WO2022114237A1 - Film de carbone - Google Patents

Film de carbone Download PDF

Info

Publication number
WO2022114237A1
WO2022114237A1 PCT/JP2021/043974 JP2021043974W WO2022114237A1 WO 2022114237 A1 WO2022114237 A1 WO 2022114237A1 JP 2021043974 W JP2021043974 W JP 2021043974W WO 2022114237 A1 WO2022114237 A1 WO 2022114237A1
Authority
WO
WIPO (PCT)
Prior art keywords
cnt
carbon film
carbon
aggregate
carbon nanotube
Prior art date
Application number
PCT/JP2021/043974
Other languages
English (en)
Japanese (ja)
Inventor
智子 山岸
貢 上島
Original Assignee
日本ゼオン株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 日本ゼオン株式会社 filed Critical 日本ゼオン株式会社
Priority to JP2022565519A priority Critical patent/JPWO2022114237A1/ja
Publication of WO2022114237A1 publication Critical patent/WO2022114237A1/fr

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/15—Nano-sized carbon materials
    • C01B32/158—Carbon nanotubes
    • C01B32/16—Preparation
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K9/00—Screening of apparatus or components against electric or magnetic fields

Definitions

  • the present invention relates to a carbon film.
  • CNT carbon nanotubes
  • CNT aggregate an aggregate composed of a plurality of CNTs
  • Patent Document 1 uses a carbon nanotube aggregate having a region of 10 nm or more in which pores having a bore size of 400 nm or more and 1500 nm or less, which are measured by a mercury intrusion method, have a Log differential pore volume of 0.006 cm 3 / g or less. Therefore, a carbon film having excellent mechanical strength is formed.
  • electromagnetic wave shielding has been attracting attention as an application of carbon film.
  • an object of the present invention is to provide a carbon film having excellent electromagnetic wave shielding performance.
  • the present inventors have made extensive studies to achieve the above object. Then, the present inventors investigated the microscopic properties of the carbon film formed by using the carbon nanotube aggregate, and the carbon film having an average surface roughness of 4.0 ⁇ m or more shields electromagnetic waves well. We have newly found what we can obtain and completed the present invention.
  • the present invention aims to solve the above problems advantageously, and the carbon film of the present invention is a carbon film made of an aggregate of carbon nanotubes, and the average value of the surface roughness is 4. It is characterized in that it is 0 ⁇ m or more.
  • the average value of the surface roughness of the carbon film is 4.0 ⁇ m or more, the carbon film is excellent in electromagnetic wave shielding performance.
  • the surface roughness of the carbon film can be measured by the method described in the examples of the present specification.
  • the average value of the surface roughness is 5.0 ⁇ m or more.
  • the electromagnetic wave shielding performance is further excellent.
  • the carbon film of the present invention is preferably a self-supporting film.
  • the carbon film which is a self-supporting film, has excellent handleability, and when used as an electromagnetic wave shielding sheet, for example, the degree of freedom in arranging the sheet can be increased.
  • the "self-supporting film” refers to a film that can maintain its film shape by itself without being damaged even in the absence of a support.
  • the carbon nanotube aggregate satisfies at least one of the following conditions (1) to (3).
  • a pore distribution curve showing the relationship between the pore diameter and the Log differential pore volume obtained from the adsorption isotherm of liquid nitrogen at 77K based on the Barrett-Joiner-Halenda method.
  • the largest peak in is in the range of pore diameters greater than 100 nm and less than 400 nm.
  • At least one peak of the two-dimensional spatial frequency spectrum of the electron microscope image of the carbon nanotube aggregate exists in the range of 1 ⁇ m -1 or more and 100 ⁇ m -1 or less.
  • a carbon film made of an aggregate of carbon nanotubes satisfying the above-mentioned predetermined conditions is further excellent in electromagnetic wave shielding performance. The sufficiency of the above-mentioned predetermined conditions can be determined according to the method described in the examples.
  • the laser microscope image obtained about the surface of the carbon film produced in Example 1 is shown.
  • the laser microscope image obtained about the surface of the carbon film produced in Example 2 is shown.
  • the laser microscope image obtained about the surface of the carbon film produced in Example 3 is shown.
  • the laser microscope image obtained about the surface of the carbon film prepared in Example 4 is shown.
  • the laser microscope image obtained about the surface of the carbon film prepared in the comparative example 1 is shown.
  • An SEM image of the CNT aggregate according to an example is shown.
  • the FIR resonance chart acquired for the CNT aggregate according to an example is shown.
  • the pore distribution curve of the CNT aggregate according to an example is shown. It is an SEM image of the CNT aggregate according to one example. It is a two-dimensional spatial frequency spectrum of the image of FIG. 8A. It is an SEM image of the CNT aggregate according to another example.
  • 9 is a two-dimensional spatial frequency spectrum of the image of FIG. 9C.
  • the schematic configuration of the CNT manufacturing apparatus is shown.
  • the carbon film of the present invention is composed of an aggregate of a plurality of carbon nanotubes (a carbon nanotube aggregate).
  • the carbon film of the present invention may contain, for example, CNT aggregates and components other than CNTs inevitably mixed in the process of producing the carbon film, but the proportion of CNTs in the carbon film is 95% by mass.
  • the above is preferable, 98% by mass or more is more preferable, 99% by mass or more is further preferable, 99.5% by mass or more is particularly preferable, and 100% by mass (that is,).
  • the carbon film consists only of CNTs) is most preferable.
  • the carbon film of the present invention is composed of an aggregate of carbon nanotubes.
  • the carbon film of the present invention is characterized in that the average value of the surface roughness is 4.0 ⁇ m or more.
  • the carbon film of the present invention having an average surface roughness of 4.0 ⁇ m or more is excellent in electromagnetic wave shielding performance. Therefore, the carbon film of the present invention is not particularly limited, but can be advantageously used, for example, as an electromagnetic wave shielding sheet.
  • the carbon film of the present invention is preferably a self-supporting film. If the carbon film is a self-supporting film, the carbon film is excellent in handleability, and when used as an electromagnetic wave shielding sheet, for example, the degree of freedom in arranging the sheet is high.
  • the carbon film of the present invention having an average surface roughness of 4.0 ⁇ m or more, there are gaps of an appropriate size or more between the carbon nanotubes as constituents, and therefore, electromagnetic waves are generated in such gaps. It is presumed that the energy of the electromagnetic wave that has entered the carbon film can be attenuated by the diffused reflection. Therefore, according to the carbon film of the present invention, it is considered that excellent electromagnetic wave shielding performance can be exhibited.
  • the average value of the surface roughness of the carbon film needs to be 4.0 ⁇ m or more, preferably 5.0 ⁇ m or more, more preferably 5.5 ⁇ m or more, and 6.5 ⁇ m or more. More preferred. When the average value of the surface roughness of the carbon film is at least the above lower limit value, excellent electromagnetic wave shielding can be exhibited.
  • the average value of the surface roughness of the carbon film may be, for example, 30 ⁇ m or less.
  • FIGS. 1 to 5 show, as an example, laser microscope images obtained for carbon film surfaces having various average surface roughness values, which were produced in Examples 1 and Comparative Examples described later.
  • FIG. 1 is one of the laser microscope images of the carbon film surface prepared in Example 1, and the average value of the surface roughness calculated for the carbon film was 10.9 ⁇ m.
  • FIG. 2 is one of the laser microscope images of the carbon film surface prepared in Example 2, and the average value of the surface roughness calculated for the carbon film was 6.3 ⁇ m.
  • FIG. 3 is one of the laser microscope images of the carbon film surface prepared in Example 3, and the average value of the surface roughness calculated for the carbon film was 5.5 ⁇ m.
  • FIG. 1 is one of the laser microscope images of the carbon film surface prepared in Example 1, and the average value of the surface roughness calculated for the carbon film was 10.9 ⁇ m.
  • FIG. 2 is one of the laser microscope images of the carbon film surface prepared in Example 2, and the average value of the surface roughness calculated for the carbon film was 6.3 ⁇ m.
  • FIGS. 1 to 5 correspond to the relative intensities of the reflected light reflected by the surface of the single-layer film and detected by the sensor of the laser microscope when irradiated with the laser light. That is, in FIGS. 1 to 5, when the laser beam is irradiated, the portion having high brightness of the reflected light is displayed on the white side, and the portion having low brightness of the reflected light is displayed on the black side. From FIGS. 1 to 5, when the laser beam is irradiated, the portion having high brightness of the reflected light is displayed on the white side, and the portion having low brightness of the reflected light is displayed on the black side. From FIGS.
  • the amount of electromagnetic waves reflected from the surface of the carbon film is small when the average value of the surface roughness is large, in other words, the electromagnetic wave shielding performance is high and the average value of the surface roughness is small. In some cases, it can be estimated that the amount of electromagnetic waves reflected from the surface of the carbon film tends to be large, in other words, the electromagnetic wave shielding performance tends to be low.
  • the carbon film of the present invention is used to form a carbon film by forming an aggregate of carbon nanotubes into a carbon film.
  • a CNT aggregate satisfying at least any one of (1) to (3) described later is used.
  • the CNT aggregate Prior to the film formation of the CNT aggregate, the CNT aggregate is subjected to a dry pulverization treatment. It can be produced by satisfying at least one of the above.
  • CNT aggregate used for preparing the carbon film for example, a known CNT aggregate such as a CNT aggregate obtained by using the super growth method (see International Publication No. 2006/011655) can also be used. However, it is preferable to use a novel CNT aggregate that satisfies at least one of the conditions (1) to (3).
  • a carbon film made of a CNT aggregate satisfying at least one of the following conditions (1) to (3) is excellent in electromagnetic wave shielding performance.
  • the plasmon resonance of the carbon nanotube dispersion is obtained. There is at least one peak based on the wave number in the range of 300 cm -1 to 2000 cm -1 or less.
  • the pore distribution curve showing the relationship between the pore diameter and the Log differential pore volume, which is obtained from the adsorption isotherm of liquid nitrogen at 77K for the carbon nanotube aggregate based on the Barrett-Joiner-Halenda method. The largest peak is in the range of pore diameters greater than 100 nm and less than 400 nm.
  • At least one peak of the two-dimensional spatial frequency spectrum of the electron microscope image of the carbon nanotube aggregate exists in the range of 1 ⁇ m -1 or more and 100 ⁇ m -1 or less.
  • FIG. 6 shows a scanning electron microscope (SEM) image of an example of a CNT aggregate satisfying at least one of the above (1) to (3).
  • SEM scanning electron microscope
  • the condition (1) is "a carbon nanotube dispersion in a spectrum obtained by Fourier transform infrared spectroscopic analysis of a carbon nanotube dispersion obtained by dispersing carbon nanotube aggregates so that the bundle length is 10 ⁇ m or more. There is at least one peak based on the plasmon resonance in the range of wavenumbers of 300 cm -1 to 2000 cm -1 or less. "
  • strong absorption characteristics in the far infrared region are widely known as optical characteristics of CNTs. It is believed that the strong absorption characteristics in the far infrared region are due to the diameter and length of the CNTs.
  • the absorption characteristics in the far-infrared region more specifically, the relationship between the peak based on the plasmon resonance of CNT and the length of CNT, the non-patent document (T.Morimoto et.al., "Length-Dependent Plasmon” Resonance in Single-Walled Carbon Nanotubes ”, pp 9897-9904, Vol.8, No.10, ACS NANO, 2014).
  • the present inventors have detected a peak based on the plasmon resonance of CNT in the spectrum obtained by Fourier transform infrared spectroscopic analysis based on the contents of the study as described in the above non-patent document and the original knowledge.
  • the position to be used could be affected by the distance between the defect points in the CNT, and verification was performed. Then, the present inventors have found that the position where the peak based on the plasmon resonance of the CNT is detected can serve as an index corresponding to the distance between the bending points in the CNT having a wavy structure, and the above conditions. (1) was set.
  • the wave number is 300 cm -1 to 2000 cm -1 or less, preferably the wave number 500 cm -1 to 2000 cm -1 or less, and more preferably the wave number 650 cm -1 to 2000 cm -1 or less. If a peak based on the plasmon resonance of the CNT is present, the CNT can exhibit good electromagnetic wave shielding performance when forming a carbon film.
  • FIG. 7 shows a spectrum (FIR resonance chart) obtained by Fourier transform infrared spectroscopic analysis of the CNT aggregates used in Examples 1 to 4 and Comparative Example 1 described later.
  • the wave number is sharp around 840 cm -1 and around 1300 cm -1 and 1700 cm -1 . Can be seen to be confirmed. These sharp peaks do not correspond to "peaks based on plasmon resonance of carbon nanotube dispersion", and each corresponds to infrared absorption derived from a functional group.
  • the sharp peak near wave number 840 cm -1 is due to the CH out-of-plane angular vibration; the sharp peak near wave number 1300 cm -1 is due to the epoxy three-membered ring expansion and contraction vibration; wave number 1700 cm.
  • a peak similar to the S1 peak is detected.
  • the upper limit of the determination of the presence or absence of a peak based on the plasmon resonance of the CNT dispersion under the condition (1) was set to 2000 -1 cm or less.
  • CNT dispersion in order to acquire the spectrum by Fourier transform infrared spectroscopic analysis, it is necessary to obtain the CNT dispersion by dispersing the CNT aggregate so that the bundle length is 10 ⁇ m or more.
  • CNT aggregate, water, and a surfactant for example, sodium dodecylbenzene sulfonate
  • a dispersion liquid in which a CNT dispersion having a length of 10 ⁇ m or more is dispersed.
  • the bundle length of the CNT dispersion can be obtained by analyzing with a wet image analysis type particle size measuring device.
  • a measuring device calculates the area of each dispersion from an image obtained by photographing the CNT dispersion, and is also referred to as the diameter of a circle having the calculated area (hereinafter, also referred to as ISO circle diameter (ISO area diameter)). There is) can be obtained. Then, in the present specification, the bundle length of each dispersion is defined as the value of the ISO circle diameter thus obtained.
  • Condition (2) stipulates that "the maximum peak in the pore distribution curve is in the range of more than 100 nm and less than 400 nm in pore diameter.”
  • the pore distribution of the carbon nanotube aggregate can be obtained from the adsorption isotherm of liquid nitrogen at 77K based on the BJH method.
  • the fact that the peak in the pore distribution curve obtained by measuring the carbon nanotube aggregate is in the range of more than 100 nm means that in the carbon nanotube aggregate, there are voids of a certain size between the CNTs, and the CNTs are present. It means that it is not in a state of being overly densely aggregated.
  • the upper limit of 400 nm is the measurement limit of the measuring device (BELSORP-mini II) used in the examples.
  • the value of the Log differential pore volume at the maximum peak of the pore distribution curve of the CNT aggregate is preferably 2.0 cm 3 / g or more. ..
  • Condition (3) stipulates that "at least one peak of the two-dimensional spatial frequency spectrum of the electron microscope image of the carbon nanotube aggregate exists in the range of 1 ⁇ m -1 or more and 100 ⁇ m -1 or less.” Satisfiability of such a condition can be determined as follows. First, the CNT aggregate to be determined is magnified and observed (for example, 10,000 times) using an electron microscope (for example, an electrolytic radiation scanning electron microscope), and a plurality of electron microscope images are obtained in a 1 cm square field (for example). For example, 10 sheets) will be acquired. The obtained plurality of electron microscope images are subjected to a fast Fourier transform (FFT) process to obtain a two-dimensional spatial frequency spectrum.
  • FFT fast Fourier transform
  • the two-dimensional spatial frequency spectra obtained for each of the plurality of electron microscope images are binarized, and the average value of the peak positions appearing on the highest frequency side is obtained.
  • the average value of the obtained peak positions was within the range of 1 ⁇ m -1 or more and 100 ⁇ m -1 or less, it was determined that the condition (3) was satisfied.
  • a clear peak obtained by performing an isolated point extraction process that is, a reverse operation of removing isolated points
  • the condition (3) is not satisfied.
  • the peak of the two-dimensional spatial frequency spectrum exists in the range of 2.6 ⁇ m -1 or more and 100 ⁇ m -1 or less.
  • the CNT aggregate preferably satisfies at least two of the above conditions (1) to (3), and the above (1) to (3). It is more preferable to satisfy all the conditions.
  • the CNT aggregate that can be used for forming the carbon film of the present invention preferably has the following properties in addition to the above conditions (1) to (3).
  • the total specific surface area of the CNT aggregate by the BET method is preferably 600 m 2 / g or more, more preferably 800 m 2 / g or more, preferably 2600 m 2 / g or less, and more preferably 1400 m 2 / g or less. Is. Further, in the case of the opening-treated one, it is preferably 1300 m 2 / g or more. According to the CNT aggregate having a high specific surface area, the electromagnetic wave can be more diffusely reflected inside the carbon film, and as a result, the electromagnetic wave shielding performance of the carbon film can be further improved.
  • the CNT aggregate may contain mainly single-walled CNTs, and may contain two-walled CNTs and multi-walled CNTs to the extent that the functions are not impaired.
  • the total specific surface area of CNTs by the BET method can be measured, for example, by using a BET specific surface area measuring device compliant with JIS Z8830.
  • the average height of the CNTs constituting the CNT aggregate is preferably 10 ⁇ m or more and 10 cm or less, and more preferably 100 ⁇ m or more and 2 cm or less.
  • the average height of the CNTs constituting the CNT aggregate is 10 ⁇ m or more, it is possible to prevent aggregation with the adjacent CNT bundle and easily disperse the CNTs.
  • the average height of the CNTs constituting the CNT aggregate is 10 ⁇ m or more, it becomes easy to form a network between the CNTs, and the CNTs can be suitably used in applications requiring conductivity or mechanical strength.
  • the average height of the CNTs constituting the CNT aggregate is 10 cm or less, the formation can be performed in a short time, so that the adhesion of carbon-based impurities can be suppressed and the specific surface area can be improved. If the average height of the CNTs constituting the CNT aggregate is 2 cm or less, it can be more easily dispersed.
  • the average height of the CNTs can be determined by measuring the height of 100 randomly selected CNTs using a scanning electron microscope (SEM).
  • the tap bulk density of the CNT aggregate is preferably 0.001 g / cm 3 or more and 0.2 g / cm 3 or less. Since the CNT aggregates in such a density range do not excessively strengthen the bonds between the CNTs, they are excellent in dispersibility and can be molded into various shapes. When the tap bulk density of the CNT aggregate is 0.2 g / cm 3 or less, the bond between the CNTs is weakened, so that when the CNT aggregate is stirred with a solvent or the like, it becomes easy to disperse it uniformly. Further, when the tap bulk density of the CNT aggregate is 0.001 g / cm 3 or more, the integrity of the CNT aggregate is improved and the handling becomes easy.
  • the tap bulk density is the apparent bulk density in a state where the powdery CNT aggregate is filled in a container, the voids between the powder particles are reduced by tapping or vibration, and the containers are tightly packed.
  • the average outer diameter of the CNTs constituting the CNT aggregate is preferably 0.5 nm or more, more preferably 1.0 nm or more, preferably 15.0 nm or less, and 10.0 nm or less. It is more preferably 5.0 nm or less, and further preferably 5.0 nm or less.
  • the average outer diameter of CNTs is 0.5 nm or more, bundling between CNTs can be reduced and a high specific surface area can be maintained.
  • the average outer diameter of CNTs is 15.0 nm or less, the ratio of multi-walled CNTs can be reduced and a high specific surface area can be maintained.
  • the average outer diameter of the CNT can be obtained by measuring the diameter (outer diameter) of 100 randomly selected CNTs using a transmission electron microscope (TEM).
  • the average diameter (Av) and standard deviation ( ⁇ ) of CNTs may be adjusted by changing the manufacturing method and manufacturing conditions of CNTs, or by combining a plurality of types of CNTs obtained by different manufacturing methods. May be good.
  • the G / D ratio of the CNT aggregate is preferably 1 or more and 50 or less. It is considered that the CNT aggregate having a G / D ratio of less than 1 has low crystallinity of single-walled CNTs, has a lot of stains such as amorphous carbon, and has a high content of multi-walled CNTs. On the other hand, CNT aggregates having a G / D ratio of more than 50 have high linearity, and CNTs tend to form bundles with few gaps, which may reduce the specific surface area.
  • the G / D ratio is an index generally used for evaluating the quality of CNTs.
  • G band Around 1600 cm -1
  • D band around 1350 cm -1
  • G band is a vibration mode derived from the hexagonal lattice structure of graphite, which is the cylindrical surface of CNT
  • D band is a vibration mode derived from an amorphous portion. Therefore, the higher the peak intensity ratio (G / D ratio) between the G band and the D band, the higher the crystallinity (linearity) of the CNT.
  • the purity of the CNT aggregate is as high as possible.
  • the term "purity" as used herein is carbon purity, and is a value indicating what percentage of the mass of the CNT aggregate is composed of carbon. Although there is no upper limit to the purity for obtaining a high specific surface area, it is difficult to obtain a CNT aggregate of 99.9999% by mass or more in manufacturing. If the purity is less than 95% by mass, it becomes difficult to obtain a specific surface area of more than 1000 m 2 / g in the unopened state.
  • the purity of the single-walled CNT is preferably 95% by mass or more.
  • the purity of a predetermined CNT aggregate satisfying at least one of the above-mentioned conditions (1) to (3) is usually 98% by mass or more, preferably 99.9% by mass, even without purification treatment. The above can be done. Almost no impurities are mixed in the CNT aggregate, and various characteristics inherent in CNT can be fully exhibited.
  • the carbon purity of the CNT aggregate can be obtained from elemental analysis using fluorescent X-rays, thermogravimetric analysis (TGA), or the like.
  • the method for producing the CNT aggregate is not particularly limited, and the production conditions can be adjusted according to the desired properties.
  • the conditions for growth of the CNT aggregate are all of the following (a) to (c). It is necessary to meet.
  • the growth rate of the CNT aggregate is 5 ⁇ m / min or more.
  • the concentration of the catalyst activator in the growth atmosphere of the CNT aggregate is 4% by volume or more.
  • C When the CNT aggregate grows, an obstacle exists in the growth direction of the CNTs constituting the CNT aggregate.
  • the above conditions (a) to (c) are not particularly limited as long as the above conditions (a) to (c) are satisfied when the CNT aggregate is grown, and known methods such as a fluidized bed method, a mobile layer method and a fixed layer method are used.
  • the CNT synthesis process according to the above can be adopted.
  • the fluidized bed method means a synthesis method for synthesizing CNTs while fluidizing a granular carrier carrying a catalyst for synthesizing CNTs (hereinafter, also referred to as a granular catalyst carrier).
  • the moving layer method and the fixed layer method mean a synthetic method for synthesizing CNTs without flowing a carrier (particulate carrier or plate-like carrier) carrying a catalyst.
  • the production method satisfying all of the above-mentioned (a) to (c) uses the catalyst carrier forming step of forming the catalyst carrier and the catalyst carrier obtained in the catalyst carrier forming step.
  • the CNT synthesis step of synthesizing the CNT and the recovery step of recovering the CNT synthesized in the CNT synthesis step are included.
  • the catalyst carrier forming step can be carried out according to a known wet or dry catalyst carrier method.
  • the recovery step can be carried out using a known separation / recovery device such as a classification device.
  • the CNT synthesis process In the CNT synthesis step, all of the above conditions (a) to (c) are satisfied when the CNT grows. Specifically, the condition (a) that "the growth rate of the carbon nanotube aggregate is 5 ⁇ m / min or more" is satisfied by appropriately adjusting the concentration and temperature of the raw material gas as a carbon source in the CNT growth atmosphere. be able to.
  • the raw material gas as a carbon source is not particularly limited, and hydrocarbon gas such as methane, ethane, ethylene, propane, butane, pentane, hexane, heptane, propylene and acetylene; methanol, ethanol and the like. Gas of lower alcohols; as well as mixtures thereof can also be used.
  • this raw material gas may be diluted with an inert gas.
  • the growth rate of the CNT aggregate is preferably 10 ⁇ m / min or more.
  • the temperature can be adjusted, for example, in the range of 400 ° C. or higher and 1100 ° C. or lower.
  • the raw material gas as a carbon source preferably contains ethylene.
  • ethylene By heating ethylene in a predetermined temperature range (700 ° C. or higher and 900 ° C. or lower), the decomposition reaction of ethylene is promoted, and when the decomposition gas comes into contact with the catalyst, high-speed growth of CNT is possible.
  • the thermal decomposition time is too long, the decomposition reaction of ethylene proceeds too much, causing deactivation of the catalyst and adhesion of carbon impurities to the CNT aggregate.
  • the thermal decomposition time is preferably 0.5 seconds or more and 10 seconds or less with respect to the ethylene concentration range of 0.1% by volume or more and 40% by volume or less.
  • the heating flow path volume is the volume of the flow path heated to a predetermined temperature T ° C. through which the raw material gas passes before coming into contact with the catalyst, and the raw material gas flow rate is a flow rate at 0 ° C. and 1 atm.
  • the concentration of the catalyst activator in the growth atmosphere of the carbon nanotube aggregate is preferably 5% by volume or more.
  • the catalyst activator is not particularly limited, and is an oxygen-containing compound having a low carbon number such as water, oxygen, ozone, acidic gas, nitrogen oxide, carbon monoxide and carbon dioxide; alcohols such as ethanol and methanol; tetrahydrofuran.
  • Ethers such as; ketones such as acetone; aldehydes; esters; and mixtures thereof. Of these, carbon dioxide is preferable.
  • a substance containing both carbon and oxygen, such as carbon monoxide and alcohols, may have both functions as a raw material gas and a catalyst activator.
  • carbon monoxide acts as a catalytically activating substance when combined with a more reactive raw material gas such as ethylene, and acts as a raw material gas when combined with a catalytically activating substance that exhibits a large catalytically activating effect even in a trace amount such as water. ..
  • the CNT synthesis step is carried out by supplying the raw material gas while supplying gas from below to flow the particulate catalyst carrier.
  • the raw material gas may be supplied while continuously transporting the particulate catalyst carrier by screw rotation.
  • the catalyst carrier has a carrier and a catalyst supported on the surface of the carrier, and the carrier is a portion forming a matrix structure for supporting, fixing, forming, or forming a catalyst on the surface of the carrier.
  • the structure of the carrier may be only the carrier, or may be a carrier with a base layer provided with an arbitrary base layer for satisfactorily supporting the catalyst on the surface of the carrier.
  • the shape of the carrier is preferably in the form of particles, and the particle size thereof is preferably 1 mm or less, more preferably 0.7 mm or less, and further preferably 0.4 mm or less in terms of volume average particle size. It is preferably 0.05 mm or more.
  • the growing CNT bundle becomes thin, which is advantageous for forming a wavy structure.
  • the apparent density of the particles is preferably 3.8 g / cm 3 or more, more preferably 5.8 g / cm 3 or more, and preferably 8 g / cm 3 or less.
  • the force applied to the growing CNT bundle is increased, which is advantageous for forming a wavy structure.
  • the material of the carrier is preferably a metal oxide containing at least one element of Al and Zr. Among them, zirconia beads containing Zr having a large elemental amount are particularly preferable.
  • a particulate carrier as a method of supporting the catalyst on the surface of the particulate carrier, for example, a method of using a rotary drum type coating device provided with a substantially cylindrical rotary drum can be mentioned. ..
  • the solution containing the components that can form the underlayer is prepared in the form of particles prior to spraying and drying the catalyst solution.
  • the underlayer is placed on the surface of the carrier by spraying and drying on the surface of the carrier. According to such a method, the catalyst layer and the base layer can be formed relatively easily and evenly.
  • a "formation step” for reducing the catalyst carried on the catalyst carrier is carried out prior to the "growth step” carried out so as to satisfy the above conditions (a) to (c).
  • a "cooling step” for cooling the catalyst carrier on which the CNT has grown can be carried out.
  • an atmosphere containing a catalyst carrier is used as a reducing gas atmosphere, and at least one of the reduced gas atmosphere or the catalyst carrier is heated to reduce and atomize the catalyst supported on the catalyst carrier. do.
  • the temperature of the catalyst carrier or the reducing gas atmosphere in the formation step is preferably 400 ° C. or higher and 1100 ° C. or lower.
  • the implementation time of the formation step may be 3 minutes or more and 120 minutes or less.
  • the reducing gas for example, hydrogen gas, ammonia gas, water vapor, or a mixed gas thereof can be used.
  • the reducing gas may be a mixed gas obtained by mixing these gases with an inert gas such as helium gas, argon gas or nitrogen gas.
  • the catalyst carrier on which the CNT has grown is cooled in an inert gas environment.
  • the inert gas an inert gas similar to the inert gas that can be used in the growth step can be used.
  • the temperature of the catalyst carrier on which the CNTs have grown is preferably lowered to 400 ° C. or lower, more preferably 200 ° C. or lower.
  • the CNT aggregate before film formation can be subjected to a dry pulverization treatment.
  • the "dry crushing treatment” means a crushing treatment in a state where the crushing target substantially does not contain a solvent (for example, a state where the solid content concentration is 95% or more).
  • the crushing device that can be used for the dry crushing process is not particularly limited as long as it is a device that can apply a physical load to an aggregate composed of fine structures by stirring or the like.
  • a mixer provided with rotating blades can be used.
  • the crushing conditions are not particularly limited.
  • the rotation speed is preferably 500 rpm or more and 5000 rpm or less
  • the crushing time is preferably 10 seconds or more and 20 minutes or less.
  • the carbon film of the present invention By filming the CNT aggregate, the carbon film of the present invention can be obtained.
  • the method for forming a film of the CNT aggregate is not particularly limited, but a CNT dispersion liquid is prepared by dispersing the CNT aggregate in a dispersion medium such as water or an organic solvent, and at least the dispersion medium is prepared from the CNT dispersion liquid. A method of removing a part thereof is preferably mentioned.
  • the method for preparing the CNT dispersion is not particularly limited, but the CNT dispersion is known to be a dispersion method using a stirring blade, a dispersion method using an ultrasonic wave, a dispersion method using a shearing force, and the like. It can be obtained by dispersing in a dispersion medium by the above method.
  • the CNTs are appropriately dispersed in the CNT dispersion liquid.
  • the CNT dispersion liquid does not contain a dispersant.
  • the CNT dispersion liquid is substantially composed only of CNT and the dispersion medium.
  • the CNT dispersion liquid is substantially composed of only CNT and the dispersion medium
  • the dispersion medium means that 99.9% by mass or more of the constituents of the CNT dispersion liquid are inevitably attached to CNT and CNT. It means that it consists of impurities and unavoidable impurities associated with the dispersion medium and the dispersion medium.
  • the method for removing the dispersion medium from the CNT dispersion liquid include known methods such as filtration and drying.
  • the filtration method is not particularly limited, and known filtration methods such as natural filtration, vacuum filtration (suction filtration), pressure filtration, and centrifugal filtration can be used.
  • drying method known drying methods such as a hot air drying method, a vacuum drying method, a hot roll drying method, and an infrared irradiation method can be used.
  • the drying temperature is not particularly limited, but is usually room temperature to 200 ° C.
  • the drying time is not particularly limited, but is usually 1 hour or more and 48 hours or less. Further, the drying can be performed on a known substrate, although the drying is not particularly limited.
  • the carbon film of the present invention can be obtained by further drying the film-shaped filter medium (primary sheet) obtained by filtering the CNT dispersion liquid.
  • the thickness of the carbon film of the present invention is preferably 5 ⁇ m or more, more preferably 10 ⁇ m or more, preferably 200 ⁇ m or less, and even more preferably 150 ⁇ m or less.
  • the carbon film can have sufficient mechanical strength and can exhibit more excellent electromagnetic wave shielding performance.
  • the thickness is 200 ⁇ m or less, the weight of the carbon film can be reduced.
  • the "thickness" of the carbon film can be measured by using the method described in Examples.
  • FT-IR ⁇ Fourier transform infrared spectroscopy
  • the effective length of plasmon is shown in Table 1.
  • the FIR resonance chart of the obtained FIR spectrum is shown in FIG. 7. As shown in FIG. 7, in the curves corresponding to the CNT aggregates used in Examples 1 to 4 and Comparative Example 1, a peak of optical density was observed above 300 cm -1 .
  • the plasmon peak top position was obtained from an approximate curve by polynomial fit using drawing software.
  • CNT aggregate ⁇ Creation of pore distribution curve (CNT aggregate)>
  • adsorption isotherms were measured using BELSORP-miniII (manufactured by Microtrac Bell) at 77 K using liquid nitrogen (adsorption equilibrium time was set to 500 seconds).
  • vacuum degassing was performed at 100 ° C. for 12 hours. From the adsorption amount of this adsorption isotherm, the pore distribution curve of each sample was obtained by the BJH method.
  • FIG. 8 in the CNT aggregates used in Examples 1 to 4 and Comparative Example 1, the maximum peak of the Log differential pore volume was confirmed in the region having a pore diameter of 100 nm or more.
  • the measurement range of the pore diameter was set to 1 nm or more and less than 400 nm.
  • FIG. 9A is one of the ten images acquired for the prepared CNT aggregate
  • FIG. 9B is a two-dimensional spatial frequency spectrum acquired for such images.
  • the component closer to the center means the low frequency component, and the component located more outward from the center corresponds to the higher frequency component.
  • the arrow indicates the peak position (3 ⁇ m -1 ) of the highest wave number among the clear peaks detected in the region of 1 to 100 ⁇ m -1 .
  • FIG. 9C is one of the 10 images acquired for the CNT aggregate used in Example 4, and
  • FIG. 9D is a two-dimensional spatial frequency spectrum acquired for such an image.
  • the component closer to the center means the low frequency component, and the component located more outward from the center corresponds to the higher frequency component.
  • ⁇ Thickness> The thickness of the carbon film was measured using a "Digimatic standard outside micrometer" manufactured by Mitutoyo.
  • ⁇ Average value of surface roughness of carbon film> For the average value of the surface roughness of the carbon film, the surface roughness was measured for four randomly set areas of 5 cm ⁇ 7 cm using a one-shot 3D shape measuring machine (“VR-5000” manufactured by KEYENCE CORPORATION). did. Then, the arithmetic mean value of the obtained four surface roughness values was calculated and used as the "average value of the surface roughness of the carbon film”.
  • the reflectance coefficient S11 and the transmission coefficient S21 were measured by the ASTM method (coaxial structure), and the electromagnetic wave shielding effect [dB] was calculated. Then, the electromagnetic wave shielding effect [dB] at the measurement frequencies of 0.1 MHz, 1 MHz, and 10 MHz was evaluated according to the following criteria. The larger the value of the electromagnetic wave shielding effect [dB] at a certain frequency, the better the electromagnetic wave shielding performance of the carbon film at that frequency.
  • B The electromagnetic wave shielding effect is 30 dB or more and less than 40 dB.
  • C The electromagnetic wave shielding effect is 20 dB or more and less than 30 dB.
  • D The electromagnetic wave shielding effect is less than 20 dB.
  • FIG. 10 shows a schematic configuration of the CNT manufacturing apparatus used at the time of synthesis.
  • the CNT manufacturing apparatus 100 shown in FIG. 10 is composed of a heater 101, a reaction tube 102, a dispersion plate 103, a reducing gas / raw material gas introduction port 104, an exhaust port 105, and a gas heating promotion unit 106.
  • Synthetic quartz was used as the material of the reaction tube 102 and the dispersion plate 103.
  • Catalyst carrier forming step >> The catalyst carrier forming step will be described below.
  • Zirconia (zirconium dioxide) beads (ZrO 2 , volume average particle diameter D50: 350 ⁇ m) as a carrier are put into a rotary drum type coating device, and the aluminum-containing solution is sprayed with a spray gun while stirring the zirconia beads (20 rpm). While spray spraying (spray amount 3 g / min, spray time 940 seconds, spray air pressure 10 MPa), compressed air (300 L / min) was supplied into the rotating drum and dried to form an aluminum-containing coating film on the zirconia beads. .. Next, firing treatment was performed at 480 ° C. for 45 minutes to prepare primary catalyst particles on which an aluminum oxide layer was formed.
  • the iron catalyst solution is spray-sprayed with a spray gun (spray amount 2 g / min, spray time 480 seconds, spray air pressure 5 MPa). ), While supplying compressed air (300 L / min) into the rotating drum, the mixture was dried to form an iron-containing coating film on the primary catalyst particles. Next, a firing treatment was carried out at 220 ° C. for 20 minutes to prepare a catalyst carrier on which an iron oxide layer was further formed.
  • ⁇ CNT synthesis process 300 g of the catalyst carrier thus produced is put into the reaction tube 102 of the CNT manufacturing apparatus 100, and the catalyst carrier 107 is fluidized by circulating gas, and the formation step, the growth step, and the cooling step are performed in this order.
  • the treatment was performed to produce a CNT aggregate.
  • the conditions of each step included in the CNT synthesis step were set as follows.
  • the CNT aggregate synthesized on the catalyst carrier was separated and recovered using a forced vortex classification device (rotation speed 3500 rpm, air air volume 3.5 Nm 3 / min). The recovery rate of the CNT aggregate was 99%.
  • the characteristics of the CNT aggregate produced by this example are tap bulk density: 0.01 g / cm 3 , CNT average height: 200 ⁇ m, BET specific surface area: 800 m 2 / g, average outer diameter: 4.0 nm, The carbon purity was 99%.
  • Example 1 Add 1000 g of water to 1 g of the CNT aggregate obtained as described above, and stir with an ultra-high-speed emulsification / dispersion device (product name "Lab Solution (registered trademark)", manufactured by Shinky Co., Ltd.) at a rotation speed of 3000 rpm for 10 minutes. Then, a CNT dispersion liquid was obtained. The obtained CNT dispersion liquid was applied onto the substrate. The coating film on the substrate was vacuum dried at a temperature of 80 ° C. for 24 hours to form a carbon film on the substrate. Then, the carbon film was peeled off from the substrate to obtain a carbon film (self-supporting film) having a thickness of 100 ⁇ m. The electromagnetic wave shielding performance of the obtained carbon film was evaluated. The results are shown in Table 1.
  • Example 2 In preparing the CNT dispersion liquid, a dispersion treatment was carried out for 10 minutes using an ultrasonic disperser (a desktop ultrasonic cleaner manufactured by Bransonic Co., Ltd.). A carbon film (self-supporting film) having a thickness of 100 ⁇ m was obtained in the same manner as in Example 1 except for these points. The electromagnetic wave shielding performance of the obtained carbon film was evaluated. The results are shown in Table 1.
  • Example 3 In preparing the CNT dispersion liquid, a jet mill (manufactured by Yoshida Kikai Kogyo Co., Ltd., NanoVeta) was used to carry out dispersion treatment under the condition of 100 MPa for 15 minutes. A carbon film (self-supporting film) having a thickness of 100 ⁇ m was obtained in the same manner as in Example 1 except for these points. The electromagnetic wave shielding performance of the obtained carbon film was evaluated. The results are shown in Table 1.
  • FIG. 11 shows a schematic configuration of the CNT aggregate manufacturing apparatus 200 used.
  • the CNT aggregate manufacturing apparatus 200 shown in FIG. 11 includes a formation unit 202, a growth unit 204, a transfer unit 207 that conveys a base material between the formation unit 202 and the growth unit 204, and the formation unit 202 and the growth unit.
  • a connection unit 208 for spatially connecting the 204 to each other and a gas mixing prevention device 203 for preventing gas from being mixed with each other between the formation unit 202 and the growth unit 204 are provided.
  • the CNT aggregate manufacturing apparatus 200 is arranged in the inlet purge device 201 arranged in the front stage of the formation unit 202, the outlet purge device 205 arranged in the rear stage of the growth unit 204, and further in the rear stage of the outlet purge device 205. It is provided with a component such as a cooling unit 206.
  • the formation unit 202 includes a formation furnace 202a for holding the reducing gas, a reducing gas injection device 202b for injecting the reducing gas, a heating device 202c for heating at least one of the catalyst and the reducing gas, and a gas in the furnace. It is composed of an exhaust device 202d or the like that discharges to the outside of the system.
  • the gas mixing prevention device 203 includes an exhaust device 203a and a purge gas injection device 203b for injecting a purge gas (seal gas).
  • the growth unit 204 includes a growth furnace 204a for maintaining the raw material gas environment, a raw material gas injection device 204b for injecting the raw material gas, a heating device 204c for heating at least one of the catalyst and the raw material gas, and the inside of the furnace. It is equipped with an exhaust device 204d or the like that discharges gas to the outside of the system.
  • the inlet purging device 201 is attached to a connecting portion 209 connecting the front chamber 213, which is a component for introducing the base material 211 into the system via the hopper 212, and the formation furnace 202a.
  • the cooling unit 206 includes a cooling container 206a for holding the inert gas, and a water-cooled cooling device 206b arranged so as to surround the inner space of the cooling container 206a.
  • the transport unit 207 is a unit that continuously transports the base material 211 by screw rotation. It is mounted by a screw blade 207a and a drive device 207b that can rotate the screw blade to exert a substrate transporting ability.
  • the heating device 214 is configured to be able to heat the inside of the system at a temperature lower than the heating temperature in the formation unit, and heats the vicinity of the drive device 207b.
  • Zirconia (zirconium dioxide) beads (ZrO 2 , volume average particle diameter D50: 650 ⁇ m) as a base material are put into a rotary drum type coating device, and the aluminum-containing solution is sprayed while stirring the zirconia beads (20 rpm). While spraying (spray amount 3 g / min, spray time 940 seconds, spray air pressure 10 MPa) and drying while supplying compressed air (300 L / min) into the rotating drum, an aluminum-containing coating film is formed on the zirconia beads. did. Next, firing treatment was performed at 480 ° C. for 45 minutes to prepare primary catalyst particles on which an aluminum oxide layer was formed.
  • the iron catalyst solution is spray-sprayed with a spray gun (spray amount 2 g / min, spray time 480 seconds, spray air pressure 5 MPa). ), While supplying compressed air (300 L / min) into the rotating drum, the mixture was dried to form an iron-containing coating film on the primary catalyst particles. Next, a calcination treatment was carried out at 220 ° C. for 20 minutes to prepare a base material on which an iron oxide layer was further formed.
  • Feeder hopper Feed speed: 1.25kg / h ⁇ Displacement: 10sLm (natural exhaust from the gap)
  • Inlet purge device Purge gas: Nitrogen 40sLm Formation unit ⁇ Temperature in the furnace: 800 °C -Reducing gas: nitrogen 6sLm, hydrogen 54sLm ⁇ Displacement: 60sLm ⁇ Processing time: 20 minutes Gas contamination prevention device ⁇ Purge gas: 20sLm ⁇ Displacement of the exhaust device: 62sLm Growth unit ⁇ Temperature in the furnace: 830 °C -Raw material gas: Nitrogen 15sLm, Ethylene 5sLm, Carbon dioxide 1sLm, Hydrogen 3sLm ⁇ Displacement: 47sLm ⁇ Processing time: 10 minutes Outlet purge device ⁇ Purge gas: Nitrogen 45sLm Cooling unit ⁇ Cooling temperature: Room temperature ⁇ Displacement: 10sLm (natural exhaust from gaps) Continuous production was performed under the above conditions.
  • the characteristics of the CNT aggregate produced by this example are typically tap bulk density: 0.02 g / cm 3 , CNT average length: 150 ⁇ m, BET-specific surface area: 900 m 2 / g, average outer diameter: It was 4.0 nm and had a carbon purity of 99%.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Nanotechnology (AREA)
  • Organic Chemistry (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Inorganic Chemistry (AREA)
  • Carbon And Carbon Compounds (AREA)

Abstract

L'invention concerne un film de carbone comprenant des agrégats de nanotubes de carbone. La valeur de rugosité de surface moyenne du film de carbone est de 4,0 µm ou plus.
PCT/JP2021/043974 2020-11-30 2021-11-30 Film de carbone WO2022114237A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2022565519A JPWO2022114237A1 (fr) 2020-11-30 2021-11-30

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2020199180 2020-11-30
JP2020-199180 2020-11-30

Publications (1)

Publication Number Publication Date
WO2022114237A1 true WO2022114237A1 (fr) 2022-06-02

Family

ID=81755702

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2021/043974 WO2022114237A1 (fr) 2020-11-30 2021-11-30 Film de carbone

Country Status (2)

Country Link
JP (1) JPWO2022114237A1 (fr)
WO (1) WO2022114237A1 (fr)

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002232185A (ja) * 2001-02-07 2002-08-16 Nisshin Steel Co Ltd 電磁波シールド材
JP2002232184A (ja) * 2001-02-07 2002-08-16 Nisshin Steel Co Ltd 電磁波シールド材
JP2016108175A (ja) * 2014-12-04 2016-06-20 日立化成株式会社 カーボンナノチューブの製造方法
WO2018066574A1 (fr) * 2016-10-04 2018-04-12 日本ゼオン株式会社 Structure de blindage électromagnétique et son procédé de production
WO2018159638A1 (fr) * 2017-02-28 2018-09-07 国立大学法人東京工業大学 Film de carbone approprié pour des éléments de réception de lumière et éléments d'alimentation électrique, qui utilisent des ondes térahertz, et dispositif de détection d'onde térahertz
JP2018145027A (ja) * 2017-03-02 2018-09-20 国立研究開発法人産業技術総合研究所 カーボンナノチューブ集合体およびカーボンナノチューブ膜
WO2020067203A1 (fr) * 2018-09-28 2020-04-02 日本ゼオン株式会社 Feuille d'absorption d'ondes électromagnétiques et son procédé de fabrication

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002232185A (ja) * 2001-02-07 2002-08-16 Nisshin Steel Co Ltd 電磁波シールド材
JP2002232184A (ja) * 2001-02-07 2002-08-16 Nisshin Steel Co Ltd 電磁波シールド材
JP2016108175A (ja) * 2014-12-04 2016-06-20 日立化成株式会社 カーボンナノチューブの製造方法
WO2018066574A1 (fr) * 2016-10-04 2018-04-12 日本ゼオン株式会社 Structure de blindage électromagnétique et son procédé de production
WO2018159638A1 (fr) * 2017-02-28 2018-09-07 国立大学法人東京工業大学 Film de carbone approprié pour des éléments de réception de lumière et éléments d'alimentation électrique, qui utilisent des ondes térahertz, et dispositif de détection d'onde térahertz
JP2018145027A (ja) * 2017-03-02 2018-09-20 国立研究開発法人産業技術総合研究所 カーボンナノチューブ集合体およびカーボンナノチューブ膜
WO2020067203A1 (fr) * 2018-09-28 2020-04-02 日本ゼオン株式会社 Feuille d'absorption d'ondes électromagnétiques et son procédé de fabrication

Also Published As

Publication number Publication date
JPWO2022114237A1 (fr) 2022-06-02

Similar Documents

Publication Publication Date Title
WO2022114235A1 (fr) Film de carbone
Hu et al. A simple large-scale synthesis of very long aligned silica nanowires
Rajabi et al. Room temperature synthesis of boehmite and crystallization of nanoparticles: effect of concentration and ultrasound
Tony et al. Effective synthesis of silicon carbide nanotubes by microwave heating of blended silicon dioxide and multi-walled carbon nanotube
WO2021172141A1 (fr) Film de carbone
Faisal et al. Synthesis and production of carbon nanospheres using noncatalytic CVD method
Patel et al. Synthesis of boron nanowires, nanotubes, and nanosheets
US20190352186A1 (en) Process for producing integral graphene films from functionalized graphene sheets
Kim et al. Synthesis of ultra-long super-aligned double-walled carbon nanotube forests
WO2022114237A1 (fr) Film de carbone
WO2021172078A1 (fr) Agrégats de nanotubes de carbone et procédé de production associé
WO2022114236A1 (fr) Film de carbone
Donato et al. Influence of carbon source and Fe-catalyst support on the growth of multi-walled carbon nanotubes
WO2022181247A1 (fr) Film de carbone
WO2022209831A1 (fr) Film de carbone
Zhang et al. The MgB 2-catalyzed growth of boron nitride nanotubes using B/MgO as a boron containing precursor
Kuthirummal et al. Synthesis and characterization of Ar-annealed zinc oxide nanostructures
Garmendia et al. Zirconia coating of carbon nanotubes by a hydrothermal method
Yamada et al. Vertically-aligned carbon nanotube growth using closely packed iron oxide nanoparticles
Zhu et al. Syntheses and growth mechanisms of 3C-SiC nanostructures from carbon and silicon powders
Ge et al. Study on the controllable scale-up growth of vertically-aligned carbon nanotube arrays
Kim et al. Synthesis and purification of single-walled carbon nanotubes by methane decomposition over iron-supported catalysts
Nazhipkyzy et al. Carbon Nanotubes Synthesized by CCVD Method using Diatomite and Shungite Minerals
WO2023153182A1 (fr) Nanotube de carbone oxydé et sa méthode de production, et liquide de dispersion de nanotubes de carbone oxydés
Miśta et al. Ultrathin graphitic carbon nitride (g-C

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21898208

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2022565519

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 21898208

Country of ref document: EP

Kind code of ref document: A1