阅读说明：本技术 石墨烯气凝胶中空纤维、其制备方法及应用 (Graphene aerogel hollow fiber, preparation method and application thereof ) 是由 张学同 李广勇 于 2019-09-29 设计创作，主要内容包括：本发明公开了一种石墨烯气凝胶中空纤维、其制备方法及应用。所述石墨烯气凝胶中空纤维具有环形、闭合的石墨烯气凝胶壁及贯穿纤维轴向的管道空腔,所述石墨烯气凝胶壁具有由石墨烯片层经三维搭接形成的、连续的三维多孔网络,所述管道空腔由石墨烯气凝胶壁围合而成。所述制备方法包括：利用同轴针头辅助的溶胶凝胶技术,制备得到石墨烯水凝胶中空纤维,之后对其进行超临界流体干燥和/或冷冻干燥处理,获得石墨烯气凝胶中空纤维。本发明的石墨烯气凝胶中空纤维具有优异的力学柔性、水传输性能及光热转换性能,在光热转换、流体输运、海水淡化等领域有着重要的应用,且制备工艺简洁,反应条件温和,可实现连续化生产。(The invention discloses a graphene aerogel hollow fiber, and a preparation method and application thereof. The graphene aerogel hollow fiber is provided with an annular closed graphene aerogel wall and a pipeline cavity penetrating through the axial direction of the fiber, the graphene aerogel wall is provided with a continuous three-dimensional porous network formed by graphene sheets through three-dimensional lap joint, and the pipeline cavity is formed by enclosing the graphene aerogel wall. The preparation method comprises the following steps: the graphene hydrogel hollow fiber is prepared by using a coaxial needle-assisted sol-gel technology, and then is subjected to supercritical fluid drying and/or freeze drying treatment to obtain the graphene aerogel hollow fiber. The graphene aerogel hollow fiber disclosed by the invention has excellent mechanical flexibility, water transmission performance and photo-thermal conversion performance, is important to be applied to the fields of photo-thermal conversion, fluid transportation, seawater desalination and the like, is simple in preparation process and mild in reaction conditions, and can realize continuous production.)

1. A graphene aerogel hollow fiber is characterized in that: the graphene aerogel hollow fiber is provided with an annular closed graphene aerogel wall and a pipeline cavity penetrating through the axial direction of the fiber, the graphene aerogel wall is provided with a continuous three-dimensional porous network formed by graphene sheets through three-dimensional lap joint, and the pipeline cavity is formed by enclosing the graphene aerogel wall.

2. The graphene aerogel hollow fiber of claim 1, wherein: the graphene aerogel wall is mainly formed by regularly arranging and overlapping graphene sheets; preferably, the three-dimensional porous network has a regular arrangement structure; preferably, the graphene aerogel wall comprises a graphene aerogel film wall;

preferably, the graphene aerogel film wall has a graphene three-dimensional porous network structure consisting of micropores, mesopores and macropores;

preferably, the thickness of the graphene aerogel film wall is 500 nm-100 μm;

preferably, the diameter of the pipeline cavity is 10 micrometers-5 mm;

preferably, the porosity of the graphene aerogel hollow fiber is 50-99%, and the specific surface area is 1-800 m² g^-1Pore volume of 0.1 to 3.0m³ g^-1。

3. The graphene aerogel hollow fiber of claim 1, wherein: the fracture strain of the graphene aerogel hollow fiber is 0.1-70%, and the fracture stress is 10 kPa-800 MPa; preferably, the conductivity of the graphene aerogel hollow fiber is 0.01-10000S/m; preferably, the contact angle between the surface of the graphene aerogel hollow fiber and water is 0-140 degrees; preferably, the full spectrum absorptivity of sunlight of the graphene aerogel hollow fiber is 10-100%;

and/or the graphene aerogel hollow fiber has fluid transmission performance, wherein the fluid comprises any one or a combination of more than two of an aqueous solution, an organic solution and an oil-water mixture; preferably, the aqueous solution comprises any one or a combination of more than two of pure water, metal salt solution, dye aqueous solution and particle suspension; preferably, the organic solution comprises any one or a combination of more than two of ethanol, methanol, acetone, N-hexane, cyclohexane, N-methylpyrrolidone and tetrahydrofuran; preferably, the oil-water mixture comprises any one or a combination of more than two of water/oil emulsion, oil/water emulsion and oil-water co-dissolved solution; preferably, the fluid transfer is performed actively and/or passively under the assistance of an atmospheric environment, external pressure or gravity; preferably, the fluid of the graphene aerogel hollow fiberThe transmission permeation amount is 10-10⁹L m^-2h^-1bar^-1(ii) a Preferably, the fluid transmission rate of the graphene aerogel hollow fiber is 0.1-100 cm/s.

4. The method for producing a graphene aerogel hollow fiber according to any one of claims 1 to 3, comprising:

1) preparing the graphene hydrogel hollow fiber by using a coaxial needle assisted sol-gel technology;

2) and carrying out supercritical fluid drying and/or freeze drying treatment on the graphene hydrogel hollow fiber to obtain the graphene aerogel hollow fiber.

5. The preparation method according to claim 4, wherein the step 1) specifically comprises:

providing graphene oxide liquid crystal;

injecting the graphene oxide liquid crystal into a coagulating bath by using an injection head, wherein the injection head is provided with an outer layer channel and an inner layer channel which are coaxially arranged, and then carrying out chemical sol-gel aging to obtain a graphene hydrogel hollow fiber;

preferably, the concentration of the graphene oxide liquid crystal is 5 mg/mL-50 mg/mL;

preferably, the preparation method comprises the following steps: injecting the graphene oxide liquid crystal into a coagulation bath at an injection speed of 10 mu L/min-10 mL/min;

preferably, the coagulation bath comprises dilute hydrochloric acid, zinc nitrate, calcium chloride, cetyltrimethylammonium bromide, dilute sulfuric acid, sodium hydroxide, potassium hydroxide, aniline hydrochloride, chitosan, ascorbic acid, hydroiodic acid, sodium ascorbate, Fe²⁺Any one or the combination of more than two of sodium bisulfite and solvent; preferably, the solvent comprises water and/or ethanol;

preferably, the concentration of the coagulation bath is 0.001 wt% to 35 wt%;

preferably, the flow rate of the coagulation bath is 10. mu.L/min to 10 mL/min.

6. The method of claim 5, wherein: the chemical sol-gel aging in the step 1) comprises any one or combination of a chemical reduction method and a hydrothermal reduction method; preferably, the reducing agent used in the chemical reduction method comprises ascorbic acid, hydroiodic acid, sodium ascorbate and Fe²⁺Any one or a combination of two or more of sodium bisulfite; preferably, the temperature of the chemical reduction method is 5-100 ℃, and the time is 0.5-72 hours; preferably, the temperature of the hydrothermal reduction method is 80-200 ℃, and the time is 1-24 h;

and/or in the step 2), the drying treatment temperature of the supercritical fluid is 30-50 ℃, and the time is 1-24 h; preferably, the temperature of the freeze drying treatment is-50 ℃, and the time is 0.5-24 h.

7. Use of the graphene aerogel hollow fibers of any of claims 1-3 in the fields of phase change energy storage, photo-thermal water evaporation, smart fluid transport, smart response, or flexible wearable devices.

8. A graphene aerogel phase-change composite hollow fiber, characterized by comprising the graphene aerogel hollow fiber of any one of claims 1 to 3, wherein a phase-change material is filled in a pipeline cavity and/or a graphene aerogel wall structure of the graphene aerogel hollow fiber; preferably, the phase change material comprises any one or a combination of more than two of paraffin, polyethylene glycol, polyalcohol, erythritol, alkane, higher fatty alcohol, higher fatty acid and polyolefin.

9. A preparation method of a graphene aerogel phase-change composite hollow fiber is characterized by comprising the following steps: filling a phase change material in the graphene aerogel hollow fiber according to any one of claims 1 to 3 to obtain the graphene aerogel phase change composite hollow fiber; preferably, the preparation method comprises the following steps: filling a phase change material in the graphene aerogel hollow fiber at least in a melting filling and/or solution filling mode.

10. A method for evaporating photothermal water, comprising:

performing array integration treatment on the graphene aerogel hollow fiber according to any one of claims 1 to 3 to prepare a graphene aerogel hollow fiber array composite material;

placing the graphene aerogel hollow fiber array composite material on a water surface, and performing photo-thermal water evaporation under the illumination condition; preferably, the water comprises seawater;

preferably, the graphene aerogel hollow fiber array composite material comprises graphene aerogel hollow fibers and a cured material arranged among the graphene aerogel hollow fibers; particularly preferably, the cured product comprises any one or the combination of more than two of silica gel, rubber, epoxy resin, water glass, cotton cloth and cotton thread;

preferably, the array integration process comprises preparation and post-treatment of fiber array reels; particularly preferably, the preparation of the fiber array reel comprises any one of or a combination of two of weaving and bundling of fibers; particularly preferably, the post-treatment comprises any one or the combination of more than two of reel solidification, hydrophilic modification, thermal insulation treatment and self-floating functional modification.

Technical Field

The invention relates to a graphene aerogel hollow fiber, a preparation method and application thereof, and belongs to the technical field of nano energy.

Background

The graphene is sp²The honeycomb crystal structure formed by the close arrangement of hybridized and connected carbon atoms has the thickness of only one carbon atom layer (0.34nm), and is the thinnest material discovered at present. Graphene can be thought of as a lattice of atoms formed by carbon atoms and their covalent bonds. The preparation method of graphene is gradually extended from the initial tape tearing method/light rubbing method to other various methods, such as epitaxial growth, CVD growth, redox method, and the like. The structure of graphene is very stable, and the carbon-carbon bond is onlyThe connection between the carbon atoms in the graphene has certain flexibility, and when external force is applied to the graphene, the carbon atom surface can be bent and deformed, so that the carbon atoms do not need to be rearranged to adapt to the external force, and the structural stability is kept. The particular geometry and electronic structure of graphene also gives it excellent properties, such as its electron mobility of 2 × 10⁵cm²V.s, conductivity up to 10⁶S/m, good thermal conductivity (5000W/(m.K)), and ultra-high specific surface area (2630 m)²,/g), etc. According to the characteristics of ultrathin graphene and ultrahigh strength, the graphene can be widely applied to various fields, such as the fields of ultralight body armor and ultralight aircraft materials. Based on the excellent conductivity of graphene, the graphene is likely to become a silicon substitute in the field of microelectronics, and an ultra-miniature transistor is manufactured to be used for producing a future super computer. In addition, the graphene material is an excellent electrode material, and has a great application market in the fields of new energy resources such as supercapacitors, lithium ion batteries and the like.

Aerogel is a low-density solid material with a continuous three-dimensional porous network structure, the dispersion medium of which is gas. Since the American chemist Samuel Stephens Kistler first used the supercritical fluid drying technique to prepare a "solid smoke" -silica aerogel in 1932, the aerogel has received attention and research as a new member of the material family. As a novel material, the graphene aerogel can show unique physical and chemical properties of graphene under a macroscopic state, has important application potential in the fields of energy, sensing, catalysis, environment and the like, and is widely concerned by people. With the continuous development of graphene aerogels, a series of graphene aerogel materials with different dimensions, different components and different microstructures are reported in sequence, and the graphene aerogel material family is greatly enriched.

The hollow fiber has a shell structure which penetrates through a fiber axial pipeline cavity and is in a closed ring shape, and is widely applied to the fields of fluid transportation, flow chemistry, water treatment, micro-nano drivers and the like. However, most of the materials of the hollow fibers at present mainly comprise polymers, which greatly limits the application of the hollow fibers in the fields of intelligent response, intelligent fluid transmission, electrochemical energy storage and the like. In addition, the limitation of the material affects the multifunctional application of the hollow fiber, and the application expansion of the hollow fiber is greatly limited.

In view of the rapid development of multifunctional graphene aerogel materials and the limitation of hollow fibers, an aerogel hollow fiber material with novel structure and performance, a preparation method and a novel application are urgently needed and provided, the purposes of simple process, short period and low cost are achieved, the advantages of aerogel materials and hollow fiber structures are fully exerted, the application of aerogel is pushed to a new height, and the requirement of social development on a novel multifunctional integrated material is further met.

Disclosure of Invention

The invention mainly aims to provide a graphene aerogel hollow fiber and a preparation method thereof, so as to overcome the defects in the prior art.

The invention also aims to provide application of the graphene aerogel hollow fiber.

In order to achieve the purpose, the technical scheme adopted by the invention comprises the following steps:

the embodiment of the invention provides a graphene aerogel hollow fiber which is provided with an annular closed graphene aerogel wall and a pipeline cavity penetrating through the axial direction of the fiber, wherein the graphene aerogel wall is provided with a continuous three-dimensional porous network formed by three-dimensional lap joint of graphene sheet layers, and the pipeline cavity is formed by enclosing the graphene aerogel wall.

In some embodiments, the graphene aerogel film wall has a graphene three-dimensional porous network structure consisting of micropores with a pore diameter of less than 2nm, mesopores with a pore diameter of 2-50nm, and macropores with a pore diameter of greater than 50 nm.

Further, the graphene aerogel hollow fiber has excellent mechanical flexibility.

Further, the graphene aerogel hollow fibers can be bent, knotted, woven, mixed and woven, twisted and the like, and the graphene aerogel film walls and the pipeline cavities of the graphene aerogel hollow fibers are not damaged.

Further, the graphene aerogel hollow fiber has excellent fluid transport properties.

The embodiment of the invention also provides a preparation method of the graphene aerogel hollow fiber, which comprises the following steps:

1) preparing the graphene hydrogel hollow fiber by using a coaxial needle assisted sol-gel technology;

2) and carrying out supercritical fluid drying and/or freeze drying treatment on the graphene hydrogel hollow fiber to obtain the graphene aerogel hollow fiber.

In some embodiments, the step 1) specifically includes:

providing graphene oxide liquid crystal, wherein the graphene oxide liquid crystal is obtained by concentrating a graphene oxide aqueous solution, carrying out high-speed centrifugation treatment on the graphene oxide aqueous solution, and collecting lower-layer dispersion liquid to obtain the graphene oxide liquid crystal;

and injecting the graphene oxide liquid crystal into a coagulating bath by using an injection head, wherein the injection head is provided with an outer layer channel and an inner layer channel which are coaxially arranged, and then carrying out chemical sol-gel aging, so as to obtain the graphene hydrogel hollow fiber.

The embodiment of the invention also provides application of the graphene aerogel hollow fiber in the fields of phase change energy storage, photo-thermal water evaporation, intelligent fluid transportation, intelligent response or flexible wearable devices and the like.

The embodiment of the invention also provides the graphene aerogel phase-change composite hollow fiber which comprises the graphene aerogel hollow fiber, wherein the phase-change material is filled in the pipeline cavity of the graphene aerogel hollow fiber and/or the graphene aerogel wall structure.

Further, the embodiment of the invention also provides a preparation method of the graphene aerogel phase-change composite hollow fiber, which comprises the following steps: and filling a phase change material in the graphene aerogel hollow fiber to obtain the graphene aerogel phase change composite hollow fiber.

The embodiment of the invention also provides a photo-thermal water evaporation method, which comprises the following steps:

carrying out array integration treatment on the graphene aerogel hollow fibers to prepare a graphene aerogel hollow fiber array composite material;

and placing the graphene aerogel hollow fiber array composite material on a water surface, and performing photo-thermal water evaporation under the illumination condition.

Compared with the prior art, the invention has the advantages that:

1) the graphene aerogel hollow fiber provided by the invention has an annular-closed graphene aerogel film wall structure and a pipeline cavity penetrating through the axial direction of the fiber; the pipeline cavity penetrating through the axial direction of the fiber is formed by surrounding and closing a graphene aerogel film wall;

2) the graphene aerogel hollow fiber provided by the invention has excellent mechanical flexibility, excellent fluid transport performance and high-efficiency photo-thermal conversion performance;

3) the graphene aerogel hollow fiber provided by the invention has important application advantages in the fields of photo-thermal water evaporation, fluid transportation, phase change energy storage, intelligent response, seawater desalination and the like;

4) the preparation process of the graphene aerogel hollow fiber provided by the invention is simple, mild in reaction condition, easy to operate, low in energy consumption and cost, green and pollution-free, and can realize large-scale continuous production.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a Scanning Electron Microscope (SEM) photograph of the graphene aerogel hollow fiber obtained in example 1 of the present invention.

Fig. 2 is a Scanning Electron Microscope (SEM) photograph of the graphene aerogel hollow fiber obtained in example 2 of the present invention.

Fig. 3 is a Scanning Electron Microscope (SEM) photograph of the graphene aerogel hollow fiber obtained in example 3 of the present invention.

Fig. 4 is a Scanning Electron Microscope (SEM) photograph of the graphene aerogel hollow fiber obtained in example 4 of the present invention.

Fig. 5 is a Scanning Electron Microscope (SEM) photograph of the graphene aerogel hollow fiber obtained in example 5 of the present invention.

Fig. 6 is a Scanning Electron Microscope (SEM) photograph of the graphene aerogel hollow fiber obtained in example 6 of the present invention.

Fig. 7 is a Scanning Electron Microscope (SEM) photograph of the graphene aerogel hollow fiber obtained in example 7 of the present invention.

Fig. 8 is a Scanning Electron Microscope (SEM) photograph of the graphene aerogel hollow fiber obtained in example 8 of the present invention.

Fig. 9 is a Scanning Electron Microscope (SEM) photograph of the aerogel film wall of the graphene aerogel hollow fiber obtained in example 1 of the present invention.

Fig. 10 is a Scanning Electron Microscope (SEM) photograph of the knotted graphene aerogel hollow fibers obtained in example 1 of the present invention.

Fig. 11 is a Scanning Electron Microscope (SEM) photograph of the graphene aerogel hollow fiber-polydimethylsiloxane composite obtained in example 1 of the present invention.

Fig. 12 is a nitrogen adsorption and desorption graph of the graphene aerogel hollow fiber obtained in example 1 of the present invention.

Fig. 13 is a pore size distribution diagram of the graphene aerogel hollow fiber obtained in example 1 of the present invention.

Fig. 14 is a unidirectional tensile stress-strain cycle curve diagram of the graphene aerogel hollow fiber obtained in example 1 of the present invention.

Fig. 15 is a cyclic tensile stress-strain cycle curve diagram of the graphene aerogel hollow fiber obtained in example 1 of the present invention.

Fig. 16 is a graph showing the mass-time curve of the hollow fiber with the corresponding water and the water evaporation rate-time curve of the graphene aerogel hollow fiber reel-polydimethylsiloxane composite obtained in example 1 of the present invention in the application of solar water evaporation.

Fig. 17 is an infrared photograph of the graphene aerogel hollow fiber obtained in example 1 of the present invention under solar radiation.

Fig. 18 is a DSC graph of the graphene aerogel hollow phase change fiber obtained in example 4 of the present invention.

Detailed Description

In view of the deficiencies in the prior art, the inventors of the present invention have made extensive studies and extensive practices to provide technical solutions of the present invention. The technical solution, its implementation and principles, etc. will be further explained as follows.

One aspect of the embodiments of the present invention provides a graphene aerogel hollow fiber, which has an annular closed graphene aerogel wall and a pipeline cavity penetrating through an axial direction of the fiber, wherein the graphene aerogel wall has a continuous three-dimensional porous network formed by three-dimensionally overlapping graphene sheets, and the pipeline cavity is enclosed by the graphene aerogel wall.

As one of the preferable schemes, the graphene aerogel wall is mainly formed by regularly arranging and overlapping graphene sheets.

As one of preferable schemes, the three-dimensional porous network has a regular arrangement structure.

As one of the preferable schemes, the graphene aerogel wall includes a graphene aerogel thin film wall. Further, the graphene aerogel thin film wall has a continuous graphene three-dimensional porous network structure formed by three-dimensional lap joint of graphene sheets.

Further, the pipeline cavity of the graphene aerogel hollow fiber is in the axial direction of the fiber.

Furthermore, the graphene aerogel film wall has a graphene three-dimensional porous network structure consisting of macro pores (the pore diameter is more than 50nm), meso pores (the pore diameter is 2-50nm) and micropores (the pore diameter is less than 2 nm).

Further, the thickness of the graphene aerogel film wall is 500 nm-100 μm.

Further, the diameter of the pipeline cavity is 10 micrometers-5 mm.

Further, the porosity of the graphene aerogel hollow fiber is 50-99%.

Further, the specific surface area of the graphene aerogel hollow fiber is 1-800 m² g^-1。

Further, the pore volume of the graphene aerogel hollow fiber is 0.1-3.0 m³ g^-1。

In some preferred embodiments, the graphene aerogel hollow fibers have excellent mechanical flexibility.

Further, the graphene aerogel hollow fibers can be bent, knotted, woven, mixed and woven, twisted and the like, and the graphene aerogel film walls and the pipeline cavities of the graphene aerogel hollow fibers are not damaged.

Further, the fracture strain of the graphene aerogel hollow fiber is 0.1-70%, and the fracture stress is 10 kPa-800 MPa.

Further, the conductivity of the graphene aerogel hollow fiber is 0.01-10000S/m.

Further, the contact angle of graphene aerogel hollow fiber surface and water is 0 ~ 140. The graphene aerogel hollow fiber has a sunlight full-spectrum absorption rate of 10-100%. The graphene aerogel hollow fiber has high absorption performance in a full solar spectrum range and shows excellent photo-thermal conversion performance.

In some preferred embodiments, the graphene aerogel hollow fibers have ultra-high water permeability and flow rate.

In some preferred embodiments, the graphene aerogel hollow fibers have excellent fluid transport properties.

Further, the fluid transport includes transport of aqueous solutions, organic solutions, oil and water mixtures, and the like.

Further, the aqueous solution includes any one or a combination of two or more of pure water, a metal salt solution, a dye aqueous solution, a particle suspension, and the like, but is not limited thereto.

Further, the organic solution includes any one or a combination of two or more of ethanol, methanol, acetone, N-hexane, cyclohexane, N-methylpyrrolidone, tetrahydrofuran, and the like, but is not limited thereto.

Further, the oil-water mixture includes any one or a combination of two or more of a water/oil emulsion, an oil/water emulsion, an oil-water co-dissolved solution, and the like, but is not limited thereto.

Further, the fluid transfer can be actively and/or passively performed under the assistance of interaction forces such as a normal pressure environment, external pressure, gravity and the like.

Further, the fluid transmission permeation quantity of the graphene aerogel hollow fibers is 10-10⁹L m^-2h^-1bar^-1。

Further, the fluid transmission rate of the graphene aerogel hollow fiber is 0.1-100 cm/s.

Another aspect of the embodiments of the present invention also provides a preparation method of the aforementioned graphene aerogel hollow fiber, including:

1) preparing the graphene hydrogel hollow fiber by using a coaxial needle assisted sol-gel technology;

2) and (2) carrying out supercritical fluid drying and/or freeze drying treatment on the graphene hydrogel hollow fiber, and removing solvent molecules in the gel while keeping the gel network undamaged to obtain the graphene aerogel hollow fiber.

In some preferred embodiments, the step 1) specifically includes:

providing graphene oxide liquid crystal, wherein the graphene oxide liquid crystal is obtained by concentrating a graphene oxide aqueous solution, carrying out high-speed centrifugation treatment on the graphene oxide aqueous solution, and collecting lower-layer dispersion liquid to obtain the graphene oxide liquid crystal;

and injecting the graphene oxide liquid crystal into a coagulating bath by using an injection head, wherein the injection head is provided with an outer layer channel and an inner layer channel which are coaxially arranged, and then carrying out chemical sol-gel aging, so as to obtain the graphene hydrogel hollow fiber.

Further, the coaxial wet spinning-sol-gel combination technology in the step 1) is to inject graphene oxide liquid crystal and a proper coagulation bath into a receiving coagulation bath through an outer layer channel and an inner layer channel of a coaxial needle respectively, and then to prepare the graphene hydrogel hollow fiber through chemical sol-gel treatment.

Further, the concentration of the graphene oxide liquid crystal used in the step 1) is 5 mg/mL-50 mg/mL.

Further, the flow rate of the graphene oxide liquid crystal is 10 mu L/min-10 mL/min.

Further, the preparation method comprises the following steps: and injecting the graphene oxide liquid crystal into the coagulation bath at an injection speed of 10 mu L/min-10 mL/min.

Further, the coagulation bath comprises dilute hydrochloric acid, zinc nitrate, calcium chloride, cetyltrimethylammonium bromide, dilute sulfuric acid, sodium hydroxide, potassium hydroxide, aniline hydrochloride, chitosan, ascorbic acid, hydroiodic acid, sodium ascorbate, Fe²⁺Any one or a combination of two or more of sodium bisulfite and the like, and a solvent which can be selected from water, ethanol solution and the like, but is not limited thereto.

Further, the concentration of the coagulation bath is 0.001 wt% to 35 wt%.

Further, the flow rate of the coagulation bath is 10 μ L/min to 10 mL/min.

In some preferred embodiments, the chemical sol-gel treatment process in step 1) includes one or two of a chemical reduction method and a hydrothermal reduction method.

Further, the reducing agent used in the chemical reduction method comprises ascorbic acid, hydroiodic acid, sodium ascorbate and Fe^{2 +}And sodium hydrogen sulfite, and the like, but is not limited thereto.

Further, the temperature of the chemical reduction method is 5-100 ℃, and the time is 0.5-72 hours.

Further, the temperature of the hydrothermal reduction method is 80-200 ℃, and the time is 1-24 hours.

In some preferred embodiments, in step 2), the temperature of the supercritical fluid drying treatment is 30 to 50 ℃ and the time is 1 to 24 hours.

Further, the temperature of the freeze drying treatment is-50 ℃, and the time is 0.5-24 hours.

The embodiment of the invention also provides application of the graphene aerogel hollow fiber in the fields of phase change energy storage, photo-thermal water evaporation, intelligent fluid transportation, intelligent response or flexible wearable devices and the like.

Further, the graphene aerogel hollow fiber is applied to phase change energy storage.

Correspondingly, another aspect of the embodiment of the invention also provides a graphene aerogel phase-change composite hollow fiber, which includes the graphene aerogel hollow fiber, and the phase-change material is filled in the pipeline cavity of the graphene aerogel hollow fiber and/or in the graphene aerogel wall structure.

Further, the graphene aerogel phase change composite hollow fiber is provided with a pipeline cavity penetrating through the axial direction of the fiber and a closed and annular graphene aerogel phase change composite film wall.

Further, the selection of the phase change material includes any one and or a combination of two or more of paraffin, polyethylene glycol, polyol, erythritol, alkane, higher fatty alcohol, higher fatty acid, polyolefin, and the like, but is not limited thereto.

Further, the preparation method of the graphene aerogel phase-change composite hollow fiber comprises the following steps: and filling a phase change material in the graphene aerogel hollow fiber to obtain the graphene aerogel phase change composite hollow fiber.

Further, the preparation method comprises the following steps: filling a phase change material in the graphene aerogel hollow fiber at least by adopting a melting filling and/or solution filling manner.

Further, the graphene aerogel hollow fiber is applied to photo-thermal seawater evaporation.

Accordingly, another aspect of an embodiment of the present invention also provides a method of photothermal water evaporation, comprising:

carrying out array integration treatment on the graphene aerogel hollow fibers to prepare a graphene aerogel hollow fiber array composite material;

the graphene aerogel hollow fiber array composite material is placed on a water surface (preferably seawater), and photo-thermal water evaporation is carried out under the illumination condition.

In some preferred embodiments, the graphene aerogel hollow fiber array composite includes graphene aerogel hollow fibers, and a cured object disposed between the graphene aerogel hollow fibers.

Further, the graphene aerogel hollow fiber array composite material has a smooth pipeline cavity and an annular graphene aerogel film wall structure.

Further, the cured material includes any one or two combined materials of silica gel, rubber, epoxy resin, water glass, cotton cloth, cotton thread, and the like, but is not limited thereto.

Further, the array integration treatment of the graphene aerogel hollow fibers comprises preparation and post-treatment of fiber array reels.

Further, the preparation of the fiber array reel includes any one or two combinations of weaving of fibers and bundling of fibers.

Further, the post-treatment of the fiber array spool includes one or more of spool curing, hydrophilic modification, thermal insulation treatment, self-floating functional modification, and the like, but is not limited thereto.

In summary, the graphene aerogel hollow fiber provided by the invention has an annular and closed graphene aerogel wall and a pipeline cavity penetrating through the axial direction of the fiber, has high porosity, excellent water transmission performance, photothermal conversion and excellent mechanical flexibility, can be bent, knotted, twisted, woven and the like, and keeps the hollow structure of the fiber intact. The method has important application in the fields of photo-thermal water evaporation, intelligent response, fluid transmission, phase change energy storage and the like. The preparation process is simple, the reaction condition is mild, the operation is easy, the energy consumption is low, the cost is low, the preparation method is green and pollution-free, and the large-scale continuous production can be realized.

The technical scheme of the invention is further explained in detail by a plurality of embodiments and the accompanying drawings. However, the examples are chosen only for the purpose of illustrating the invention and are not to be construed as limiting the scope of the invention.