KR20170114510A - Hybrid materials by carbon nanocoils and carbon microcoils and manufactring method - Google Patents

Abstract

The present invention is a carbon nano-coil - C ₂ in that, in step, a raw material gas into the deposition chamber to place the ceramic substrate in the deposition chamber for performing the thermal chemical vapor deposition process of the carbon micro-coil hybrid material and a method of manufacturing the same Injecting H ₂ gas and injecting SF ₆ gas as an additive gas while injecting the C ₂ H ₂ gas for the entire deposition time and implanting the SF ₆ gas by on-off modulation at least twice, The carbon nanocoil-carbon micro-coil hybrid material synthesized by artificially controlling the injection of the SF ₆ gas according to the reaction time can be produced.

Description

TECHNICAL FIELD [0001] The present invention relates to a carbon nanocoil-carbon micro-coil hybrid material and a method for manufacturing the same. BACKGROUND ART [0002]

The present invention relates to a carbon nanocoil-carbon micro-coil hybrid material synthesized by artificially controlling the injection of SF ₆ gas during the course of a thermal chemical vapor deposition (TCVD) process and a method of manufacturing the same .

As is well known, carbon coils have properties such as high elasticity, low electrical resistance, high surface area in spiral shape, and so on. Therefore, they are promising materials for electromagnetic wave absorbers, nano / micro scale tactile sensors, actuators, resonators and mechanical springs. Be in the spotlight.

The shape of such a carbon coil varies in growth state, its diameter can be changed from nano size to micro size, and the electrical characteristics of a helical coil can be changed according to geometry such as coil diameter, pitch, length, It is important to control the geometry as it can change.

In addition, carbon coils generally have a large specific surface area of around 100 m ² / g and have a semiconductor characteristic in which the electrical resistance decreases with increasing temperature. Carbon coils with a large diameter and small carbon coils have a diameter of about 15 times And it is known to have an elasticity of supersensitivity.

On the other hand, the carbon coil can be produced through a chemical vapor deposition (CVD) process using a catalyst that pyrolyzes C ₂ H ₂ containing a trace amount of sulfur impurities under a catalyst such as Ni, If the growth conditions are very difficult and the catalyst, reaction conditions, and device conditions are not optimized, carbon fine powder or straight carbon fibers can be obtained instead of carbon coils.

That is, the carbon coils produced through the above-described catalytic chemical vapor deposition process have low yields, and the geometrical structure of the carbon coils is randomly formed, making it difficult to increase the production rate of carbon coils.

To solve these problems, a modulation process has been proposed in which the process of cycling the C ₂ H ₂ / H ₂ gas injection on / off cycle in the in-situ reaction system has been proposed, thereby manufacturing (synthesizing) excellent carbon coils We have been continuously researching and developing the optimized process conditions that can control the geometry.

Meanwhile, researches for improving the properties (for example, electromagnetic shielding performance, etc.) of carbon materials through synthesis of carbon materials including carbon nanotubes, carbon nanofibers, graphenes, carbon nanocoils, .

Conventionally, it is known that hybridization between carbon nanotubes and carbon nanofibers is very difficult because the transition metal used as a catalyst for growing carbon nanotubes can easily diffuse to the carbon substrate during the reaction.

In order to overcome this problem, Li et al. Studied the coating of a stainless steel metal film on a graphite foil to prevent internal diffusion of a metal catalyst on a carbon substrate (Li WZ, Wang DZ, Yang SX, Wen JG, Ren Physics Lett 2001; 335 (3-4): 141-9).

Song et al. Studied carbon nanotube-nanofiber hybrid materials by coating a pyrocarbon layer on the surface of the carbon nanofibers before synthesis to prevent diffusion of the metal catalyst into the carbon nanotubes (Song Q, Li Kz, Li HI, Li HJ, Ren C. Grafting straight carbon nanotubes and radial on carbon fibers and their effects on carbon / carbon composites. Carbon 2012; 50 (10): 3949-52).

In addition, Zhu et al. Have attempted to reduce the temperature of the synthesis reaction to reduce the rapid diffusion of metal iron used as a catalyst into carbon fibers (Zhu S, Su CH, Lehoczky SL, Muntele I, Ila D. Carbon nanotube growth on carbon fibers. Diamond Relat Mater 2003; 34 (12): 1825-8).

Another method is injection CVD, which reduces the internal diffusion of the transition metal at the carbon surface by minimizing the contact time between the transition metal and the carbon fiber surface used as catalyst, In this study, we have synthesized multi-walled carbon nanotube bundles by using the multi-walled carbon nanotubes and fabricated hybrid materials of multi-walled carbon nanotubes (Zhao ZG, Ci LJ, Cheng HM, Bai JB. morphologies on carbon fibers. Carbon 2005; 43 (3): 663-5).

On the other hand, studies on the synthesis of carbon micro-coils and carbon fiber hybrid materials have been conducted by a few researchers of Liu et al. (Liu L, Zhou K, He P, Chen T. Synthesis and microwave absorption properties of carbon coil- Mater Lett 2013; 110: 76-9, Liu L, He P, Zhou K, Chen T. Microwave absorption properties of carbon fibers with different co-morphologies (double microcoils and single nanocoils) grown on them. J Mater Sci 2014; 49: 4379-86).

They studied how to uniformly grow carbon micro-coils on the surface of carbon fibers using pre-coated nickel nanoparticles on carbon nanofibers under thermochemical vapor deposition (TCVD).

Here, a two-step process was used to fabricate a carbon micro-coil in a carbon fiber hybrid material. The first step was to apply the nickel nanoparticles to the carbon fiber prepared by the uniform precipitation reduction method, and then the carbon microcoils were grown on the carbon nanoparticles coated with nickel nanoparticles in the second step.

As described above, in order to improve the properties of carbon nanomaterials, researches on hybrid synthesis between various carbon materials have been continuously carried out to date.

1. Korean Patent No. 10-1213602 (Registered on Dec. 12, 2012): Manufacturing of Geometrically Controlled Micro or Nano-sized Carbon Coils Using Hexafluoride Gas 2. United States Patent No. 07354626 (registered on Apr. 8, 2008): Method for increasing fiber density in electrostatic flocking

The invention in-situ (in-situ) state one step (one-step) as a thermal chemical vapor deposition (TCVD) SF according to the injection of ₆ gas to the reaction time, the artificially controlled by synthesizing carbon nanocoils in traveling the in- Carbon micro-coil hybrid material and a manufacturing method thereof.

In addition, the present invention is the introduction of C ₂ H ₂ gas as a raw material gas, but injected with SF ₆ gas as additive gas, C ₂ H ₂ gas into the thermal chemical vapor deposition process is continuously supplied to the SF ₆ gas is at least twice on Carbon micro-coil hybrid material capable of producing a hybrid material in which carbon nano-coils are grown on the surface of a carbon micro-coil by being supplied in an off-modulating period to increase the density of carbon nano-coils diffused while being grown, and a manufacturing method thereof .

The present invention provides a controllable synthesis method for growing and dispersing a plurality of carbon nanocoils on a surface of a carbon substrate while growing a carbon microcoil on a ceramic substrate by manipulating an injection gas, A carbon nano-coil-carbon micro-coil hybrid material capable of producing a unique carbon nano-coil-carbon micro-coil hybrid material and a method of manufacturing the same.

In addition, the present invention can control not only the direct growth of carbon nanocoils on the surface of carbon micro-coils but also the synthesis of carbon micro-coils and carbon nanocoils at the same time, thereby simplifying the manufacturing process, Carbon micro-coil hybrid material capable of producing a carbon nanocoil-carbon micro-coil hybrid material capable of providing a carbon nanocoil-carbon micro-coil hybrid material capable of providing a carbon nanocoil-carbon micro-coil hybrid material.

The objects of the embodiments of the present invention are not limited to the above-mentioned objects, and other objects not mentioned can be clearly understood by those skilled in the art from the following description .

According to an aspect of the present invention, there can be provided a carbon nanocoil-carbon micro-coil hybrid material including a carbon micro-coil and carbon nanocoils diffused while being grown on the surface of the carbon micro-coil.

According to another aspect of the present invention, SF ₆ by thermal chemical vapor comprising the steps of: placing the ceramic substrate in the deposition chamber for performing a deposition process, C ₂ H ₂ gas inlet, and addition of gas to a raw material gas inside the deposition chamber And injecting the C ₂ H ₂ gas during the entire deposition time, and injecting the SF ₆ gas at least twice while on-off modulating the carbon nanocoil-carbon micro-coil hybrid material. Can be provided.

The present invention can produce a carbon nanocoil-carbon micro-coil hybrid material synthesized by artificially controlling the injection of SF ₆ gas during the thermochemical vapor deposition (TCVD) process from the in situ state to the one-step manner .

In addition, the present invention is the introduction of C ₂ H ₂ gas as a raw material gas, but injected with SF ₆ gas as additive gas, C ₂ H ₂ gas into the thermal chemical vapor deposition process is continuously supplied to the SF ₆ gas is at least twice on Or an off-modulation period, it is possible to manufacture a hybrid material in which carbon nano-coils are grown on the surface of the carbon micro-coil and are diffused to increase the density of the carbon nanocoils.

The present invention first provides a controllable synthesis method of growing a carbon microcoil on a ceramic substrate by manipulating an injection gas while simultaneously growing and diffusing a plurality of carbon nanocoils on the surface thereof, A carbon nano-coil-carbon micro-coil hybrid material can be manufactured.

In addition, the present invention not only allows carbon nanocoils to grow directly on the surface of carbon micro-coils but also synthesizes carbon micro-coils and carbon nano-coils simultaneously, thereby simplifying the manufacturing process and achieving excellent carbon < RTI ID = 0.0 > Nanocoil-carbon micro-coil hybrid material can be manufactured.

FIG. 1 is a flowchart illustrating a process of manufacturing a carbon nanocoil-carbon micro-coil hybrid material according to an embodiment of the present invention.
2 is a view illustrating a thermochemical vapor deposition apparatus used in manufacturing a carbon nanocoil-carbon micro-coil hybrid material according to an embodiment of the present invention,
3 and 4 are views for explaining various process conditions for manufacturing a hybrid material according to an embodiment of the present invention,
5 to 11 are graphs showing results of analysis of hybrid materials manufactured according to an embodiment of the present invention
Fig.

Advantages and features of embodiments of the present invention and methods of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The following terms are defined in consideration of the functions in the embodiments of the present invention, which may vary depending on the intention of the user, the intention or the custom of the operator. Therefore, the definition should be based on the contents throughout this specification.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a flow chart showing a process of manufacturing a carbon nanocoil-carbon micro-coil hybrid material according to an embodiment of the present invention. FIG. 2 is a flow chart illustrating a process of manufacturing a carbon nanocoil-carbon micro-coil hybrid material according to an embodiment of the present invention. FIG. 1 is a diagram illustrating a thermochemical vapor deposition apparatus to be used.

Referring to FIGS. 1 and 2, a ceramic substrate is placed inside a device for performing chemical vapor deposition (CVD) (step 102). Here, a thermo-chemical vapor deposition apparatus as shown in Fig. 2 can be used to perform the chemical vapor deposition process.

In the TCVD process, a ceramic substrate (for example, silicon oxide (SiO ₂ ), silicon (Si), alumina (Al ₂ O ₃ ), stainless steel or the like) is first placed in the deposition chamber, Carbon coils of a desired shape and size can be produced by growing a carbon coil on a substrate. In order to synthesize and grow carbon coils on a substrate, a raw material of carbon coils (for example, acetylene (C ₂ H ₂ ), methane (CH ₄ ), propane (C ₃ H ₈ ), benzene (C ₆ H ₆ ), and the like) to improve the reactivity, and a carbon nanocoil and a carbon microcoil are synthesized .

Herein, the thermochemical deposition process (TCVD) for producing the carbon nanocoil-carbon micro-coil hybrid material is performed under conditions of total pressure of 90-110 Torr, total deposition time of 130-170 minutes and substrate temperature of 600-900 <Lt; / RTI > Preferably a total pressure of 100 Torr, a total deposition time of 150 minutes and a substrate temperature of 750 < 0 > C.

During the entire deposition period in which the TCVD process is in progress, C ₂ H ₂ gas is continuously injected while the SF ₆ gas is on-off modulated at least twice to inject carbon nanocoils on the surface of the carbon micro- The grown hybrid material can be produced (step 104). Here, the C ₂ H ₂ gas can be injected into the deposition chamber at a flow rate of 450-550 sccm, the SF ₆ gas can be injected into the deposition chamber at a flow rate of 30-50 sccm, the C ₂ H ₂ gas The injection time of the SF ₆ gas may be adjusted within the entire deposition time to perform the on or off modulation at least twice while the injection time of the SF ₆ gas is adjusted to 130-170 minutes as the total deposition time. Here, the injection on time and the injection off time can be set to the same time, and one modulation cycle is defined as "C ₂ H ₂ + SF ₆ flow injection for 25 minutes → C ₂ H ₂ flow injection for 25 minutes" .

For example, to fabricate a carbon nanocoil-carbon microcoil hybrid material, the conditions of a total pressure of 100 Torr, a total deposition time of 150 minutes and a substrate temperature of 750 ° C and a C ₂ H ₂ gas flow rate of 5000 sccm SF ₆ gas is injected at a flow rate of 400 sccm for three cycles of on or off modulation at the same time under the condition of being injected for thermochemical vapor deposition (TCVD) "C ₂ H ₂ + SF ₆ flow 25 min injection → C ₂ H ₂ flow 25 min injection → C ₂ H ₂ + SF ₆ flow 25 min injection → C ₂ H ₂ flow 25 min injection → C ₂ H ₂ + SF ₆ flow 25 min injection → C ₂ H ₂ flow 25 min injection " A carbon nanocoil-carbon micro-coil hybrid material can be manufactured.

By performing the above-described TCVD in one step in an in-situ state, it is possible to produce a hybrid material in which carbon nanocoils are grown on the surface of the carbon micro-coil, In this process, the shape and density of the carbon coils can be adjusted at once.

Further, thermochemical, but injected with C ₂ H ₂ gas as the source gas for carrying out the vapor deposition process, and injecting the SF ₆ gas as additive gas, C ₂ H ₂ gas is injected during the entire deposition time and, SF ₆ gas is at least A hybrid material capable of growing carbon nanocoils on the surface of a carbon microcoil while growing a carbon microcoil on a ceramic substrate by two on-off modulation injections increases the on-off modulation period of the SF ₆ gas, The density of the carbon nanocoils grown on the substrate can be increased.

When the modulation period is set to less than two in the manufacturing process as described above, the carbon nano-coil is not sufficiently grown on the surface of the carbon micro-coil, and the hybrid material characteristic that can be obtained by forming the carbon nanocoil and the carbon micro- (For example, electromagnetic shielding performance, etc.) can not be sufficiently provided. Therefore, it is preferable that the modulation period of on or off of the SF ₆ flow rate proceeds at least twice.

That is, the hybrid material manufactured through the above-described process is a carbon nanocoil grown on the surface of a carbon microcoil, which is synthesized through a TCVD process, and a C ₂ H ₂ gas and a SF ₆ gas , And can be synthesized by on-off modulation injection of SF ₆ gas.

This hybrid material is, it is possible to increase the density, as the on-off modulation period of the SF ₆ gas is increased, the carbon nano-coil is grown on the surface of the carbon micro-coil is wave-shaped carbon nanotube in accordance with the on-off modulation period of the SF ₆ gas Coil, a narrow linear carbon nano-coil, or a myelinated carbon nano-coil.

Accordingly, the present invention provides a carbon nanocoil-carbon micro-coil hybrid material synthesized by artificially controlling the injection of SF ₆ gas during the thermochemical vapor deposition (TCVD) process from the in situ state to the one-step manner .

In addition, the present invention is the introduction of C ₂ H ₂ gas as a raw material gas, but injected with SF ₆ gas as additive gas, C ₂ H ₂ gas into the thermal chemical vapor deposition process is continuously supplied to the SF ₆ gas is at least twice on Or an off-modulation period, it is possible to manufacture a hybrid material in which carbon nano-coils are grown on the surface of the carbon micro-coil and are diffused to increase the density of the carbon nanocoils.

The present invention first provides a controllable synthesis method of growing a carbon microcoil on a ceramic substrate by manipulating an injection gas while simultaneously growing and diffusing a plurality of carbon nanocoils on the surface thereof, A carbon nano-coil-carbon micro-coil hybrid material can be manufactured.

Further, the present invention can control not only the direct growth of carbon nanocoils on the surface of carbon micro-coils but also the synthesis of carbon micro-coils and carbon nanocoils at the same time, thereby simplifying the manufacturing process, Carbon nanocoil-carbon micro-coil hybrid material which can be utilized in the field of the present invention can be manufactured.

The hybrid material produced through the above-described process has excellent electromagnetic shielding characteristics by including both the carbon nano-coil structure and the carbon micro-coil structure, and the characteristics of the hybrid material manufactured under various process conditions will be described do.

FIGS. 3 and 4 are views for explaining various process conditions for manufacturing a hybrid material according to an embodiment of the present invention. FIGS. 5 to 11 illustrate analysis results of a hybrid material manufactured according to an embodiment of the present invention Fig.

3 to 11, about 0.01 g of Ni powder (99.7%) having a particle diameter in the range of 10-100 mu m is coated on the alumina substrate in the case of the nickel catalyst for the production of the carbon nanocoil-carbon microcoil hybrid material sample As shown in FIG. 3, in the case of the carbon coil deposition, C ₂ H ₂ and SF ₆ were used as a raw material gas and an SF ₆ gas in a thermochemical vapor deposition (TCVD) system, and C ₂ H ₂ and SF ₆ Were set at 500 sccm and 40 sccm, respectively.

The cyclic modulation process of the SF ₆ gas flow rate in the manufacturing process of the hybrid material samples as described above was simply performed by turning on or off of the SF ₆ flow rate. The order of the gas flow according to the reaction process was C ₂ H ₂ + SF ₆ flow (C ₂ H ₂ flow rate and SF ₆ flow rate on) and C ₂ H ₂ flow (C ₂ H ₂ flow rate on and SF ₆ flow rate off), and one cycle of the cyclic modulation cycle (ie, one cycle) "(Gas injection time including C ₂ H ₂ and SF ₆ ) + (C ₂ H ₂ gas injection time)".

The detailed morphology and chemical composition of the prepared hybrid material samples were measured by field emission scanning electron microscope (FESEM) and energy dispersive X-ray fluorescence spectrometer (ED-XRF) , And nanostructures including carbon microcoils and carbon nanocoils were irradiated with a high resolution scanning electron microscope (HRTEM).

For example, a sample for a high resolution transmission electron microscope (HRTEM) was dispersed in acetone in an ultrasonic bath, the suspension was dropped on a carbon film supported by a Cu grid, and then the Cu grid was subjected to a high resolution transmission electron microscope (HRTEM) Placed in a chamber and obtained a detailed morphological image of the samples.

Here, PROCESS II, PROCESS III and PROCESS IV, cyclic modulation processes of the SF ₆ gas flow rate, were performed with different cyclic modulation cycles. As shown in FIG. 4, the SF ₆ flow injection time for one cyclic modulation cycle was 37.5 (PROCESS II), 25.0 / 25.0 minutes (PROCESS III) and 12.5 / 12.5 minutes (PROCESS IV).

That is, since the times for one cyclic modulation cycle corresponding to PROCESS II, PROCESS III and PROCESS IV are 75.0 minutes, 50.0 minutes, and 25.0 minutes, respectively, the number of cycles for these processes was 2, 3, and 6, In this case, the total injection time of the SF ₆ flow rate was maintained at 75.0 minutes during the entire process.

For comparison with the hybrid materials produced through the above processes, a process in which the SF ₆ flow rate was completely mixed (PROCESS I: continuous C ₂ H ₂ + SF ₆ flow rate) was performed.

5 and 6 show the surface morphological FESEM images of Sample A, Sample B, Sample C and Sample D and their high magnification FESEM images, respectively, for the hybrid material samples produced according to various process conditions as described above, In the case of Sample A produced through PROCESS I having a continuous C ₂ H ₂ + SF ₆ flow rate, the presence of various carbon material shapes such as linear, coil, etc. as shown in FIG. 5 (a) As shown in Fig. 6 (a), a well-developed double helix-shaped carbon microcoil as well as an entangled-carbon microcoil can be observed. In this case, it can be seen that the diameter of the carbon nanofibers constituting carbon shapes of various shapes is in the range of 1-5 탆.

Further, in sample B prepared through PROCESS II in which the cyclic on or off modulation process of the SF ₆ flow rate was performed twice, narrow line-shaped morphologies were observed as shown in FIG. 5 (b) Was observed on the entire surface of the substrate, and the narrow linear shape as shown in Fig. 6 (b) proved to be a typical double helical carbon microcoil. It can be seen that the diameter (0.1-0.5 μm) of the carbon nanofibers composing the carbon microcoils was much smaller than that of the sample A, and the carbon nanocoils having wave-like type geometries were formed on the substrate And they are attached to the surface of the carbon micro-coil as shown in the inset image of Fig. 6 (b).

In Sample C prepared through PROCESS III in which the cyclic on or off modulation process of the SF ₆ flow rate is three times, a narrow linear shape similar to Sample B is formed on the substrate as shown in Fig. 5 (c) However, in this case, the narrow linear shape has carbon nanocoils formed along the surface of the carbon microcoil, and most carbon microcoil surfaces are covered by the carbon nanocoils as shown in FIG. 6 (c) It seems that there seems to be.

On the other hand, in the sample D prepared through the PROCESS IV in which the cyclic on or off modulation process of the SF ₆ flow rate is 6 times, the shape of bush-like shaped morphologies as shown in FIG. 5 (d) As shown in FIG. 6 (d), a number of carbon nano-coils were formed mainly on carbon micro-coils in the form of a few seconds. In this case, It can be seen that the microcoil acts as a backbone for supporting a plurality of carbon nanocoils, and that the carbon nanocoils diffuse on the surface of a carbon microcoil such as a backbone, and the insertion image of FIG. 6 (d) It can be seen that a typical carbon nanocoil is formed on the surface of the carbon microcoil.

Next, FIG. 7 shows a TEM image around the coil head region. Using a TEM image, a detailed nanostructure of a carbon nanocoil-carbon micro-coil hybrid material was examined. The hollow space was a carbon It can be seen that the nanofibers are almost invisible inside the nanofiber, and this result shows that the growth of the carbon nanofibers is followed by the fiber type nanostructure rather than the tube type.

7 (b) and 7 (c) show a high-resolution TEM image near the surface of a carbon micro-coil having several carbon nanocoils and several carbon micro-coils, respectively, As shown in the image, the coexistence of various kinds of lattice structures is due to the interposition of the carbon nanocoil lattice on the lattice structure of the carbon micro-coil. As a result, the carbon nanocoils are formed on the carbon micro- It can be confirmed that it is formed directly from the surface of the carbon micro-coil by the intervention of the coil lattice.

On the other hand, it can be seen that only a single-like lattice structure can be observed on the surface of a carbon microcoil having several carbon nanocoils as shown in the inset image of FIG. 7 (c).

As described above with reference to FIGS. 5 to 7, it can be seen that the carbon nanocoil-carbon micro-coil hybrid material can be manufactured using an on or off cyclic modulation process of SF ₆ flow rate. For example, it can be seen that carbon nanocoils are formed on the carbon microcoils by on or off modulation of two cycles of SF ₆ , and when the cycle period is increased from 2 to 3, carbon It was found that the nanocoil was formed, and in the 6th cycle, the number of carbon nanocoils diffused from the surface of the carbon microcoil.

Next, in order to understand the formation of the carbon nanocoil-carbon microcoil hybrid material, pure SF ₆ gas was firstly injected into the nickel catalyst for 0.5 minute reaction (sample E, Fig. 8 (a)), 0.5 min reaction by injecting a C ₂ H ₂ gas (sample F, (b in FIG. 8)) sikimyeo, by injecting the SF ₆ gas flow rate to the nickel catalyst to 40sccm and C ₂ H ₂ gas flow rate to 500 sccm 0.5 min reaction ( Sample G, Fig. 8 (c)), the surface morphology was examined. In Sample E prepared according to the pure SF ₆ gas flow rate condition, no significant change in the morphology of the nickel catalyst (10-100 占 퐉) in a non-circular shape in which a plurality of small-sized carbon nanofibers were grown around the nickel catalyst as shown in Fig. 8 (b) (C) in Fig. 8 (c) As a result, it was found that the formation of the nickel catalyst was observed in a small round shape having various diameters (1-10 탆), and the size of the nickel catalyst was further reduced than that of the sample F described above.

Figure 9 shows FESEM images for Sample H, Sample I and Sample J, respectively, produced at different C ₂ H ₂ / SF ₆ flow rates, namely 100/50 sccm, 250/50 sccm and 500/50 sccm, As the C ₂ H ₂ / SF ₆ flow rate increases, the catalyst size decreases and the water density of the small size carbon nanofibers increases.

Thus, it can be seen that the enriched C ₂ H ₂ gas condition during the process reaction reduces the size of the nickel catalyst and facilitates formation of multiple small-sized carbon nanofibers around the nickel catalyst.

10 (a) and 10 (b) are graphs showing the results of the same experimental conditions for Sample A in which reaction times of 25 minutes and 50 minutes were reduced, respectively, Shows the FESEM image of the surface shape of the sample K and the sample L. Fig.

10 (a) and 10 (b), the number density of the small-size carbon nanofibers decreases as the reaction time increases, as shown in the inside of the circle indicated by the dotted line in FIG. 10 . In this case, it can be seen that the continuous SF ₆ gas flow rate can inhibit the formation of small-sized carbon nanofibers on the substrate as the reaction time increases.

10 (c) and 10 (d) show FESEM images of the surface morphologies of Sample M and Sample N under the same experimental conditions for Sample D with reduced reaction times of 25 minutes and 50 minutes, respectively, d, it can be seen that as the reaction time increases due to the circulating water increased from 1 to 2 as shown in the dotted circle, the density of the small size carbon nanocoils around the carbon microcoil is increased. These results show that the increase in the number of circulations (i.e., the circulation period) can improve the formation of small-sized carbon nanocoils around the carbon nanocoils.

On the other hand, by a circular turning on or off the modulation process of the SF ₆ flow rate, it appears the injection period of the rich C ₂ H ₂ gas as shown in Figure 4, as shown in Figure 11 (b) pure C ₂ H ₂ gas condition is generated under the condition of injecting a C ₂ H ₂ gas rich in carbon nanocoils of small size into a plurality of small-sized carbon nanofibers.

In addition, with respect to the difference in density of carbon nanocoils according to the number of cycles (i.e., the cycle), a richer C ₂ H ₂ injection cycle can diffuse the nickel catalyst inside the carbon microcoil, The number of carbon nanocoils in the vicinity of the carbon microcoil in the lower circulating cyclic condition can not be increased by the addition of nickel in the interior of the carbon microcoil because of the inability to promote the formation of carbon nanocoils on the surface of the carbon microcoil, And it decreases with the diffusion of the catalyst.

11 (a) shows an FESEM image of the carbon microcoil in the sample M, and FIG. 11 (b) shows the FESEM image of the carbon microcoil in the sample M. In this case, The results of EDS as shown in (c) and (c) show that C and Ni are mainly located in the carbon microcoils, and since the formation of carbon nanocoils originates from a nickel catalyst similar to carbon nanotubes, It can be seen that it is located on the upper surface of the coil.

By simply applying a cyclically turning on or off the modulation process of the SF ₆ flow rate as described above can form a composite material comprising a carbon nano-coil and carbon micro-coil, the number of carbon nanocoil is a SF ₆ flow cyclically on or in Can be increased with an increase in the number of cycles of the off-modulation process (i.e., the cycle period).

In addition, the carbon nanocoils directly originate from the surface of the carbon microcoils and diffuse from the surface of the carbon microcoils. In the cyclic on or off modulation process of the SF ₆ flow rate, abundant C2H2 gas conditions reduce the size of the nickel catalyst, Lt; RTI ID = 0.0 > carbon nanofibers < / RTI >

On the other hand, excessive C ₂ H ₂ injection in the cyclic on or off modulation process of the SF ₆ flow rate can diffuse the nickel catalyst inside the carbon microcoil, so that at a relatively lower circulating water (i.e., circulation cycle) It can be seen that the number density of carbon nanocoils around the microcoil decreases with the diffusion of the nickel catalyst inside the carbon microcoil.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be readily apparent that such substitutions, modifications, and alterations are possible.

Claims (10)

Carbon micro-coil,
The carbon nanocoils grown on the surface of the carbon micro-
Carbon micro-coil hybrid material.
The method according to claim 1,
The hybrid material is a carbon nanocoil-carbon micro-coil hybrid material that is synthesized by performing a thermochemical vapor deposition (TCVD) process in an in-situ state by one step.
3. The method of claim 2,
The hybrid material is a carbon nanocoil-carbon micro-coil hybrid material which is produced by using C ₂ H ₂ gas and SF ₆ gas, and synthesized by on-off modulation injection of the SF ₆ gas.
The method of claim 3,
The hybrid material is a carbon nanocoil-carbon micro-coil hybrid material in which the density of the carbon nanocoils increases as the on-off modulation period of the SF ₆ gas increases.
The method of claim 3,
The carbon nanocoil is a carbon nanocoil-carbon micro-coil hybrid material that grows into a wave-like carbon nanocoil, narrow linear carbon nanocoil, or aqueduct carbon nanocoil according to the on-off modulation period of the SF ₆ gas.
Disposing a ceramic substrate in a deposition chamber for performing a thermal chemical vapor deposition process,
As the raw material gas into the deposition chamber, injecting a C ₂ H ₂ gas, but injected with SF ₆ gas as additive gas, the C ₂ H ₂ gas is injected during the entire deposition time, the SF ₆ gas is at least twice on Off-modulation and implanting
Carbon micro-coil hybrid material.
The method according to claim 6,
The thermochemical vapor deposition process is performed in one step in-situ, wherein the total pressure of 90-110 Torr, the total deposition time of 130-170 minutes, and the substrate temperature of 600-900 < 0 > C Carbon nanocoil-carbon micro-coil hybrid material.
The method according to claim 6,
The thermochemical vapor deposition process is a carbon nanocoil-carbon micro-coil hybrid material which is injected at a flow rate of 450-550 sccm for the C ₂ H ₂ gas and at a flow rate of 30-50 sccm for the SF ₆ gas Gt;
9. The method according to any one of claims 6 to 8,
Wherein the hybrid material is diffused while growing carbon nanocoils on the surface of the carbon microcoils grown on the ceramic substrate.
8. The method of claim 7,
Wherein the density of the carbon nanocoils increases as the on-off modulation period of the SF ₆ gas increases.

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