阅读说明：本技术 碳纳米管-铜复合纤维及其制备方法 (Carbon nanotube-copper composite fiber and preparation method thereof ) 是由 宋远强 宋付膑 于 2021-01-22 设计创作，主要内容包括：本发明涉及一种碳纳米管-铜复合纤维及其制备方法,所述制备方法包括：将气态的碳源、铁源、硫源以及铜源混合得到气态前驱体,并将所述气态前驱体进行反应,得到含铜的碳纳米管连续体；对所述含铜的碳纳米管连续体进行收缩处理,得到含铜的碳纳米管纤维；以及,将所述含铜的碳纳米管纤维置于铜电镀液中进行电镀,得到碳纳米管-铜复合纤维。本发明制备方法得到的碳纳米管-铜复合纤维具有高导电性,同时兼具优异柔韧性和强度等机械性能。(The invention relates to a carbon nano tube-copper composite fiber and a preparation method thereof, wherein the preparation method comprises the following steps: mixing gaseous carbon source, iron source, sulfur source and copper source to obtain a gaseous precursor, and reacting the gaseous precursor to obtain a copper-containing carbon nanotube continuum; performing contraction treatment on the copper-containing carbon nanotube continuum to obtain copper-containing carbon nanotube fibers; and placing the copper-containing carbon nanotube fiber in copper electroplating solution for electroplating to obtain the carbon nanotube-copper composite fiber. The carbon nanotube-copper composite fiber prepared by the preparation method has high conductivity and simultaneously has mechanical properties such as excellent flexibility and strength.)

1. A method for preparing carbon nanotube-copper composite fiber is characterized by comprising the following steps:

mixing gaseous carbon source, iron source, sulfur source and copper source to obtain a gaseous precursor, and reacting the gaseous precursor to obtain a copper-containing carbon nanotube continuum;

performing contraction treatment on the copper-containing carbon nanotube continuum to obtain copper-containing carbon nanotube fibers; and

and (3) placing the copper-containing carbon nanotube fiber in copper electroplating solution for electroplating to obtain the carbon nanotube-copper composite fiber.

2. The method of claim 1, wherein the gaseous carbon source is selected from a carbon-containing gas or a gas obtained by gasifying a carbon-containing compound, the carbon-containing compound includes at least one of methanol, benzene, toluene, and ethanol, and the carbon-containing gas includes at least one of methane, ethane, ethylene, and acetylene.

3. The method of manufacturing a carbon nanotube-copper composite fiber according to claim 1, wherein the gaseous iron source is gasified from an iron-containing compound comprising at least one of ferrocene, iron acetylacetonate, and iron pentacarbonyl.

4. The method of claim 1, wherein the gaseous sulfur source is selected from a sulfur-containing gas, a gas derived from elemental sulfur, or a gas derived from a sulfur-containing compound, the sulfur-containing gas comprises hydrogen sulfide, and the sulfur-containing compound comprises at least one of thiophene and thiourea.

5. The method of claim 1, wherein the gaseous copper source is formed by gasifying a copper-containing compound, and the copper-containing compound comprises at least one of copper chloride, copper nitrate, and copper acetate.

6. The method of claim 1, wherein the atomic ratio of carbon, iron, sulfur and copper in the gaseous precursor is 100 (0.2-5): 0.1-10): 0.05-10).

7. The method of claim 1, further comprising mixing the gaseous precursor with a carrier gas, wherein the carrier gas comprises hydrogen and/or a shielding gas, and wherein the shielding gas comprises at least one of nitrogen and a noble gas, before the reacting the gaseous precursor.

8. The method of preparing a carbon nanotube-copper composite fiber according to claim 1, wherein the reaction temperature of the gaseous precursor is 1000 ℃ to 1250 ℃.

9. The method of manufacturing a carbon nanotube-copper composite fiber according to claim 1, wherein the step of subjecting the copper-containing carbon nanotube continuous body to a shrinking treatment comprises: immersing the copper-containing carbon nanotube continuum in a liquid.

10. The method of claim 1, wherein the copper-containing carbon nanotube fiber is electroplated in a copper plating solution by a pulse electroplating method, wherein the pulse electroplating method comprises a current of 5mA-70mA, a current conduction time of 0.5s-2s, a current interval time of 0.5s-2s, and a number of pulse cycles of 30-1200.

11. A carbon nanotube-copper composite fiber, which is produced by the method for producing a carbon nanotube-copper composite fiber according to any one of claims 1 to 10.

12. The carbon nanotube-copper composite fiber according to claim 11, wherein the carbon nanotube-copper composite fiber has a diameter of 20 μm to 100 μm;

and/or the tensile strength of the carbon nano tube-copper composite fiber is 1GPa-2 GPa;

and/or the electrical conductivity of the carbon nano tube-copper composite fiber is 0.5 multiplied by 10⁷S/m-6×10⁷S/m；

And/or the density of the carbon nano tube-copper composite fiber is 3.5g/cm³-5.4g/cm³。

Technical Field

The invention relates to an inorganic composite material, in particular to a carbon nano tube-copper composite fiber and a preparation method thereof.

Background

Carbon nanotube fibers are fibers in which carbon nanotubes are highly aligned in one direction, and have excellent mechanical properties such as flexibility and tensile strength, however, carbon nanotube fibers have poor electrical conductivity.

The conventional method for improving the conductivity of the carbon nanotube fiber mainly comprises the following steps: (1) the conductive metal layer is electroplated on the surface of the carbon nanotube fiber to improve the conductivity of the carbon nanotube fiber, but the conductive metal layer is only attached to the surface of the carbon nanotube fiber to form a carbon nanotube core-conductive metal skin structure, so that the tensile strength and the flexibility of the carbon nanotube-metal composite fiber are reduced; (2) the carbon nanotube fiber with a loose structure is adopted, copper is filled into gaps of the carbon nanotubes through processes of chemical deposition, electroplating and the like to form the carbon nanotube-copper composite fiber, however, the copper content in the carbon nanotube-copper composite fiber obtained by the method is too high, the density of the composite fiber is large, and the specific strength and the flexibility of the composite fiber are reduced.

Disclosure of Invention

In view of the above, it is necessary to provide a carbon nanotube-copper composite fiber having high conductivity while having excellent flexibility and strength, and a method for preparing the same.

A preparation method of a carbon nanotube-copper composite fiber comprises the following steps:

mixing gaseous carbon source, iron source, sulfur source and copper source to obtain a gaseous precursor, and reacting the gaseous precursor to obtain a copper-containing carbon nanotube continuum;

performing contraction treatment on the copper-containing carbon nanotube continuum to obtain copper-containing carbon nanotube fibers; and

and (3) placing the copper-containing carbon nanotube fiber in copper electroplating solution for electroplating to obtain the carbon nanotube-copper composite fiber.

In one embodiment, the gaseous carbon source is selected from a carbon-containing gas or is gasified from a liquid carbon-containing compound, the liquid carbon-containing compound comprises at least one of methanol, benzene, toluene and ethanol, and the carbon-containing gas comprises at least one of methane, ethane, ethylene and acetylene.

In one embodiment, the gaseous iron source is gasified from an iron-containing compound comprising at least one of ferrocene, iron acetylacetonate, and iron pentacarbonyl.

In one embodiment, the gaseous sulfur source is selected from the group consisting of a sulfur-containing gas comprising hydrogen sulfide, a gasification of elemental sulfur, and a gasification of a sulfur-containing compound comprising at least one of thiophene and thiourea.

In one embodiment, the gaseous copper source is vaporized from a copper-containing compound comprising at least one of copper chloride, copper nitrate, and copper acetate.

In one embodiment, the atomic ratio of carbon, iron, sulfur and copper in the gaseous precursor is 100 (0.2-5): 0.1-10): 0.05-10.

In one embodiment, before reacting the gaseous precursor, the method further comprises mixing the gaseous precursor with a carrier gas, wherein the carrier gas comprises hydrogen and/or a shielding gas, and the shielding gas comprises at least one of nitrogen and a noble gas.

In one embodiment, the gaseous precursors are reacted at a reaction temperature of 1000 ℃ to 1250 ℃.

In one embodiment, the step of shrinking the copper-containing carbon nanotube continuum comprises: immersing the copper-containing carbon nanotube continuum in a liquid.

In one embodiment, the method for electroplating the copper-containing carbon nanotube fiber in the copper electroplating solution is a pulse electroplating method, wherein the current of the pulse electroplating method is 5mA-70mA, the current conduction time is 0.5s-2s, the current interval time is 0.5s-2s, and the pulse cycle number is 30-1200 times.

The carbon nanotube-copper composite fiber is prepared by the preparation method of the carbon nanotube-copper composite fiber.

In one embodiment, the diameter of the carbon nanotube-copper composite fiber is 20 μm to 100 μm;

and/or the tensile strength of the carbon nano tube-copper composite fiber is 1GPa-2 GPa;

and/or the electrical conductivity of the carbon nano tube-copper composite fiber is 0.5 multiplied by 10⁷s/m-6×10⁷s/m；

And/or the density of the carbon nano tube-copper composite fiber is 3.5g/cm³-5.4g/cm³。

In the preparation method of the carbon nano tube-copper composite fiber, the carbon nano tube is prepared by adopting a gas phase flow catalytic chemical vapor deposition method, and meanwhile, because a gaseous copper source is introduced into a gaseous precursor for preparing the carbon nano tube, the gaseous copper source can be decomposed into copper nano particles, so that the copper nano particles and the carbon nano tube are assembled together to obtain an ordered copper-containing carbon nano tube continuous body, and the copper-containing carbon nano tube continuous body is shrunk to obtain the copper-containing carbon nano tube fiber. Furthermore, when the copper-containing carbon nanotube fiber is placed in a copper electroplating solution for electroplating, the copper nanoparticles assembled in the copper-containing carbon nanotube fiber can be used as a growth seed layer of a copper layer to induce uniform and compact growth of the copper layer, so that the bonding strength between the copper layer and the carbon nanotube fiber is higher, and the grown copper layer is mostly filled in gaps of the carbon nanotube fiber, so that the flexibility of the carbon nanotube fiber is not influenced. Therefore, the carbon nanotube-copper composite fiber obtained by the preparation method has high conductivity and simultaneously has excellent mechanical properties such as flexibility, strength and the like.

Drawings

Fig. 1 is an SEM image of the carbon nanotube-copper composite fiber obtained in example 1 and an EDS image of the distribution of carbon element and copper element;

FIG. 2 is an SEM image of copper-containing carbon nanotube fibers obtained in examples 7 to 10;

fig. 3 is a raman spectrum of the copper-containing carbon nanotube fiber obtained in example 7 and example 8 and the carbon nanotube fiber obtained in comparative example 1;

FIG. 4 is a graph of tensile strength for copper-containing carbon nanotube fibers obtained in examples 7-10 and carbon nanotube fibers obtained in comparative example 1;

FIG. 5 is a graph of the electrical conductivity of the copper-containing carbon nanotube fibers obtained in examples 7-10 and the carbon nanotube fibers obtained in comparative example 1;

FIG. 6 is a graph showing tensile strength curves and electrical conductivities of the carbon nanotube-copper composite fibers obtained in examples 7 to 10 and the copper-coated carbon nanotube fiber obtained in comparative example 1;

fig. 7 is SEM images of the copper-plated carbon nanotube fiber obtained in comparative example 1 and the carbon nanotube-copper composite fiber obtained in example 6.

Detailed Description

The carbon nanotube-copper composite fiber and the method for preparing the same according to the present invention will be further described below.

The invention provides a preparation method of a carbon nano tube-copper composite fiber, which comprises the following steps:

s1, mixing a gaseous carbon source, an iron source, a sulfur source and a copper source to obtain a gaseous precursor, and reacting the gaseous precursor to obtain a copper-containing carbon nanotube continuum;

s2, performing contraction treatment on the copper-containing carbon nanotube continuum to obtain copper-containing carbon nanotube fibers;

and S3, placing the copper-containing carbon nanotube fiber in copper electroplating solution for electroplating to obtain the carbon nanotube-copper composite fiber.

In step S1, the reaction temperature of the gaseous precursor is 1000 ℃ to 1250 ℃, preferably 1050 ℃ to 1200 ℃.

In the reaction process, a gaseous carbon source in the gaseous precursor can be cracked into carbon atoms, a gaseous iron source can be cracked into iron nanoparticles, and the iron nanoparticles are used as a catalyst and can catalyze and induce the carbon atoms to be attached to the surface of the carbon atoms and be regularly arranged to generate carbon nanotubes, so that the carbon nanotubes are prepared by a gas-phase flow catalytic chemical vapor deposition method and can be further assembled to obtain an ordered carbon nanotube continuum.

In addition, the gaseous sulfur source is used as a promoter, and can promote the solubility of the gaseous carbon source in the gaseous iron source so as to promote the growth of the carbon nano tube.

Meanwhile, the gaseous precursor also comprises a gaseous copper source, the gaseous copper source can be decomposed into copper nanoparticles in the reaction process, and the copper nanoparticles are synchronously formed along with the growth of the carbon nanotubes and the assembly process of the continuum, so that the copper nanoparticles can be assembled with the carbon nanotubes together, and the ordered copper-containing carbon nanotube continuum is obtained and is a cylindrical continuum.

In order to ensure the normal growth of the carbon nanotubes and control the proportion of the carbon nanotubes and the copper nanoparticles in the obtained copper-containing carbon nanotube continuous body, further control the proportion of the carbon nanotubes and the copper in the carbon nanotube-copper composite fiber, and ensure the conductivity, the flexibility, the strength and the like of the carbon nanotube-copper composite fiber, in one embodiment, the atomic ratio of carbon, iron, sulfur and copper in the gaseous precursor is 100:0.2-5:0.1-10:0.05-10, preferably 100:0.5-2:0.2-5: 0.1-5.

In one embodiment, the gaseous carbon source is selected from a carbon-containing gas or is gasified from a carbon-containing compound, the carbon-containing compound comprises at least one of methanol, benzene, toluene and ethanol, and the carbon-containing gas comprises at least one of methane, ethane, ethylene and acetylene.

In one embodiment, the gaseous iron source is gasified from an iron-containing compound comprising at least one of ferrocene, iron acetylacetonate, iron pentacarbonyl.

In one embodiment, the gaseous sulfur source is selected from the group consisting of a sulfur-containing gas comprising hydrogen sulfide, elemental sulfur gasified, or a sulfur-containing compound comprising at least one of thiophene and thiourea.

In one embodiment, the gaseous copper source is gasified from a copper-containing compound comprising at least one of copper chloride, copper nitrate, and copper acetate.

In the actual preparation process, the step can be carried out in a tube furnace, and the tube furnace can be at least one of a vertical tube furnace, a horizontal tube furnace and a tube furnace with a certain inclined angle.

In one embodiment, when the gaseous carbon source is a carbon-containing gas and the gaseous sulfur source is a sulfur-containing gas, the iron-containing compound and the copper-containing compound can be directly gasified in the tube furnace to obtain a gaseous iron source and a gaseous copper source, and then mixed with the carbon-containing gas and the sulfur-containing gas to obtain a gaseous precursor.

In one embodiment, when the gaseous carbon source is formed by gasifying a carbon-containing compound, and the gaseous sulfur source is formed by gasifying elemental sulfur and/or a sulfur-containing compound, the iron-containing compound, the copper-containing compound, the carbon-containing compound, the elemental sulfur and/or the sulfur-containing compound may be first mixed, stirred, ultrasonically treated, etc. to form a precursor solution, and the precursor solution may be gasified in the tube furnace to obtain a gaseous precursor.

In an embodiment, before the reacting of the gaseous precursor, the method further includes mixing the gaseous precursor with a carrier gas, the carrier gas includes hydrogen and/or a protective gas, the protective gas includes at least one of nitrogen and a rare gas, and on one hand, the carrier gas can convey the gaseous precursor to the reaction zone of the tube furnace for reacting, and on the other hand, can prevent the gaseous precursor from being oxidized.

In addition, the hydrogen can also reduce the catalyst, which is beneficial to keeping higher activity of the catalyst, and simultaneously, the cracking rate of the gaseous carbon source is controlled, so that carbon atoms can be regularly arranged on the surface of the iron nano-particles to form the carbon nano-tubes.

In one embodiment, when the carrier gas comprises both hydrogen and a shielding gas, the volume ratio of the hydrogen to the shielding gas is from 1:1 to 5:1.

In step S2, the step of shrinking the copper-containing carbon nanotube continuum includes: immersing the copper-containing carbon nanotube continuum in a liquid.

In one embodiment, the liquid is selected from water or an aqueous liquid, wherein the aqueous liquid comprises ethanol, methanol, and the like.

In step S3, when the copper-containing carbon nanotube fiber is plated in a copper plating solution, the copper nanoparticles assembled in the copper-containing carbon nanotube fiber can serve as a growth seed layer of the copper layer to induce uniform and dense growth of the copper layer, so that the bonding strength between the copper layer and the carbon nanotube fiber is higher, and the grown copper layer is mostly filled in the gaps between the carbon nanotube fibers, without affecting the flexibility of the carbon nanotube fiber.

In one embodiment, the method for electroplating the copper-containing carbon nanotube fiber in the copper electroplating solution is a pulse electroplating method, wherein the current of the pulse electroplating method is 5mA-70mA, preferably 10mA-50mA, the current conduction time is 0.5s-2s, preferably 0.7s-1.5s, the current interval time is 0.5s-2s, preferably 0.7s-1.5s, and the pulse cycle number is 30-1200 times. Preferably 50 times to 1000 times to limit the overgrowth of copper particles and form a uniform and dense copper layer.

The invention also provides a carbon nanotube-copper composite fiber, which is prepared by the preparation method of the carbon nanotube-copper composite fiber, and the carbon nanotube-copper composite fiber comprises the carbon nanotube fiber and a copper layer, wherein the copper layer is filled in the gap of the carbon nanotube fiber.

It is to be noted that it is not excluded that a small portion of the copper layer is coated on the surface of the carbon nanotube fiber.

Therefore, the electrical conductivity of the carbon nanotube-copper composite fiber of the present invention can reach 0.5 × 10⁷s/m-6×10⁷s/m, high conductivity, and the carbon nanotube-copper composite fiber has a diameter of 20-100 μm and a density of 3.5g/cm³-5.4g/cm³The tensile strength is 1GPa-2GPa, the material can bear more than 10000 times of bending, has excellent mechanical properties such as flexibility, strength and the like, and can be applied to the fields of special light leads, flexible electrodes and the like.

Hereinafter, the carbon nanotube-copper composite fiber and the method for preparing the same will be further described with reference to the following specific examples.

Example 1

Methanol, iron pentacarbonyl, elemental sulfur and copper chloride are prepared into mixed body fluid by the processes of mixing, stirring, ultrasound and the like in sequence according to the molar ratio of 100:0.628:0.2: 0.844.

Injecting the solution into a tube furnace at a flow rate of 25mL/H for evaporation, and introducing 1500sccm H₂And Ar of 500sccm is used as a carrier gas to drive the vaporized mixture to enter a high-temperature reaction zone of 1100 ℃ along a pipeline, and finally a cylindrical copper-containing carbon nano tube continuous body is formed and flows out along with the gas flow from the tail of the furnace tube. Introducing the copper-containing carbon nanotube continuum into water to shrink into copper-containing carbonThe nanotube fibers are collected by the rollers of the drum.

And (2) placing the copper-containing carbon nanotube fiber in saturated copper sulfate electroplating solution to serve as a negative electrode, using a copper rod as a positive electrode, and electroplating by adopting a pulse electroplating method, wherein the current is set to be 5mA, the conduction time is 0.5s, the interval time is 0.5s, and the cycle number is 300 times, so that the carbon nanotube-copper composite fiber is obtained.

The carbon nanotube-copper composite fiber obtained in this example was subjected to EDS characterization, as shown in fig. 1, and it can be seen from fig. 1 that the carbon nanotube fiber and copper form a highly uniform mixture in the carbon nanotube-copper composite fiber.

The carbon nanotube-copper composite fiber obtained in this example was subjected to performance characterization: the fiber diameter was about 20 μm and the density was 3.5g/cm³Tensile strength of about 1GPa and electric conductivity of 0.5X 10⁷s/m。

Example 2

Benzene, iron pentacarbonyl, elemental sulfur and copper chloride are prepared into mixed body fluid by processes of mixing, stirring, ultrasound and the like in sequence according to a molar ratio of 100:3.865:3.23: 1.538.

Injecting the solution into a tube furnace at a flow rate of 25mL/H for evaporation, and introducing 1500sccm H₂And Ar of 500sccm is used as a carrier gas to drive the vaporized mixture to enter a high-temperature reaction zone of 1100 ℃ along a pipeline, and finally a cylindrical copper-containing carbon nano tube continuous body is formed and flows out along with the gas flow from the tail of the furnace tube. The copper-containing carbon nanotube continuous body is introduced into water to be shrunk into copper-containing carbon nanotube fibers, and is collected by a roller of a rotating drum.

And (2) placing the copper-containing carbon nanotube fiber in saturated copper sulfate electroplating solution to serve as a negative electrode, using a copper rod as a positive electrode, and electroplating by adopting a pulse electroplating method, wherein the current is set to be 30mA, the conduction time is 1s, the interval time is 0.5s, and the cycle number is 500 times, so that the carbon nanotube-copper composite fiber is obtained.

The carbon nanotube-copper composite fiber obtained in this example was subjected to performance characterization: the fiber diameter was about 35 μm and the density was 3.8g/cm³Tensile strength of about 1.2GPa and electric conductivity of 0.8X 10⁷s/m。

Example 3

Ethanol, ferric acetylacetonate, thiophene and copper chloride are prepared into a mixed body fluid by the processes of mixing, stirring, ultrasound and the like in turn according to the molar ratio of 100:3.835:1.826: 1.465.

Injecting the solution into a tube furnace at a flow rate of 25mL/H for evaporation, and introducing 1500sccm H₂And Ar of 500sccm is used as a carrier gas to drive the vaporized mixture to enter a 1200 ℃ high-temperature reaction region along a pipeline, and finally a cylindrical copper-containing carbon nano tube continuous body is formed and flows out along with the gas flow from the tail of the furnace tube. The copper-containing carbon nanotube continuous body is introduced into water to be shrunk into copper-containing carbon nanotube fibers, and is collected by a roller of a rotating drum.

And (2) placing the copper-containing carbon nanotube fiber in saturated copper sulfate electroplating solution to serve as a negative electrode, using a copper rod as a positive electrode, and electroplating by adopting a pulse electroplating method, wherein the current is set to be 50mA, the conduction time is 1s, the interval time is 2s, and the cycle number is 500 times, so that the carbon nanotube-copper composite fiber is obtained.

The carbon nanotube-copper composite fiber obtained in this example was subjected to performance characterization: the fiber diameter was about 55 μm and the density was 4.5g/cm³Tensile strength of about 1.5GPa and electric conductivity of 2X 10⁷s/m。

Example 4

Toluene, ferrocene, thiophene and copper acetate are prepared into mixed body fluid by the processes of mixing, stirring, ultrasound and the like in sequence according to the molar ratio of 100:3.53:3.2: 7.6.

Injecting the solution into a tube furnace at a speed of 25ml/H for evaporation, and introducing 1500sccm H₂And Ar of 500sccm is used as a carrier gas to drive the vaporized mixture to enter a 1200 ℃ high-temperature reaction region along a pipeline, and finally a cylindrical copper-containing carbon nano tube continuous body is formed and flows out along with the gas flow from the tail of the furnace tube. The copper-containing carbon nanotube continuous body is introduced into water to be shrunk into copper-containing carbon nanotube fibers, and is collected by a roller of a rotating drum.

And (2) placing the copper-containing carbon nanotube fiber in saturated copper sulfate electroplating solution to serve as a negative electrode, using a copper rod as a positive electrode, and electroplating by adopting a pulse electroplating method, wherein the current is set to be 50mA, the conduction time is 1s, the interval time is 2s, and the cycle number is 500 times, so that the carbon nanotube-copper composite fiber is obtained.

The carbon nanotube-copper composite fiber obtained in this example was subjected to performance characterization: the fiber diameter was about 80 μm, 4.8g/cm³Tensile strength of about 1.75GPa and electric conductivity of 4.5X 10⁷s/m。

Example 5

Toluene, ferrocene and copper acetate are prepared into mixed body fluid by processes of mixing, stirring, ultrasound and the like in sequence according to the molar ratio of 100:7: 10.25.

Injecting the solution into a tubular furnace at a speed of 20mL/H for evaporation, introducing 5sccm hydrogen sulfide as a gaseous sulfur source, and simultaneously introducing 1200sccm H₂And Ar of 300sccm is used as a carrier gas to drive the vaporized mixture to enter a high-temperature reaction zone at 1150 ℃ along a pipeline, and finally a cylindrical copper-containing carbon nanotube continuous body is formed and flows out along with the gas flow from the tail of the furnace tube. The copper-containing carbon nanotube continuous body is introduced into water to be shrunk into copper-containing carbon nanotube fibers, and is collected by a roller of a rotating drum.

And (2) placing the copper-containing carbon nanotube fiber in saturated copper sulfate electroplating solution to serve as a negative electrode, using a copper rod as a positive electrode, and electroplating by adopting a pulse electroplating method, wherein the current is set to be 60mA, the conduction time is 2s, the interval time is 2s, and the cycle number is 1000 times, so that the carbon nanotube-copper composite fiber is obtained.

The carbon nanotube-copper composite fiber obtained in this example was subjected to performance characterization: the fiber diameter was about 95 μm and the density was 5.4g/cm³Tensile strength of about 2GPa and electric conductivity of 6X 10⁷s/m。

Example 6

Ethanol, ferrocene, thiophene and copper chloride are prepared into mixed body fluid by processes of mixing, stirring, ultrasound and the like in sequence according to the molar ratio of 100:11.16:10.08: 20.25.

Injecting the solution into a tube furnace at a flow rate of 25mL/H for evaporation, and introducing 1500sccm H₂And Ar of 500sccm is used as carrier gas to drive the vaporized mixture to enter a high-temperature reaction zone of 1200 ℃ along a pipeline, and finally a cylindrical copper-containing carbon nano tube continuous body is formed and is aerated from the tail part of the furnace tubeThe flow drifts out. The copper-containing carbon nanotube continuous body is introduced into water to be shrunk into copper-containing carbon nanotube fibers, and is collected by a roller of a rotating drum.

And (2) placing the copper-containing carbon nanotube fiber in saturated copper sulfate electroplating solution to serve as a negative electrode, using a copper rod as a positive electrode, and electroplating by adopting a pulse electroplating method, wherein the current is set to be 50mA, the conduction time is 1s, the interval time is 2s, and the cycle number is 500 times, so that the carbon nanotube-copper composite fiber is obtained.

The carbon nanotube-copper composite fiber obtained in this example was subjected to performance characterization: the fiber diameter was about 80 μm and the density was 5.0g/cm³Tensile strength of about 1.75GPa and electric conductivity of 4.5X 10⁷s/m。

Example 7

Ethanol, ferrocene, thiophene and copper chloride are prepared into mixed body fluid by processes of mixing, stirring, ultrasound and the like in sequence according to the molar ratio of 100:11.16:10.08: 5.58.

Injecting the solution into a tube furnace at a flow rate of 25mL/H for evaporation, and introducing 1500sccm H₂And Ar of 1000sccm is used as carrier gas to drive the vaporized mixture to enter a 1250 ℃ high-temperature reaction region along a pipeline, and finally a cylindrical copper-containing carbon nano tube continuous body is formed and flows out along with the gas flow from the tail of the furnace tube. The copper-containing carbon nanotube continuous body is introduced into water to be shrunk into copper-containing carbon nanotube fibers, and is collected by a roller of a rotating drum.

And (2) placing the copper-containing carbon nanotube fiber in saturated copper sulfate electroplating solution to serve as a negative electrode, using a copper rod as a positive electrode, and electroplating by adopting a pulse electroplating method, wherein the current is set to be 50mA, the conduction time is 1s, the interval time is 2s, and the cycle number is 500 times, so that the carbon nanotube-copper composite fiber is obtained.

The carbon nanotube-copper composite fiber obtained in this example was subjected to performance characterization: the fiber diameter was about 75 μm and the density was 4.6g/cm³Tensile strength of about 1.48GPa and electric conductivity of 3.8X 10⁷s/m。

Example 8

Ethanol, ferrocene, thiophene and copper chloride are prepared into mixed body fluid by processes of mixing, stirring, ultrasound and the like in sequence according to the molar ratio of 100:11.16:10.08: 11.16.

Injecting the solution into a tube furnace at a flow rate of 25mL/H for evaporation, and introducing 1500sccm H₂And Ar of 1000sccm is used as carrier gas to drive the vaporized mixture to enter a 1250 ℃ high-temperature reaction region along a pipeline, and finally a cylindrical copper-containing carbon nano tube continuous body is formed and flows out along with the gas flow from the tail of the furnace tube. The copper-containing carbon nanotube continuous body is introduced into water to be shrunk into copper-containing carbon nanotube fibers, and is collected by a roller of a rotating drum.

And (2) placing the copper-containing carbon nanotube fiber in saturated copper sulfate electroplating solution to serve as a negative electrode, using a copper rod as a positive electrode, and electroplating by adopting a pulse electroplating method, wherein the current is set to be 50mA, the conduction time is 1s, the interval time is 2s, and the cycle number is 500 times, so that the carbon nanotube-copper composite fiber is obtained.

The carbon nanotube-copper composite fiber obtained in this example was subjected to performance characterization: the fiber had a diameter of about 78 μm and a density of 4.75g/cm³Tensile strength of about 1.5GPa and electric conductivity of 4X 10⁷s/m。

Example 9

Ethanol, ferrocene, thiophene and copper chloride are prepared into mixed body fluid by processes of mixing, stirring, ultrasound and the like in sequence according to the molar ratio of 100:11.16:10.08: 16.74.

Injecting the solution into a tube furnace at a flow rate of 25mL/H for evaporation, and introducing 1500sccm H₂And Ar of 1000sccm is used as carrier gas to drive the vaporized mixture to enter a 1250 ℃ high-temperature reaction region along a pipeline, and finally a cylindrical copper-containing carbon nano tube continuous body is formed and flows out along with the gas flow from the tail of the furnace tube. The copper-containing carbon nanotube continuous body is introduced into water to be shrunk into copper-containing carbon nanotube fibers, and is collected by a roller of a rotating drum.

And (2) placing the copper-containing carbon nanotube fiber in saturated copper sulfate electroplating solution to serve as a negative electrode, using a copper rod as a positive electrode, and electroplating by adopting a pulse electroplating method, wherein the current is set to be 50mA, the conduction time is 1s, the interval time is 2s, and the cycle number is 500 times, so that the carbon nanotube-copper composite fiber is obtained.

The carbon nanotube-copper composite obtained in this exampleAnd (3) performing performance characterization on the synthetic fiber: the fiber diameter was about 80 μm and the density was 5.0g/cm³Tensile strength of about 1.7GPa and electric conductivity of 4.3X 10⁷s/m。

Example 10

Ethanol, ferrocene, thiophene and copper chloride are prepared into mixed body fluid by processes of mixing, stirring, ultrasound and the like in sequence according to the molar ratio of 100:11.16:10.08: 22.32.

Injecting the solution into a tube furnace at a flow rate of 25mL/H for evaporation, and introducing 1500sccm H₂And Ar of 1000sccm is used as carrier gas to drive the vaporized mixture to enter a 1250 ℃ high-temperature reaction region along a pipeline, and finally a cylindrical copper-containing carbon nano tube continuous body is formed and flows out along with the gas flow from the tail of the furnace tube. The copper-containing carbon nanotube continuous body is introduced into water to be shrunk into copper-containing carbon nanotube fibers, and is collected by a roller of a rotating drum.

And (2) placing the copper-containing carbon nanotube fiber in saturated copper sulfate electroplating solution to serve as a negative electrode, using a copper rod as a positive electrode, and electroplating by adopting a pulse electroplating method, wherein the current is set to be 50mA, the conduction time is 1s, the interval time is 2s, and the cycle number is 500 times, so that the carbon nanotube-copper composite fiber is obtained.

The carbon nanotube-copper composite fiber obtained in this example was subjected to performance characterization: the fiber diameter was about 84 μm and the density was 5.2g/cm³Tensile strength of about 1.8GPa and electric conductivity of 4.6X 10⁷s/m。

Comparative example 1

Ethanol, ferrocene and thiophene are prepared into mixed body fluid by processes of mixing, stirring, ultrasound and the like in sequence according to the molar ratio of 100:11.16: 10.08.

Injecting the solution into a tube furnace at a flow rate of 25mL/H for evaporation, and introducing 1500sccm H₂And Ar of 1000sccm is used as carrier gas to drive the vaporized mixture to enter a 1250 ℃ high-temperature reaction region along a pipeline, and finally a cylindrical object containing the carbon nano tube is formed and flows out along with the gas flow from the tail part of the furnace tube. The cylindrical object containing the carbon nano tube is led into water to be contracted into carbon nano tube fiber, and the carbon nano tube fiber is collected through a roller of a rotary drum.

And (2) placing the carbon nanotube fiber in saturated copper sulfate electroplating solution to serve as a negative electrode, using a copper rod as a positive electrode, and electroplating by adopting a pulse electroplating method, wherein the current is set to be 50mA, the conduction time is 1s, the interval time is 2s, and the cycle number is 500 times, so that the copper-plated carbon nanotube fiber is obtained.

The carbon nanotube-copper composite fiber obtained in this example was subjected to performance characterization: the fiber diameter was about 50 μm and the density was 4g/cm³Tensile strength of about 0.2GPa and electric conductivity of 0.8X 10⁷s/m。

In example 7, example 8, example 9, example 10 and comparative example 1 described above, the atomic ratios of copper to iron were 0.5:1, 1:1, 1.5:1, 2:1 and 0:1, respectively. The copper-containing carbon nanotube fibers of the intermediate products of examples 7 to 10 and the carbon nanotube fibers of the intermediate product of comparative example 1 were characterized, and the results were as follows.

As shown in fig. 2, by introducing a copper source into the precursor, the amorphous carbon on the surface of the carbon nanotube fiber decreases as the copper content increases, and in example 10, i.e., the atomic ratio of copper to iron is 2:1, there is almost no amorphous carbon on the surface of the carbon nanotube.

As shown in FIG. 3, a copper source is introduced into the precursor, and as the copper content increases, I_G/I_DThe ratio is increased, which indicates that the defects and impurities of the carbon nano tube are reduced, and the purity and the order degree are increased.

As shown in fig. 4, the strength of the copper-containing carbon nanotube fiber increased significantly with the increase of the copper content by introducing the copper source into the precursor, and when the copper content was increased to an atomic ratio of copper to iron of 2:1, the strength of the copper-containing carbon nanotube fiber reached 1.8GPa, which is about 8 times the tensile strength of pure copper, and the elongation at break of the copper-containing carbon nanotube fiber also increased with the increase of the copper content, indicating that the flexibility of the copper-containing carbon nanotube fiber also increased with the increase of the copper content.

As shown in fig. 5, the electrical conductivity of the copper-containing carbon nanotube fiber gradually increases as the copper content increases. Therefore, the introduction of copper element into the gaseous precursor can obviously improve the conductivity of the copper-containing carbon nanotube fiber, and the conductivity of the copper-containing carbon nanotube fiber is improved along with the increase of the copper content in a certain range.

As shown in fig. 6, after introducing the copper source into the precursor, the carbon nanotube-copper composite fiber obtained by electroplating has a significant order of magnitude improvement in both tensile strength and electrical conductivity.

SEM characterization was performed on the copper-coated carbon nanotube fiber obtained in comparative example 1 and the carbon nanotube-copper composite fiber obtained in example 6, as shown in fig. 7, in which fig. 7(a) and 7(b) are SEM images of the copper-coated carbon nanotube fiber obtained in comparative example 1, and fig. 7(c) and 7(d) are SEM images of the carbon nanotube-copper composite fiber obtained in example 6.

As can be seen from fig. 7, in comparative example 1, the surface of the copper-electroplated layer of the carbon nanotube fiber without copper doping is rough after copper electroplating, and larger copper particles with crystalline morphology are formed; in example 6, the surface of the copper electroplated layer of the copper-containing carbon nanotube fiber formed fine, dense and uniform particles, and did not exhibit a crystalline morphology. Therefore, the carbon nanotube copper-doped fiber is beneficial to inducing densification and non-crystallization of subsequent electroplating copper, realizes uniform compounding of the carbon nanotube and the copper, and is beneficial to improving the mechanical properties of the carbon nanotube-copper composite fiber, such as conductivity, tensile strength, flexibility and the like.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.