Wearable electromagnetic shielding fabric and preparation method thereof

Abstract

The invention relates to the technical field of wet spinning, in particular to a wearable electromagnetic shielding fabric and a preparation method thereof. Thermoplastic polyurethane and polybenzodifuran diketone conductive ink are mixed and then dissolved in dimethyl sulfoxide, and a spinning solution is obtained; spinning by using the spinning solution and the molten octadecane as shell liquid and core liquid respectively through a coaxial needle head to obtain fibers; carrying out solvent exchange on the fibers in deionized water, and drying to obtain PC-PU fibers; the PC-PU fibers and the round wax threads are subjected to tatting, and the wearable electromagnetic shielding fabric is obtained. According to the method for preparing the electromagnetic shielding fabric, the conductive filler is directly mixed into the fiber forming solution, integrated fiber forming is achieved through the wet spinning technology, operation is simple, most of the prior art is spraying of a conductive coating, and the fiber prepared through the novel method not only has the electromagnetic shielding function, but also keeps wear resistance and air permeability, and the electromagnetic shielding fabric has the good application prospect. The characteristics are important for practical application.

Description

Technical Field

[0001] This invention relates to the field of wet spinning technology, specifically to a wearable electromagnetic shielding fabric and its preparation method. Background Technology

[0002] Electromagnetic shielding fabrics not only prevent interference between electronic devices but also protect users from electromagnetic radiation. In military, aerospace, medical, and information security fields, electromagnetic shielding fabrics are crucial for ensuring normal equipment operation and information security. Furthermore, as wearable technology evolves towards comfort and multifunctionality, electromagnetic shielding fabrics have become key materials for meeting these needs, bringing new application prospects to related industries. These fabrics are lightweight, flexible, and high-strength, and offer advantages such as controllable structure, strong molding adaptability, washability, and cost-effectiveness. With the rapid development of wearable technology, electromagnetic shielding fabrics have become an important material for realizing the multifunctionality and integration of devices.

[0003] Existing technologies fabricate wearable electromagnetic shielding fabrics by constructing an electromagnetic shielding network within a porous, network-like solid system. Metal nanowire coating technology can significantly improve the electromagnetic shielding effect of the fabric. However, it is worth noting that the conductive coating is prone to delamination under mechanical stresses such as bending, abrasion, or scratching, which can easily lead to a decrease in the electromagnetic shielding effect of the wearable fabric. To address this issue, some researchers have attempted to add a layer of polymer material to the conductive coating. While these synthetic fabrics can pass cyclic abrasion and bending tests, and their superhydrophobic surface ensures reliable conductivity as an electromagnetic shielding material under harsh conditions, their extremely poor breathability makes them unsuitable for meeting the demands of wearable electromagnetic shielding fabrics.

[0004] Therefore, there is an urgent need to develop a method for preparing wearable electromagnetic shielding fabrics with good breathability. Summary of the Invention

[0005] To address the above problems, this invention provides a wearable electromagnetic shielding fabric, its preparation method, and its application. It solves the problem that in existing technologies for preparing wearable electromagnetic shielding fabrics, when using metal nanowire coating technology to improve the electromagnetic shielding effect, the conductive coating is prone to delamination under mechanical stress such as bending, abrasion, or scratching, leading to a decrease in the electromagnetic shielding effect and poor breathability of the wearable fabric.

[0006] This invention is achieved through the following technical solution: A method for preparing a wearable electromagnetic shielding fabric specifically includes the following steps: Thermoplastic polyurethane and polybenzodifurandione conductive ink are mixed and then dissolved in dimethyl sulfoxide to obtain a spinning solution; the weight ratio of thermoplastic polyurethane, polybenzodifurandione conductive ink and dimethyl sulfoxide is 5:1.91~4.35:31.25.

[0007] Octadecane is melted.

[0008] The spinning solution and molten octadecane are used as the shell liquid and core liquid, respectively, and spun through a coaxial needle to obtain fibers; the fibers are subjected to solvent exchange in deionized water and dried to obtain PC-PU fibers; the weight ratio of the spinning solution to molten octadecane is 50~70:50~70.

[0009] Wearable electromagnetic shielding fabric is obtained by weaving PC-PU fibers and round waxed yarns; the weight ratio of PC-PU fibers to round waxed yarns is 60~80:60~80.

[0010] Or specifically include the following steps: Thermoplastic polyurethane and polybenzodifurandione conductive ink are mixed and then dissolved in dimethyl sulfoxide to obtain solution A; the weight ratio of thermoplastic polyurethane, polybenzodifurandione conductive ink and dimethyl sulfoxide is 5:1.91~4.35:15.

[0011] Silver-coated copper nanosheets were added to dimethyl sulfoxide and sonicated to obtain a dispersion; the weight ratio of the silver-coated copper nanosheets to dimethyl sulfoxide was 0~46.35:16.25.

[0012] Add all of the dispersion to solution A to obtain the spinning solution.

[0013] Octadecane is melted.

[0014] The spinning solution and molten octadecane are used as the shell liquid and core liquid, respectively, and spun through a coaxial needle to obtain PC-PU fibers; the weight ratio of the spinning solution to the molten octadecane is 50~70:50~70.

[0015] Wearable electromagnetic shielding fabric is obtained by weaving PC-PU fibers and round waxed yarns; the weight ratio of PC-PU fibers to round waxed yarns is 60~80:60~80.

[0016] Preferably, the concentration of the polybenzodifurandione conductive ink is selected to be 10 mg / ml to 12 mg / ml.

[0017] Preferably, the melting temperature is 50℃~70℃.

[0018] Preferably, the ultrasound duration is 10-15 minutes and the power is 400W.

[0019] Preferably, the spinning temperature is 40℃~60℃.

[0020] Preferably, the shell liquid spinning speed is 0.14 mm / min; the core liquid spinning speed is 0.10 mm / min.

[0021] Preferably, the coaxial needle consists of an outer needle and an inner needle; the outer needle has a specification of 17G; and the inner needle has a specification of 21G.

[0022] Preferably, the diameter of the round waxed wire is 0.55mm to 0.57mm.

[0023] Preferably, PC-PU fibers are used as weft threads and round waxed threads are used as warp threads to weave PC-PU fabric; the density of the warp threads is 2 to 3 threads / cm; the density of the weft threads is 2 to 3 threads / cm.

[0024] The electromagnetic shielding fabric is prepared by the aforementioned preparation method.

[0025] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a method for preparing wearable electromagnetic shielding fabric, specifically including the following steps: mixing thermoplastic polyurethane with polybenzodifurandione conductive ink and dissolving it in dimethyl sulfoxide to obtain a spinning solution; the weight ratio of the thermoplastic polyurethane, polybenzodifurandione conductive ink, and dimethyl sulfoxide is 5:1.91~4.35:31.25; melting octadecane; using the spinning solution and the melted octadecane as the shell liquid and core liquid respectively, spinning through a coaxial needle to obtain fibers; exchanging the fibers with deionized water and drying them to obtain PC-PU fibers; the weight ratio of the spinning solution to the melted octadecane is 50~70:50~70; weaving the PC-PU fibers and round waxed yarn to obtain wearable electromagnetic shielding fabric; the weight ratio of the PC-PU fibers and round waxed yarn is 60~80:60~80. Or specifically, it includes the following steps: mixing thermoplastic polyurethane with polybenzodifurandione conductive ink and dissolving it in dimethyl sulfoxide to obtain solution A; the weight ratio of the thermoplastic polyurethane, polybenzodifurandione conductive ink, and dimethyl sulfoxide is 5:1.91~4.35:15; adding silver-coated copper nanosheets to dimethyl sulfoxide and sonicating to obtain a dispersion; the weight ratio of the silver-coated copper nanosheets to dimethyl sulfoxide is 0~46.35:16.25; the dispersion... All of the ingredients are added to solution A to obtain a spinning solution; octadecane is melted; the spinning solution and the melted octadecane are used as the shell liquid and core liquid, respectively, and spun through a coaxial needle to obtain PC-PU fibers; the weight ratio of the spinning solution to the melted octadecane is 50~70:50~70; the PC-PU fibers and round waxed yarn are woven to obtain wearable electromagnetic shielding fabric; the weight ratio of the PC-PU fibers to the round waxed yarn is 60~80:60~80.

[0026] The method for preparing electromagnetic shielding fabric provided by this invention involves directly mixing conductive fillers into a fiber-forming solution and then forming fibers in an integrated manner using wet spinning technology. This method is simple to operate, unlike existing technologies which mostly involve spraying conductive coatings. The fibers prepared by this novel method not only possess electromagnetic shielding capabilities but also maintain breathability, properties crucial for practical applications. Furthermore, this invention is the first to use polybenzodifuran dione and silver flakes simultaneously as conductive fillers to prepare wearable electromagnetic shielding fabric, achieving a combination of a novel highly conductive n-type polymer and traditional silver-based materials. Simultaneously, the n-doped conductivity mechanism of polybenzodifuran dione and the free electron conduction mechanism of silver flakes work synergistically, providing new ideas for electromagnetic shielding material design and adapting to the needs of multiple fields such as electronic protection and information security. The PC-PU fabric is prepared using a specific weaving process with PC-PU fibers as the weft and commercially available high-strength round waxed yarn as the warp. It can achieve adjustable electromagnetic shielding effectiveness from 52.56 dB to 83.61 dB depending on the angle between the PC-PU fabric and the incident electromagnetic wave electric field. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 The electromagnetic shielding performance of PC-PU fabrics prepared in different embodiments of the present invention is shown when the weft yarn is perpendicular to the direction of the incident electromagnetic wave electric field.

[0029] Figure 2 The diagram shows the electromagnetic shielding performance of PC-PU fabrics prepared according to different embodiments of the present invention when the weft threads are parallel to the direction of the incident electromagnetic wave electric field.

[0030] Figure 3 The diagram shows the electromagnetic shielding performance of PC-PU fabrics prepared in different comparative proportions of this invention when the weft yarn is perpendicular to the direction of the incident electromagnetic wave electric field.

[0031] Figure 4 The diagram shows the electromagnetic shielding performance of PC-PU fabrics prepared in different comparative proportions of this invention when the weft threads are parallel to the direction of the incident electromagnetic wave electric field.

[0032] Figure 5 Tensile curves of PC-PU fibers prepared according to different embodiments of the present invention.

[0033] Figure 6 This is a SEM image of the PC-PU fibers prepared in Example 5 of the present invention during knotting.

[0034] Figure 7 The current-voltage curve of the PC-PU fiber prepared in Example 5 of this invention.

[0035] Figure 8 Time-temperature curves of PC-PU fibers prepared in Example 5 of this invention under different driving voltages.

[0036] Figure 9 The air permeability test of the PC-PU fabric prepared in Example 5 of the present invention; Figure 9 In the diagram, A is a schematic diagram of the bottle opening closed; B is a schematic diagram of the bottle opening open. Detailed Implementation

[0037] To facilitate understanding of the present invention, a more comprehensive description is provided below, along with preferred embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0038] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this invention and in its specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0039] The inventive concept of this invention is as follows: This invention discloses a wearable electromagnetic shielding fabric and its preparation method, comprising: uniformly mixing polyurethane and polybenzodifuran diketone conductive ink, then dissolving the mixture in dimethyl sulfoxide at 60°C; subsequently adding different weight parts of a dispersion of silver-coated copper nanosheets-dimethyl sulfoxide solution to prepare a shell liquid: a polyurethane-silver-coated copper nanosheet spinning solution. Simultaneously, octadecane, a phase change material, is placed in a 40°C oven as a core liquid and completely melted. The wet spinning process is carried out in a constant temperature chamber at 35°C to ensure the molten state of octadecane. A coaxial wet spinning strategy is used to continuously prepare fibers with a liquid core liquid of octadecane and a shell of polyurethane / silver-coated copper nanosheets. After spinning, the solvent is exchanged in a deionized aqueous solution to obtain phase change polyurethane (PC-PU) fibers. The PC-PU fibers are used as the weft, and commercially available high-strength round waxed yarn is used as the warp to weave the PC-PU fabric using a shuttle weaving process. This invention is the first to use polybenzodifurandione and silver flakes simultaneously as conductive fillers to prepare wearable electromagnetic shielding fabrics. It achieves a combination of a novel highly conductive n-type polymer and traditional silver-based conductive materials. The n-doping conductivity of polybenzodifurandione and the free electron conduction mechanism of silver flakes work synergistically, meeting the needs of multiple fields such as electronic protection and information security. The invention also provides a method for preparing electromagnetic shielding fabrics, which, after preparing the spinning solution, directly and continuously prepares porous polyurethane fibers with a silver-coated copper outer layer through a coaxial wet spinning strategy. These fibers possess phase change energy storage and excellent tensile strength. Furthermore, this invention provides a specific weaving process, enabling the prepared PC-PU fabric to achieve adjustable electromagnetic shielding effectiveness from 52.56 dB to 83.61 dB depending on the angle between the PC-PU fabric and the incident electromagnetic field. Meanwhile, the excellent thermal insulation and Joule heating properties of this fabric effectively solve the key problems of traditional electromagnetic shielding fabrics, such as significant decrease in electromagnetic shielding effectiveness, poor air permeability, and poor temperature control performance under physical damage. At the same time, it realizes the composite application of multiple functional fillers, providing a new idea for the preparation of novel wearable multifunctional fabrics.

[0040] The beneficial effects of the present invention will be illustrated below through specific embodiments.

[0041] Fiber-forming polymer (polyurethane): Purchased from Huntsman Polyurethanes Ltd.; Specification: P4393.

[0042] Dimethyl sulfoxide: Purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0043] Silver-coated copper nanosheets: Purchased from Guangzhou Yinfeng Metal Technology Co., Ltd.; Specification: yf-Q250; Nanoscale size: 20 micrometers.

[0044] Octadecane: Purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0045] Polybenzodifurandione conductive ink: purchased from Dongguan Fu'an Optoelectronics Technology Co., Ltd.; the polybenzodifurandione conductive solution was prepared using dimethyl sulfoxide as a solvent, with a concentration of 10 mg / mL. -1 ~12mg mL -1 The ratio of dimethyl sulfoxide to polybenzodifuran dione is 99:1.

[0046] Waxed round thread: Purchased from Guangdong Kangfa Thread Industry Technology Co., Ltd.

[0047] Example 1 A method for preparing a wearable electromagnetic shielding fabric includes the following steps: Five parts by weight of thermoplastic polyurethane and 1.91 parts by weight of polybenzodifurandione conductive ink were mixed evenly and then added to 31.25 parts by weight of dimethyl sulfoxide. The mixture was fully dissolved at 50°C to obtain a spinning solution. At the same time, octadecane, a phase change material, was placed in an oven at 40°C and completely melted as a core liquid. The concentration of the polybenzodifurandione conductive ink was 10 mg / ml.

[0048] A coaxial wet spinning strategy was used to spin fibers by using 50 parts by weight of spinning solution and 50 parts by weight of molten octadecane as the shell liquid and core liquid, respectively, through a coaxial needle. The fibers were then placed in a coagulation bath for 24 hours to allow for sufficient solvent exchange, and then dried at room temperature to obtain PC-PU fibers. The coaxial needle consisted of an outer needle and an inner needle, with the outer needle having a specification of 17G and the inner needle having a specification of 21G. The shell liquid spinning speed was 0.14 mm / min and the core liquid spinning speed was 0.10 mm / min. The spinning temperature was 40℃.

[0049] A wearable electromagnetic shielding fabric, denoted as PC-PU fabric, is woven from 60 parts by weight of PC-PU fiber and 60 parts by weight of 0.55mm diameter round waxed yarn using a weaving process. PC-PU fiber serves as the weft, and the round waxed yarn serves as the warp; the warp density is 2 threads / cm, and the weft density is 2 threads / cm.

[0050] Example 2 A method for preparing a wearable electromagnetic shielding fabric includes the following steps: After mixing 5 parts by weight of polyurethane and 2.51 parts by weight of polybenzodifurandione conductive ink evenly, the mixture is added to 15 parts by weight of dimethyl sulfoxide and dissolved completely at 50°C to obtain solution A.

[0051] 11.55 parts by weight of silver-coated copper nanosheets and 16.25 parts by weight of dimethyl sulfoxide were added and ultrasonically dispersed to obtain a dispersion. The ultrasonication time was 10 min and the power was 400 W.

[0052] Add all of the dispersion to solution A to obtain the spinning solution.

[0053] The phase change material octadecane was placed in an oven at 40°C and completely melted as the core liquid; the selected concentration of the polybenzodifuran diketone conductive ink was 10 mg / ml.

[0054] A coaxial wet spinning strategy was employed, using 50 parts by weight of spinning solution and 50 parts by weight of molten octadecane as the shell liquid and core liquid, respectively, through a coaxial needle to obtain fibers. The fibers were then placed in a coagulation bath for 24 hours to allow for sufficient solvent exchange, and subsequently dried at room temperature to obtain PC-PU fibers. The coaxial needle consisted of an outer needle and an inner needle; the outer needle had a specification of 17G, and the inner needle had a specification of 21G. The shell liquid spinning speed was 0.14 mm / min, and the core liquid spinning speed was 0.10 mm / min; the spinning temperature was 40℃.

[0055] A wearable electromagnetic shielding fabric, denoted as PC-PU fabric, is woven from 60 parts by weight of PC-PU fiber and 60 parts by weight of 0.55mm diameter round waxed yarn using a weaving process. PC-PU fiber serves as the weft, and the round waxed yarn serves as the warp; the warp density is 2 threads / cm, and the weft density is 2 threads / cm.

[0056] Example 3 A method for preparing a wearable electromagnetic shielding fabric includes the following steps: After mixing 5 parts by weight of polyurethane and 2.95 parts by weight of polybenzodifurandione conductive ink evenly, the mixture is added to 15 parts by weight of dimethyl sulfoxide and dissolved completely at 60°C to obtain solution A.

[0057] 19.85 parts by weight of silver-coated copper nanosheets and 16.25 parts by weight of dimethyl sulfoxide were added and ultrasonically dispersed to obtain a dispersion; the ultrasonic time was 13 min and the power was 400 W.

[0058] Add all of the dispersion to solution A to obtain the spinning solution.

[0059] The phase change material octadecane was placed in an oven at 40°C and completely melted as the core liquid; the selected concentration of the polybenzodifuran diketone conductive ink was 12 mg / ml.

[0060] A coaxial wet spinning strategy was employed, using 60 parts by weight of spinning solution and 60 parts by weight of molten octadecane as the shell liquid and core liquid, respectively, through a coaxial needle to obtain fibers. The fibers were then placed in a coagulation bath for 24 hours to allow for sufficient solvent exchange, and subsequently dried at room temperature to obtain PC-PU fibers. The coaxial needle consisted of an outer needle and an inner needle; the outer needle had a specification of 17G, and the inner needle had a specification of 21G. The shell liquid spinning speed was 0.14 mm / min, and the core liquid spinning speed was 0.10 mm / min; the spinning temperature was 50℃.

[0061] A wearable electromagnetic shielding fabric, denoted as PC-PU fabric, is woven from 70 parts by weight of PC-PU fiber and 70 parts by weight of 0.56 mm diameter round waxed yarn using a weaving process. PC-PU fiber serves as the weft, and the round waxed yarn serves as the warp; the warp density is 3 threads / cm, and the weft density is 3 threads / cm.

[0062] Example 4 A method for preparing a wearable electromagnetic shielding fabric includes the following steps: After mixing 5 parts by weight of polyurethane and 3.53 parts by weight of polybenzodifurandione conductive ink evenly, the mixture is added to 15 parts by weight of dimethyl sulfoxide and dissolved completely at 70°C to obtain solution A.

[0063] 30.85 parts by weight of silver-coated copper nanosheets and 16.25 parts by weight of dimethyl sulfoxide were added and ultrasonically dispersed to obtain a dispersion. The ultrasonication time was 15 min and the power was 400 W.

[0064] Add all of the dispersion to solution A to obtain the spinning solution.

[0065] The phase change material octadecane was placed in an oven at 40°C and completely melted as the core liquid; the selected concentration of the polybenzodifuran diketone conductive ink was 10 mg / ml.

[0066] A coaxial wet spinning strategy was employed, using 70 parts by weight of spinning solution and 70 parts by weight of molten octadecane as the shell liquid and core liquid, respectively, through a coaxial needle to obtain fibers. The fibers were then placed in a coagulation bath for 24 hours to allow for sufficient solvent exchange, and subsequently dried at room temperature to obtain PC-PU fibers. The coaxial needle consisted of an outer needle and an inner needle; the outer needle had a specification of 17G, and the inner needle had a specification of 21G. The shell liquid spinning speed was 0.14 mm / min, and the core liquid spinning speed was 0.10 mm / min; the spinning temperature was 60℃.

[0067] A wearable electromagnetic shielding fabric, denoted as PC-PU fabric, was woven from 80 parts by weight of PC-PU fiber and 80 parts by weight of 0.57mm diameter round waxed yarn using a weaving process. PC-PU fiber served as the weft, and the round waxed yarn served as the warp; the warp density was 2 threads / cm, and the weft density was 2 threads / cm.

[0068] Example 5 A method for preparing a wearable electromagnetic shielding fabric includes the following steps: After mixing 5 parts by weight of polyurethane and 4.35 parts by weight of polybenzodifurandione conductive ink evenly, the mixture is added to 15 parts by weight of dimethyl sulfoxide and dissolved completely at 50°C to obtain solution A.

[0069] 46.35 parts by weight of silver-coated copper nanosheets and 16.25 parts by weight of dimethyl sulfoxide were added and ultrasonically dispersed to obtain a dispersion. The ultrasonication time was 10 min and the power was 400 W.

[0070] Add all of the dispersion to solution A to obtain the spinning solution.

[0071] The phase change material octadecane was placed in an oven at 40°C and completely melted as the core liquid; the selected concentration of the polybenzodifuran diketone conductive ink was 10 mg / ml.

[0072] A coaxial wet spinning strategy was employed, using 70 parts by weight of spinning solution and 70 parts by weight of molten octadecane as the shell liquid and core liquid, respectively, through a coaxial needle to obtain fibers. The fibers were then placed in a coagulation bath for 24 hours to allow for sufficient solvent exchange, and subsequently dried at room temperature to obtain PC-PU fibers. The coaxial needle consisted of an outer needle and an inner needle; the outer needle had a specification of 17G, and the inner needle had a specification of 21G. The shell liquid spinning speed was 0.14 mm / min, and the core liquid spinning speed was 0.10 mm / min; the spinning temperature was 40℃.

[0073] A wearable electromagnetic shielding fabric, denoted as PC-PU fabric, is woven from 80 parts by weight of PC-PU fiber and 80 parts by weight of 0.55mm diameter round waxed yarn using a weaving process. PC-PU fiber serves as the weft, and the round waxed yarn serves as the warp; the warp density is 2 threads / cm, and the weft density is 2 threads / cm.

[0074] Comparative Example 1 A method for preparing a wearable electromagnetic shielding fabric includes the following steps: Five parts by weight of thermoplastic polyurethane were added to 31.25 parts by weight of dimethyl sulfoxide and dissolved completely at 50°C to obtain a dimethyl sulfoxide spinning solution of thermoplastic polyurethane; at the same time, octadecane, a phase change material, was placed in an oven at 40°C and completely melted as the core liquid.

[0075] A coaxial wet spinning strategy was employed, using 50 parts by weight of a dimethyl sulfoxide spinning solution of thermoplastic polyurethane and 50 parts by weight of molten octadecane as the shell liquid and core liquid, respectively, through a coaxial needle to obtain fibers. The fibers were then placed in a coagulation bath for 24 hours to allow for sufficient solvent exchange, and then dried at room temperature to obtain PC-PU fibers. The coaxial needle consisted of an outer needle and an inner needle, with the outer needle having a specification of 17G and the inner needle having a specification of 21G. The shell liquid spinning speed was 0.14 mm / min and the core liquid spinning speed was 0.10 mm / min. The spinning temperature was 40℃.

[0076] PC-PU fabric is woven from 60 parts by weight of PC-PU fiber and 60 parts by weight of 0.55mm diameter round waxed yarn using a weaving process. The PC-PU fiber serves as the weft, and the round waxed yarn serves as the warp; the warp density is 2 threads / cm, and the weft density is 2 threads / cm.

[0077] Comparative Example 2 A method for preparing a wearable electromagnetic shielding fabric includes the following steps: Five parts by weight of thermoplastic polyurethane were added to 15 parts by weight of dimethyl sulfoxide and dissolved completely at 50°C to obtain a dimethyl sulfoxide solution of thermoplastic polyurethane. Simultaneously, 11.55 parts by weight of silver-coated copper nanosheets were added to 16.25 parts by weight of the dimethyl sulfoxide solution and ultrasonically dispersed to obtain a silver-coated copper nanosheet-dimethyl sulfoxide dispersion. Finally, the entire silver-coated copper nanosheet-dimethyl sulfoxide dispersion was added to the dimethyl sulfoxide solution of thermoplastic polyurethane and stirred thoroughly to prepare a thermoplastic polyurethane-silver-coated copper nanosheet spinning solution. At the same time, octadecane, a phase change material, was placed in an oven at 40°C to completely melt as a core liquid.

[0078] A coaxial wet spinning strategy was employed, using 50 parts by weight of thermoplastic polyurethane-silver-coated copper nanosheet spinning solution and 50 parts by weight of molten octadecane as the shell liquid and core liquid, respectively, through a coaxial needle to obtain fibers. The fibers were then placed in a coagulation bath for 24 hours to allow for sufficient solvent exchange, and then dried at room temperature to obtain PC-PU fibers. The coaxial needle consisted of an outer needle and an inner needle, with the outer needle having a specification of 17G and the inner needle having a specification of 21G. The shell liquid spinning speed was 0.14 mm / min and the core liquid spinning speed was 0.10 mm / min. The spinning temperature was 40℃.

[0079] PC-PU fabric is woven from 60 parts by weight of PC-PU fiber and 60 parts by weight of 0.55mm diameter round waxed yarn using a weaving process. The PC-PU fiber serves as the weft, and the round waxed yarn serves as the warp; the warp density is 2 threads / cm, and the weft density is 2 threads / cm.

[0080] Comparative Example 3 A method for preparing a wearable electromagnetic shielding fabric includes the following steps: Five parts by weight of thermoplastic polyurethane were added to 15 parts by weight of dimethyl sulfoxide and dissolved completely at 60°C to obtain a dimethyl sulfoxide solution of thermoplastic polyurethane. Simultaneously, 19.85 parts by weight of silver-coated copper nanosheets were added to 16.25 parts by weight of the dimethyl sulfoxide solution and ultrasonically dispersed to obtain a silver-coated copper nanosheet-dimethyl sulfoxide dispersion. Finally, the entire silver-coated copper nanosheet-dimethyl sulfoxide dispersion was added to the dimethyl sulfoxide solution of thermoplastic polyurethane and stirred thoroughly to prepare a thermoplastic polyurethane-silver-coated copper nanosheet spinning solution. Meanwhile, octadecane, a phase change material, was placed in an oven at 40°C and completely melted as a core liquid. A coaxial wet spinning strategy was employed, using 60 parts by weight of thermoplastic polyurethane-silver-coated copper nanosheet spinning solution and 60 parts by weight of molten octadecane as the shell liquid and core liquid, respectively, to spin fibers through a coaxial needle. The fibers were then placed in a coagulation bath for 24 hours to allow for sufficient solvent exchange, and then dried at room temperature to obtain PC-PU fibers. The coaxial needle consisted of an outer needle and an inner needle, with the outer needle having a specification of 17G and the inner needle having a specification of 21G. The shell liquid spinning speed was 0.14 mm / min and the core liquid spinning speed was 0.10 mm / min. The spinning temperature was 50℃.

[0081] PC-PU fabric is woven from 70 parts by weight of PC-PU fiber and 70 parts by weight of 0.56 mm diameter round waxed yarn using a weaving process. The PC-PU fiber serves as the weft, and the round waxed yarn serves as the warp; the warp density is 3 threads / cm, and the weft density is 3 threads / cm.

[0082] Comparative Example 4 A method for preparing a wearable electromagnetic shielding fabric includes the following steps: Five parts by weight of thermoplastic polyurethane were added to 15 parts by weight of dimethyl sulfoxide and dissolved completely at 70°C to obtain a dimethyl sulfoxide solution of thermoplastic polyurethane. Simultaneously, 30.85 parts by weight of silver-coated copper nanosheets were added to 16.25 parts by weight of the dimethyl sulfoxide solution and ultrasonically dispersed to obtain a silver-coated copper nanosheet-dimethyl sulfoxide dispersion. Finally, the entire silver-coated copper nanosheet-dimethyl sulfoxide dispersion was added to the dimethyl sulfoxide solution of thermoplastic polyurethane and stirred thoroughly to prepare a thermoplastic polyurethane-silver-coated copper nanosheet spinning solution. Meanwhile, octadecane, a phase change material, was placed in an oven at 40°C and completely melted as a core liquid. A coaxial wet spinning strategy was employed, using 70 parts by weight of thermoplastic polyurethane-silver-coated copper nanosheet spinning solution and 70 parts by weight of molten octadecane as the shell solution and core solution, respectively, through a coaxial needle to obtain fibers. The fibers were then placed in a coagulation bath for 24 hours to allow for sufficient solvent exchange, and subsequently dried at room temperature to obtain PC-PU fibers. The coaxial needle consisted of an outer needle (17G) and an inner needle (21G). The shell solution spinning speed was 0.14 mm / min, and the core solution spinning speed was 0.10 mm / min. The spinning temperature was 60℃.

[0083] PC-PU fabric is woven using a shuttle weaving process, consisting of 80 parts by weight of PC-PU fiber and 80 parts by weight of 0.57 mm diameter round waxed yarn. The PC-PU fiber serves as the weft, and the round waxed yarn serves as the warp; the warp density is 2 threads / cm, and the weft density is 2 threads / cm.

[0084] Comparative Example 5 A method for preparing a wearable electromagnetic shielding fabric includes the following steps: Five parts by weight of thermoplastic polyurethane were added to 15 parts by weight of dimethyl sulfoxide and dissolved completely at 50°C to obtain a dimethyl sulfoxide solution of thermoplastic polyurethane. Simultaneously, 46.35 parts by weight of silver-coated copper nanosheets were added to 16.25 parts by weight of the dimethyl sulfoxide solution and ultrasonically dispersed to obtain a silver-coated copper nanosheet-dimethyl sulfoxide dispersion. Finally, the entire silver-coated copper nanosheet-dimethyl sulfoxide dispersion was added to the dimethyl sulfoxide solution of thermoplastic polyurethane and stirred thoroughly to obtain a thermoplastic polyurethane-silver-coated copper nanosheet spinning solution. Meanwhile, octadecane, a phase change material, was placed in an oven at 40°C and completely melted as a core liquid. A coaxial wet spinning strategy was employed, using 70 parts by weight of thermoplastic polyurethane-silver-coated copper nanosheet spinning solution and 70 parts by weight of molten octadecane as the shell liquid and core liquid, respectively, through a coaxial needle to obtain fibers. The fibers were then placed in a coagulation bath for 24 hours to allow for sufficient solvent exchange, and then dried at room temperature to obtain PC-PU fibers. The coaxial needle consisted of an outer needle and an inner needle, with the outer needle having a specification of 17G and the inner needle having a specification of 21G. The shell liquid spinning speed was 0.14 mm / min and the core liquid spinning speed was 0.10 mm / min. The spinning temperature was 40℃.

[0085] PC-PU fabric is woven from 80 parts by weight of PC-PU fiber and 80 parts by weight of 0.55mm diameter round waxed yarn using a weaving process. The PC-PU fiber serves as the weft, and the round waxed yarn serves as the warp; the warp density is 2 threads / cm, and the weft density is 2 threads / cm.

[0086] Figure 1 and Figure 2 Examples 1-5 show the electromagnetic shielding effectiveness indicated by the PC-PU fabric when the weft of the PC-PU is perpendicular to and parallel to the electric field direction of the incident electromagnetic wave. Figure 3 and Figure 4 The figures for Comparative Examples 1-5 show the electromagnetic shielding effectiveness indicated by the PC-PU fabric when the weft of the PC-PU fabric is perpendicular and parallel to the electric field direction of the incident electromagnetic wave. It is evident that the introduction of polybenzodifurandione significantly enhances the electromagnetic shielding performance of the fabric. This is due to the synergistic effect of the n-doped conductivity mechanism of polybenzodifurandione and the free electron conduction mechanism of the silver sheet. With the increase in the weight percentage of silver-coated copper nanosheets, the electromagnetic shielding effectiveness of the PC-PU fabric significantly improves. Furthermore, when the weft of the PC-PU fabric is parallel to the electric field direction of the incident electromagnetic wave, the electromagnetic shielding effectiveness indicated by the PC-PU fabric is significantly higher than that indicated when the weft of the PC-PU fabric is perpendicular to the electric field direction of the incident electromagnetic wave. This phenomenon can be explained by Maxwell's equations. When the incident electromagnetic wave generates a surface current density on the surface of the conductive material, this surface current density, under the influence of the time-varying electromagnetic wave, generates a secondary electric field perpendicular to the electric field direction of the incident electromagnetic wave, thereby attenuating the incident electromagnetic energy. The surface current density generates a perpendicular magnetic field and a secondary electric field opposite to the incident electromagnetic wave's electric field, which attenuates the incident electromagnetic energy under the influence of the time-varying electromagnetic wave. When the weft of the PC-PU fabric is parallel to the direction of the incident electromagnetic wave's electric field, the conductive path along the weft maximizes the induced surface current density. This attenuates the electromagnetic wave in the optimal way, thus achieving the most effective shielding performance. Conversely, when the weft of the PC-PU fabric is perpendicular to the direction of the incident electromagnetic wave's electric field, the discontinuity of the conductive path reduces the induced current density and exhibits weaker electromagnetic wave attenuation.

[0087] Table 1 Mechanical properties of PC-PU fibers prepared in Examples 1-5 and Comparative Examples 1-5 Note: " / " indicates that this item is not present.

[0088] Considering that the mechanical properties of textiles are very important indicators in practical applications, tensile tests were conducted on PC-PU fibers from different embodiments. For example... Figure 5 As shown in Table 1, the mechanical properties of the comparative example and the examples are not significantly different, indicating that the introduction of polybenzodifuran diketone has little impact on the mechanical properties of the fiber. The fiber strength of Example 1 is 2.6 MPa, and the elongation is as high as 650%. Adding silver-coated copper nanosheets reduces the strength and elongation of the fabric. The fiber strength and elongation of Example 5 are 1.9 MPa and 490%, respectively, but both still exhibit excellent mechanical properties and can meet the weaving requirements, such as... Figure 6 As shown.

[0089] Table 2. Different enthalpy values ​​and phase transition temperatures of fibers prepared in Examples 1-5 and Comparative Examples 1-5. Note: " / " indicates that this item is not present.

[0090] The phase transition enthalpy and phase transition temperature of PC-PU fibers were analyzed using differential scanning calorimetry (DSC). As can be seen from Table 2, the enthalpy and phase transition temperature of PC-PU fibers in Examples 1-5 and Comparative Examples 1-5 are almost identical, indicating that the introduction of polybenzodifuran diketone has no effect on the phase change material inside the fiber.

[0091] At the same time, such as Figure 7 The current-voltage (IU) curves of the PC-PU fabric show a near-linear relationship, and the material exhibits impressively low resistivity. This indicates that the HPU fabric can achieve a thermally driven effect at low voltages, thereby significantly improving energy efficiency. Furthermore, the temperature rise under different driving voltages was measured, and data was recorded using an infrared detector, such as... Figure 8 As shown in the figure, the study found that both the heating rate and equilibrium temperature of the fabric increased with increasing applied driving voltage. After continuously applying driving voltages of 1.2V, 1.4V, 1.6V, 1.8V, 2.0V, and 2.2V for 90 seconds, the PC-PU fabrics reached stable temperatures of 30.2℃, 32.7℃, 36℃, 39.4℃, 43.4℃, and 48.7℃, respectively. It is noteworthy that plateau periods occurred during both heating and cooling. This is because, during heating, when the temperature reaches the melting point, octadecane begins to melt, absorbing a large amount of heat, thus resulting in a plateau.

[0092] In addition, such as Figure 9As shown, a water vapor permeability test was conducted on the PC-PU fabric. The PC-PU fabric of Example 5 was placed over an open glass bottle containing hot dilute hydrochloric acid, and another open glass bottle containing ammonia was placed to its side. If the hydrochloric acid gas (from the hot dilute hydrochloric acid) could permeate the PC-PU fabric, it would encounter the ammonia gas released from the other bottle, and the two would react chemically to form ammonium chloride. During this process, a large amount of white smoke rapidly rose from above the PC-PU fabric. This phenomenon visually demonstrates the excellent gas permeability of the PC-PU fabric, allowing gas molecules to pass through freely.

[0093] It should be noted that the water vapor permeability test was conducted using the PC-PU fabrics in Examples 1 to 4, and the results were similar to those in Example 5, so they will not be described further.

[0094] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0095] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. Those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of this invention should be determined by the appended claims.

Claims

1. A method of making a wearable electromagnetic shielding fabric, characterized by, Specifically comprising the following steps: The thermoplastic polyurethane and the polybenzodifuranone conductive ink are mixed and dissolved in dimethyl sulfoxide to obtain a spinning solution; the weight ratio of the thermoplastic polyurethane, the polybenzodifuranone conductive ink and dimethyl sulfoxide is 5:1.91-4.35:31.25; The octadecane is melted; The spinning solution and the melted octadecane are respectively used as a shell liquid and a core liquid to perform spinning through a coaxial needle to obtain a fiber; the fiber is subjected to solvent exchange in deionized water and dried to obtain a PC-PU fiber; the weight ratio of the spinning solution and the melted octadecane is 50-70:50-70; The PC-PU fiber and the round wax thread are weaved to obtain a wearable electromagnetic shielding fabric; the weight ratio of the PC-PU fiber and the round wax thread is 60-80:60-80. Or specifically comprising the following steps: The thermoplastic polyurethane and the polybenzodifuranone conductive ink are mixed and dissolved in dimethyl sulfoxide to obtain a solution A; the weight ratio of the thermoplastic polyurethane, the polybenzodifuranone conductive ink and dimethyl sulfoxide is 5:1.91-4.35:15; Silver-coated copper nanosheets are added to dimethyl sulfoxide and ultrasonically treated to obtain a dispersion liquid; the weight ratio of the silver-coated copper nanosheets and dimethyl sulfoxide is 0-46.35:16.25; The dispersion liquid is added to the solution A to obtain a spinning solution; The octadecane is melted; The spinning solution and the melted octadecane are respectively used as a shell liquid and a core liquid to perform spinning through a coaxial needle to obtain a PC-PU fiber; the weight ratio of the spinning solution and the melted octadecane is 50-70:50-70; The PC-PU fiber and the round wax thread are weaved to obtain a wearable electromagnetic shielding fabric; the weight ratio of the PC-PU fiber and the round wax thread is 60-80:60-80.

2. The production method according to claim 1, characterized by, The selected concentration of the polybenzodifuranone conductive ink is 10-12 mg / ml.

3. The preparation method according to claim 1, characterized in that, The temperature of the dissolving is 50-70℃.

4. The method of claim 1, wherein, The ultrasonic treatment is performed for 10-15 min at a power of 400 W.

5. The preparation method according to claim 1, characterized in that, The temperature of the spinning is 40-60℃.

6. The method of claim 1, wherein, The speed of the shell liquid spinning is 0.14 mm / min and the speed of the core liquid spinning is 0.10 mm / min.

7. The preparation method according to claim 1, characterized in that, The coaxial needle is composed of an outer needle and an inner needle; the specification of the outer needle is 17G and the specification of the inner needle is 21G.

8. The method of claim 1, wherein, The diameter of the round wax thread is 0.55-0.57 mm.

9. The method of claim 1, wherein, The PC-PU fiber is used as weft and the round wax thread is used as warp to weave a PC-PU fabric; the density of the warp is 2-3 threads / cm and the density of the weft is 2-3 threads / cm.

10. An electromagnetic shielding fabric prepared by the preparation method according to any one of claims 1-9.

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