KR20180104799A - A method for preparation of a cellulose hybrid fiber comprising an oxygen-containing graphene crosslinked by metal ions - Google Patents

Abstract

The present invention relates to a production method of a cellulose hybrid fiber crosslinked by metal ions and comprising graphene with oxygen atoms on the surface. The present invention also relates to the cellulose hybrid fiber which is produced by the method, and has improved both or either of the tensile strength and elongation compared to hybrid fibers which are not crosslinked.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method for producing a cellulose composite fiber including graphene having an oxygen-containing crosslinked structure and a crosslinked metal ion,

The present invention relates to a method for producing a cellulose composite fiber comprising graphene having an oxygen atom on its surface and crosslinked with a metal ion and a method for producing the cellulose composite fiber having improved tensile strength, elongation or both, Fiber.

Petroleum-based synthetic fibers, which are widely used in clothing as well as in industrial fields, are polluted in the production process, and are not decomposed in the natural environment when they are disposed of, resulting in permanent persistence of environmental pollution. As the global awareness of the environment increases, interest in natural fibers using environmentally friendly polymers is increasing to solve these problems.

Currently, cellulose, which is represented by natural polymers, produces more than 100 billion tons a year. Unlike petroleum-based fossil resources, cellulose is low in production costs because it has no concern about depletion and is biodegradable in its natural state as glucose (glucose) It is an eco-friendly material with unlimited potential as a material. In particular, cellulose has a chain structure in which glucose constituting the cellulose is strongly bonded by forming intermolecular hydrogen bonds, but has a disadvantage that industrial availability is limited from the overall viewpoint due to relatively low mechanical properties as compared with synthetic fibers made of a synthetic polymer .

Therefore, as a method for improving the strength of a natural polymer resin such as cellulose, a composite fiber is prepared by adding a carbon nanomaterial such as graphene, carbon nanotube, or carbon nanofiber. However, the interface between the additive and the polymer resin It is difficult to achieve the expected improvement in physical properties.

In order to improve the mechanical properties, the present inventors have made intensive researches to find out a method for improving the bonding between cellulose and graphene by preparing grafting agent of conjugated fiber by adding graphene to cellulose, which is a natural polymer resin, Like graphene, by adding graphene containing oxygen atoms to the surface of cellulose, adding metal ions directly to the raw material and spinning it to produce a conjugated fiber, or adding graphene containing the oxygen atom It is possible to provide a composite fiber improved in both tensile strength and elongation by more than 20% when the cellulose composite fiber is post-treated with an aqueous solution of a metal ion.

One object of the present invention is to provide a method for producing a cellulose composite fiber comprising graphene having an oxygen atom on its surface and having a tensile strength, elongation, or both improved compared to a non-crosslinked conjugated fiber, A first step of preparing a conjugate fiber comprising graft having an oxygen atom on the surface of 1 to 10 parts by weight with respect to the cellulose; And a second step of contacting the composite fibers obtained from the previous step with a solution containing metal ions.

Another object of the present invention is to provide a method for producing a cellulose composite filament comprising graphene having an oxygen atom on its surface and having a tensile strength, elongation, or both improved compared to a non-crosslinked conjugated fiber and crosslinked with a metal ion, A first step of preparing a mixed solution containing graphene having an oxygen atom at a surface of 1 to 10 parts by weight based on the cellulose and a metal ion at a final concentration of 0.05 to 0.2 M; And a second step of preparing a composite fiber from the mixed solution.

Another object of the present invention is to provide a method for producing a cellulose film, which comprises 100 parts by weight of cellulose and 1 to 10 parts by weight of the cellulose with graphene having oxygen atoms on its surface, wherein the cellulose and the graphene having oxygen atoms on its surface are crosslinked with metal ions , And the tensile strength, the elongation, or both are improved as compared with the non-crosslinked conjugated fiber.

To achieve the above object, a first aspect of the present invention is to provide a cellulose composite fiber comprising graphene having an oxygen atom on its surface and having improved tensile strength, elongation, or both, as compared with a non-crosslinked conjugate fiber, A first step of preparing a composite fiber comprising 100 parts by weight of cellulose and 1 to 10 parts by weight of the conjugated fiber containing graphene having oxygen atoms on the surface of the cellulose; And a second step of contacting the composite fiber obtained from the previous step with a solution containing a metal ion.

A second aspect of the present invention is a method for producing a cellulose composite fiber comprising graphene having an oxygen atom on its surface and having a tensile strength, elongation, or both improved compared to a non-crosslinked fiber and crosslinked with a metal ion, A first step of preparing a mixed solution containing graphene having an oxygen atom on the surface of the cellulose in an amount of 1 to 10 parts by weight and a metal ion at a final concentration of 0.05 to 0.2 M; And a second step of preparing a conjugate fiber from the mixed solution.

The third aspect of the present invention relates to a cellulose acylate film comprising 100 parts by weight of cellulose and 1 to 10 parts by weight of the cellulose with graphene having an oxygen atom on its surface and the cellulose and graphene having oxygen atoms on its surface are crosslinked with metal ions , And the tensile strength, the elongation, or both are improved as compared with the non-crosslinked conjugated fiber.

Hereinafter, the present invention will be described in more detail.

In order to overcome the disadvantage of low mechanical strength of cellulose, a biodegradable natural polymer, carbon nanostructures are added to produce composite fibers, wherein graphene containing oxygen atoms on the surface is used as the carbon nanostructure And that the metal ion can be directly added to the raw material, or extruded with the composite fiber, and then treated with the aqueous solution of the metal ion to crosslink the composite fiber, thereby improving both the tensile strength and the elongation of the composite fiber. Particularly, even when graphene is used in a small amount of 10% by weight or less with respect to cellulose, the tensile strength and elongation can both be improved by 20% or more. In the case of tensile strength, It is a feature of the present invention that it can be improved up to 45%.

The present invention provides a method for producing a cellulose composite fiber comprising graphene having an oxygen atom on its surface and having improved tensile strength, elongation, or both, as compared with a non-crosslinked conjugate fiber, A first step of preparing a conjugate fiber comprising graphene having an oxygen atom on the surface of 1 to 10 parts by weight with respect to cellulose; And a second step of contacting the composite fiber obtained from the previous step with a solution containing a metal ion.

At this time, the metal ion may be an ion capable of forming an oxygen atom on the surface of graphene and an oxygen atom of cellulose to form a bond by electrostatic attraction and to be crosslinked.

The present invention also provides a method for producing a cellulose composite fiber comprising graphene having an oxygen atom on its surface and having improved tensile strength, elongation, or both, compared with unbridged fiber, A first step of preparing a mixed solution containing graphene having an oxygen atom on the surface of the cellulose in an amount of 1 to 10 parts by weight and a metal ion at a final concentration of 0.05 to 0.2 M; And a second step of preparing a composite fiber from the mixed solution.

At this time, the metal ion may form a chemical bond with the oxygen atom on the surface of the graphene and the oxygen atom of the cellulose and may be crosslinked.

The above conjugated fibers can be produced by using the polymer fiber manufacturing method known in the art without limitation. For example, a solution containing graphene and cellulose having an oxygen atom on its surface and containing a metal ion may be obtained by extruding / radiating and coagulating a solution containing a metal ion, but not limited thereto. The solution may be a solution obtained by melting a solid form of the dope containing the active ingredients, or a solution in which the above components are dispersed in a solvent. As the solvent, any solvent known in the art can be used without limitation as long as it is a solvent capable of uniformly dispersing both graphene and cellulose having oxygen atoms on their surface. For example, the solvent may be NMMO (N-methylmorpholine N-oxide), or water, but is not limited thereto.

For example, the metal ion may be at least one selected from the group consisting of Fe, Ca, Mg, Cu, Ni, Ba, Cd, Pb, Zn, (Au), silver (Ag) and strontium (Sr), but it is not limited thereto, and it is possible to form two or more bonds with oxygen atoms in the solution, Is not limited to a kind of metal as long as it can crosslink through the oxygen atom of the graphene surface and the oxygen atom of the graphene surface.

For example, the graphene having oxygen atoms on the surface can be oxidized graphene, oxidized multilayer graphene, functionalized graphene, or functionalized multilayer graphene. Specifically, it may be oxidized graphene or oxidized multi-layered graphene. However, it is not limited thereto, and oxidized graphene may be purchased, or may be used after having oxygen atoms on the surface through pretreatment using graphene. The graphene having an oxygen atom on the surface used in the production method of the present invention may contain an oxygen atom in the form of a functional group such as a hydroxyl group, a carboxyl group, a ketone group and / or an epoxy group. The functional groups may be chemically or electrostatically bound to the metal ion through the oxygen atom contained therein.

For example, the cellulose may be wood-based cellulose, non-wood-based cellulose, bacterial cellulose or a mixture of two or more thereof, but is not limited thereto.

The cellulose composite fiber crosslinked with a metal ion produced by the production method of the present invention may have a tensile strength of 28 to 44% or an elongation of 24 to 29%, as compared with a non-crosslinked cellulose composite fiber, but is not limited thereto. For example, the rate of increase in tensile strength and elongation for non-crosslinked conjugated fibers may be somewhat increased or decreased depending on the type of metal ion added.

Further, the present invention relates to a coating composition comprising 100 parts by weight of cellulose and 1 to 10 parts by weight of graphene having an oxygen atom on the surface of the cellulose, wherein the cellulose and the graphene having an oxygen atom on the surface thereof are crosslinked with a metal ion, The tensile strength, elongation, or both may be improved as compared to the non-conjugated fibers.

For example, the composite fiber may be manufactured by a method according to the first or second aspect of the present invention, but is not limited thereto.

Specifically, the cellulose composite fiber may have an increased tensile strength of 28 to 44% or an elongation of 24 to 29% as compared with a non-crosslinked cellulose composite fiber, but the present invention is not limited thereto. For example, the rate of increase in tensile strength and elongation to non-crosslinked conjugated fibers may be slightly increased or decreased depending on the type of the added metal ion, and accordingly, a proper metal ion may be selected in consideration of the tensile strength and elongation required for the product to be applied .

The production method of the present invention is characterized in that a small amount of graphene oxide having a functional group containing an oxygen atom on its surface is added to cellulose as a natural biodegradable fiber material to produce a conjugate fiber, A high strength and high ductility composite fiber having both tensile strength and elongation increased by 20% or more can be provided by a simple method of post treatment with a metal ion aqueous solution.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing a surface image and an internal structure of a cellulose composite fiber including an oxidized graphene according to an embodiment of the present invention. FIG. (a) shows a scanning electron microscope image, and (b) shows a fiber internal structure obtained by three-dimensional X-ray tomography.
FIG. 2 is a graph showing the results of (a) bright field transmission electron microscopy (BF TEM) image and (b) scanning transmission electron microscope (SEM) images of the cellulose composite fiber containing oxidized graphene according to an embodiment of the present invention. (STEM) high angle annular dark field (HAADF) images.
FIG. 3 is a graph showing the relationship between the calcium chloride treatment time of the composite fibers (GO-CeHFs) and the cellulose fibers (CeFs) cross-linked with the calcium chloride after treatment with the grafted oxide graphene according to an embodiment of the present invention, Tensile strength and (b) elongation.
FIG. 4 is a view showing a composite fiber having improved tensile strength and elongation, obtained by post-treating a cellulose composite fiber including graphene oxide with calcium chloride according to an embodiment of the present invention.
FIG. 5 is a diagram showing an STEM HAADF image and an EDS element mapping image of a composite fiber (GO-CeHFs) obtained by post-treating a cellulose composite fiber including oxidized graphene with calcium chloride according to an embodiment of the present invention. (a) shows the STEM HAADF image, and (b) to (c) show the carbon, oxygen and calcium element distribution by EDS element mapping, respectively.
FIG. 6 is a diagram showing the XPS analysis results of the composite fiber obtained by post-treating the cellulose composite fiber including the graft oxide according to the embodiment of the present invention with a metal ion solution and the chemical structure derived therefrom.
FIG. 7 is a graph showing the tensile strength of a composite fiber obtained by post-treating and crosslinking a cellulose composite fiber including a graphene oxide according to an embodiment of the present invention. FIG.
8 is a graph showing elongation of a composite fiber obtained by post-treating a cellulose composite fiber including a graft oxide with a metal ion solution and crosslinking according to an embodiment of the present invention.
FIG. 9 is a view showing a cellulose composite fiber spinning dope comprising oxidized graphene prepared using a solvent containing a metal ion according to an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples are for further illustrating the present invention, and the scope of the present invention is not limited by these examples.

Manufacturing example  1: Oxidation Grapin  Preparation of Added Cellulose Composite Fiber

The graphene oxide was added to an aqueous solution of 50 wt% of NMMO (N-methylmorpholine N-oxide) in an amount of 0.2 wt% relative to the cellulose, and then the water was removed by distillation under reduced pressure to prepare 86.7 wt% of a graft oxide / NMMO spinning solution , Which was solidified at room temperature to prepare an oxidized graphene / NMMO powder. N-propyl gallate was added as an antioxidant to solid phase oxide graphene / NMMO and cellulose to 0.2 wt% of cellulose, and powder was mixed with heat generated in the blender while the NMMO particles were mixed with the composite Were prepared. ≪ tb > < TABLE > The prepared granules were stirred in an oil bath maintained at 120 캜 for 40 minutes and then solidified at room temperature to prepare a solid phase dope. The constituent material content of the prepared dope was 86.7% NMMO 88 g, cellulose 12 g, and oxidized graphene 0.24 g.

The cellulose dope powder to which solid oxide graphene was added was put into a spinning apparatus and melted by maintaining the vacuum state at 110 DEG C for 90 minutes. Then, the spinning temperature was set to 105 ° C, and a dry air wet spinning fiber was produced by placing a 10 cm air layer between the surface of the spinning nozzle and the coagulating bath. A spinning nozzle with a hole number of 3 holes and a diameter of 0.3 mm was used, and L / D was set to 1, and the nozzle was spun while maintaining the nitrogen pressure constant. The composite fiber extruded from the radiator into the air layer was passed through a coagulation bath filled with distilled water and a water bath, and then wound on a bobbin. The composite fibers wound on a bobbin were placed in distilled water for 24 hours to remove NMMO and left to stand at room temperature (25 ° C) for 24 hours.

The surface of the resultant composite fiber was observed and the result was shown in FIG. 1A. The internal structure of the fiber was observed by three-dimensional X-ray tomography (XRadia XRM, Carl Zeiss, USA) Respectively. As shown in FIGS. 1A and 1B, it was confirmed that the composite fibers according to the present invention had smooth surfaces as well as uniformly dispersed and distributed graphen oxide. Further, the inside of the composite fiber is subjected to a bright field transmission electron microscopy (BF) TEM image and a scanning transmission electron microscopy (STEM) high angle annular dark field (HAADF) image , And the EDS point profile was observed to confirm that the nanoparticles were graphene grains which had actually observed a contrast difference. The results are shown in FIG. 2 and Table 1, respectively. As shown in FIG. 2A, it was confirmed that nanoparticles having a remarkable contrast difference exist in the inside of the conjugate fiber, and as shown in FIG. 2B, the same area selected at one point and the other areas selected in the corresponding area The EDS point profile was measured at the other point of the sample, and the difference in atomic content was confirmed. The results are shown in Table 1 below.

Point 1 Point 2 C-K 93.71 78.57 O-K 3.93 11.06

As shown in Table 1 above, the carbon content was significantly higher at point 1 compared to point 2, indicating that the nanoparticles exhibiting contrast differences are oxidized graphene.

Further, the tensile strength, modulus and elongation of the cellulose composite fiber to which the oxidized graphene fiber was added and the cellulose fiber itself as a control group were measured and the results are shown in Table 2 below .

Cellulose fiber Oxidized graphene / cellulose fibers Tensile Strength (MPa) 362.1 + - 46.6 403.5 + - 76.0 Elastic modulus (GPa) 2.1 ± 0.2 2.3 ± 0.5 Elongation (%) 6.0 ± 0.6 4.5 ± 0.5

Example  1: with calcium ion Post-processed Bridged  Cellulose fiber and cellulose / oxidation Grapina  Manufacture of composite fibers

Cellulose composite fiber to which oxidized graphene prepared according to Preparation Example 1 was added and cellulose fiber not containing oxidized graphene as a control group were immersed in a calcium chloride aqueous solution having a concentration of 0.1 M. In order to confirm the effect of the treatment time, samples were sampled every 10 minutes from 10 minutes to 60 minutes. The fibers immersed in the calcium chloride aqueous solution were taken out, washed with distilled water until the pH became neutral, and then dried at 50 ° C for 2 hours under tension to remove moisture. The tensile strength, elastic modulus and elongation of the cellulosic composite fibers (GO-CeHFs) and cellulose fibers (CeFs) to which the grafted oxide grafted with calcium ions thus obtained had been post-treated and crosslinked were measured, Respectively.

Processing time 0 minutes 10 minutes 20 minutes 30 minutes 40 minutes 50 minutes 60 minutes CeFs The tensile strength
(MPa) 362.1
± 46.6 377.3
± 35.2 422.4
± 32.5 423.9
± 56.2 416.2
± 43.0 413.5
± 40.6 414.1
± 47.6 Modulus of elasticity
(GPa) 2.1
± 0.2 2.3
± 0.3 2.2
± 0.3 2.2
± 0.3 2.3
± 0.4 2.2
± 0.2 2.1
± 0.3 Elongation
(%) 6.0
± 0.6 6.0
± 0.4 6.2
± 0.5 6.2
± 0.3 6.2
± 0.5 6.1
± 0.5 6.3
± 0.2 GO-CeHFs The tensile strength
(MPa) 403.5
± 76.0 504.6
± 54.2 544.7
± 37.0 550.4
± 37.5 544.1
± 45.4 533.5
± 46.9 542.9
± 15.8 Modulus of elasticity
(GPa) 2.3
± 0.5 2.8
± 0.3 3.0
± 0.3 2.9
± 0.2 3.0
± 0.3 2.9
± 0.2 2.9
± 0.3 Elongation
(%) 4.5
± 0.5 5.8
± 0.3 6.0
± 0.3 5.8
± 0.4 5.8
± 0.2 5.7
± 0.3 5.7
± 0.1

As shown in FIG. 3 and Table 3, in the case of the cellulose composite fiber to which the oxidized graphene was added, both the tensile strength, the elastic modulus and the elongation were remarkably improved by treating with a calcium chloride solution and crosslinking. However, Although the tensile strength was somewhat improved according to calcium chloride, the rate of increase was significantly lower than that of the composite fiber including the graphene oxide according to the present invention, and the modulus of elasticity and the elongation were hardly changed.

Example  2: with calcium ion Post-processed Bridged  Manufacture of composite fibers

The cellulose composite fiber to which the oxidized graphene fiber prepared according to Preparation Example 1 was added was immersed in a 0.1 M aqueous solution of calcium chloride for 30 minutes. The fibers immersed in the calcium aqueous solution were taken out, washed with distilled water until the pH became neutral, and dried at 50 ° C for 2 hours under tension to remove water. FIG. 4 is a photograph showing the shape of the cellulose composite fiber to which the oxidized graphene grafted with the crosslinked calcium ion thus obtained is post-treated.

Further, the distribution of atoms present in the grafted cellulose composite fiber to which the calcium ion was treated by cross-linking through EDS mapping analysis through TEM was confirmed, and the results are shown in FIG. FIG. 5 is a STEM HADDF image and an EDS element mapping image of the composite fiber treated with calcium ions. From FIG. 5A, it was confirmed that nanometer-sized particles were present inside the conjugate fiber. From FIGS. 5B and 5C, Sized particles are distributed in a relatively large proportion compared to the other regions. This indicates that nanometer-sized particles existing in the composite fiber are graphene grains. On the other hand, FIG. 5D shows the distribution of calcium atoms in the composite fibers, and shows a distribution of sharper calcium atoms in the region where the graphene oxide is present. This indicates that the metal ion penetrates the interface between the cellulose and the oxide graphene to relatively influence the interfacial bonding force.

In addition, the chemical structure was derived by XPS analysis, and the results are shown in Fig. As shown in Fig. 6, peaks corresponding to Ca and O-Ca peaks were observed together on XPS. This is due to the formation of a carboxyl chelate structure by the ring opening phenomenon induced by binding of the metal ion to the epoxy group and bonding with the carboxyl group, as shown in the lower part of Fig.

The tensile strength and elongation of the cellulose composite fiber to which the grafted oxide grafted with the calcium ion had been post-treated and crosslinked were measured, And 8, and specific values are shown in Table 4 below.

Example  3: with magnesium ion Post-processed Bridged  Manufacture of composite fibers

A cellulose composite fiber to which a grafted oxide grafted with magnesium ions was post-treated by the same method as in Example 2 except that 0.1 M aqueous magnesium chloride solution was used instead of 0.1 M calcium chloride aqueous solution was prepared, Strength and elongation were measured, And 8, and specific values are shown in Table 4 below.

Example  4: with barium ion Post-processed Bridged  Manufacture of composite fibers

A cellulose composite fiber to which a graft oxide grafted with barium ions was subjected to post treatment to prepare a cellulose composite fiber was prepared in the same manner as in Example 2 except that 0.1 M aqueous barium chloride solution was used instead of 0.1 M calcium chloride aqueous solution, Strength and elongation were measured, And 8, and specific values are shown in Table 4 below.

Comparative Example  1: Compound fiber not subjected to ion treatment

The cellulose composite fiber to which oxidized graphene obtained in Production Example 1 was added was directly used as a sample of Comparative Example 1 to measure tensile strength and elongation. The results are shown in Figs. 2 and 3. Specific values are shown in Table 4 Respectively.

Tensile Strength (MPa) Elongation (%) Example 2 550.4 ± 54.2 5.8 ± 0.4 Example 3 514.4 ± 36.4 5.7 ± 0.4 Example 4 578.9 ± 24.9 5.6 ± 0.3 Comparative Example 1 403.5 + - 76.0 4.5 ± 0.5

As shown in FIG. 7 and Table 4, the tensile strength of the crosslinked composite fibers after the treatment with metal ions prepared according to Examples 2 to 4 of the present invention was higher than that of the composite fibers without the metal ion treatment (Comparative Example 1 ) ≪ / RTI > increased by about 28 to 44%. Specifically, as the size of ions from magnesium to barium increased, the tensile strength increase rate increased from 28% to 44% depending on the metal ion.

On the other hand, as shown in FIG. 8 and Table 4, the elongation ratios of the crosslinked conjugated fibers after the treatment with the metal ions prepared according to Examples 2 to 4 of the present invention were higher than those of the untreated conjugated fibers 1) It was confirmed that the elongation was increased by about 24 to 29%. However, the rate of increase of the rate of increase according to the type of metal ion showed a similar rate of increase regardless of the type of metal ion within the error range.

In comparison with the non-crosslinked composite fibers as described above, the tensile strength and the elongation ratio of the composite fibers crosslinked by the metal ion treatment are shown by the fact that metal ions are introduced at the interface between the oxidized graphene and the cellulose to form crosslinks through the functional groups, It is believed that this is because it improves the bonding force. At this time, the elongation rate shows a similar rate of increase regardless of the type of metal ion treated, whereas the tensile strength increases with increasing size of the treated metal ion, As the gap between the graphene and the cellulose is introduced, the void space at the interface can be filled more, so that the force against the force externally applied is strengthened and the mechanical properties are considered to be higher. This indicates that it is possible to control the strength of the composite fiber produced by selecting and treating the appropriate metal ions.

Example  5: Using metal ion added solvent Bridged  Manufacture of composite fibers

Cellulose dope to which 0.2 wt% of graphene oxide was added was prepared using an NMMO solvent containing 0.1 M of magnesium chloride, calcium chloride and barium chloride, respectively, and solidified. The form of the solidified dope was photographed and shown in Fig. Unlike Examples 2 to 4, which are post-treated with a metal ion aqueous solution and crosslinked, even when the metal ion is directly added to a solvent for dissolving the raw material, the electrostatic raw materials are connected by covalent bonds instead of electrostatic attraction, It is possible to further improve the mechanical properties of the material. This indicates that it is possible to provide a product with improved mechanical properties without additional processing by directly adding metal ions to the raw material and molding the same. Based on this, it is possible to provide a variety of products including tire cord, automobile interior material, It can be widely applied to eco-friendly materials in the product group.

Claims (11)

A method for producing a cellulose composite fiber comprising graphene having an oxygen atom on its surface, which is improved in tensile strength, elongation, or both, as compared with a non-crosslinked conjugate fiber,
A first step of preparing a composite fiber comprising 100 parts by weight of cellulose and 1 to 10 parts by weight with respect to the cellulose, the composite fiber comprising graphene having an oxygen atom on its surface; And
And a second step of contacting the composite fiber obtained from the previous step with a solution containing a metal ion.
The method according to claim 1,
Wherein the metal ion is an ion capable of forming a bond with an oxygen atom on the surface of graphene and an oxygen atom of cellulose to form a bond by an electrostatic attractive force.
A process for producing a cellulose composite fiber comprising graphene having an oxygen atom on its surface, which is improved in tensile strength, elongation, or both, compared with unbridged fibers, and which is crosslinked with metal ions,
Preparing a mixed solution comprising 100 parts by weight of cellulose, 1 to 10 parts by weight of the cellulose with graphene having an oxygen atom on its surface, and a final concentration of 0.05 to 0.2 M metal ions; And
And a second step of preparing a composite fiber from the mixed solution.
The method of claim 3,
Wherein the metal ion is an ion capable of forming a chemical bond with the oxygen atom on the surface of the graphene and the oxygen atom of the cellulose and capable of crosslinking.
5. The method according to any one of claims 1 to 4,
The metal ion may be at least one selected from the group consisting of Fe, Ca, Mg, Cu, Ni, Ba, Cd, Pb, Is at least one metal ion selected from the group consisting of gold (Au), silver (Ag) and strontium (Sr).
5. The method according to any one of claims 1 to 4,
Wherein the graphene having oxygen atoms on the surface is at least one selected from the group consisting of oxide graphene, oxidized multilayer graphene, functionalized graphene, and functionalized multilayer graphene.
5. The method according to any one of claims 1 to 4,
Wherein the cellulose is at least one selected from the group consisting of woody cellulosic, non-woody cellulose and bacterial cellulose.
5. The method according to any one of claims 1 to 4,
Wherein the cellulose composite fiber crosslinked with the metal ion has a tensile strength of 28 to 44% or an elongation of 24 to 29% higher than that of the non-crosslinked cellulose composite fiber.
And a graphene having oxygen atoms on the surface of the cellulose in an amount of 1 to 10 parts by weight based on the cellulose, wherein the cellulose and the graphene having an oxygen atom on the surface are crosslinked with a metal ion, Wherein the tensile strength, elongation, or both are improved.
10. The method of claim 9,
Wherein the composite fiber is produced by the method of any one of claims 1 to 4.
10. The method of claim 9,
Wherein the cellulose composite fiber has a tensile strength of 28 to 44% or an elongation of 24 to 29% higher than that of the non-crosslinked composite fiber.

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