Aerogel fibers having specific cross-sectional morphological characteristics, a method and an apparatus for manufacturing the same, graphene fibers and a method for manufacturing the same, and applications of these fibers

Abstract

The present invention discloses an aerogel fiber having a specific cross-sectional morphology and a method and device for producing the same. The cross-sectional two-dimensional nanosheet arrangement of the aerogel fiber can be adjusted, and the adjustment method is as follows. At the same time as wet spinning, a rotating flow field device is added before the spinning solution fluid is ejected, and the rotating flow field causes the two-dimensional nanosheet to form a specific sheet layer arrangement in the cross-sectional direction of the gel fiber due to the rotational shear action, and the gel fiber having a specific cross-sectional structure is obtained by preparing graphene oxide aerogel fiber having a specific morphological structure (concentric circles and spiral lines) under freeze-drying conditions. The present invention further performs drying and densification, stretching, and reduction on such a hydrogel fiber with a concentric structure to obtain graphene fiber with high elasticity and high thermal conductivity, and improves its thermal conductivity and elasticity compared to conventional graphene fiber.

Description

Technical Field

[0001] The present invention relates to the field of nanomaterials, and in particular 、 aerogel fibers having specific cross-sectional morphological characteristics , this and this manufacturing is done method and device relates to graphene fibers, a method for producing the same, and the applications of these fibers 。

Background Art

[0002] Aerogel fibers are emerging materials that combine the excellent properties of two types of materials, aerogels and fibers, and refer to fiber varieties with light weight, high specific surface area, and high porosity obtained by subjecting gel fibers prepared by wet spinning to conditions such as freeze-drying or atmospheric pressure drying. Two-dimensional sheet-like molecules are molecules having an extremely large aspect ratio with a single atomic layer thickness. Taking graphene as an example, it has extremely high tensile strength, Young's modulus, high electrical conductivity, and the highest thermal conductivity at room temperature. Aerogel fibers manufactured using two-dimensional sheet-like molecules as assembly units have excellent mechanical-electrical-thermal performance in addition to typical properties such as high porosity.

[0003] However, currently, research on aerogel fibers assembled with such two-dimensional nanosheets has only reached the starting point of successful manufacturing, and no control method for the internal structure of aerogel fibers has been proposed. In particular, the two-dimensional nanosheets have spatial two-dimensional anisotropy, which not only has axial orientation inside the fiber, but also the two-dimensional nanosheets are arranged in an orderly or disorderly state in the circumferential cross-sectional direction of the fiber. The disorderliness of the arrangement of two-dimensional nanosheets in the circumferential cross-sectional direction of aerogel fibers will inevitably reduce the compressive resistance performance of aerogel fibers, affect the application of aerogel fibers in real life, and at the same time, the uncontrolled arrangement form in the cross-sectional direction will also affect the effective transmission of electrons and phonons between highly conductive and highly thermally conductive two-dimensional nanosheets, affecting the conductive performance of aerogel fibers. Therefore, exploring a strategy to effectively and accurately control the regularity of the internal two-dimensional sheet arrangement of aerogel fibers has become a research direction. By accurately controlling the arrangement of two-dimensional nanosheets inside aerogel fibers, aerogel fibers with specific cross-sectional morphological characteristics can be manufactured, thereby promoting the practical application of aerogel fibers.

[0004] In 2011, the research group led by Gao Chao at Zhejiang University invented macro graphene fibers with single-layer graphene as the assembly unit, creating a new route for manufacturing carbonaceous fibers using natural graphite as the raw material. Currently, pure graphene fibers exhibit excellent characteristics in terms of thermal conductivity, far higher than conventional carbon fibers. However, the mechanical performance of graphene fibers is not sufficient. The mechanical strength of its single fiber can currently reach 3.4 GPa, but its elastic modulus does not exceed 400 GPa, which does not conform to the rule of simultaneously improving the elastic modulus and thermal conductivity in conventional carbon fibers. That is, the thermal conductivity of graphene fibers is much higher than that of conventional carbon fibers, but its elastic modulus is lower than that of conventional carbon fibers.

[0005] High thermal conductivity and high elastic modulus are two important indicators that are simultaneously improved in conventional carbon fibers and are generally closely related to the fiber orientation degree and density. Currently, the orientation degree of graphene fibers can reach more than 90%. However, graphene fibers are directly assembled from single-layer graphene. Graphene is a typical two-dimensional polymer structure, and the regularity of its folding arrangement ultimately determines the density of graphene fibers. Therefore, by improving the regularity of the two-dimensional graphene sheet arrangement in graphene fibers, the density of graphene fibers can be improved, thereby manufacturing graphene fibers with high elastic modulus and high thermal conductivity.

Summary of the Invention

[0006] In order to overcome the above-mentioned prior art deficiencies, the present invention provides aerogel fibers having specific cross-sectional morphological characteristics and a manufacturing method and device thereof, and obtains graphene fibers with high elastic modulus and high thermal conductivity.

[0007] In this application, for two-dimensional planar nanosheets, based on the huge aspect ratio unique to two-dimensional planar nanosheets, they are provided with good lyotropic liquid crystal phenomena. Based on the polymer unique to two-dimensional planar nanosheets, the kinetic stability of its liquid crystal is improved. After the two-dimensional planar nanosheet liquid crystal spinning solution passes through a rotating flow field, hydrogel fibers with a specific structure are formed. Such gel fibers are freeze-dried to obtain aerogel fibers with a specific cross-sectional morphology. After the hydrogel fibers are dried and densified, primary oxidized graphene fibers can be obtained. Plasticizing stretching, chemical reduction, and heat treatment are performed on such primary oxidized graphene fibers to obtain graphene fibers with high elastic modulus and high thermal conductivity.

[0008] On the other hand, the aerogel fibers having specific cross-sectional morphological characteristics in the present invention are composed of two-dimensional nanosheets, and the fiber cross-section is arranged in concentric circular sheet layers or radially arranged spiral sheet layers.

[0009] The manufacturing method of the above aerogel fiber is as follows: extrude the dispersion liquid of two-dimensional nanosheets into a coagulation bath, fix the structure after coagulation, and obtain aerogel fibers with specific cross-sectional morphological characteristics. The extrusion speed includes an axial speed along the extrusion direction and a circumferential rotational speed perpendicular to the axial speed.

[0010] Furthermore, the above circumferential speed is brought about by introducing a circumferential rotational shear force into the dispersion liquid of two-dimensional nanosheets.

[0011] Furthermore, the above two-dimensional nanosheets are nanosheets with two-dimensional anisotropy such as graphene oxide, graphene, Mxene, molybdenum disulfide, montmorillonite, and a plurality of mixed two-dimensional nanosheets.

[0012] Furthermore, the concentration of the dispersion liquid of the above two-dimensional nanosheets is greater than 1 mg / g.

[0013] The present invention further relates to an apparatus for manufacturing aerogel fibers with specific cross-sectional morphological characteristics, including at least one extrusion device, one coagulation bath, and one freeze-drying system. The above extrusion device includes a spinning tube, and the spinning tube has a circumferential rotational shear force inside.

[0014] Furthermore, there is a rotor inside the above spinning tube, and the rotor is located at the axial center position of the spinning tube.

[0015] Furthermore, the rotor in the above spinning tube rotates along its axis.

[0016] On the other hand, the present invention further provides graphene fibers with high elastic modulus and high thermal conductivity, which are composed of graphene two-dimensional nanosheets, and the fiber cross-section exhibits a concentric circular sheet layer arrangement. The above graphene two-dimensional nanosheets are arranged in an oriented manner along the axial direction. The above graphene sheets are composed of a plurality of graphite crystals with an axial length of 200 nm or more and a radial length of 100 nm or more. The density of the graphene fiber is 1.9 g / cm 3 or more.

[0017] The present invention further relates to a method for manufacturing the above graphene fiber, and the method is as follows: extrude a dispersion of graphene oxide two-dimensional nanosheets into a coagulation bath, and after drying, obtain primary graphene oxide fibers. Subsequently, perform plasticizing stretching, chemical reduction, and heat treatment in sequence to obtain graphene fibers with high elastic modulus and high thermal conductivity. Here, the extrusion speed includes an axial speed along the extrusion direction and a circumferential rotational speed perpendicular to the axial speed.

[0018] Furthermore, the circumferential speed is brought about by introducing a circumferential rotational shear force into the dispersion of two-dimensional nanosheets.

[0019] Furthermore, the dispersion of the graphene oxide two-dimensional nanosheets is an aqueous dispersion of graphene oxide, a DMF phase dispersion, a DMAc phase dispersion, or a DMSO phase dispersion, and the coagulation bath is ethyl acetate, dichloromethane, acetic acid, ethanol, isopropanol, chloroform, acetone, etc. and a mixed coagulation bath thereof, or an aqueous solution coagulation bath of a high-valent salt, and the high-valent salt is calcium chloride, ferrous chloride, or iron sulfate.

[0020] Furthermore, plasticizing stretching means immersing the fiber in a plasticizer and stretching it. The plasticizer is selected from glycerin, propylene glycol, ethylene glycol, triethylene glycol, acetone, isopropanol, acetic acid, methanol, tetraethylene glycol, pentaethylene glycol, hydrochloric acid, dilute sulfuric acid, organic amines, etc. or a mixed plasticizer thereof.

[0021] Furthermore, the reagents used for chemical reduction are hydroiodic acid, hydrazine hydrate, sodium ascorbate, stannous chloride, etc., and the heat treatment temperature is 1300 - 3000 degrees Celsius.

[0022] Finally, the present invention further provides the application of the above fibers in sensing, phase change energy storage, and catalytic energy.

[0023] The beneficial effects of the present invention are as follows: 1) By accurately controlling the arrangement of two-dimensional nanosheets inside the aerogel fiber, aerogel fibers with specific cross-sectional morphological characteristics can be manufactured, solving the problem that the two-dimensional nanosheets inside the aerogel fiber cannot accurately control the arrangement of the sheet layers. Thereby, the mechanical performance and conduction performance of the aerogel fiber are improved, and the practical application of the aerogel fiber is promoted. 2) By constructing a graphene fiber structure with a specific structure, the regularity of the graphene sheet arrangement inside the fiber is improved. Thereby, the density of the final heat-treated graphene fiber is improved, and the crystallinity of graphene is significantly improved during the heat treatment process, and the crystal size is significantly increased, greatly improving the thermal conductivity and elastic modulus of the graphene fiber.

Brief Description of the Drawings

[0024] [Figure 1] Figure 1 is a schematic diagram of a self-made rotary extrusion spinning device. [Figure 2] Figure 2 is the rotor structure in the rotary extrusion device. [Figure 3] Figure 3 is the cross-sectional morphology of graphene aerogel fibers manufactured at different graphene liquid crystal spinning solution concentrations and different rotor rotation speeds. [Figure 4] Figure 4 is the cross-sectional morphology of three typical types of graphene aerogel fibers. a is an irregular distribution cross-sectional structure, b is a concentric circle cross-sectional structure, and c is a spiral cross-sectional structure. [Figure 5] Figure 5 is the mechanical curve of the graphene fiber. Concentric GF is the graphene fiber after the gel fiber with a concentric circle distribution has undergone coagulation drying and heat treatment, and Random GF is the graphene fiber after the gel fiber with an irregular distribution has undergone coagulation drying and heat treatment.

Embodiments for Carrying out the Invention

[0025] Comparative Example 1 (1) A graphene oxide aqueous liquid crystal spinning solution with a concentration of 6 mg / g is pushed into a circular spinning tube with a diameter of 500 μm at a speed of 0.2 mL / min. When pushing the liquid crystal spinning solution into the spinning tube, the liquid crystal spinning solution passes through a device that rotates the rotor, and the rotation speed of the rotor is 0 rpm. At this time, the graphene oxide liquid crystal spinning solution does not undergo the shearing action of rotor rotation. (2) Subsequently, the graphene oxide liquid crystal spinning solution is extruded into a coagulation bath of 3 wt% calcium chloride aqueous solution. After coagulation, graphene oxide gel fibers are obtained. The gel fibers are immersed in deionized water three times to wash away excess free calcium ions. (3) The graphene oxide gel fibers are frozen in a refrigerator at -80 °C for one hour, and then put into a freeze dryer for freeze drying to obtain graphene oxide aerogel fibers after drying. The cross-sectional shape of the manufactured graphene oxide aerogel fibers is as shown in Figure 4a.

[0026] Example 1 (1) A graphene oxide aqueous liquid crystal spinning solution with a concentration of 6 mg / g is pushed into a circular spinning tube with a diameter of 500 μm at a speed of 0.2 mL / min. When pushing the liquid crystal spinning solution into the spinning tube, the liquid crystal spinning solution passes through a device that rotates the rotor, and the rotation speed of the rotor is 100 rpm. At this time, the graphene oxide liquid crystal spinning solution forms a concentric array structure due to the shearing action of rotor rotation. (2) Subsequently, the graphene oxide liquid crystal spinning solution arranged in concentric circles is extruded into a coagulation bath of 3 wt% calcium chloride aqueous solution. After coagulation, graphene oxide gel fibers are obtained. The gel fibers are immersed in deionized water three times to wash away excess free calcium ions. (3) The graphene oxide gel fibers are frozen in a refrigerator at -80 °C for one hour, and then put into a freeze dryer for freeze drying to obtain graphene oxide aerogel fibers after drying.

[0027] The cross-sectional shape of the fabricated graphene oxide aerogel fiber is shown in Fig. 4b. Since graphene oxide is a polymer, its stability in the dynamics of liquid crystals is relatively good, and it can retain a specific structure after passing through a rotational flow field. Finally, the arrangement structure of the graphene polymer after passing through the rotational flow field continues to the corresponding graphene oxide aerogel fiber of the graphene oxide aerogel fiber.

[0028] Based on this Example 1, the concentration of graphene oxide and the rotor speed are controlled, and the results are shown in Fig. 3. The cross-sectional morphology of the aerogel fiber is mainly determined by the concentration of the graphene oxide liquid crystal spinning solution and the rotor rotation speed. The concentration of the graphene oxide solution determines whether it can form a liquid crystal. As common knowledge in this field, the concentration of the graphene oxide solution can form a liquid crystal when it is 0.1 wt% or more. When the concentration is fixed, as the rotor rotation speed increases, the cross-section of the graphene oxide aerogel fiber first exhibits a concentric circle structure. When the rotation speed is further increased, the fiber cross-section exhibits a spiral structure. Adjusting the graphene oxide concentration to form a liquid crystal is common knowledge in this field, and those skilled in the art can adjust the cross-sectional shape of the gel fiber based on the above rules of the rotation speed.

[0029] Example 2 (1) An aqueous-phase graphene oxide liquid crystal spinning solution with a concentration of 6 mg / g is pushed into a circular spinning tube with a diameter of 500 μm at a speed of 0.2 mL / min. When pushing it into the spinning tube, the liquid crystal spinning solution passes through a device that rotates the rotor, and the rotation speed of the rotor is 500 rpm. At this time, the graphene oxide liquid crystal spinning solution forms a spiral arrangement structure due to the shearing action of the rotor rotation. (2) Subsequently, the graphene oxide liquid crystal spinning solution arranged in a spiral is extruded into a coagulation bath of 3 wt% calcium chloride aqueous solution. After coagulation, graphene oxide gel fibers are obtained. The gel fibers are immersed in deionized water three times to wash away excess free calcium ions. (3) The graphene oxide gel fibers are frozen in a refrigerator at -80 °C for one hour, and then put into a freeze dryer for freeze drying to obtain graphene oxide aerogel fibers after drying. The cross-sectional shape of the fabricated graphene oxide aerogel fiber is shown in Fig. 4c.

[0030] Example 3 (1) Push the aqueous-phase graphene liquid crystal spinning solution with a concentration of 8 mg / g into a circular spinning tube with a diameter of 300 μm at a speed of 0.2 mL / min. When pushing it into the spinning tube, the liquid crystal spinning solution passes through a device that rotates the rotor, and the rotation speed of the rotor is 50 rpm. At this time, the graphene liquid crystal spinning solution forms a concentric array structure under the shearing action of the rotor rotation. (2) Subsequently, extrude the concentrically arranged graphene liquid crystal spinning solution into a coagulation bath of 3 wt% ferrous chloride aqueous solution. After coagulation, graphene gel fibers are obtained. Immerse the gel fibers in deionized water three times to wash away the excess free divalent iron ions. (3) Immerse the cleanly washed graphene gel fibers in a 1% sodium ascorbate aqueous solution, heat to 80 °C, and reduce for 12 hours to obtain chemically reduced graphene gel fibers, and then replace them cleanly with deionized water. (4) Freeze the produced graphene gel fibers in a liquid nitrogen environment at -120 °C for one hour, and then put them into a freeze dryer for freeze drying. After drying, graphene aerogel fibers are obtained. (5) Perform heat treatment on the dried graphene aerogel fibers with a concentric arrangement at 2800 degrees Celsius in an argon gas environment to finally obtain pure graphene aerogel fibers. Through testing, the produced graphene aerogel fibers after heat treatment have a relatively high thermal conductivity, reaching 15 W / (m K). In contrast, the thermal conductivity of randomly arranged graphene aerogel fibers is only less than 10 W / (m K). The graphene aerogel fiber frame with high thermal conductivity can be used as a functional material for heat, electricity, and light response.

[0031] Example 4 (1) Push the Mxene spinning solution with a concentration of 6 mg / g into a circular spinning tube with a diameter of 500 μm at a speed of 0.2 mL / min. When pushing it into the spinning tube, the spinning solution passes through a device that rotates the rotor, and the rotation speed of the rotor is 200 rpm. At this time, the spinning solution forms a concentric array structure under the shearing action of the rotor rotation. (2) Subsequently, the Mxene spinning solution arranged in concentric circles is extruded into a coagulation bath of 6 wt% ammonium chloride aqueous solution. After coagulation, Mxene gel fibers are obtained. The gel fibers are immersed three times in a deionized water mixed cleaning solution to thoroughly wash away excess free ions. (3) The Mxene gel fibers are frozen in a refrigerator at -80 °C for one hour, and then put into a freeze dryer for freeze-drying to obtain Mxene aerogel fibers after drying.

[0032] Example 5 (1) An aqueous phase graphene oxide liquid crystal spinning solution with a concentration of 6 mg / g is pushed into a circular spinning tube with a diameter of 500 μm at a speed of 0.2 mL / min. When pushing into the spinning tube, the spinning tube rotates under an external mechanical action. Due to the rotational action of the spinning tube, the two-dimensional graphene oxide nanosheets undergo a circumferential rotational shear action to form a concentric array structure. (2) Subsequently, the graphene oxide liquid crystal spinning solution arranged in concentric circles is extruded into a coagulation bath of 3 wt% calcium chloride aqueous solution. After coagulation, graphene oxide gel fibers are obtained. The gel fibers are immersed three times in deionized water to wash away excess free calcium ions. (3) The graphene oxide gel fibers are frozen in a refrigerator at -80 °C for one hour, and then put into a freeze dryer for freeze-drying to obtain graphene oxide aerogel fibers after drying.

[0033] Example 6 (1) A spinning solution of graphene oxide and montmorillonite with a concentration of 10 mg / g is pushed into a circular spinning tube with a diameter of 500 μm at a speed of 0.2 mL / min. When pushing into the spinning tube, the spinning solution passes through a device that rotates a rotor, and the rotational speed of the rotor is 400 rpm. At this time, the spinning solution undergoes a shear action of the rotor rotation to form a helical array structure. (2) Subsequently, the spinning solution arranged in a helix is extruded into a coagulation bath of 4 wt% calcium chloride aqueous solution. After coagulation, mixed gel fibers of graphene oxide and montmorillonite are obtained. The gel fibers are immersed three times in a deionized water mixed cleaning solution to thoroughly wash away excess free ions. (3) Freeze the mixed gel fiber of graphene oxide and montmorillonite in a liquid nitrogen environment for one hour, and then put it into a freeze dryer for freeze drying to obtain the mixed aerogel fiber of graphene oxide and montmorillonite after drying.

[0034] Example 7 (1) Push the DMF-phase graphene oxide liquid crystal spinning solution with a concentration of 6 mg / g into a circular spinning tube with a diameter of 100 μm at a speed of 0.2 mL / min. Before pushing it into the spinning tube, the liquid crystal spinning solution passes through a device that rotates the rotor, and the rotation speed of the rotor is 100 rpm. At this time, the graphene oxide liquid crystal is driven by the rotation of the rotating rotor to form a concentric structure, as shown in Figure 2. (2) Subsequently, extrude the concentric-structured graphene oxide liquid crystal spinning solution into an ethyl acetate coagulation bath, and after drying, obtain the as-spun graphene oxide fiber. (3) Immerse the as-spun graphene oxide fiber in acetic acid for plasticization, perform plasticizing drawing on the plasticized graphene oxide fiber, and the drawing ratio is 30%. Subsequently, dry while maintaining the current length. (4) Perform chemical reduction with hydroiodic acid and heat treatment at 2700 °C on the dried graphene oxide fiber to obtain graphene fiber with high elastic modulus and high thermal conductivity. According to the mechanical test, the strength of the graphene fiber manufactured from the concentric gel fiber reaches 3 GPa, the elastic modulus is 833 GPa, and the thermal conductivity reaches 1590 W / (m K). The mechanical curve is shown in Figure 5 Concentric GF.

[0035] Comparative Example 2 This comparative example is the same as Example 7, and the difference lies in the extrusion into a rotorless spinning tube. (1) Push the DMF-phase graphene oxide liquid crystal spinning solution with a concentration of 6 mg / g into a circular spinning tube with a flow path diameter of 100 μm at a speed of 0.2 mL / min. There is no rotor in the spinning tube. At this time, the graphene oxide liquid crystal is not driven by the rotating flow field and does not form a concentric structure, but is in a typical uncontrolled disordered distribution state. (2) Subsequently, extrude the irregularly distributed graphene oxide liquid crystal spinning solution into an ethyl acetate coagulation bath, and after drying, obtain the as-spun graphene oxide fiber. (3) Immerse the as - prepared graphene oxide fibers in acetic acid for plasticization, perform plastic stretching on the plasticized graphene oxide fibers, with a stretching ratio of 30%, and then dry while maintaining the current length. (4) Perform chemical reduction with hydroiodic acid and heat treatment at 2700 °C on the dried graphene oxide fibers to obtain graphene fibers made of randomly distributed gel fibers. According to mechanical tests, these non - microfibrillated graphene fibers have a strength of 3.1 GPa, an elastic modulus of 343 GPa, and a thermal conductivity of 1400 W / (m K). The mechanical curve is shown in Figure 5 Random GF.

[0036] Example 8 (1) Push a DMF - phase graphene oxide liquid crystal spinning solution with a concentration of 8 mg / g into a circular spinning tube with a diameter of 100 μm at a speed of 0.2 mL / min. Before pushing it into the spinning tube, the liquid crystal spinning solution passes through a device that rotates a rotor, and the rotation speed of the rotor is 50 rpm. At this time, the graphene oxide liquid crystal is driven by the rotation of the rotating rotor to form a concentric - circle structure. (2) Subsequently, extrude the concentric - circle - structured graphene oxide liquid crystal spinning solution into an ethyl acetate coagulation bath, and after drying, obtain as - prepared graphene oxide fibers. (3) Immerse the as - prepared graphene oxide fibers in ethanol for plasticization, perform plastic stretching on the plasticized graphene oxide fibers, with a stretching ratio of 10%, and then dry while maintaining the current length. (4) Perform chemical reduction with hydroiodic acid and heat treatment at 2700 °C on the dried graphene oxide fibers to obtain the final graphene fibers. According to mechanical tests, the graphene fibers produced under these conditions reach a strength of 2 GPa, an elastic modulus of 650 GPa, and a thermal conductivity of 1490 W / (m K).

[0037] Example 9 This example is the same as Example 8, and the difference is that the rotor rotation speed is 500 rpm, forming a spiral structure. (1) The DMF-phase graphene oxide liquid crystal spinning solution with a concentration of 8 mg / g was pushed into a circular spinning tube with a diameter of 100 μm at a speed of 0.2 mL / min. Before being pushed into the spinning tube, the liquid crystal spinning solution passed through a device that rotated the rotor, and the rotation speed of the rotor was 500 rpm. At this time, the graphene oxide liquid crystal was driven by the rotation of the rotating rotor to form a helical structure. (2) Subsequently, the graphene oxide liquid crystal spinning solution with a helical structure was extruded into an ethyl acetate coagulation bath, and after drying, the as-spun graphene oxide fibers were obtained. (3) The as-spun graphene oxide fibers were immersed in ethanol for plasticization, and plastic stretching was performed on the plasticized graphene oxide fibers. The stretching ratio was 10%, and then they were dried while maintaining the current length. (4) Chemical reduction with hydroiodic acid and heat treatment at 2700 °C were performed on the dried graphene oxide fibers to obtain the final graphene fibers. According to mechanical tests, the graphene fibers produced under these conditions reach a strength of 1.8 GPa, an elastic modulus of 500 GPa, and a thermal conductivity of 1360 W / (m K).

Claims

1. An aerogel fiber composed of two-dimensional nanosheets, wherein the fiber cross-section has a specific cross-sectional morphological feature characterized in that the two-dimensional nanosheets are arranged in a concentric or radially helical layer pattern.

2. A method for manufacturing the aerogel fiber according to Claim 1, wherein a dispersion of two-dimensional nanosheets is extruded into a coagulation bath, and after coagulation, the aerogel fiber structure is freeze-dried to obtain an aerogel fiber having a specific cross-sectional morphological feature, and the extrusion speed includes an axial speed along the extrusion direction and a circumferential rotational speed perpendicular to the axial speed, which is a characteristic of the method.

3. The method according to Claim 2, wherein the circumferential speed is brought about by introducing a circumferential rotational shear force into the dispersion of two-dimensional nanosheets.

4. The two-dimensional nanosheets are graphene oxide, graphene, Mxene, molybdenum disulfide, montmorillonite, which are two-dimensional anisotropic nanosheets, and a mixture of multiple types of two-dimensional nanosheets composed of different compounds, which is a characteristic of the method according to Claim 2.

5. The method according to Claim 2, wherein the concentration of the dispersion of the two-dimensional nanosheets is greater than 1 mg / g.

6. An apparatus for manufacturing the aerogel fiber according to Claim 1, comprising at least one extrusion device, one coagulation bath, and one freeze-drying system, wherein the extrusion device includes a spinning tube having a circumferential rotational shear force inside the spinning tube, which is an apparatus for manufacturing an aerogel fiber having a specific cross-sectional morphological feature.

7. The apparatus according to Claim 6, wherein the spinning tube has a rotor located at the axial center position of the spinning tube.

8. The apparatus according to Claim 6, wherein the rotor in the spinning tube rotates along its axis.

9. Applications of the fibers according to any one of Claims 1, 6 to 8 in sensing, phase change energy storage, and structural materials.

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