Carbon tube / glassy carbon composite film and preparation method and application thereof

Abstract

The invention provides a carbon tube / glassy carbon composite film as well as a preparation method and application thereof, the method utilizes an alcohol spraying method to enable a carbon nanotube film to form a densified carbon tube film, and then the glassy carbon is loaded on the carbon tube film by chemical vapor deposition, so that the contact resistance between carbon tubes is reduced, and the performance of the carbon tube / glassy carbon composite film is improved. And blocking the relative movement between the single-walled carbon nanotubes to obtain the carbon tube / glassy carbon composite film. According to the invention, a two-step densification method of alcohol spraying and glassy carbon loading is adopted, so that the carbon tube / glassy carbon composite film has very high strength, electromagnetic shielding effectiveness and electric heating performance.

Description

Technical Field

[0001] The invention relates to the technical field of nanomaterials, and in particular to a carbon tube / glassy carbon composite film and a preparation method and application thereof. Background Art

[0002] With the continuous development of intelligent, portable and wearable electronic devices, the demand for high-performance electromagnetic shielding materials is becoming more and more urgent. These materials not only need to have excellent electromagnetic shielding performance, but also must meet various functional and performance requirements to adapt to different application scenarios. Traditional metal electromagnetic shielding materials are limited by their high density, poor flexibility, low corrosion resistance and inefficient heat conversion performance, and are no longer suitable for the diverse needs of modern electronic devices.

[0003] In the current context, carbon-based materials, including carbon tubes, graphene, carbon nanofibers, etc., are leading a new trend in the field of electromagnetic shielding materials. These materials are widely regarded as ideal substitutes for traditional metals due to their excellent properties, such as high strength, outstanding conductivity, excellent corrosion resistance and light weight. However, the requirements for high-performance electromagnetic shielding materials are not limited to shielding performance, but also include multiple standards such as mechanical strength, flexibility, reliability, wear resistance and durability to adapt to the diverse application scenarios of modern electronic devices. It is worth noting that the normal operation of electronic devices within a specific temperature range is crucial for many applications. Therefore, incorporating Joule heating performance into electromagnetic shielding materials has become an indispensable trend. The integration of this function enables the material to generate local heating by controlling the current, thereby effectively managing the temperature of the equipment. Especially in specific application areas such as anti-icing, deicing and temperature sensors, the importance of Joule heating performance has become more and more significant.

[0004] In summary, high-performance electromagnetic shielding materials have become a key driving factor in the evolution of electronic devices. At the same time, the superior performance and versatility of carbon-based materials make them a highly sought-after material choice to meet the diverse needs of modern electronic devices.

[0005] Patent document CN112176313 A discloses a glassy carbon / carbon nanotube film composite material and its preparation method and application. Glassy carbon is directly deposited on a carbon nanotube film by vapor phase chemical deposition to obtain a glassy carbon / carbon nanotube film composite material. The tensile strength of the material is 80-90 MPa, and there is a problem that the mechanical strength needs to be further improved. In addition, direct deposition of glassy carbon on the surface of the carbon nanotube film can easily cause the carbon nanotube film to break, resulting in the inability to effectively deposit glassy carbon. Summary of the invention

[0006] The present invention provides a carbon tube / glassy carbon composite film and a preparation method and application thereof. Alcohol spraying is used to improve the density of the carbon nanotube film, increase the mutual contact between the carbon nanotubes, hinder the relative movement between the carbon nanotubes, and reduce the contact resistance between the carbon nanotubes. Finally, glassy carbon is loaded on the carbon tubes through a chemical vapor deposition method to form an interconnected welding network. The welding network further hinders the relative movement between the carbon tubes, thereby improving the mechanical properties of the carbon tube film.

[0007] The technical solution of the present invention is achieved as follows: A method for preparing a carbon tube / glassy carbon composite film comprises the following steps:

[0008] (1) spraying a carbon nanotube film with alcohol to form a densified carbon nanotube film;

[0009] (2) Chemical vapor deposition is used to load glassy carbon on the densified carbon tube film to obtain a carbon tube / glassy carbon composite film.

[0010] Furthermore, in step (1), the alcohol spraying method is as follows: the alcohol spraying flow rate is 3mL / min to 10mL / min, and the spraying time is 1min to 3min. The morphology of the carbon tubes in the internal structure of the densified carbon tube film will be different depending on the nozzle flow rate and the spraying time.

[0011] The carbon nanotube film is sprayed with alcohol to form a densified carbon tube film. The alcohol is sprayed with a sprayer to increase the mutual contact between the carbon nanotubes to obtain a densified carbon tube film.

[0012] Furthermore, in step (2), the method of loading glassy carbon on the densified carbon tube film by chemical vapor deposition is as follows: using ferrocene and 1,2-dichlorobenzene as carbon sources, hydrogen-argon mixed gas as carrier gas, reaction temperature 900°C, deposition 1-3h, to obtain a carbon tube / glassy carbon composite film.

[0013] Furthermore, in step (1), the carbon nanotube film is prepared by chemical vapor deposition.

[0014] Furthermore, in step (1), the preparation method of the carbon nanotube film is as follows: using ferrocene, sublimed sulfur and xylene as carbon sources, in a hydrogen-argon mixed gas atmosphere, the reaction temperature is 1200° C., to obtain the carbon nanotube film.

[0015] A carbon tube / glassy carbon composite film is prepared by adopting the preparation method.

[0016] Furthermore, the carbon tube / glassy carbon composite film comprises a densified carbon tube film, and the surface of the carbon tube film is loaded with glassy carbon to form an interconnected welding network.

[0017] Application of carbon tube / glassy carbon composite films in electromagnetic shielding.

[0018] Beneficial effects of the present invention:

[0019] The carbon nanotube film has very long carbon nanotubes, which can reach tens of centimeters in length. These carbon nanotubes form a mesh structure in an interwoven manner, and the interaction force between each other is very strong. However, in the process of loading glassy carbon, the carbon nanotube film is still easily damaged. In order to solve this problem, the present invention utilizes the method of alcohol spraying to shrink the carbon nanotube film in the thickness direction, increase the interaction between the carbon nanotubes, reduce the contact resistance between the carbon nanotubes, obtain a densified carbon tube film, and avoid the subsequent loading of glassy carbon. The carbon nanotube film is damaged. Further, the chemical vapor deposition method is used to load glassy carbon on the carbon nanotubes, and the adjacent carbon nanotubes are welded to form a welding network, which hinders the relative movement between the carbon nanotubes, so that the performance of the carbon nanotube fiber in mechanical strength, electromagnetic shielding and electric heating is significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 This is an electron microscope image of the carbon tube / glassy carbon composite film of the present invention;

[0022] Figure 2 It is a mechanical curve diagram of the carbon tube / glassy carbon composite film of the present invention. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] Example 1

[0025] A method for preparing a carbon tube / glassy carbon composite film comprises the following steps:

[0026] (1) spraying a carbon nanotube film with alcohol to form a densified carbon nanotube film;

[0027] The continuous carbon tube film is prepared by chemical vapor deposition. The specific method is as follows:

[0028] Ferrocene and sublimed sulfur were used as catalysts and dispersed in xylene at concentrations of 50 mg / mL and 1 mg / mL, respectively, to prepare a carbon source; 10 mL of the carbon source was placed upstream of the gas, and a precision injection pump was used to slowly push the carbon source into the tubular furnace at a rate of 360 μL / h; in a hydrogen-argon mixed gas atmosphere with a hydrogen concentration of 20%, the gas flow rate was set to 2000 sccm, the reaction zone temperature was set to 1200°C, and the carbon nanotube film was continuously grown and collected for 3 hours to obtain a uniform carbon nanotube film with a thickness of 3 mm.

[0029] A 3mm thick carbon nanotube film was fixed in the length and width directions, and alcohol was evenly sprayed on the carbon tube film using a sprayer. The alcohol spraying flow rate was 5mL / min and the spraying time was 3min, so that it shrunk in the thickness direction to obtain a densified carbon tube film. At this time, the fracture stress of the carbon tube film was 30MPa.

[0030] (2) Using chemical vapor deposition to load glassy carbon on the densified carbon tube film, the specific method is as follows:

[0031] Ferrocene was used as a catalyst and dispersed in 1,2-dichlorobenzene at a concentration of 60 mg / mL to prepare a carbon source; a densified carbon tube film was placed in a chemical vapor deposition reaction zone, 30 mL of the carbon source was taken and placed upstream of the gas, and a precision injection pump was used to slowly push the carbon source into the tubular furnace at a speed of 10 mL / h; a hydrogen-argon mixture with a hydrogen concentration of 10% was used as a carrier gas, and the gas flow rate was set to 3000 sccm, and the carbon source with the catalyst was brought into the chemical vapor deposition reaction zone at a temperature of 900°C, and deposited for 3 hours to obtain a carbon tube / glassy carbon composite film.

[0032] The conductivity of the carbon tube / glassy carbon composite film prepared in Example 1 was tested by four-probe testing technology, and the thickness of the film was tested by scanning electron microscopy. The conductivity of the composite film was calculated to be 2000 S / cm.

[0033] The carbon tube / glassy carbon composite film prepared in Example 1 was cut into 2 cm in length and 0.5 cm in width. Both ends were respectively fixed on the fixed clamp and the movable clamp of the stretching machine clamp. The length of the composite film exposed between the clamps was 1 cm. The stretching speed was 0.5 mm / min. The elongation and stress generated of the carbon tube and glassy carbon composite film were recorded synchronously until it broke. The thickness of the carbon tube and glassy carbon composite film was tested by scanning electron microscopy, and the film strength was calculated to be 500 MPa.

[0034] The carbon tube / glassy carbon composite film prepared in Example 1 was cut to have a length and width of 22.86±0.01 mm×10.16±0.01 mm. Its electromagnetic parameters were tested using a vector network analyzer, and the electromagnetic shielding effectiveness of the 7 μm thick carbon tube and glassy carbon composite film was calculated to be 70 dB.

[0035] The carbon tube / glassy carbon composite film prepared in Example 1 was cut into pieces with a length and width of 1 cm×2 cm. Silver wire electrodes were connected to both ends of the film through silver glue. A Keithley 2400 was used to provide a DC voltage, which could reach 200°C at a voltage of 3V.

[0036] Example 2

[0037] This embodiment is basically the same as Embodiment 1, except that the alcohol spraying flow rate is 3 mL / min and the spraying time is 3 min.

[0038] Example 3

[0039] This embodiment is basically the same as Embodiment 1, except that the alcohol spraying flow rate is 10 mL / min and the spraying time is 1 min.

[0040] Comparative Example 1

[0041] This embodiment is basically the same as embodiment 1, except that in step (1), the carbon nanotube film with a thickness of 3 mm is directly subjected to step (2) without being densified by alcohol and placed in the reaction zone of chemical vapor deposition. During the glassy carbon deposition process, the carbon nanotube film is easily damaged, resulting in the failure of the glassy carbon to be loaded onto the carbon nanotubes and poor mechanical strength.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a carbon tube / glassy carbon composite film, characterized in that: The following steps are involved: (1) spraying a carbon nanotube film with alcohol to form a densified carbon nanotube film; (2) Chemical vapor deposition is used to load glassy carbon on the densified carbon tube film to obtain a carbon tube / glassy carbon composite film.

2. The method for preparing a carbon tube / glassy carbon composite film according to claim 1, characterized in that: In step (1), the method of alcohol spraying is as follows: the alcohol spraying flow rate is 3mL / min to 10mL / min, and the spraying time is 1min to 3min.

3. The method for preparing a carbon tube / glassy carbon composite film according to claim 1, characterized in that: In step (1), the carbon nanotube film is prepared by chemical vapor deposition.

4. A carbon tube / glassy carbon composite film prepared by the preparation method according to any one of claims 1 to 3.

5. The carbon tube / glassy carbon composite film according to claim 4, characterized in that: The carbon tube / glassy carbon composite film comprises a densified carbon tube film on which glassy carbon is loaded to form an interconnected welding network.

6. Use of the carbon tube / glassy carbon composite film according to claim 4 or 5 in electromagnetic shielding.

Images