invention

[0006] The purpose of the present invention is to overcome the shortcomings of the existing technology and provide a heterogeneous block fiber that successfully integrates multiple materials into a single fiber in the form of blocks, making the fiber different from traditional homogeneous fibers. Multiple materials with different or even opposite functions can be independently integrated into a single fiber while maintaining the continuity of the fiber, creating a series of new concept multifunctional fibers.

[0007] Specifically, the heterogeneous segmented fiber described in the present invention includes at least a first fiber segment composed of a first material and a second fiber segment composed of a second material, the first fiber segment and the second fiber segment are continuous, and the first material and the second material are heterogeneous, the length of the first fiber segment and the second fiber segment ranges from 740 μm to more; and the fiber diameter ranges from 20 to 300 μm.

[0008] In some preferred embodiments of the present invention, there is a transition section between the first fiber segment and the second fiber segment. The transition section is a mixture of the first material and the second material, which can ensure close bonding between the first material and the second material segments, thereby maintaining the continuity of the fiber.

[0009] The first material and the second material are pure substances or mixtures. The "heterogeneous" mentioned in the present invention refers to materials that are not completely the same, including but not limited to different substances, different compositions, and different crystal structures or physical states of the same substance;

[0010] In certain embodiments of the present invention, the first material and the second material are selected from one or more of sodium polyacrylate, polyacrylamide, carboxymethyl cellulose, sodium alginate, polyvinyl alcohol, polyacrylonitrile, polyvinyl pyrrolidone, polylactic acid, polyester, polystyrene, polyvinylidene fluoride, polymethyl methacrylate, polyurethane, carbon nanotubes, metal carbide, and graphene oxide.

[0011] In some preferred embodiments of the present invention, the first material and the second material have the same matrix component; and at least one of the first material and the second material contains a functional modifier.

[0012] The matrix component is one or more of sodium polyacrylate, polyacrylamide, carboxymethyl cellulose, sodium alginate, polyvinyl alcohol, polyacrylonitrile, polyvinyl pyrrolidone, polylactic acid, polyester, polystyrene, polyvinylidene fluoride, polymethyl methacrylate, and polyurethane.

[0013] The functional modifier is a conductive modifier, a ferromagnetic modifier, a diamagnetic modifier, an infrared absorbing modifier, an infrared reflecting modifier, or a mechanical strengthening modifier;

[0014] The conductive modifier is one or more of graphene, metal carbide, and carbon nanotubes;

[0015] The ferromagnetic modifier is one or more of iron oxide and ferrosoferric oxide;

[0016] The antimagnetic modifier is: aluminum oxide;

[0017] The infrared absorption modifier is one or more of graphene and graphene oxide;

[0018] The infrared reflection modifier is: titanium dioxide;

[0019] The mechanical enhancement modifier is one or more of graphene, carbon nanotubes, and silicate nanosheets.

[0020] Therefore, based on the above functional modification, each fiber segment in the fiber can have different functions, which can give the fiber adjustable properties along the length and realize the integration of multiple applications in a single fiber, including but not limited to the following situations:

[0021] (1) The first material is polyurethane mixed with graphene, metal carbide or carbon nanotubes; the second material is polyurethane; polyurethane fibers forming a conductive-insulating sequence (polyurethane can be replaced with other polymers or polymer combinations).

[0022] (2) The first material is a hard polyurethane mixed with graphene, carbon nanotubes or silicate nanosheets; the second material is a soft polyurethane; and polyurethane fibers are formed in a high tensile modulus-low tensile modulus sequence.

[0023] (3) The first material is: polyurethane mixed with iron oxide or tetraoxide; the second material is: aluminum oxide polyurethane; polyurethane fibers forming a ferromagnetic-diamagnetic sequence (polyurethane can be replaced with other polymers or polymer combinations).

[0024] (4) The first material is: polyurethane mixed with graphene or graphene oxide; the second material is: titanium dioxide polyurethane; forming infrared absorption-infrared reflection polyurethane fiber (polyurethane can be replaced with other polymers or polymer combinations).

[0025] Certain preferred embodiments of the present invention further include a third fiber segment composed of a third material, wherein the first, second, and third fiber segments are arranged in a continuous sequence, and the mechanical properties of the first, second, and third fiber segments are gradually enhanced. Fibers with gradually enhanced mechanical properties enable step-by-step strain control, resolving the significant difference in modulus and mechanical behavior between electronic devices and human tissue, providing a new approach for the application of smart fabrics capable of integrating electronic devices.

[0026] The present invention also relates to a method for preparing the aforementioned fiber, comprising sequentially injecting a first spinning solution and a second spinning solution into an extrusion channel, and sequentially extruding the fibers through the channel to form continuous first and second fiber segments. The fiber diameter can be controlled by adjusting the diameter of the extrusion channel. In an embodiment of the present invention, by controlling the diameter of the extrusion channel, the resulting fiber diameter is between 20 and 300 μm.

[0027] The present invention can control the injection amounts of the first spinning solution and the second spinning solution through a controller, thereby controlling the lengths of the first fiber block and the second fiber block.

[0028] In some preferred embodiments of the present invention, the extrusion channel is located on a microfluidic chip. For example, a multi-channel microfluidic chip is used in combination with a program-controlled electromagnetic valve. First, the required spinning solution is prepared and marked with a dye. The microfluidic chip is placed vertically, and the chip outlet is immersed in a coagulation bath. The syringe is connected to the electromagnetic valve, and then connected to the inlet of the microfluidic chip through a one-way valve. The syringe is pushed by an injection pump to push the spinning solution into the electromagnetic valve; the opening and closing of the spinning channel is controlled by the opening and closing of the electromagnetic valve, so that the spinning solution selectively circulates; after passing through the one-way valve, the spinning solution forms a block structure in the microfluidic chip and flows out, and is solidified in the coagulation bath to form a fiber with a block structure.

[0029] Furthermore, the microfluidic chip is made of polydimethylsiloxane or glass and has at least two channel inlets and one main outlet.

[0030] Furthermore, the microfluidic chip has a two to five channel structure.

[0031] Furthermore, the microfluidic chip has a flow channel width ranging from 50 to 1000 μm and a depth ranging from 50 to 500 μm.

[0032] For a spinning solution suitable for wet spinning, the first and second spinning solutions are extruded through an extrusion channel, coagulated in a coagulation bath, and dried to form continuous first and second fiber blocks. For example, the first spinning solution may be an aqueous sodium polyacrylate solution, the second material may be an aqueous polyacrylamide solution, and the coagulation bath may be an aqueous calcium chloride solution.

[0033] For spinning solutions suitable for dry spinning, the first and second spinning solutions are extruded through an extrusion channel, and the solvents are evaporated to form continuous first and second fiber blocks. For example, the first spinning solution may be a polyvinyl pyrrolidone ethanol solution, and the second material may be a polyethylene oxide ethanol solution. An infrared lamp is placed at the extrusion port to rapidly evaporate the solvent from the fiber blocks.

[0034] For spinning solutions suitable for in-situ polymerization spinning, the first and second spinning solutions are extruded through an extrusion channel and then polymerized to form the continuous first and second fiber blocks. For example, the first spinning solution is an aqueous solution of acrylamide monomer, UV photoinitiator, and crosslinker, while the second material is an aqueous solution of N-isopropylacrylamide monomer, UV photoinitiator, and crosslinker. A UV lamp is placed at the extrusion port, and in-situ polymerization is performed under a nitrogen atmosphere to form segmented gel fibers. The resulting segmented fibers exhibit localized temperature-driven responsiveness and have promising applications in flexible robotics.

[0035] For spinning solutions suitable for freeze forming, the first and second spinning solutions are extruded through an extrusion channel and then coagulated at low temperature to form the continuous first and second fiber blocks. For example, the first spinning solution is a polyvinyl alcohol aqueous solution, and the second material is a polyvinyl alcohol / graphene aqueous solution. The extrusion port is connected to a long polytetrafluoroethylene tube and placed in a -20°C environment to freeze and coagulate the segmented fibers.

[0036] For spinning solutions suitable for high-temperature crosslinking, the first and second spinning solutions are extruded through an extrusion channel, where reactive components crosslink at high temperatures to form the continuous first and second fiber blocks. For example, the first spinning solution may be a polydimethylsiloxane precursor mixed solution, and the second material may be a polydimethylsiloxane precursor / graphene mixed solution. The extruder is then placed in 200°C silicone oil for thermal crosslinking to form the segmented fibers.

[0037] The above selection of spinning solution is not substantially different from the selection of spinning solution in the existing spinning method.

[0038] The present invention has the beneficial effect of enabling fiber segmentation, which frees fibers from the single performance limitations of traditional homogeneous fibers. This allows for the integration of multiple materials and functions into a single fiber, meeting the growing demand for heterogeneous materials and functional fabrics. The preparation method provided by the present invention is simple to operate and automated, enabling the sophisticated design of heterogeneous fiber segmentation structures and the integration of multiple materials into a single fiber. This provides a new approach for the large-scale preparation of highly arrayed and high-density segmented heterogeneous fibers. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a diagram of the microfluidic chip during the preparation process of Example 1.

[0040] Figure 2 This is the morphology of the two-block fiber prepared in Example 1.

[0041] Figure 3 This is a picture of the soft segment-hard segment polyurethane fiber prepared in Example 14.

[0042] Figure 4 This is a picture of the ferromagnetic-diamagnetic fiber prepared in Example 16.

[0043] Figure 5 Schematic diagram of the tri-block fiber extrusion device of Example 5. DETAILED DESCRIPTION

[0044] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0045] In order to demonstrate the feasibility of preparing fiber blocks of the present invention, in Examples 1 to 5, pigments were added to the matrix components to form heterogeneous materials. After the heterogeneous materials of different colors were extruded by the present invention, continuous fiber blocks of different colors were obtained. Figure 2 .

[0046] Example 1:

[0047] A dual-channel microfluidic chip was selected as the spinning outlet flow channel, and polyurethane (TPU1180A) was used as the spinning raw material, dissolved in DMF to prepare a 20wt% solution. The spinning solution was divided into two parts and marked with blue and yellow using commercially available dyes.

[0048] A program-controlled microfluidic spinning device was built, which consists of a syringe pump-syringe-solenoid valve-one-way valve-microfluidic chip-coagulation bath-collector. During the spinning process, the syringe pump pushes the syringe to squeeze out the PU spinning solution into the solenoid valve. The corresponding solenoid valve can be opened and closed by a set computer program, and the corresponding spinning channel can selectively flow the required spinning solution. The backflow effect caused by the opening and closing of the solenoid valve is eliminated by the check valve, which can ensure the one-way conduction of the spinning solution. Finally, the blue and yellow spinning solutions converge in the dual-channel microfluidic chip. When the program controls the solenoid valve corresponding to the yellow spinning solution to open and the blue one to close, a yellow polyurethane sequence is obtained, and vice versa. The program controls the two solenoid valves to open and close repeatedly, and a two-block structure with alternating yellow and blue colors is obtained, which is solidified into a two-block structure fiber in a water coagulation bath.

[0049] By adjusting the spinning rate and the corresponding solenoid valve spinning time, the length and proportion of each block can be precisely controlled; by setting the flow channel diameter of the microfluidic chip, the fiber diameter can be controlled.

[0050] The maximum block precision can reach 740 μm (1350 blocks / meter), and the fiber diameter is adjustable between 20 and 300 μm. In this example, under the experimental conditions of a spinning speed of 50 μL / min and a block spinning time of 2 seconds, automated spinning and collection for 10 hours were used to achieve large-scale preparation of segmented fibers.

[0051] Example 2:

[0052] A dual-channel microfluidic chip was used as the spinning outlet channel, and sodium alginate was dissolved in deionized water to prepare a 20 wt% solution. The spinning solution was divided into two parts and marked with blue and yellow using commercially available dyes.

[0053] A program-controlled microfluidic spinning device was constructed, which consists of a syringe pump, syringe, solenoid valve, one-way valve, microfluidic chip, coagulation bath, and collector. During the spinning process, the syringe pump pushes the syringe to squeeze the sodium alginate spinning solution into the solenoid valve. The corresponding solenoid valve can be opened and closed by a pre-set computer program, and the corresponding spinning channel can selectively flow the required spinning solution. The backflow effect caused by the opening and closing of the solenoid valve is eliminated by the check valve, which can ensure the one-way flow of the spinning solution. Ultimately, the blue and yellow spinning solutions converge in the dual-channel microfluidic chip. When the program controls the solenoid valve corresponding to the yellow spinning solution to open and the blue one to close, a yellow polyurethane sequence is obtained, and vice versa, a blue sequence is obtained. The program controls the two solenoid valves to open and close repeatedly, resulting in a two-block structure with alternating yellow and blue colors, which is solidified into a two-block structure fiber in a 5wt% CaCl2 aqueous solution coagulation bath.

[0054] Example 3:

[0055] A dual-channel microfluidic chip was used as the spinning outlet channel, and graphene oxide was dissolved in deionized water to prepare a 1wt% solution. The spinning solution was divided into two parts and marked with commercially available dyes in black and yellow.

[0056] A program-controlled microfluidic spinning device was constructed, consisting of a syringe pump, syringe, solenoid valve, one-way valve, microfluidic chip, coagulation bath, and collector. During the spinning process, the syringe pump pushes the syringe to squeeze the sodium alginate spinning solution into the solenoid valve. The corresponding solenoid valve can be opened and closed by a pre-set computer program, and the corresponding spinning channel can selectively flow the required spinning solution. The backflow effect caused by the opening and closing of the solenoid valve is eliminated by the check valve, which can ensure the one-way flow of the spinning solution. Ultimately, the blue and black spinning solutions converge in the dual-channel microfluidic chip. When the program controls the solenoid valve corresponding to the yellow spinning solution to open and the black one to close, a yellow polyurethane sequence is obtained, and vice versa, a black sequence is obtained. The program controls the two solenoid valves to open and close repeatedly, resulting in a two-block structure with alternating yellow and black colors, which is solidified into a two-block structure fiber in a 2wt% CaCl2 aqueous solution coagulation bath.

[0057] Example 4:

[0058] choose Figure 5 The triblock fibers of this example were prepared using a three-channel extruder. Polyurethane (TPU1180A) was used as the spinning raw material and dissolved in DMF to form a 20 wt% solution. The spinning solutions were divided into three portions and marked with commercially available dyes in red, blue, and yellow.

[0059] The three-channel injection buckle is connected to the injection pump-syringe-solenoid valve-check valve respectively, and a coagulation bath-collector is set at the extrusion head. During the spinning process, the injection pump pushes the syringe to extrude the PU spinning solution into the solenoid valve. The corresponding solenoid valve can be opened and closed by a set computer program, and the corresponding spinning channel can selectively circulate the required spinning solution. The backflow effect caused by the opening and closing of the solenoid valve is eliminated by the check valve, which can ensure the unidirectional conduction of the spinning solution. Finally, the red, blue and yellow spinning solutions converge in the three-channel microfluidic chip. The program controls the repeated opening and closing of the three solenoid valves to obtain a three-block structure with alternating red, blue and yellow colors, which is solidified into a three-block structure fiber in a water coagulation bath.

[0060] Example 5:

[0061] A four-channel microfluidic chip was selected as the spinning outlet flow channel, and polyurethane (TPU1180A) was used as the spinning raw material, dissolved in DMF to prepare a 20wt% solution. The spinning solution was divided into four parts and marked with red, green, blue and yellow using commercially available dyes.

[0062] A program-controlled microfluidic spinning device was built, which consists of a syringe pump-syringe-solenoid valve-check valve-microfluidic chip-coagulation bath-collector. During the spinning process, the syringe pump pushes the syringe to squeeze out the PU spinning solution into the solenoid valve. The corresponding solenoid valve can be opened and closed by a set computer program, and the corresponding spinning channel can selectively flow the required spinning solution. The backflow effect caused by the opening and closing of the solenoid valve is eliminated by the check valve, which can ensure the one-way conduction of the spinning solution. Finally, the four spinning solutions of red, green, blue and yellow converge in the four-channel microfluidic chip. The four solenoid valves are repeatedly opened and closed under the control of the program to obtain a four-block structure with alternating red-green-blue-yellow colors, which is solidified into a four-block structure fiber in a water coagulation bath.

[0063] Example 6:

[0064] A dual-channel microfluidic chip was selected as the spinning outlet flow channel, and polyacrylonitrile (PAN) and polyvinylidene fluoride (PVDF) were respectively used as spinning raw materials and dissolved in DMF to prepare a 20 wt % solution.

[0065] A program-controlled microfluidic spinning device was built, which consists of an injection pump-injector-solenoid valve-one-way valve-microfluidic chip-coagulation bath-collector. During the spinning process, the injection pump pushes the syringe to squeeze out the PAN and PVDF spinning solutions into the solenoid valve respectively. The corresponding solenoid valves can be opened and closed by a set computer program, and the corresponding spinning channels can selectively flow the required spinning solution. The backflow effect caused by the opening and closing of the solenoid valve is eliminated by the check valve, which can ensure the one-way conduction of the spinning solution. Finally, the two spinning solutions of PAN and PVDF converge in the dual-channel microfluidic chip. The two solenoid valves are repeatedly opened and closed under the control of the program to obtain a block structure with PAN-PVDF, which is solidified into a PAN-PVDF block structure fiber in a water coagulation bath.

[0066] Example 7:

[0067] A dual-channel microfluidic chip was selected as the spinning outlet flow channel, and polyacrylonitrile (PAN) and polyurethane (PU) were respectively used as spinning raw materials and dissolved in DMF to prepare a 20 wt % solution.

[0068] A program-controlled microfluidic spinning device was built, which consists of an injection pump-injector-solenoid valve-one-way valve-microfluidic chip-coagulation bath-collector. During the spinning process, the injection pump pushes the syringe to squeeze out the PAN and PU spinning solutions into the solenoid valve respectively. The corresponding solenoid valves can be opened and closed by a set computer program, and the corresponding spinning channels can selectively flow the required spinning solution. The backflow effect caused by the opening and closing of the solenoid valve is eliminated by the check valve, which can ensure the one-way conduction of the spinning solution. Finally, the two spinning solutions of PAN and PU converge in the dual-channel microfluidic chip. The two solenoid valves are repeatedly opened and closed under the control of the program to obtain a block structure with PAN-PU, which is solidified into a PAN-PU block structure fiber in a water coagulation bath.

[0069] Example 8:

[0070] A dual-channel microfluidic chip was selected as the spinning outlet flow channel, and polyvinylidene fluoride (PVDF) and polyurethane (PU) were respectively used as spinning raw materials and dissolved in DMF to prepare a 20 wt% solution.

[0071] A program-controlled microfluidic spinning device was built, which consists of an injection pump-injector-solenoid valve-one-way valve-microfluidic chip-coagulation bath-collector. During the spinning process, the injection pump pushes the syringe to extrude the PVDF and PU spinning solutions into the solenoid valve respectively. The corresponding solenoid valves can be opened and closed by a set computer program, and the corresponding spinning channels can selectively flow the required spinning solution. The backflow effect caused by the opening and closing of the solenoid valve is eliminated by the check valve, which can ensure the one-way conduction of the spinning solution. Finally, the PVDF and PU spinning solutions converge in the dual-channel microfluidic chip. The two solenoid valves are repeatedly opened and closed under the control of the program to obtain a block structure with PVDF-PU, which is solidified into a PVDF-PU block structure fiber in a water coagulation bath.

[0072] Example 9:

[0073] A dual-channel microfluidic chip was selected as the spinning outlet flow channel, and sodium alginate (Alg) and carboxymethyl cellulose (CMC) were respectively used as spinning raw materials and dissolved in deionized water to prepare a 2wt% solution.

[0074] A program-controlled microfluidic spinning device was constructed, consisting of a syringe pump, syringe, solenoid valve, one-way valve, microfluidic chip, coagulation bath, and collector. During the spinning process, the syringe pump pushes the syringe to squeeze out the Alg and CMC spinning solutions into the solenoid valves, respectively. A pre-set computer program controls the opening and closing of the corresponding solenoid valves, allowing the corresponding spinning channels to selectively flow the required spinning solutions. The backflow effect caused by the opening and closing of the solenoid valves is eliminated by the check valve, ensuring the one-way flow of the spinning solutions. Ultimately, the Alg and CMC spinning solutions converge in the dual-channel microfluidic chip. The program controls the repeated opening and closing of the two solenoid valves to obtain an Alg-CMC block structure, which is then solidified into Alg-CMC block structure fibers in a 2wt% CaCl2 coagulation bath.

[0075] Example 10:

[0076] A dual-channel microfluidic chip was selected as the spinning outlet flow channel, and sodium alginate (Alg) and sodium polyacrylate (PAS) were respectively used as spinning raw materials and dissolved in deionized water to prepare a 2 wt % solution.

[0077] A program-controlled microfluidic spinning device was built, which consists of a syringe pump, syringe, solenoid valve, one-way valve, microfluidic chip, coagulation bath, and collector. During the spinning process, the syringe pump pushes the syringe to squeeze out the Alg and PAS spinning solutions into the solenoid valves respectively. The corresponding solenoid valves can be opened and closed by a pre-set computer program, and the corresponding spinning channels can selectively flow the required spinning solution. The backflow effect caused by the opening and closing of the solenoid valves is eliminated by the check valve, which can ensure the one-way conduction of the spinning solution. Finally, the Alg and PAS spinning solutions converge in the dual-channel microfluidic chip. The two solenoid valves are repeatedly opened and closed under program control to obtain a block structure with Alg-PAS, which is solidified into Alg-PAS block structure fibers in a 2wt% CaCl2 coagulation bath.

[0078] Example 11:

[0079] A dual-channel microfluidic chip was selected as the spinning outlet flow channel, and carboxymethyl cellulose (CMC) and sodium polyacrylate (PAS) were respectively used as spinning raw materials and dissolved in deionized water to prepare a 2 wt % solution.

[0080] A program-controlled microfluidic spinning device was constructed, consisting of a syringe pump, syringe, solenoid valve, one-way valve, microfluidic chip, coagulation bath, and collector. During the spinning process, the syringe pump pushes the syringe to squeeze out the CMC and PAS spinning solutions into the solenoid valves respectively. The corresponding solenoid valves can be opened and closed by a pre-set computer program, and the corresponding spinning channels can selectively flow the required spinning solutions. The backflow effect caused by the opening and closing of the solenoid valves is eliminated by the check valve, ensuring the one-way flow of the spinning solution. Ultimately, the CMC and PAS spinning solutions converge in the dual-channel microfluidic chip. The two solenoid valves are repeatedly opened and closed under program control to obtain a CMC-PAS block structure, which is then solidified into CMC-PAS block structure fibers in a 2wt% CaCl2 coagulation bath.

[0081] Example 12:

[0082] A three-channel microfluidic chip was selected as the spinning outlet flow channel, and carboxymethyl cellulose (CMC), sodium polyacrylate (PAS), and sodium alginate (Alg) were respectively used as spinning raw materials and dissolved in deionized water to prepare a 2wt% solution.

[0083] A program-controlled microfluidic spinning device was constructed, consisting of a syringe pump, syringe, solenoid valve, one-way valve, microfluidic chip, coagulation bath, and collector. During the spinning process, the syringe pump pushes the syringe to extrude CMC, PAS, and Alg spinning solutions into the solenoid valves. A pre-programmed computer program controls the opening and closing of the corresponding solenoid valves, allowing the desired spinning solution to flow selectively through the corresponding spinning channels. The backflow effect caused by the opening and closing of the solenoid valves is eliminated by the check valve, ensuring unidirectional flow of the spinning solution. Ultimately, the three spinning solutions, CMC, PAS, and Alg, converge in a three-channel microfluidic chip. By repeatedly opening and closing the three solenoid valves under program control, a CMC-PAS-Alg block structure was obtained, which was then solidified into CMC-PAS-Alg block structure fibers in a 2wt% CaCl2 coagulation bath.

[0084] Example 13:

[0085] A three-channel microfluidic chip was selected as the spinning outlet flow channel, and polyacrylonitrile (PAN), polyurethane (PU), and polyvinylidene fluoride (PVDF) were respectively used as spinning raw materials and dissolved in DMF to prepare a 20 wt% solution.

[0086] A program-controlled microfluidic spinning device was built, which consists of an injection pump-injector-solenoid valve-one-way valve-microfluidic chip-coagulation bath-collector. During the spinning process, the injection pump pushes the syringe to extrude PAN, PU and PVDF spinning solutions into the solenoid valve respectively. The corresponding solenoid valves can be opened and closed by a set computer program, and the corresponding spinning channels can selectively circulate the required spinning solution. The backflow effect caused by the opening and closing of the solenoid valve is eliminated by the check valve, which can ensure the one-way conduction of the spinning solution. Finally, the three spinning solutions of PAN, PU and PVDF converge in the three-channel microfluidic chip. The three solenoid valves are repeatedly opened and closed under program control to obtain a block structure of PAN-PU-PVDF, which is solidified into a PAN-PU-PVDF block structure fiber in a water coagulation bath.

[0087] Example 14:

[0088] Hard polyurethane (3072D) and soft polyurethane (1170A) were selected as spinning raw materials, added to DMF to prepare 20 wt% solutions, and marked with commercially available dyes as blue (hard) and yellow (soft), respectively.

[0089] The microfluidic spinning device is built in the order of injection pump-valve-chip-coagulation bath. The spinning process is as follows: First, the injection pump pushes the functional spinning solution into the corresponding solenoid valve. By regulating the opening of the solenoid valve, the corresponding spinning channel state becomes flowable, thereby selectively introducing the required functional spinning solution. When the valve corresponding to the hard polyurethane is controlled to open, a hard polyurethane block is obtained, and vice versa, a soft polyurethane block is obtained. By setting the state of the two valves to switch alternately through the program, a hard polyurethane-soft polyurethane alternating structure can be designed, which is solidified into a mechanical segmented super fiber in a water coagulation bath.

[0090] The block length and ratio can be controlled by the spinning rate. The mechanical properties of the segmented microfiber were tested using a universal testing machine. The Young's modulus of the hard block was 232 MPa, while that of the soft block was 29 MPa. Under uniform uniaxial stretching to 100% global strain, the soft block exhibited a local strain approximately 20 times greater than that of the hard block.

[0091] Example 15:

[0092] Rigid polyurethane (3072D) was selected as the spin fiber matrix, and graphene was used as the conductive filler. The polyurethane was added to DMF to create a 20 wt% solution. This solution was split into two portions, and ultrasonically dispersed graphene was added to one portion (graphene:polyurethane = 1:4). The graphene / polyurethane portion corresponded to the desired conductive block, while the polyurethane portion corresponded to the insulating block.

[0093] The microfluidic spinning device is built in the order of injection pump-valve-chip-coagulation bath. The spinning process is as follows: First, the injection pump pushes the functional spinning solution into the corresponding solenoid valve. By regulating the opening of the solenoid valve, the corresponding spinning channel state becomes flowable, thereby selectively introducing the required functional spinning solution. When the valve corresponding to the graphene / polyurethane is controlled to open, the graphene / polyurethane block is obtained, and vice versa, the pure polyurethane block is obtained. By setting the state of the two valves to switch alternately through the program, a graphene / polyurethane-pure polyurethane alternating structure can be designed, which is solidified into an electrical segmented superfiber in a water coagulation bath.

[0094] The conductive properties of the electrical block superfiber were tested using a digital source meter. The average conductivity of the graphene / polyurethane block was 6.13S / m, while the pure polyurethane block exhibited insulating properties.

[0095] Example 16:

[0096] Rigid polyurethane (3072D) was selected as the spinning fiber matrix, with ferroferric oxide and aluminum oxide as magnetic fillers. The polyurethane was added to DMF to create a 20wt% solution. The solution was divided into two portions, with ferroferric oxide added to one portion (ferroferric oxide:polyurethane = 1:4) and aluminum oxide added to the other portion (aluminum oxide:polyurethane = 1:4). The ferroferric oxide / polyurethane portion corresponded to the desired ferromagnetic block, while the ferroferric oxide / polyurethane portion corresponded to the diamagnetic block.

[0097] The microfluidic spinning device is built in the order of injection pump-valve-chip-coagulation bath. The spinning process is as follows: First, the injection pump pushes the functional spinning solution into the corresponding solenoid valve. By regulating the opening of the solenoid valve, the corresponding spinning channel state becomes flowable, thereby selectively introducing the required functional spinning solution. When the valve corresponding to ferroferric oxide / polyurethane is controlled to open, ferroferric oxide / polyurethane blocks are obtained, and vice versa, aluminum oxide / polyurethane blocks are obtained. By setting the state of the two valves to switch alternately through the program, a structure with ferroferric oxide / polyurethane-aluminum oxide / polyurethane alternating can be designed, which is solidified into a magnetic segmented superfiber in a water coagulation bath.

[0098] The magnetization intensity of the magnetic segmented superfiber was tested using a low-temperature magnetic field test system. Under an applied magnetic field of 1 T, the average magnetization intensity of the ferroferric oxide / polyurethane segment was 0.63 emu / g, while that of the aluminum oxide / polyurethane segment was 0.0019 emu / g.

[0099] Example 17:

[0100] Rigid polyurethane (3072D) was selected as the spinning fiber matrix, with graphene and titanium dioxide as photothermal fillers. Polyurethane was added to DMF to create a 20wt% solution. The solution was divided into two portions, with graphene added to one (graphene:polyurethane = 1:4) and titanium dioxide added to the other (titanium dioxide:polyurethane = 1:4). The graphene / polyurethane portion corresponded to the desired infrared absorbing block, while the titanium dioxide / polyurethane portion corresponded to the infrared reflecting block.

[0101] The microfluidic spinning device is built in the order of injection pump-valve-chip-coagulation bath. The spinning process is as follows: First, the injection pump pushes the functional spinning solution into the corresponding solenoid valve. By regulating the opening of the solenoid valve, the corresponding spinning channel state becomes flowable, thereby selectively introducing the required functional spinning solution. When the valve corresponding to the graphene / polyurethane is controlled to open, the graphene / polyurethane block is obtained, and vice versa, the titanium dioxide / polyurethane block is obtained. By setting the state of the two valves to switch alternately through the program, a graphene / polyurethane-titanium dioxide / polyurethane alternating structure can be designed, which is solidified into a photothermal segmented superfiber in a water coagulation bath.

[0102] The temperature changes of the photothermal block superfibers under infrared light (100W, 40cm) were recorded using an infrared thermal imager. Within 80 seconds of irradiation, the temperature of the graphene / polyurethane block increased by 20°C, while that of the titanium dioxide / polyurethane block increased by 7.5°C.

Claims

1. A method for preparing heterogeneous segmented fibers, characterized in that: injecting a first spinning solution and a second spinning solution into an extrusion channel in sequence, and sequentially extruding through the extrusion channel to form a continuous first fiber block and a second fiber block; The heterogeneous segmented fiber includes a first fiber segment composed of a first material and a second fiber segment composed of a second material. The first fiber segment and the second fiber segment are continuous, and the first material and the second material are heterogeneous. The length range of the first fiber segment and the second fiber segment is above 740 μm; the fiber diameter range is 20-300 μm; the first material is: a hard polyurethane mixed with graphene, carbon nanotubes or silicate nanosheets; the second material is: a soft polyurethane; there is a transition section between the first fiber segment and the second fiber segment, and the transition section is a mixture of the first material and the second material.

2. The preparation method according to claim 1, characterized in that The injection amounts of the first spinning solution and the second spinning solution are controlled by a controller, thereby controlling the lengths of the first fiber block and the second fiber block.

3. The preparation method according to claim 1, characterized in that The extrusion channel is located on a microfluidic chip.

4. The preparation method according to claim 1, characterized in that The first spinning solution and the second spinning solution are extruded through the extrusion channel and coagulated in a coagulation bath, and then dried to form continuous first fiber blocks and second fiber blocks.

5. The preparation method according to claim 1, characterized in that The first spinning solution and the second spinning solution are extruded through the extrusion channel to volatilize the solvents, thereby forming continuous first fiber blocks and second fiber blocks.

6. The preparation method according to claim 1, characterized in that The first spinning solution and the second spinning solution are extruded through an extrusion channel and then polymerized to form the continuous first fiber block and the second fiber block.

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