• Composites Research
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• v.33 no.6
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• pp.415-420
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• 2020

The interfacial properties in carbon fiber composites, which control the overall mechanical properties of the composites, are very important. Effective interface enhancement work is conducted on the modification of the carbon fiber surface with carbon nanotubes (CNTs). Nonetheless, most surface modifications methods do have their own drawbacks such as high temperatures with a range of 600~1000℃, which should be implemented for CNT growth on carbon fibers that can cause carbon fiber damages affecting deterioration of composites properties. This study includes the use of in-situ interfacial polymerization of polyamide 610/CNT to fabricate the carbon fiber composites. The process is very fast and continuous and can disperse CNTs with random orientation in the interface resulting in enhanced interfacial properties. Scanning electron microscopy was conducted to investigate the CNT dispersion and composites morphology, and the thermal stability of the composites was analyzed via thermogravimetric analysis. In addition, fiber pull-out tests were used to assess interfacial strength between fiber and matrix.

• Journal of the Korean Ceramic Society
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• v.46 no.3
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• pp.263-270
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• 2009

The effect of photoelectrocatalytic (PEC) degradation for different dyes with the CNT/$TiO_2$ electrode was studied. The prepared electrode was characterized with surface properties, structural crystallinity, elemental identification, and PEC activity. The $N_2$ adsorption data showed that the composites had decreased surface area compared with the pristine CNT. This indicated the blocking of micropores on the surface of CNT, which was further supported by observation via FESEM. XRD patterns of the composites showed that the CNT/$TiO_2$ composite contained a mixing anatase and rutile phase. EDX spectra showed the presence of C, O and Ti peaks for all samples. The decomposition efifciency of the prepared electrode was evaluated by the PEC degradation of three dyes (methylene blue (MB), rhodamine B (RH.B), methyl orange (MO)). The variations of the FT-IR spectra and pH value of dye solutions were measured during the PEC system; it was found that the CNT/$TiO_2$ electrode has better PEC degradation for MB solution than that of RH.B and MO. The proposed degradation mechanism was present.

• Journal of Powder Materials
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• v.16 no.6
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• pp.424-430
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• 2009

Electromagnetic wave energies are consumed in the form of thermal energy, which is mainly caused by magnetic loss, dielectric loss and conductive loss. In this study, CNT was added to the nanocrystalline soft magnetic materials inducing a high magnetic loss, in order to improve the dielectric loss of the EM wave absorption sheet. Generally, the aspect ratio and the dispersion state of CNT can be changed by the pre-ball milling process, which affects the absorbing properties. After the various ball-milling processes, 1wt% of CNTs were mixed with the nanocrystalline $Fe_{73}Si_{16}B_7Nb_{3}Cu_1$ base powder, and then further processed to make EM absorption sheets. As a result, the addition of CNT to Fe-based nanocrystalline materials improved the absorption properties. However, the increase of ball-milling time for more than 1h was not desirable for the powder mixture, because the ballmilling caused the shortening of CNT length and the agglomeration of the CNT flakes.

• Textile Coloration and Finishing
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• v.28 no.2
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• pp.101-108
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• 2016

Polypropylene(PP)/multiwalled carbon nanotubes(MWCNT) nanocomposites films and PP/poly(vinyl alcohol)/CNT nanocomposites films were prepared through melt mixing method by the extruder. The PP/CNT nanocomposites films, which contain CNT of a variable content, were prepared for the first time and research on a appropriate content of the CNT on the PP/CNT nanocomposites films was conducted. The effects of take-up speed of the extruder on the mechanical and chemical properties of the PP/CNT and PP/PVA/CNT nanocomposites film were studied. Field emission scanning electron microscope(FE-SEM) was used to examine the surface morphology and the DSC measurement and tensile test were conducted. It was found that the properties decreased when take-up speed was increased.

• Bulletin of the Korean Chemical Society
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• v.31 no.7
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• pp.1981-1987
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• 2010

A novel composite (Ag-CNT/$TiO_2$) of silver treated carbon nanotubes (Ag-CNT) and $TiO_2$ was synthesized via wet chemistry followed by a heat treatment. The dispersion and structure of the silver in the synthesized composites determined by X-ray diffraction (XRD), energy dispersive X-ray (EDX) spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy(TEM). XRD patterns of the composites showed that the composites contained a mixing anatase and rutile phase. The EDX spectra showed the presence of C, O, Ti and Ag peaks. The $TiO_2$ particles were distributed uniformly in the CNT network, and silver particles were virtually fixed on the surface of the tube. The photocatalysis degraded behaviors of the Ag-CNT/$TiO_2$ composites of the methylene blue, which increased with an increase of the silver component. The Ag-CNT/$TiO_2$ composites have excellent antibacterial activities against Escherichia coli (E. Coli), Pseudomonas aeruginosa (P. Aeru) and Bacillus subtilis (B. Sub) under visible light.

• Bulletin of the Korean Chemical Society
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• v.31 no.2
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• pp.423-428
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• 2010

To reduce polarization of electrochemical capacitor based on carbon nanotube, titanium oxide nanoparticles were deposited by ultrasound. The pore distribution of $TiO_2$/CNT nanoparticle exhibited surface area of $341\;m^2g^{-1}$ when $TiO_2$ content was 4 wt %, which was better than that of pristine CNT with surface area of $188\;m^2g^{-1}$. The analyses indicated that titanium oxide (particle diameter < 20 nm) was deposited on the CNT surface. The electrochemical performance was evaluated by using cyclic voltammetry (CV), impedance measurement, and constant-current charge/discharge cycling techniques. The $TiO_2$/CNT composite electrode showed relatively better electrochemical behaviors than CNT electrode by increasing the specific capacitance from $22\;Fg^{-1}$ to $37\;Fg^{-1}$ in 1 M $H_2SO_4$ solution. A symmetric cell assembled with the composite electrodes showed the specific capacitance value of $11\;Fg^{-1}$ at a current loading of $0.5\;mAcm^{-2}$ during initial cycling.

• Carbon letters
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• v.24
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• pp.41-46
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• 2017

The microstructure, flexural properties, electrical conductivity, thermal conductivity and electromagnetic interference (EMI) shielding effectiveness (SE) of epoxy composites filled with multi-walled carbon nanotubes (CNTs), exfoliated graphite nanoplatelets (xGnPs) and CNT-xGnP hybrid filler were investigated. The EMI SE of the CNT-xGnP hybrid composite was higher than 25 dB at 100 MHz while that of the xGnP based composite was almost zero. The flexural modulus of the CNT-xGnP based epoxy composite continuously increased to 3.32 GPa with combined filler content up to 10 wt% while that of the CNT based epoxy composites slightly decreased to 1.96 GPa at 4 wt% CNT, and dropped to 1.57 GPa at 5 wt% loading, which is lower than that of epoxy. The CNT and CNT-xGnP samples had the same EMI SE at the same surface resistivity, because samples with the same surface conductivity have the same amount of the charge carriers.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.866-869
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• 2004

A carbon nanotube field emission display(CNT FED) panel with a 2 inch diagonal size was fabricated by using a screen printing of a prepared photo-sensitive CNT paste and vacuum in-line sealing technology. After a surface treatment of the patterned CNT, only the carbon nanotube tips are uniformly exposed on the surface. The diameter of the exposed CNTs are usually about 20nm. The sealing temperature of the panel was around 390 $^{\circ}C$ and the vacuum level was obtained with $1.4{\times}10^{-5}$torr at the sealing. The field emission properties of the diode type CNT FED panel were characterized Now, we are developing a triode type CNT FED with a self-aligned gate-emitter structure.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.8
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• pp.381-386
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• 2006

In this study, we have investigated electrical and mechanical properties of semiconducting materials for power cable caused by CNT. Specimens were made of sheet form with the four of specimens for measurement. Volume resistivity of specimens was measured by volume resistivity meter after 10 minutes in the pre-heated oven of both $23{\pm}\;1\;[^{\circ}C]\;and\;90{\pm}\;1\;[^{\circ}C]$. And stress-strain of specimens was measured by TENSOMETER 2000. A speed of measurement was 200[mm/min], ranges of stress and strain were 400[Kgf/Cm2] and 600[%]. From this experimental results, the volume resistivity had different properties because of PTC/NTC tendency at between $23[^{\circ}C]\;and\;90[^{\circ}C]$. Also volume resistivity was low by increasing the content of CNT. It means that a small amount of CNT has a excellent electrical properties. And stress was increased, while strain was decreased by increasing the content of CNT. Thus, we could know that a small amount of CNT has a excellent electrical and mechanical oroperties.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.331-334
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• 2007

탄소나노튜브는 화학적 안정성과 고전도성을 갖는 동시에 높은 비표면적을 지니고 있다. 이와 같은 특정으로 염료감응형태양전지의 상대전극으로 사용 가능이 기대되어 지고 있으나, 아직 성공적인 연구가 발표되고 있지 않다. 많은 연구자들이 CNT 자체만으로 원하는 효과를 얻지 못하고 있기 때문에, CNT 조작(가공)을 통해 CNT 특성을 올리고자 노력하였다. 그러나 본 연구에서, 가공하지 않은 CNT powder를 이용하여 paste를 제조하고 doctro-blade법으로 코팅하여 CNT counter electrode를 제조하여 DSSC의 상대전극으로써의 적용 가능성을 조사 해 보았다. 제조된 CNT counter electrode에 대한 CNT 자체만의 전기화학적 특성을 측정하였다. 그리고 DSSC 에 직접 적용하여 전지의 광전특성을 측정하였다. 그 결과 탄소나노튜브의 고전도성 특성과 넓은 비표면적 특성에 의해 상대전극의 전해질/전극계변에서의 전해질의 산화환원 반응에 대한 촉매 작용을 향상시키고, 상대전극 표변에서의 전자전달 속도를 높여 염료감응형 태양전지의 효율을 높이는 것으로 확인되어졌다.