CN113321430A

CN113321430A - Method for preparing graphene glass fibers

Info

Publication number: CN113321430A
Application number: CN202110716320.7A
Authority: CN
Inventors: 刘忠范; 程熠; 时鹏程; 李隽良; 亓月
Original assignee: Peking University; Beijing Graphene Institute BGI
Current assignee: Peking University; Beijing Graphene Institute BGI
Priority date: 2021-06-25
Filing date: 2021-06-25
Publication date: 2021-08-31
Anticipated expiration: 2041-06-25
Also published as: CN113321430B

Abstract

The present application provides a method of preparing graphene glass fibers, comprising: providing glass fiber with a conductive carbon layer on the surface; and applying pulse current to the glass fiber with the conductive carbon layer on the surface to obtain the graphene glass fiber. The method disclosed by the invention utilizes the Joule heat generated by the current passing through the conductor to enable the surface of the fiber to reach high temperature quickly, and the graphitization of the carbon layer on the surface of the fiber can be realized in a short time. The method can greatly improve the preparation efficiency of the graphene glass fiber, and effectively reduce the thermal damage of the graphene. The graphene prepared by the method has high graphitization degree, is tightly attached to a fiber substrate, and has good composite stability.

Description

Method for preparing graphene glass fibers

Technical Field

The invention belongs to the field of new material preparation, and particularly relates to a method for preparing graphene glass fibers by a rapid electric heating oscillation method.

Background

Glass fiber is a traditional inorganic non-metallic material, has the characteristics of light weight, high strength, heat resistance, corrosion resistance, heat insulation, sound insulation and the like, and is often used as a reinforcing material or an electrical insulating material in the fields of aerospace, construction, machinery, electronic information and the like. The glass fiber is compounded with the functional material, so that the glass fiber has excellent characteristics of electric conduction, heat conduction and the like, and the application field of functionalization is expanded.

Early researchers coated a metal coating on the surface of glass fiber by chemical plating, sputtering, etc. to impart conductive properties to the glass fiber. However, such a metallization scheme seriously affects the flexibility of the intrinsic glass fibers, and the treatment process inevitably causes heavy metal contamination.

Graphene combines high electrical conductivity (10-10) due to its monoatomic layer thickness, excellent mechanical flexibility⁸Sm^-1) Thermal conductivity (-5300 Wm)^-1K^-1) And the preparation method has the advantages that the graphene/glass fiber composite material is compounded with the glass fiber, so that the preparation of the high-performance graphene/glass fiber composite material can be effectively realized. Researchers initially realized simple compounding of graphene and glass fibers by using a coating (Ning, n.et al.polymer 2013,54,303.) or film transfer (Bao, q.et al.adv.funct.mater.2009,19,3077.), but the graphene-glass composite fibers prepared by the method have weak interaction between two phase interfaces and poor compounding stability, and simultaneously the prepared sample has a small size, so that large-scale preparation of the graphene glass fibers is realized. The chemical vapor deposition preparation technology developed subsequently effectively realizes the stable compounding of graphene and quartz fibers (Cui, g.et al. acs Nano 2020,14,5938.), but the high-temperature treatment process limits the selection of fiber substrates, only the high-temperature-resistant quartz and alumina fibers are suitable for the growth of graphene, and the growth time is often as long as several hours for ensuring the quality of graphene.

Therefore, the invention provides a novel method for preparing graphene glass fibers simply, conveniently, quickly and quickly by electrothermal oscillation based on the problems in the preparation process of the graphene glass fibers.

It is noted that the information disclosed in the foregoing background section is only for enhancement of background understanding of the present disclosure and therefore it may contain information that does not constitute prior art that is known to a person of ordinary skill in the art.

Disclosure of Invention

A main object of the present disclosure is to overcome at least one of the above drawbacks of the prior art, and to provide a method for preparing graphene glass fibers by rapid electrothermal oscillation, so as to solve the problems of time consumption, energy consumption, large thermal loss of the fibers, and the like in the conventional graphene glass fiber preparation process.

The application provides a method for preparing graphene glass fibers, which comprises the following steps:

providing glass fiber with a conductive carbon layer on the surface;

and applying pulse current to the glass fiber with the conductive carbon layer on the surface to obtain the graphene glass fiber.

In one embodiment, the glass fiber having a conductive carbon layer on the surface thereof is obtained by pre-depositing a carbon layer on the surface of the glass fiber, or by applying a polymer to the surface of the glass fiber followed by a carbonization treatment.

In one embodiment, the pulse current has a peak current intensity of 0.1 to 5A and a frequency of 1 to 100 Hz.

In one embodiment, the pulsed current is applied for a time in the range of 1-100 s.

In one embodiment, a pulsed current is applied to the glass fiber having a conductive carbon layer on the surface as follows:

connecting two ends of the glass fiber with the conductive carbon layer on the surface with electrodes respectively;

the pulsed current is applied to both electrodes.

In one embodiment, the pressure within the system is <5Pa or >1000Pa when the pulsed current is applied.

In one embodiment, the method further comprises introducing one or more of a nitrogen-containing precursor, a boron-containing precursor while applying the pulsed current.

In one embodiment, the nitrogen-containing precursor is selected from one or more of ammonia, acetonitrile, pyridine, pyrrole, and methylamine, and the boron-containing precursor is selected from one or more of phenylboronic acid, diborane, boron powder, and triethylborane.

The application also relates to graphene glass fibers obtained by the method of the application.

According to the method, the surface of the fiber is promoted to be effectively changed into graphite by applying the pulse current to the fiber coated with the conductive carbon layer, so that the energy consumption and the thermal damage to the fiber caused by long-time high-temperature heating in the traditional chemical vapor deposition process are avoided, the rapid preparation of the graphene fiber is realized, the batch preparation of the graphene glass fiber can be realized by adding a roll-to-roll transmission system subsequently, and the production cost of the graphene glass fiber is greatly reduced. The method disclosed by the invention utilizes the Joule heat generated by the current passing through the conductor to enable the surface of the fiber to reach high temperature quickly, and the graphitization of the carbon layer on the surface of the fiber can be realized in a short time. The method can greatly improve the preparation efficiency of the graphene glass fiber, and effectively reduce the thermal damage of the graphene. The graphene prepared by the method has high graphitization degree, is tightly attached to a fiber substrate, and has good composite stability. Meanwhile, the prepared graphene fiber has more excellent electric conduction, heat conduction and mechanical properties, and has a good application prospect.

Drawings

The following drawings are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the principles of the disclosure and not to limit the disclosure.

Fig. 1 is an apparatus for preparing graphene glass fibers according to the present application;

FIG. 2 is a graph showing the change in the surface temperature of the fiber under the action of a single pulse of current in example 1.

FIG. 3 is a comparison of Raman spectra of the surface of the glass fiber before and after thermal shock (pulse current applied) in example 1;

FIG. 4 is a comparison of Raman spectra of the surface of the glass fiber before and after thermal shock (pulse current applied) in example 2;

fig. 5 shows the change of the electrical conductivity of the graphene glass fiber prepared in example 2 when the graphene glass fiber is bent at different bending radii, wherein the bending times are 100 times.

Wherein the reference numerals are as follows:

100. 101: electrode for electrochemical cell

101: glass fiber with conductive carbon layer on surface

Detailed Description

The technical solution of the present invention is further explained below according to specific embodiments. The scope of protection of the invention is not limited to the following examples, which are set forth for illustrative purposes only and are not intended to limit the invention in any way.

providing glass fiber with a conductive carbon layer on the surface;

The method of the invention applies pulse current to the glass fiber with the conductive carbon layer on the surface to generate Joule heat to convert the conductive carbon layer on the surface into graphene, thereby obtaining the graphene glass fiber. By applying pulse current, the conversion of the surface-coated carbon layer to the high-crystallinity graphene is promoted through the process of electrothermal oscillation. The method effectively endows the traditional glass fiber material with excellent functional characteristics of electric conduction and heat conduction, and greatly widens the application prospect of the glass fiber material. Compared with other methods, the method for preparing the graphene fiber has the advantages of simple steps, low cost, low energy consumption and strong interface bonding stability of graphene and glass fiber, and is expected to promote the rapid, low-cost and batch preparation of the graphene glass fiber.

Glass fibers useful in the present application may include a series of inorganic non-metallic fibers such as quartz fibers, soda lime glass fibers, alumina fibers, mullite fibers, boron fibers, and the like. The fiber morphology includes fiber monofilaments, fiber bundles, fiber cloth, fiber felt and the like.

The carbon layer is pre-deposited on the surface of the glass fiber by adopting a chemical vapor deposition method, and a low-crystallinity carbon layer can be pre-deposited on the surface of the glass fiber. The conditions for chemical vapor deposition may be: placing the glass fiber sample in a tubular furnace, introducing a carbon source under the conditions of 50-300sccm hydrogen and 50-300sccm argon, wherein the heating rate is 5-50 ℃/min, the growth time is 30min-5h, the growth temperature is 600-1200 ℃, the carbon source can be methane, ethylene, acetylene, methanol, ethanol, acetone, toluene, benzene, benzoic acid and the like, naturally cooling to room temperature after growing for a period of time, and taking out. Preferably, the temperature is raised to 1050 ℃ at the heating rate of 20 ℃/min under the condition of 200sccm argon and 50sccm hydrogen, 50sccm methane (or other carbon sources such as ethylene and ethanol) is introduced, the deposition is carried out for 1h, and then the temperature is naturally reduced to room temperature and the mixture is taken out.

The carbonization process after the polymer is coated on the surface of the glass fiber can be performed as follows: the surface of the glass fiber is coated with polymer, and then is subjected to pre-carbonization treatment under the protection of inert gas at low temperature. The polymer coated may be epoxy, acrylic, and the like. The conditions of the pre-carbonization treatment may be: placing the glass fiber sample in a tubular furnace, under the conditions of 50-300sccm hydrogen and 50-300sccm argon, the heating rate is 5-20 ℃/min, the heat preservation time is 30min-5h, and the heat preservation temperature is 600-1000 ℃. Preferably, the temperature is raised to 800 ℃ at the speed of 10 ℃/min under the protection of 200sccm hydrogen and 200sccm argon, the temperature is kept for 1h, and the mixture is cooled and taken out.

After pulse current is applied, the surface of the fiber is heated, and the highest temperature can reach 1500-2500 ℃.

In one embodiment, a pulsed current may be applied to the glass fiber having a conductive carbon layer on the surface as follows:

the pulsed current is applied to both electrodes.

This process may be carried out in the apparatus shown in fig. 1, with a glass fiber 200 having a conductive carbon layer on the surface thereof wound around the two

electrodes

100, 101 and placed in a reaction chamber. In one embodiment, the distance between the two ends of the fiber and the potential connection point of the electrode is 0.5cm to 20 cm.

In one embodiment, when the pulse current is applied, it is desirable to control the pressure within the system to be <5Pa or >1000Pa, since system pressures in the range of 5-1000Pa are prone to electrical discharge resulting in fiber breakage. Wherein, the gas can be introduced into the reactor and comprises one or more of nitrogen, argon and hydrogen.

In one embodiment, one or more of a nitrogen-containing precursor and a boron-containing precursor may be introduced to dope the graphene glass fiber while the pulse current is applied. In one embodiment, the nitrogen-containing precursor is selected from one or more of ammonia, acetonitrile, pyridine, pyrrole, and methylamine, and the boron-containing precursor is selected from one or more of phenylboronic acid, diborane, boron powder, and triethylborane.

The present invention will be described in further detail with reference to specific examples, which are conventional unless otherwise specified. The starting materials are commercially available from the open literature unless otherwise specified.

Example 1:

1) commercially available quartz glass fiber bundles were placed in a three inch tube furnace and heated to 600 c and annealed in an air atmosphere to remove the surface-applied polymer coating.

2) And closing the air valve, heating the tube furnace to 900 ℃, sequentially introducing 500sccm argon gas, 100sccm hydrogen gas and 20sccm ethylene, and depositing a low-crystallinity carbon layer on the surface of the quartz fiber bundle. And taking out the sample from the tube furnace after the sample is cooled along with the furnace.

3) Winding the pre-deposited carbon layer quartz fiber bundle obtained in the step 2) in a device shown in figure 1, opening a vacuum pump to keep the system pressure less than 10Pa, applying a pulse current with the frequency of 1Hz and the peak current intensity of 5A between two electrodes, cooling after treating for 5min, and taking out a target fiber sample.

FIG. 2 shows the change of the surface temperature of the fiber under the action of the single pulse current in example 1, and it can be seen that the surface of the glass fiber reaches above its softening point in a short time before and after the electrothermal oscillation (pulse current application), which is beneficial to the graphitization transformation of the carbon layer. Fig. 3 is a comparison of raman spectra of the surface of the glass fiber before and after the electrothermal oscillation (pulse current application) in example 1, and typical characteristic peaks (D peak, G peak, 2D peak) of graphene appear, which proves that the surface of the glass fiber has graphene coating.

Example 2:

1) and putting the common glass fiber coated with the epoxy resin on the surface into a three-inch tube furnace, heating to 500 ℃, carbonizing for 2 hours under the protection of 300sccm argon and 100sccm hydrogen, cooling to room temperature, and taking out.

2) The carbonized glass fiber obtained in step 1) was mounted on an apparatus as shown in FIG. 1. And then, opening a vacuum pump, keeping the low-pressure state (1 Pa) of the system, introducing pulse current 5s with the frequency of 2Hz and the peak current intensity of 2A, closing a power supply, and taking out the sample after the sample is cooled.

Fig. 4 is a comparison graph of raman spectra of the graphene glass fibers before and after the electrothermal oscillation (pulse current application) of example 2, and it can be seen from fig. 5 that the carbon layer defect sites on the fiber surface after the joule heat flash evaporation treatment are significantly reduced, and the graphitization degree is significantly improved. Fig. 5 is a bending performance test result of the graphene glass fiber after the electrothermal oscillation (pulse current application) of example 2, and it can be seen that the change of the electrical conductivity before and after bending is very small, which indicates that the graphene is tightly attached to the fiber substrate and the composite fiber has good flexibility.

It should be noted by those skilled in the art that the described embodiments of the present disclosure are merely exemplary, and that various other substitutions, alterations, and modifications may be made within the scope of the present disclosure. Accordingly, the present disclosure is not limited to the above-described embodiments, but only by the claims.

Claims

1. A method of making graphene glass fibers, comprising:

providing glass fiber with a conductive carbon layer on the surface;

2. The method as claimed in claim 1, wherein the glass fiber having the conductive carbon layer on the surface thereof is obtained by pre-depositing a carbon layer on the surface of the glass fiber, or by applying a polymer to the surface of the glass fiber followed by a carbonization treatment.

3. The method according to claim 1, wherein the pulse current has a peak current intensity of 0.1-5A and a frequency of 1-1000 Hz.

4. The method of claim 1, wherein the pulsed electrical current is applied for a time of 1-100 s.

5. The method of claim 1, wherein the pulsed electrical current is applied to the glass fiber having a conductive carbon layer on the surface as follows:

the pulsed current is applied to both electrodes.

6. The method of claim 5, wherein the pressure within the system is <5Pa or >1000Pa when the pulsed current is applied.

7. The method of claim 5, further comprising introducing one or more of a nitrogen-containing precursor, a boron-containing precursor while applying the pulsed current.

8. The method of claim 7, wherein the nitrogen-containing precursor is selected from one or more of ammonia, acetonitrile, pyridine, pyrrole, and methylamine, and the boron-containing precursor is selected from one or more of phenylboronic acid, diborane, boron powder, and triethylborane.

9. Graphene glass fibers obtained by the process of claims 1-8.