Method for producing self-powered heat-generating thermal knitwear

Abstract

The application relates to a preparation method of a self-powered heating and warm-keeping knitted fabric, and relates to the field of thermal textile materials. The self-powered heating and warm-keeping knitted fabric is prepared by doubling electrically-conductive cotton yarn and thermal nylon yarn, and weaving a double-reverse air layer double-layer knitted fabric through an arbitrary commercial flat knitting machine; the electrically-conductive cotton yarn is cotton yarn immersed with silver nanowires, and the thermal nylon yarn is a nylon filament yarn. In this case, based on the principle of a friction nanogenerator, mechanical energy is converted into electrical energy, and then efficient electrothermal conversion is realized by using the metal characteristics, that is, the unique structure of the knitted fabric is used to improve the conversion efficiency among mechanical energy, electrical energy and thermal energy, and the double-layer knitted fabric itself has the warm-keeping performance, so that self-powered heating and warm-keeping are realized.

Description

Technical Field

[0001] This application relates to the field of thermal insulation textile materials technology, and in particular to a method for preparing a self-powered heating thermal insulation knitted fabric. Background Technology

[0002] Throughout history, people have invented clothing to combat the cold. From leaves and animal hides to fiber products, and now to common cotton-padded coats, down jackets, and windbreakers, these are all the crystallization of human wisdom developed over thousands of years to fight the cold. Traditional warm clothing achieves its function by increasing the thickness of the garment and adding insulating air layers to reduce the thermal conductivity of the clothing, thereby insulating it against the cold.

[0003] In recent years, self-heating fabrics have attracted much attention. Unlike traditional thermal insulation materials, they are actively heating fabrics. Fabrics based on triboelectric nanogenerators (TENGs) can convert external mechanical energy into electrical energy through contact generation and electrostatic induction coupling. This allows for efficient self-powered heating of the fabric using Joule heating capabilities, effectively solving the current challenges of thermal insulation knitted fabrics.

[0004] However, existing heated fabrics not only lack self-powered heating capabilities, but also suffer from discomfort due to the poor fit between the attached electronic components and the fabric, causing a noticeable foreign body sensation. Furthermore, this method results in thicker and heavier fabrics, which, when made into clothing, restrict normal human movement and reduce comfort. Additionally, the attached heating components are either non-recyclable or require an external power source. The proposed solution combines TENG (thermal energy harvesting) with traditional flexible wearable heated fabrics to create novel smart wearable electronic products that meet the requirements for energy harvesting and self-powered operation while preserving the breathability and comfort of the fabric. Summary of the Invention

[0005] The purpose of this application is to provide a method for preparing a self-powered heating and warm knitted fabric to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0007] In a first aspect, this application provides a method for preparing a self-powered heating and warm knitted fabric, comprising combining conductive cotton yarn and thermal insulation methylene yarn, and knitting a double-layer knitted fabric with double reverse air layers using any commercial flat knitting machine; wherein the conductive cotton yarn is cotton yarn impregnated with silver nanowires, and the thermal insulation methylene yarn is methylene filament yarn.

[0008] In one possible implementation, the preparation of the conductive cotton yarn specifically includes:

[0009] S1. Commercial cotton yarn is ultrasonically cleaned in acetone solution and ethanol solution in sequence, and then ultrasonically cleaned with deionized water to obtain the first cleaned cotton yarn.

[0010] S2. Place the cleaned cotton yarn in an oven to dry, and obtain the first dried cotton yarn;

[0011] S3. The dried cotton yarn is soaked in silver nanowire dispersion (solvent: ethanol) and ultrasonically cleaned at a preset temperature to obtain a second cleaned cotton yarn.

[0012] S4. Dry the second washed cotton yarn at room temperature in the dark to obtain the second dried cotton yarn.

[0013] S5. Repeat steps S3 to S4 above for 5 cycles to obtain the conductive cotton yarn.

[0014] In one possible implementation, step S3, the preparation of the silver nanowire dispersion (solvent: ethanol), specifically includes:

[0015] S31. Dissolve silver nitrate and polyvinylpyrrolidone completely in ethylene glycol to obtain a mixed solution;

[0016] S32. Add sodium chloride-ethylene glycol solution to the mixed solution and heat and stir at a preset temperature to obtain the reaction solution;

[0017] S33. In response to the reaction solution cooling to room temperature, the reaction solution is transferred to a centrifuge tube and an appropriate amount of acetone solution is added. The solution is centrifuged at a preset speed for several minutes and repeated 2 to 3 times to obtain the first centrifuged solution.

[0018] S34. Remove the supernatant of the first centrifuged solution, leaving the precipitate. Add an appropriate amount of anhydrous ethanol to the centrifuge tube and mix evenly. Centrifuge at a preset speed for several minutes. Repeat 2 to 3 times to obtain the second centrifuged solution.

[0019] S35. After centrifugation and purification, the second centrifuged solution is dispersed in an ethanol solution to obtain the silver nanowire dispersion (solvent: ethanol).

[0020] In one possible implementation, in step S1:

[0021] The commercial cotton yarn is ultrasonically cleaned sequentially in acetone solution and ethanol solution for 30 minutes, and then ultrasonically cleaned in deionized water for 15 minutes to obtain the first cleaned cotton yarn; wherein the ethanol solution contains 75% ethanol and the acetone solution contains 80% to 85% acetone.

[0022] In one possible implementation, in step S2:

[0023] The washed cotton yarn is placed in an oven at 50°C to dry, thus obtaining the first dried cotton yarn.

[0024] In one possible implementation, in step S3:

[0025] The dried cotton yarn is then soaked in a silver nanowire dispersion (solvent: ethanol) and simultaneously ultrasonically cleaned at 20°C for 30 minutes to obtain a second cleaned cotton yarn.

[0026] In one possible implementation, in step S32:

[0027] The sodium chloride-ethylene glycol solution is added to the mixed solution, and the mixture is heated and stirred at 170°C for 2 hours to obtain the post-reaction solution.

[0028] In one possible implementation, in step S33:

[0029] The response is to cool the post-reaction solution to room temperature, transfer the post-reaction solution to a centrifuge tube and add an appropriate amount of acetone solution, centrifuge at 5000 rpm for 5 minutes, and repeat 2 to 3 times to obtain a first post-centrifugation solution; wherein the acetone solution contains 80% to 85% acetone.

[0030] In one possible implementation, in step S34:

[0031] Remove the supernatant of the first centrifuged solution, leaving the precipitate. Add an appropriate amount of anhydrous ethanol to the centrifuge tube and mix evenly. Centrifuge at 5000 rpm for 5 minutes. Repeat 2 to 3 times to obtain the second centrifuged solution.

[0032] Secondly, this application provides a self-powered heating and thermal insulation knitted fabric, which is prepared by the self-powered heating and thermal insulation knitted fabric preparation method described above.

[0033] The beneficial effects of the technical solution provided in this application include at least the following:

[0034] The self-powered heating and thermal insulation knitted fabric provided in this application is a double-layered knitted fabric with double reverse air layers, created by combining conductive cotton yarn and thermal insulation methylene yarn using any commercial flat knitting machine. The conductive cotton yarn is coated with silver nanowires, and the thermal insulation methylene yarn is methylene filament yarn. Based on the principle of triboelectric nanogenerators, mechanical energy is converted into electrical energy, and then efficiently converted to heat using the properties of metals. This utilizes the unique structure of the knitted fabric to improve the conversion efficiency between mechanical energy, electrical energy, and thermal energy. Furthermore, the inherent thermal insulation properties of the double-layered knitted fabric enable self-powered heating and thermal insulation. Attached Figure Description

[0035] The accompanying drawings are provided to further illustrate the present application and form part of the specification. They are used together with the embodiments of the present application to explain the application and do not constitute a limitation thereof. In the drawings:

[0036] Figure 1 A flowchart illustrating a method for preparing a self-powered heating and warm knitted fabric according to an exemplary embodiment of this application is shown.

[0037] Figure 2 The diagram illustrates the resistance curves of self-powered heating and thermal insulation knitted fabrics prepared by a method for preparing self-powered heating and thermal insulation knitted fabrics according to an exemplary embodiment of this application. The fabrics were prepared by a single immersion and drying of commercial cotton yarn and silver nanowire dispersions (solvent: ethanol) of different concentrations.

[0038] Figure 3 The diagram illustrates the resistance curve of a self-powered heating and thermal insulation knitted fabric prepared by repeatedly soaking commercial cotton yarn in a 10 mg / ml concentration silver nanowire dispersion (solvent: ethanol) and drying it, according to an exemplary embodiment of this application.

[0039] Figure 4 The diagram illustrates the AC voltage output curve at a constant frequency of a self-powered heating and thermal insulation knitted fabric prepared by a method for preparing a self-powered heating and thermal insulation knitted fabric according to an exemplary embodiment of this application. The fabric was prepared by soaking commercial cotton yarn in a 10 mg / ml concentration silver nanowire dispersion (solvent: ethanol) five times and then drying it.

[0040] Figure 5 The diagram illustrates the temperature change curves of a self-powered heating and thermal insulation knitted fabric prepared by a method for preparing a self-powered heating and thermal insulation knitted fabric according to an exemplary embodiment of this application. The fabric was prepared by soaking commercial cotton yarn in a 10 mg / ml concentration of silver nanowire dispersion (solvent: ethanol) five times and then drying it. The temperature change curves were obtained under a constant current (1A) over different time periods. Detailed Implementation

[0041] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0042] In this specification, identical components are represented by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "upper," and "lower" used in the following description refer to directions in the accompanying drawings, while the terms "bottom surface," "top surface," "inner," and "outer" refer to directions towards or away from a specific component, respectively. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this specification, "multiple" means two or more.

[0043] The present application will be further described below with reference to the accompanying drawings and embodiments.

[0044] Figure 1 A flowchart of a method for preparing a self-powered heating and thermal insulation knitted fabric according to an exemplary embodiment of this application is shown. The method includes: combining conductive cotton yarn and thermal insulation methylene yarn, and knitting a double-layer knitted fabric with double reverse air layers using any commercial flat knitting machine; the conductive cotton yarn is cotton yarn impregnated with silver nanowires, and the thermal insulation methylene yarn is methylene filament yarn.

[0045] In detail, the preparation of the above-mentioned conductive cotton yarn includes the following steps:

[0046] Step S1: The commercial cotton yarn is ultrasonically cleaned in acetone solution and ethanol solution in sequence, and then ultrasonically cleaned with deionized water to obtain the first cleaned cotton yarn.

[0047] In this embodiment, commercial cotton yarn is ultrasonically cleaned sequentially in acetone solution and ethanol solution for 30 minutes, and then ultrasonically cleaned with deionized water for 15 minutes to obtain the first cleaned cotton yarn; wherein, the ethanol solution contains 75% ethanol and the acetone solution contains 80% to 85% acetone.

[0048] Step S2: Place the washed cotton yarn in an oven to dry, and obtain the first dried cotton yarn.

[0049] In this embodiment, the washed cotton yarn is dried in an oven at 50°C to obtain the first dried cotton yarn.

[0050] Step S3: Soak the dried cotton yarn in silver nanowire dispersion (solvent: ethanol) and simultaneously perform ultrasonic cleaning at a preset temperature to obtain the second cleaned cotton yarn.

[0051] In this embodiment, the dried cotton yarn was soaked in a silver nanowire dispersion (solvent: ethanol) and ultrasonically cleaned for 30 minutes at 20°C to obtain the second cleaned cotton yarn.

[0052] Step S4: Dry the second washed cotton yarn at room temperature in the dark to obtain the second dried cotton yarn.

[0053] Step S5: Repeat steps S3 to S4 above for 5 cycles to obtain conductive cotton yarn.

[0054] Furthermore, in step S3 above, the preparation of the silver nanowire dispersion (solvent: ethanol) specifically includes the following steps:

[0055] Step S31: Completely dissolve silver nitrate (AgNO3) and polyvinylpyrrolidone (PVP) in ethylene glycol (EG) to obtain a mixed solution.

[0056] Step S32: Add sodium chloride-ethylene glycol solution (NaCl-EG, 0.1 mol / L) to the mixed solution and heat and stir at a preset temperature to obtain the reaction solution.

[0057] In this embodiment, a sodium chloride-ethylene glycol solution was added to the mixed solution, and the mixture was heated and stirred at 170°C for 2 hours to obtain the post-reaction solution.

[0058] Step S33: In response to the reaction solution cooling to room temperature, transfer the reaction solution to a centrifuge tube and add an appropriate amount of acetone solution. Centrifuge at a preset speed for several minutes and repeat 2 to 3 times to obtain the first centrifuged solution.

[0059] In this embodiment, in response to the reaction solution cooling to room temperature, the reaction solution is transferred to a centrifuge tube and an appropriate amount of acetone solution is added. The solution is centrifuged at 5000 rpm for 5 minutes and repeated 2 to 3 times to obtain the first centrifuged solution; wherein the acetone solution contains 80% to 85% acetone.

[0060] Step S34: Remove the supernatant of the solution after the first centrifugation, leaving the precipitate. Add an appropriate amount of anhydrous ethanol to the centrifuge tube and mix evenly. Centrifuge at the preset speed for several minutes. Repeat 2 to 3 times to obtain the solution after the second centrifugation.

[0061] In this embodiment, the supernatant of the first centrifuged solution is removed, leaving the precipitate. An appropriate amount of anhydrous ethanol is added to the centrifuge tube and mixed evenly. The mixture is centrifuged at 5000 rpm for 5 minutes and repeated 2 to 3 times to obtain the second centrifuged solution.

[0062] Step S35: After centrifugation and purification, the solution after the second centrifugation is dispersed in an ethanol solution to obtain a silver nanowire dispersion (solvent: ethanol).

[0063] In this embodiment, the solute ratio of the solution can be calculated based on the obtained second centrifuged solution to prepare silver nanowire dispersions of different concentrations (solvent: ethanol).

[0064] Effect verification:

[0065] In one example, the above method is used to prepare a self-powered heating and warm knitted fabric:

[0066] The difference is that in step S35, based on the obtained second centrifuged solution, the solute ratio of the solution is calculated, and silver nanowire dispersions (solvent: ethanol) with concentrations of 1 mg / ml, 3 mg / ml, 5 mg / ml, 7 mg / ml and 10 mg / ml are prepared respectively.

[0067] The difference is that in step S5, steps S3 to S4 are repeated once, and the surface of the commercial cotton yarn changes from white to light silver-gray, thus obtaining conductive cotton yarn.

[0068] In this case, see Appendix Figure 2 As shown in the figure, the higher the concentration of the silver nanowire dispersion (solvent: ethanol), the lower the resistance of the conductive cotton yarn and the better the conductivity.

[0069] In another example, the above method was used to prepare a self-powered heating and warm knitted fabric:

[0070] The difference is that in step S35, the solute ratio of the solution is calculated based on the obtained second centrifuged solution, and then a silver nanowire dispersion with a concentration of 10 mg / ml (solvent: ethanol) is prepared.

[0071] The difference is that in step S5, steps S3 to S4 are repeated 1, 2, 3, 4 and 5 times respectively, and the surface of the commercial cotton yarn changes from white to silver-gray, thus obtaining conductive cotton yarn.

[0072] In this case, see Appendix Figure 3 As shown in the figure, the more times steps S3 to S4 are repeated (i.e., the more times "impregnation and drying" are performed), the lower the resistance of the conductive yarn and the better the conductivity.

[0073] In another example, the above method was used to prepare a self-powered heating and warm knitted fabric:

[0074] The difference is that in step S35, the solute ratio of the solution is calculated based on the obtained second centrifuged solution, and then a silver nanowire dispersion with a concentration of 10 mg / ml (solvent: ethanol) is prepared.

[0075] The difference is that in step S5, steps S3 to S4 are repeated for 5 cycles, and the surface of the commercial cotton yarn changes from white to silver-gray, thus obtaining conductive cotton yarn.

[0076] In this case, see Appendix Figure 4 Through contact-separation friction at a frequency of 1Hz, this self-powered heating and insulating knitted fabric can output a stable voltage. See appendix. Figure 5 Under this voltage effect, the self-powered heating and warming knitted fabric can heat up to 40 degrees Celsius within 200 seconds and remain stable.

[0077] In summary, the self-powered heating and insulating knitted fabric provided in this application is a double-layered knitted fabric with double reverse air layers, created by combining conductive cotton yarn and insulating methylene yarn using any commercial flat knitting machine. The conductive cotton yarn is coated with silver nanowires, and the insulating methylene yarn is methylene filament yarn. Based on the principle of triboelectric nanogenerators, mechanical energy is converted into electrical energy, and then efficiently converted to heat using the properties of metals. This utilizes the unique structure of the knitted fabric to improve the conversion efficiency between mechanical energy, electrical energy, and heat energy. Furthermore, the inherent insulating properties of the double-layered knitted fabric enable self-powered heating and insulation.

[0078] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method for preparing a self-powered heating and warm knitted fabric, characterized in that, The invention includes combining conductive cotton yarn and thermal insulation methylene yarn, and weaving a double-layer knitted fabric with double reverse air layers using any commercial flat knitting machine; the conductive cotton yarn is cotton yarn coated with silver nanowires, and the thermal insulation methylene yarn is methylene filament yarn. The preparation of the conductive cotton yarn specifically includes: S1. Commercial cotton yarn is ultrasonically cleaned in acetone solution and ethanol solution in sequence, and then ultrasonically cleaned with deionized water to obtain the first cleaned cotton yarn. S2. Place the first washed cotton yarn in an oven to dry, and obtain the first dried cotton yarn. S3. The first dried cotton yarn is soaked in silver nanowire dispersion and ultrasonically cleaned at a preset temperature to obtain the second cleaned cotton yarn. S4. Dry the second cleaned cotton yarn at room temperature in the dark to obtain the second dried cotton yarn. S5. Repeat steps S3 to S4 above for 5 cycles to obtain the conductive cotton yarn. In step S3, the preparation of the silver nanowire dispersion specifically includes: S31. Dissolve silver nitrate and polyvinylpyrrolidone completely in ethylene glycol to obtain a mixed solution; S32. Add sodium chloride-ethylene glycol solution to the mixed solution and heat and stir at a preset temperature to obtain the reaction solution; S33. In response to the reaction solution cooling to room temperature, the reaction solution is transferred to a centrifuge tube and an appropriate amount of acetone solution is added. The solution is centrifuged at a preset speed for several minutes and repeated 2 to 3 times to obtain the first centrifuged solution. S34. Remove the supernatant of the first centrifuged solution, leaving the precipitate. Add an appropriate amount of anhydrous ethanol to the centrifuge tube and mix evenly. Centrifuge at a preset speed for several minutes. Repeat 2 to 3 times to obtain the second centrifuged solution. S35. After centrifugation and purification, the second centrifuged solution is dispersed in an ethanol solution to obtain the silver nanowire dispersion. In step S1: The commercial cotton yarn is ultrasonically cleaned sequentially in acetone solution and ethanol solution for 30 minutes, and then ultrasonically cleaned with deionized water for 15 minutes to obtain the first cleaned cotton yarn.

2. The method for preparing self-powered heating and warm knitted fabric according to claim 1, characterized in that, The ethanol solution contains 75% ethanol, and the acetone solution contains 80% to 85% acetone.

3. The method for preparing self-powered heating and warm knitted fabric according to claim 1, characterized in that, In step S2: The washed cotton yarn was placed in an oven at 50°C to dry, resulting in the first dried cotton yarn.

4. The method for preparing self-powered heating and warm knitted fabric according to claim 1, characterized in that, In step S3: The dried cotton yarn was soaked in a silver nanowire dispersion and then ultrasonically cleaned for 30 minutes at 20°C to obtain the second cleaned cotton yarn.

5. The method for preparing self-powered heating and warm knitted fabric according to claim 1, characterized in that, In step S32: Add sodium chloride-ethylene glycol solution to the mixed solution and heat and stir at 170°C for 2 hours to obtain the post-reaction solution.

6. The method for preparing self-powered heating and warm knitted fabric according to claim 1, characterized in that, In step S33: In response to the reaction solution cooling to room temperature, the reaction solution was transferred to a centrifuge tube and an appropriate amount of acetone solution was added. The solution was centrifuged at 5000 rpm for 5 minutes and repeated 2 to 3 times to obtain the first centrifuged solution. The acetone solution contains 80% to 85% acetone.

7. The method for preparing self-powered heating and warm knitted fabric according to claim 1, characterized in that, In step S34: Remove the supernatant of the solution after the first centrifugation, leaving the precipitate. Add an appropriate amount of anhydrous ethanol to the centrifuge tube and mix well. Centrifuge at 5000 rpm for 5 minutes. Repeat 2 to 3 times to obtain the solution after the second centrifugation.

8. A self-powered heating and warm knitted fabric, characterized in that, It is prepared by the method for preparing self-powered heating and warm knitted fabric according to any one of claims 1 to 7.

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