WO2017188564A1 - Method for manufacturing graphene oxide fiber, graphene fiber, and graphene or graphene (oxide) composite fiber by using electric field-induced wet spinning process - Google Patents

Abstract

The present invention provides a method for manufacturing a graphene oxide fiber or a graphene fiber, comprising the steps of: dispersing graphene oxide or graphene in a solvent so as to prepare a spinning solution; wet spinning the same in a coagulation bath in a state in which an electric field is applied in the discharge direction of the spinning solution, so as to manufacture a gel fiber; and drying the gel fiber.

Description

Method for producing graphene oxide fiber, graphene fiber, graphene or graphene (oxide) composite fiber using the field induced wet spinning process

The present invention relates to a method for producing a fiber, a composite fiber containing graphene oxide or graphene (reduced graphene oxide), specifically, graphene oxide fibers, graphene fibers, graphene using a wet spinning method (Oxide) It is related with the method of manufacturing a composite fiber.

Nano carbon-based materials such as graphene and carbon nanotubes (CNT) are excellent in electrical properties, thermal properties, flexibility, and mechanical strength, which are used as next-generation electronic materials, heat-dissipating materials, and ultra-high strength structural materials. It is a high-tech material.

Graphene is a two-dimensional carbon allotrope in which carbon atoms form a hexagonal honeycomb lattice structure with sp ² hybrids. Graphene has high electrical conductivity and specific surface area, so electrodes (electrode active materials) for supercapacitors, sensors, batteries, and actuators, touch panels, flexible displays, high efficiency solar cells, heat-dissipating films, coating materials, seawater desalination filters, and secondary batteries It is used in various fields such as an electrode and an ultra-fast charger, and a method of manufacturing fibers using graphene has been developed.

Conventional manufacturing method of the graphene fiber is produced by discharging a graphene oxide (graphene oxide) or graphene dispersion as a spinning solution to the coagulation bath through a wet spinning method, as shown in Figure 1, the alignment process of graphene As shown in Fig. 2, graphene oxide, which is non-directional and disorderly located in the syringe, is moved along the radial nozzle of fine inner diameter and aligned in the axial direction of the nozzle by shear stress between fluids (I), After discharging, the aligned graphene oxide or graphene is formed into gel fibers by self-assembly through a solvent change process (II), and the gel fibers undergo a series of washing and drying processes. It is made of graphene oxide or graphene fiber. The prepared graphene oxide fiber is subjected to an additional process of thermally or chemically reducing the graphene oxide fiber for electrical properties.

Republic of Korea Patent Publication No. 10-2015-0122928 is a graphene-based using interlayer self-assembly comprising the step of spinning the graphene oxide dispersion in a coagulation bath containing a polyamine to produce a crosslinked nanocarbon fiber with the polyamine A method for producing nanocarbon fibers is disclosed.

Republic of Korea Patent Publication No. 10-2012-0107026 is a) preparing a dispersion by dispersing graphene (reduced graphene or reduced graphene oxide) in a solvent with a surfactant; b) preparing a composite fiber by wet spinning the dispersion in a water-soluble polymer coagulation bath such as PVA and PMMA and then drying it; c) It discloses a graphene fiber manufacturing method comprising the step of removing the polymer by heat treating the composite fiber with a strong acid.

In the conventional wet spinning method, the graphene oxide or graphene is aligned in the direction of the fiber axis by shear stress while moving along the spinning nozzle, but partially misalignmnet as shown in FIG. 4 (a). A void is generated and the degree of orientation of the graphene is lowered, which acts as a factor of lowering the mechanical properties (tensile strength, elongation, etc.) of the graphene fiber.

The present invention is introduced by a new wet spinning method to improve the alignment characteristics of the graphene (oxide) in the production of graphene oxide fiber or graphene fiber to improve the orientation degree graphene having excellent mechanical properties (tensile strength, elongation, etc.) and electrical properties It is an object to provide a method for producing pin oxide or graphene fiber.

In order to solve the above technical problem, the present invention comprises the steps of preparing a spinning solution by dispersing graphene oxide or graphene in a solvent; Preparing gel fibers by wet spinning in a coagulation bath while an electric field is applied in a direction in which the spinning solution is discharged; And it provides a graphene oxide fiber or graphene fiber manufacturing method comprising the step of drying the gel fibers.

The electric field of the spinning solution is preferably made by applying a voltage between the spinning nozzle and the coagulation bath.

The applied electric field strength is at least 15 V / cm, preferably at least 30 V / cm, more preferably at least 60 V / cm, most preferably at least 120 V / cm.

The dried graphene oxide fiber may further comprise the step of reducing the graphene oxide to provide electrical properties.

The solvent of the graphene oxide spinning solution is distilled water, dimethylformamide, methanol, ethanol, ethylene glycol, n-butanol, tert-butyl alcohol, isopropyl alcohol, n-propanol, ethyl acetate, dimethyl sulfoxide, tetrahydrofuran Can be selected from.

Surfactants for dispersing the graphene spinning solution, sodium dodecyl benzene sulfonate (SDBS), sodium dodecyl sulfonate (SDS), sodium lignosulfonate (SLS), sodium laureth sulfonate (SLES), lauryl Anionic surfactants with hydrophilic sulfonic acid groups (SO ₃ ⁻ ) of ether sodium sulfonate (SLES), sodium myreth sulfate, or cetyltrimethylammonium bromide (CTAB), cetyltrimethylammonium chloride (CTAC) , Cetylpyridinium chloride (CPC), dodecyltrimethylammonium bromide (DTAB), tetradecyltrimethylammonium bromide (TTAB), dioctadecyldimethylammonium bromide (DODAB), dimethyldioctadecylammonium chloride (DODMAC) Or Tween 20, 40, 60, 80, Triton X-100, Glycerol alkyl esters, Glyceryl laurate esters, Polyethylene glycol sorbitan alkyl Requester may be selected from the group consisting of nonionic surfactant (Polyoxyethylene glycol sorbitan alkyl esters).

The spinning solution may further include carbon nanotubes or polymers as an additional component in addition to graphene oxide or graphene. The polymer is polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polymethyl methacryl (PMMA), polymethacrylic acid (PMAA), polyacrylic acid (PAA), polyvinyl chloride (PVC), polylactic acid ( PLA), polycaprolactone (PCL), polyurethane (PU), polystyrene (PS), polyethylene oxide (PEO), polyvinylacetate (PVAC), polyacrylonitrile (PAN), nylon, polycarbonate (PC), It may be selected from the group consisting of polyetherimide (PEI), polyester (PET), polyester sulfone (PES), polybenzimidazole (PBI).

The graphene oxide (or graphene): the carbon nanotube or the weight content ratio of the polymer may be 9: 1 to 1: 9.

Graphene oxide fiber, graphene fiber or graphene (oxide) composite fiber manufacturing method according to the present invention through the simple process of applying an electric field along the discharge progress direction of the spinning solution, to increase the orientation of the graphene oxide or graphene By providing an effect of improving the mechanical properties of the graphene (oxide) fibers or composite fibers.

1 is a schematic diagram showing a conventional wet spinning method using a graphene oxide or graphene spinning solution.

Figure 2 is a schematic diagram showing a process of aligning the graphene oxide or graphene in the wet spinning process.

3 is a schematic diagram showing an electric field induced wet spinning method according to an embodiment of the present invention.

Figure 4 is a schematic diagram showing the alignment state of the graphene fibers prepared by the conventional wet spinning method (Fig. 4 (a)) and the electric field induced wet spinning method (Fig. 4 (b)) according to the present invention.

5 is an electron scanning microscope (SEM) and a polarization microscope picture of the graphene oxide fiber prepared according to Example 1 and Comparative Example of the present invention, Figure 5 (a) is a SEM image of the graphene oxide fiber of the comparative example, Figure 5 (b) is a polarization micrograph of the graphene oxide fiber of the comparative example, Figure 5 (c) is a SEM image of the graphene oxide fiber of Example 1, Figure 5 (d) is a polarization of the graphene oxide fiber of Example 1 Photomicrograph.

Figure 6 is a graph showing the breaking stress (breaking stress) according to the electric field (field) strength of the graphene oxide fiber prepared according to Examples 1 to 5 and Comparative Examples of the present invention.

7 is a graph showing a strain-stress curve of the graphene oxide fiber prepared according to Example 1 and Comparative Example of the present invention (room temperature, humidity 30%).

8 is a graph showing the electrical conductivity of the graphene oxide fiber prepared according to Example 1 and Comparative Examples of the present invention.

Terms

In the present invention, the term "graphene" includes not only pure graphene, but also thermally or chemically reduced graphene oxide.

In the present invention, the term "graphene (oxide)" is used to mean graphene oxide or graphene.

In the present invention, the term “graphene oxide or graphene fiber” means graphene oxide fiber, graphene fiber or graphene oxide / graphene mixed fiber.

In the present invention, the term "composite fiber" is a fiber in which two or more kinds of materials are combined, and in the present invention, a fiber manufactured by including carbon nanotubes, a polymer material, and the like together with graphene (oxide) component.

The inventors of the present invention when manufacturing the graphene fibers or graphene fibers by wet spinning method using the graphene oxide dispersion or graphene dispersion as a spinning solution, as shown in Figure 3 in the discharge direction to the graphene oxide or graphene spinning solution When spinning with an electric field applied, it was surprisingly found that the alignment and degree of orientation of graphene oxide or graphene in the fibers produced were remarkably improved, resulting in a significant increase in mechanical strength. The invention has been completed.

Graphene oxide or graphene fiber manufacturing method according to the present invention comprises the steps of preparing a spinning solution by dispersing the graphene oxide or graphene in a solvent; Preparing gel fibers by wet spinning in a coagulation bath while an electric field is applied in a direction in which the spinning solution is discharged; And drying the gel fibers.

Graphene oxide

Graphene oxide is generally manufactured using chemical exfoliation which chemically oxidizes graphite and separates it from the solution phase. Graphene oxide has a structure in which various oxygen functional groups, such as epoxy, hydroxyl, carbonyl, or carboxylic acid, are formed on the terminal or / and surface of graphene.

Since the graphene oxide is polar and hydrophilic by the oxygen functional group, it is well dispersed in a polar solvent such as water. Examples of the dispersion solvent of the graphene oxide include distilled water, dimethylformamide, methanol, ethanol, ethylene glycol, n-butanol, tert-butyl alcohol, isopropyl alcohol, n-propanol, ethyl acetate, dimethyl sulfoxide, tetrahydrofuran, and the like. This can be used. Graphene oxide concentration in the spinning solution is preferably 1 to 20 mg / mL, but is not limited thereto.

As the graphene oxide of the present invention, chemically modified graphene oxide may also be used. Chemical modification of the graphene oxide may be, for example, by covalently bonding the oxygen functional groups of the graphene oxide with isocyanate organic monomolecules through an amidation or esterification reaction to modify the surface of graphene, and function as an isocyanate. Vaporized graphene oxide is greatly improved in dispersibility in polar solvents (S. Stankovich, RD Piner, ST Nguyen, and RS Ruoff, Carbon, 44, 3342 (2006)).

As a coagulation bath of graphene oxide, a known coagulation medium such as CTAB, CaCl ₂ , or NaOH aqueous solution may be used.

Graphene

Graphene according to the present invention can be prepared by mechanical peeling, chemical vapor deposition (CVD), epitaxial growth (Epitaxial Growth), non-oxidative exfoliation (Nonoxidative Exfoliation), but the above-described graphene oxide at high temperature heat treatment Or it is preferable to use reduced graphene oxide (reduced GO, rGO) prepared by chemical reduction. As the graphene according to the present invention, chemically modified graphene (CCG) and chemically modified reduced graphene (reduced CCG, rCCG) may also be used. Graphene according to the present invention is more preferably a reduced graphene oxide having a slight polarity.

Examples of the reducing agent for graphene include hydrazine, sodium hydrazine, hydrazine hydride (hydrazine hydrate), hydroquinone (hydroquinone), sodium borohydride (NaBH ₄ ), ascorbic acid (ascorbic acid), glucose (glucose) And the like are known.

Graphene or reduced graphene oxide has a nonpolar or weak polarity and hydrophobicity, so it is dispersed in a solvent using a surfactant. The surfactant may be sodium dodecylbenzenesulfonate (SDBS), sodium dodecylsulfonate (SDS), sodium lignosulfonate (SLS), sodium laureth sulfonate (SLES), lauryl ether sodium sulfonate (SLES), Anionic surfactants with hydrophilic sulfonic acid groups (SO ₃ ⁻ ), such as sodium myreth sulfate, or cetyltrimethylammonium bromide (CTAB), cetyltrimethylammonium chloride (CTAC), cetylpyridinium chloride (CPC ), Cationic surfactants such as dodecyltrimethylammonium bromide (DTAB), tetradecyltrimethylammonium bromide (TTAB), dioctadecyldimethylammonium bromide (DODAB), dimethyldioctadecylammonium chloride (DODMAC), or Tween 20, 40 , 60, 80, Triton X-100, Glycerol alkyl esters, Glyceryl laurate esters, Polyethylene glycol sorbitan alkyl esters Nonionic surfactants such as sorbitan alkyl esters can be used. Although not limited in the present invention, it is preferable to disperse using an anionic surfactant having a hydrophilic sulfonic acid group (SO ₃ ⁻ ). Sonication may be added to effectively disperse the graphene according to the present invention.

The graphene or graphene oxide is present in the form of a sheet piece, and may be referred to as "graphene flake", "graphene sheet", or "graphene crystal". The average diameter of the graphene flakes according to the present invention is several μm or more, and the number of layers of graphene or graphene oxide is preferably three or less layers.

The main feature of the present invention is to introduce a new element called electric field (magnetic field) induction in the conventional wet spinning method to produce graphene oxide or graphene fibers.

3 is a schematic diagram showing an electric field induction wet spinning process according to an embodiment of the present invention. In the wet spinning process according to the present invention, when discharging graphene oxide or graphene spinning solution, an electric field is applied in a direction in which the spinning solution is discharged.

The present invention shows that the graphene oxide flakes in the fluid align and show very good nematic liquid crystal properties by the electric field applied to the electrode between the nozzle and the coagulation bath as well as the shear stress in the fluid flow. As shown in Fig. 6), the orientation of the graphene oxide is markedly improved due to the reduction of the void in the fiber axis direction and the alignment of the non-directional graphene flakes, and consequently the mechanical / electrical properties are also improved.

The wet spinning process according to the present invention can be used in both an air-gap method and an immersion method, but it is more preferably carried out in an air gap method in terms of mechanical properties.

Graphene oxide fiber prepared according to the present invention, when the applied electric field strength is 15 V / cm or less, there was no difference in the tensile tensile strength compared to the graphene oxide fiber prepared without applying an electric field, 30 V / cm or more In the apparent difference, the mechanical strength was significantly increased by increasing the electric field strength to 60 V / cm, 90 V / cm, 120 V / cm through the experiment of the present invention.

In addition, the graphene oxide fiber prepared by the conventional wet spinning process shows a low electrical conductivity of ~ 10 ^-2 S / m by the insulation of the graphene oxide, whereas the graphene oxide fiber prepared according to the present invention is ~ 10 ² It was confirmed that the graphene oxide is partially reduced by the electric field induction according to the present invention showing the electrical conductivity of S / m.

The graphene oxide fibers according to the present invention may additionally be made of graphene fibers reduced through known thermal reduction methods or chemical reduction methods.

The thermal reduction method is not limited, but may be achieved by increasing the temperature at a rate of 0.1 to 10 ℃ / min from 200 to 1000 ℃ at room temperature.

The chemical reduction method is a known reducing agent such as hydrazine, hydroiodic acid, hydrobromic acid, sodium borohydride, lithium aluminum hydride, and sulfuric acid. Can be made.

On the other hand, the spinning solution according to the present invention may be made of graphene oxide-CNT composite fiber, graphene-CNT composite fiber further comprising a carbon nanotube (CNT) in addition to graphene oxide or graphene.

In the present invention, carbon nanotubes (CNT) may be multi-walled carbon nanotubes (MWNT), but single-walled carbon nanotubes (SWNTs) are more useful in consideration of electrical conductivity and mechanical properties. Carbon nanotubes are non-polar and do not dissolve well in polar solvent water. Therefore, in order to effectively disperse the carbon nanotubes, it is preferable to disperse the above-mentioned hydrophilic surfactant. Although not limited in the present invention, it is preferable to disperse the carbon nanotubes using an anionic surfactant having a hydrophilic sulfonic acid group (SO ₃ ⁻ ). Ultrasonic treatment is also possible for effective dispersion of carbon nanotubes.

The graphene oxide (or graphene): the content ratio of carbon nanotubes is 9: 1 to 1: 9, preferably 8: 2 to 2: 8, more preferably 6: 4 to 4: 6 Can be. After the dispersion is prepared for each of the above components, these dispersions may be appropriately mixed to prepare a spinning solution.

On the other hand, the spinning solution according to the present invention may further be made of graphene oxide-polymer composite fiber, graphene-polymer composite fiber further comprising a polymer material in addition to graphene oxide or graphene.

The polymer material is polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polymethylmethacrylic (PMMA), polymethacrylic acid (PMAA), polyacrylic acid (PAA), polyvinyl chloride (PVC), polylactic acid (PLA), polycaprolactone (PCL), polyurethane (PU), polystyrene (PS), polyethylene oxide (PEO), polyvinylacetate (PVAC), polyacrylonitrile (PAN), nylon, polycarbonate (PC) It may be selected from one or more selected from polyetherimide (PEI), polyester (PET), polyester sulfone (PES), polybenzimidazole (PBI).

The graphene oxide (or graphene): the content ratio of the polymer may be mixed in a 9: 1 to 1: 9, preferably 8: 2 to 2: 8, more preferably 6: 4 to 4: 6. . After the dispersion is prepared for each of the above components, these dispersions may be appropriately mixed to prepare a spinning solution.

Hereinafter, the graphene oxide or the graphene fiber manufacturing method according to the present invention will be described in detail.

Example  One: Electric field induction  Used Graphene oxide  Fabrication (field strength: 120 V / cm)

A) Preparation of Graphene Oxide Dispersion

A graphene oxide dispersion was prepared by a method known from Korean Patent Publication No. 10-2015-0122928.

2.4 g of graphite flakes were added to 10 mL of sulfuric acid in which 2.0 g of potassium persulfate and 2.0 g of phosphorus pentoxide were dissolved, followed by reacting at 80 ° C. for 72 hours. After diluting the graphite, obtained through vacuum filtration, expanded graphite was obtained by drying at room temperature in a vacuum for 24 hours.

After dispersing the obtained expanded graphite in 92 mL of sulfuric acid, 12.0 g of potassium permanganate was dissolved and reacted at 35 ° C. for 2 hours and 30 minutes, and then 1.0L of distilled water was added for 30 minutes so that the temperature of the entire dispersion did not exceed 45 ° C., The reaction was terminated by adding 20 mL of 30% hydrogen peroxide water.

Thereafter, the reaction mixture was centrifuged at 10,000 rpm for 10 minutes and then centrifuged three times or more by adding 1.0M aqueous hydrochloric acid solution, followed by centrifugation for 40 minutes at 13,000 rpm using water. Repeating five or more times to obtain a graphene oxide dispersion.

B) Field induced wet spinning

A voltage was applied between the spinning nozzle and the coagulation bath of the wet spinning device. A variable transformer (~ 400V) was used for the voltage application, and an electrode was installed in each of the top of the spinning nozzle with an internal diameter of 0.3 mm and a coagulation bath, and then connected to the transformer.

After preparing the prepared graphene oxide dispersion as a 10 mg / ml spinning solution, and put into a 5ml syringe and applying a 400V voltage under a 120V / cm electric field, spinning below 1 mL / min through a 0.3 mm spinneret inside diameter While maintaining the rate, a graphene oxide fiber in a gel form was prepared by injecting a spinning solution into a 0.5 mg / mL CTAB (Hexadecyltrimethyl ammonium bromide) coagulation bath in a rotational or linear manner. After 30 minutes of spinning solution injection, the graphene oxide fibers were briefly transferred to distilled water to remove the remaining coagulation bath, and dried at room temperature for 24 hours.

Example  2: Electric field induction  Used Graphene oxide  Fabrication (field strength: 90 V / cm)

The wet spinning was performed in the same manner as in Example 1, except that 300V voltage was applied between the spinning nozzle and the coagulation bath to prepare graphene oxide fibers under a 90V / cm electric field.

Example  3: Electric field induction  Used Graphene oxide  Fabrication (field strength: 60 V / cm)

The wet spinning was performed in the same manner as in Example 1, but 200 V voltage was applied between the spinning nozzle and the coagulation bath to prepare graphene oxide fibers under a 60 V / cm electric field.

Example  4: Electric field induction  Used Graphene oxide  Fabrication (field strength: 30 V / cm)

The wet spinning was performed in the same manner as in Example 1, but 100 V voltage was applied between the spinning nozzle and the coagulation bath to prepare graphene oxide fibers under an electric field of 30 V / cm.

Example  5: Electric field induction  Used Graphene oxide  Fabrication (field strength: 15 V / cm)

The wet spinning was performed in the same manner as in Example 1, except that 50V voltage was applied between the spinning nozzle and the coagulation bath to prepare graphene oxide fiber under an electric field of 15V / cm.

Example  6: Electric field induction  Used Graphene oxide / Carbon Nanotube Composite Fiber (Electric Field Strength: 120V / cm)

The graphene oxide dispersion prepared by the method of Example 1 was prepared.

Single-wall carbon nanotubes and 1wt% SDBS surfactant were added to distilled water and sonicated for 1 hour to prepare a carbon nanotube dispersion.

The graphene oxide dispersion and the nano carbonate dispersion was mixed in a weight ratio of 1: 1 to prepare a spinning solution, and then wet spinning in the same manner as in Example 1 to prepare a graphene oxide / carbon nanotube boksam fiber.

Comparative Example: Preparation of Graphene Oxide Fiber (No Electric Field)

It was carried out in the same manner as in Example 1, but by spinning without applying an electric field to prepare a graphene oxide fiber.

Experimental Example 1: Morphology of graphene oxide fibers

Graphene oxide fiber prepared according to Example 1 and the graphene fiber prepared in Comparative Example as a control was taken with an electron scanning microscope (SEM) and a polarizing microscope and the results are shown in FIG.

Figure 5 (a) is a SEM picture of the graphene oxide fiber of the comparative example, Figure 5 (b) is a polarization microscope picture of the graphene oxide fiber of the comparative example, Figure 5 (c) is a SEM picture of the graphene oxide fiber of Example 1 FIG. 5 (d) is a polarization micrograph of the graphene oxide fiber of Example 1. FIG.

Graphene oxide fiber according to Example 1 is more dense than the graphene oxide fiber of the comparative example, it can be seen that the orientation (orientation) is significantly improved without misalignment.

Experimental Example 2: Analysis of fracture tensile strength of graphene oxide fiber according to electric field strength

The mechanical properties of the graphene oxide fibers prepared in Examples 1 to 5 and the graphene oxide fibers prepared in Comparative Example were maintained at a humidity of 30% at room temperature using a thermal mechanical analyzer (TMA). Analyzed.

Figure 6 is a graph showing the breaking stress (breaking stress) according to the electric field (field) strength of the graphene fibers prepared according to Examples 1 to 5 and Comparative Examples of the present invention.

As shown in FIG. 6, the graphene oxide fiber of Example 4 prepared in Comparative Example and Example 5 showed no tensile strength at break of about 258 MPa, but the graphene oxide fiber of Example 4 prepared under an electric field of 30 V / cm. It can be seen that the wavelength tensile strength is significantly improved to 280 MPa, the wavelength tensile strength increases linearly with the increase of the electric field strength, it can be seen that significantly increased to about 400 MPa in the electric field of 120 V / cm.

Experimental Example 3: Strain-Stress curve analysis

The stress-stress curve was analyzed using a thermal mechanical analyzer (TMA) while maintaining a humidity of 30% at room temperature.

7 is a graph showing a strain-stress curve of graphene oxide fibers prepared according to Example 1 and Comparative Example of the present invention.

As shown in Figure 7, it can be seen that the graphene oxide fiber prepared according to Example 1 has an excellent tensile strength (stress) compared to the strain (graph) compared to the graphene oxide fiber according to the comparative example.

Experimental Example 4: Uniformity Analysis of Graphene Oxide Fibers

Tensile strength at break of 2 cm graphene oxide fibers prepared in Example 1 and Comparative Example was used as a sample to test the tensile strength at break.

The graphene oxide fiber of the comparative example showed a breakage tensile strength variation of 35 MPa, while the graphene oxide fiber of Example 1 had a deviation of 12 MPa and the deviation was reduced to about 1/3 compared to the comparative example to improve the fiber uniformity. I could confirm it.

Experimental Example 5 Analysis of Electrical Conductivity of Graphene Oxide Fibers

The conductivity characteristics of the graphene oxide fibers prepared in Examples 1 to 5 and the graphene oxide fibers prepared in Comparative Examples were measured and shown in FIG. 8.

As shown in Figure 8, the graphene oxide fiber of the comparative example shows a low electrical conductivity of ~ 10 ^-2 S / m by the insulating properties of the graphene oxide, while the graphene oxide fibers prepared in Examples 1 to 5 It can be confirmed that the graphene oxide is partially reduced by the electric field induction according to the present invention by showing an electrical conductivity of ˜10 ² S / m.

The present invention relates to a method for producing a fiber, a composite fiber containing graphene oxide or graphene (reduced graphene oxide), specifically, graphene oxide fibers, graphene fibers, graphene using a wet spinning method (Oxide) It is related with the method of manufacturing a composite fiber.

Claims (10)

a) preparing a spinning solution by dispersing graphene oxide or graphene in a solvent; b) wet spinning in a coagulation bath while an electric field is applied in a direction in which the spinning solution is discharged to produce gel fibers; And c) drying said gel fibers; Graphene oxide fiber or graphene fiber manufacturing method. The method of claim 1, The electric field of the spinning solution is characterized in that by applying a voltage between the spinning nozzle and the coagulation bath, graphene oxide fiber or graphene fiber manufacturing method. The method according to claim 1 or 2, The applied electric field strength is 15 V / cm or more, graphene oxide fiber or graphene fiber manufacturing method. The method according to claim 1 or 2, The applied electric field strength is characterized in that more than 30 V / cm, graphene oxide fiber or graphene fiber manufacturing method. The method according to claim 1 or 2, A method for producing reduced graphene fibers, further comprising the step of thermally or chemically reducing the dried graphene oxide fibers. The method according to claim 1 or 2, The solvent of the graphene oxide spinning solution is distilled water, dimethylformamide, methanol, ethanol, ethylene glycol, n-butanol, tert-butyl alcohol, isopropyl alcohol, n-propanol, ethyl acetate, dimethyl sulfoxide, tetrahydrofuran Will be selected, graphene oxide fiber or graphene fiber manufacturing method. The method according to claim 1 or 2, Surfactants for dispersing the graphene spinning solution, sodium dodecyl benzene sulfonate (SDBS), sodium dodecyl sulfonate (SDS), sodium lignosulfonate (SLS), sodium laureth sulfonate (SLES), lauryl Anionic surfactants with hydrophilic sulfonic acid groups (SO ₃ ⁻ ) of ether sodium sulfonate (SLES), sodium myreth sulfate, or cetyltrimethylammonium bromide (CTAB), cetyltrimethylammonium chloride (CTAC) , Cetylpyridinium chloride (CPC), dodecyltrimethylammonium bromide (DTAB), tetradecyltrimethylammonium bromide (TTAB), dioctadecyldimethylammonium bromide (DODAB), dimethyldioctadecylammonium chloride (DODMAC) Or Tween 20, 40, 60, 80, Triton X-100, Glycerol alkyl esters, Glyceryl laurate esters, Polyethylene glycol sorbitan alkyl A requester, a graphene oxide or graphene textile fiber production method is selected from the group consisting of a nonionic surfactant (Polyoxyethylene glycol sorbitan alkyl esters). The method according to claim 1 or 2, The spinning solution is characterized in that it further comprises a carbon nanotube or a polymer, graphene oxide or graphene fiber manufacturing method. The method of claim 8, The polymer is polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polymethyl methacryl (PMMA), polymethacrylic acid (PMAA), polyacrylic acid (PAA), polyvinyl chloride (PVC), polylactic acid ( PLA), polycaprolactone (PCL), polyurethane (PU), polystyrene (PS), polyethylene oxide (PEO), polyvinylacetate (PVAC), polyacrylonitrile (PAN), nylon, polycarbonate (PC), Polyetherimide (PEI), polyester (PET), polyester sulfone (PES), polybenzimidazole (PBI) is selected from the group consisting of, graphene oxide fiber or graphene fiber manufacturing method. The method of claim 8, The graphene oxide (or graphene): the content ratio of carbon nanotubes or polymer is 9: 1 to 1: 9, characterized in that the graphene oxide fiber or graphene fiber manufacturing method.

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