Stretchable conductive fabric based on two-dimensional nano material and preparation method thereof

Abstract

The invention relates to a stretchable conductive fabric modified by a two-dimensional nano material. The conductive fabric has an elastic stretchable substrate, the surface microcosmic result comprising continuous loading of a two-dimensional conductive material. The conductive fabric is mainly realized through multiple times of surface friction loading under different deformation conditions, firstly, the conductive fabric is washed clean, surface impurities are removed, then high-conductivity graphene, MXene and other two-dimensional materials are used as conductive agents, a nanometer conductive sheet layer is loaded on the surface of the elastic fabric in a friction mode under certain pressure, good conductivity of the fabric is realized, and the conductive fabric is prepared. In order to further improve the conductivity of the fabric under high-multiple deformation, conductive active materials are loaded under different deformation conditions in a friction mode, finally continuous distribution of the conductive layer on the surface of the fabric under various stretching conditions is achieved, and continuous large-scale preparation of the stretchable conductive fabric is achieved. By utilizing the excellent conductivity, the fabric is expected to be widely applied to the wearable fields of electromagnetic shielding, electrochemical energy storage, static electricity resistance, electric heating and the like.

Description

Technical Field

[0001] The present invention belongs to the field of elastic highly conductive functional fabrics, and particularly relates to a preparation method and application of a fabric modified with a highly conductive two-dimensional conductive material. Background Art

[0002] In recent years, with the rapid development of wearable electronic devices, the demand for highly conductive fabrics with good elasticity and conductivity in high-end intelligent devices has been increasing day by day. Since the discovery of two-dimensional conductive nanosheets represented by MXene and graphene, they have shown great application potential in energy storage and conversion, sensors and intelligent monitoring, etc. However, traditional fabrics woven with elastic polymer fibers are difficult to be directly compounded with two-dimensional conductive materials due to their inert surface characteristics. In addition, during the stretching process of elastic fabrics, it often leads to the cracking and peeling of the conductive layer on the surface of the fibers inside the fabric, ultimately affecting the performance of the conductive fabric. Therefore, in the construction of fabrics and conductive materials, surface modification and activation methods are often used to enhance the interaction between the two (J. Mater. Sci.-Mater. El., 2018, 29, 8010.; Synthetic Met., 2015, 202, 110.; Mater. Chem. Phys., 2020, 241, 122371.). In terms of maintaining conductivity under high stretching conditions of elastic fabrics or fibers, it is achieved by means of loading and structural elasticity under stretching conditions (Adv. Mater., 2020, 32, 1907495.; Soft Robot., 2019, 6, 6.). However, surface modification and activation often result in the loss of functions of elastic fibers and conductive materials, and the overly long operation process leads to low efficiency in the fiber preparation process; loading under stretching conditions can ensure good conductivity of fibers or fabrics under large deformation conditions, but its working stability still needs to be further improved. Summary of the Invention

[0003] The purpose of the present invention is to provide a stretchable conductive fabric based on two-dimensional nanomaterials and a simple and easy-to-implement preparation method for solving the problems of poor elasticity of conductive fabrics at the present stage, discontinuous surface conductive layers under stretching conditions, and serious decline in conductivity after stretching, so as to achieve the continuous and green preparation of highly conductive elastic fabrics.

[0004] To achieve the above purpose, according to the first aspect of the present invention, the following technical solutions are adopted:

[0005] A stretchable conductive fabric based on two-dimensional nanomaterials, characterized in that: it has a structure in which two-dimensional conductive nanosheets wrap the surface of the elastic fabric; wherein, the conductive nanosheets are mainly loaded by means of multiple frictions under pressure.

[0006] Further, the thickness of the elastic fabric is 1-10 mm; the fabric structure is woven fabric, knitted fabric, non-woven fabric or three-dimensional braided fabric, and the conductive material is graphene, MXene or a mixture of both.

[0007] Further, the fabric types include polyether ester fabric, polyurethane fabric or diene elastic fabric.

[0008] According to the second aspect of the present invention, the present invention provides a method for preparing the above-mentioned stretchable conductive fabric based on two-dimensional nanomaterials. The present invention adopts the following technical solutions:

[0009] A method for preparing a stretchable conductive fabric based on two-dimensional nanomaterials, characterized by comprising the following specific steps:

[0010] (1) Cleaning of elastic fabric: The elastic fabric is ultrasonically cleaned with deionized water and ethanol for multiple times to wash away the grease and solid particles on the surface, and the surface-clean elastic fibers are obtained after air drying.

[0011] (2) Loading of two-dimensional conductive material: The graphene, MXene or the mixed powder of the two is evenly spread on the surface of the elastic fabric. Using a grinding machine as the loading tool, the two-dimensional conductive material powder is directly loaded on the surface of the elastic fabric after multiple grindings under pressure conditions, ensuring full contact between the conductive sheet layer and the fabric surface and realizing stable loading of the sheet layer.

[0012] (3) Improvement of fastness: Wash the fabric surface with ethanol to remove the graphene that is not fully loaded on the surface layer, and improve the loading fastness of the conductive layer on the fabric surface.

[0013] (4) Repeated loading: Repeat the above steps (2) and (3), and perform friction loading on the fabric under the condition of 10-200% stretching of the fabric to further increase the loading amount of the conductive layer on the fabric surface and realize the construction of the stretchable conductive fabric.

[0014] Further, graphene is prepared by mechanical exfoliation method, electrochemical exfoliation method and chemical reduction of graphene oxide. The graphene prepared by the mechanical exfoliation method is obtained after being treated by a grinding and dispersing machine; the graphene exfoliated by the electrochemical method is obtained by the three-electrode method; the graphene obtained by the chemical reduction method is obtained by reacting the graphene oxide prepared by the Hummers method in reducing agents such as hydroiodic acid, hydrazine hydrate, ascorbic acid, etc.

[0015] Furthermore, MXene is obtained by etching the aluminum layer through a lithium fluoride / hydrochloric acid system and centrifugally washing it until neutral. The specific description is as follows: First, 2.0 g of lithium fluoride and 40 mL of 9.0 M hydrochloric acid are mixed and stirred for 30 min to generate hydrofluoric acid, and then 1.0 g of Ti3AlC2 MAX powder is added and etched for 48 h to synthesize Ti3C2T x MXene nanosheets. Put them into a centrifuge tube, wash the etched powder with deionized water, and then centrifuge repeatedly (at a rotational speed of 3500 r.p.m.) until the pH of the supernatant is close to 6.0.

[0016] Furthermore, the chassis of the grinding machine used is made of rubber, the pressure range for grinding is 0.01 - 1 MPa, and the grinding time is 1 - 10 min.

[0017] In the present invention, after each loading, the excess powder is washed with ethanol fluid to significantly improve the fastness and enhance the continuity of the conductive network, realizing the large-scale construction of two-dimensional sheet conductive fabrics. Furthermore, the pressure for flushing the ethanol fluid is 0.1 - 10 MPa, and the flushing time is 5 - 60 s.

[0018] Furthermore, the number of repetitions of steps (2) and (3) is 2 - 5 times.

[0019] Furthermore, in step (1), the elastic fabric is immersed in a mixed solution of deionized water and ethanol, ultrasonically treated for 10 min, and the fabric with surface particle impurities and grease removed is dried in a blast drying oven for 1 h to finally obtain a fabric with a clean surface.

[0020] The present invention loads two-dimensional conductive materials such as graphene and MXene in a direct mechanical friction manner, which will greatly shorten the processing flow of conductive fabrics and realize the stable loading of high-conductivity two-dimensional materials on the surface of elastic fabrics; in terms of maintaining electrical properties under large stretching conditions of elastic conductive fibers, it is achieved through multiple loadings and washings under certain stretching conditions. After the conductive materials are loaded, through multiple solvent flushes, the conductive nanosheet layers with insufficient fastness are removed, improving the overall loading amount of the conductive agent inside the fabric and the working stability under large deformations. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 SEM image of the graphene-modified stretchable fabric for Example 4. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The embodiments of the present invention are described below: These embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation manners and operation processes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0023] Example 1

[0024] (1) Fabric surface cleaning: A 5×5 cm polyurethane fabric was placed in a mixed solvent of deionized water and ethanol and ultrasonically washed for 5 min to remove particulate impurities and grease on the surface. Then the fabric was dried in a forced-air oven at 80 °C for 6 h to obtain a fabric substrate with a clean surface.

[0025] (2) Loading of the conductive layer: 5 g of MXene powder was evenly spread on the fabric surface. A grinding machine with a rubber chassis was selected as the grinding tool. Under a pressure condition of 0.01 MPa, the conductive powder and the fabric were rubbed against each other for 1 min using the grinding machine, so that the two-dimensional conductive sheet layer could be in full contact with and interact with the fabric surface, realizing the in-situ loading of the conductive agent on the fabric surface.

[0026] (3) Improvement of fastness: First, the unloaded MXene powder on the fabric surface was removed by shaking. To further improve the adhesion of the conductive sheet layer on the fabric surface, the fabric was rinsed with an ethanol stream at a pressure of 0.1 Mpa for 20 s to remove the incompletely loaded or insufficiently firmly loaded sheet layers on the surface layer, improving the overall loading fastness and continuity of the conductive layer on the fabric surface.

[0027] (4) Repeated loading: To obtain a highly conductive fabric, the conductive fabric was repeatedly loaded and washed under tensile conditions. The elastic fabric loaded with MXene was stretched by 100% and then frictionally loaded 4 more times to increase the loading amount and fastness of the MXene sheet layer on the polyurethane fabric surface. Finally, a conductive fabric with a conductivity of 15 Ω under normal conditions and conductivities of 17 and 20 Ω under 50% and 100% stretching conditions was achieved.

[0028] Example 2

[0029] (1) Fabric surface cleaning: A 5×5 cm diene elastic fabric was placed in a mixed solvent of deionized water and ethanol and ultrasonically washed for 5 min to remove particulate impurities and grease on the surface. Then the fabric was dried in a forced-air oven at 80 °C for 6 h to obtain a fabric substrate with a clean surface.

[0030] (2) Loading of the graphene conductive layer: 5 g of graphene powder was evenly spread on the fabric surface. A grinding machine with a rubber chassis was selected as the grinding tool. Under a pressure condition of 0.5 MPa, the graphene and the fabric were rubbed against each other for 5 min using the grinding machine, so that the graphene sheet layer could be in full contact with and interact with the fabric surface, realizing the in-situ loading of the conductive agent on the fabric surface.

[0031] (3) Improved fastness: First, the unloaded graphene powder on the fabric surface is removed by shaking. In order to further improve the adhesion of the conductive layer on the fabric surface, the fabric is rinsed with an ethanol stream at a pressure of 0.2 MPa for 40 seconds to remove the layers on the surface that are not fully loaded or have insufficient loading fastness, thereby improving the overall loading fastness and continuity of the conductive layer on the fabric surface.

[0032] (4) Repeated loading: In order to obtain highly conductive fabrics, the conductive fabrics were repeatedly loaded multiple times under stretching conditions and then washed. The diene elastic fabric loaded with MXene was stretched by 50% and then frictionally loaded for 5 times to increase the loading amount and fastness of the graphene sheets on the surface of the diene elastic fabric. Finally, a conductive fabric with a conductivity of 8Ω under normal conditions and a conductivity of 10 and 30Ω under stretching of 50% and 100% was achieved.

[0033] Example 3

[0034] (1) Fabric surface cleaning: A 5×5 cm diene elastic fabric was placed in a mixed solvent of deionized water and ethanol and ultrasonically washed for 5 min to remove surface particulate impurities and grease. The fabric was then dried in a forced air oven at 80° C. for 6 h to obtain a fabric substrate with a clean surface.

[0035] (2) Conductive layer loading: 5 g of MXene powder was evenly spread on the fabric surface, and a grinder with a rubber base was used as a grinding tool. Under a pressure of 1 MPa, the conductive powder and the fabric were rubbed against each other for 5 min using the grinder, so that the two-dimensional conductive layer could fully contact and interact with the fabric surface, thereby realizing the in-situ loading of the conductive agent on the fabric surface.

[0036] (3) Fastness improvement: First, the unloaded MXene powder on the fabric surface is removed by shaking. In order to further improve the adhesion of the conductive layer on the fabric surface, the fabric is rinsed with an ethanol stream at a pressure of 1 MPa for 5 seconds to remove the layers on the surface that are not fully loaded or have insufficient loading fastness, thereby improving the overall loading fastness and continuity of the conductive layer on the fabric surface.

[0037] (4) Repeated loading: In order to obtain highly conductive fabrics, the conductive fabrics were repeatedly loaded multiple times under stretching conditions and then washed. The elastic fabric loaded with MXene was stretched by 150% and then frictionally loaded for 4 more times to increase the loading amount and fastness of the MXene layer on the surface of the polyurethane fabric. Finally, a conductive fabric with a conductivity of 6Ω under normal conditions and a conductivity of 7 and 10Ω under stretching of 50% and 100% was achieved.

[0038] Example 4

[0039] (1) Fabric surface cleaning: A 5×5 cm polyether ester elastic fabric was placed in a mixed solvent of deionized water and ethanol and ultrasonically washed for 5 min to remove particulate impurities and grease on the surface. Then the fabric was dried in a blast oven at 80 °C for 6 h to obtain a fabric substrate with a clean surface.

[0040] (2) Loading of the conductive layer: 5 g of a powder with a mass ratio of MXene to graphene of 1:1 was evenly spread on the fabric surface. A grinding machine with a rubber chassis was selected as the grinding tool. Under a pressure condition of 0.5 MPa, the conductive powder and the fabric were rubbed against each other for 5 min using the grinding machine, enabling the two-dimensional conductive sheet layer to come into full contact and interaction with the fabric surface, and realizing the in-situ loading of the conductive agent on the fabric surface.

[0041] (3) Improvement of fastness: First, the unloaded mixed powder on the fabric surface was removed by shaking. To further improve the adhesion of the conductive sheet layer on the fabric surface, the fabric was rinsed with an ethanol stream at a pressure of 1 Mpa for 5 s to remove the incompletely loaded or insufficiently firmly loaded sheet layers on the surface layer, and to improve the overall loading fastness and continuity of the conductive layer on the fabric surface ( Figure 1 ).

[0042] (4) Repeated loading: To obtain a highly conductive fabric, the conductive fabric was repeatedly loaded and washed under tensile conditions. The elastic fabric loaded with the mixed conductor was stretched by 100% and then frictionally loaded 5 more times to increase the loading amount and fastness of the sheet layer on the surface of the polyether ester fabric. Finally, a conductive fabric with a conductivity of 15 Ω under normal conditions, 16 Ω under 50% stretching, and 27 Ω under 100% stretching was achieved.

Claims

1. A stretchable conductive fabric based on two-dimensional nanomaterials, characterized in that: It has a structure with a two-dimensional conductive nanosheet coating on the surface of an elastic fabric; wherein, the conductive nanosheet is mainly loaded by means of multiple frictions under pressure conditions.

2. The stretchable conductive fabric according to claim 1, wherein The thickness of the elastic fabric is 1 to 10 mm; the fabric structure is woven fabric, knitted fabric, non-woven fabric or three-dimensional woven fabric, and the conductive material is graphene, MXene or a mixture of both.

3. The stretchable conductive fabric according to claim 1, characterized in that The fabric types include polyether ester fabric, polyurethane fabric or diene elastic fabric.

4. Preparation method of stretchable conductive fabric based on two-dimensional nanomaterials, characterized in that: It includes the following specific steps: (1) Cleaning of the elastic fabric: The elastic fabric is ultrasonically cleaned with deionized water and ethanol multiple times to wash away the grease and solid particles on the surface, and after air drying, a clean-surface elastic fiber is obtained. (2) Loading of the two-dimensional conductive material: The graphene, MXene or the mixed powder of the two is evenly spread on the surface of the elastic fabric. Using a grinding machine as the loading tool, the two-dimensional conductive material powder is directly loaded on the surface of the elastic fabric after multiple grindings under pressure conditions. (3) Improvement of fastness: The surface of the fabric is washed with ethanol to remove the graphene or MXene that is not fully loaded on the surface layer, and the loading fastness of the conductive layer on the fabric surface is improved. After drying, an elastic fabric with a conductive layer loaded is obtained. (4) Repeated loading: Repeat the above steps (2) and (3), and perform friction loading on the fabric under the condition of 10 to 200% stretching of the fabric to further increase the loading amount of the conductive layer on the fabric surface and realize the construction of a stretchable conductive fabric.

5. The preparation method according to claim 4, characterized in that, Graphene is prepared by mechanical exfoliation method, electrochemical exfoliation method and chemical reduction of graphene oxide.

6. The preparation method according to claim 4, characterized in that, MXene is obtained by etching the aluminum layer with a lithium fluoride / hydrochloric acid system and centrifugally washing it to neutral.

7. The grinding process according to claim 4, characterized in that, The chassis of the grinding machine used is made of rubber material, the pressure range for grinding is 0.01 to 1 MPa, and the grinding time is 1 to 10 min.

8. The fastness improvement process according to claim 4, characterized in that, The pressure of the rinsing ethanol fluid is 0.1 to 10 MPa, and the rinsing time is 5 to 60 s.

9. The repeated load washing process according to claim 4, characterized in that, The number of repetitions of steps (2) and (3) is 2 to 5 times.

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