• Carbon letters
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• 제11권2호
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• pp.102-106
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• 2010

In this work, the effect of aminized multi-walled carbon nanotubes (NH-MWNTs) on the mechanical interfacial properties of epoxy nanocomposites was investigated by means of fracture toughness, critical stress intensity factor ($K_{IC}$), and impact strength testing, and their morphology was examined by scanning electron microscope (SEM). It was found that the incorporation of amine groups onto MWNTs was confirmed by the FT-IR and Raman spectra. The mechanical interfacial properties of the epoxy nanocomposites were remarkably improved with increasing the NH-MWNT content. It was probably attributed to the strong physical interaction between amine groups of NH-MWNTs and epoxide groups of epoxy resins. The SEM micrographs showed that NH-MWNTs were uniformly embed and bonded with epoxy resins, resulted in the prevention of the deformation and crack propagation in the NH-MWNTs/epoxy nanocomposites.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.382-383
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• 2008

In this paper we presented experimental results of a gas sensor utilizing multi-walled carbon nanotube (MWNT)composites for the alcohol detection which is useful to checking drinking and driving, for example. The MWNT-composites were deposited using spray method on PES substrates suitable for use in low-cost and flexible sensors. We observed the variation of conductance from the sensors exposed to alcohol vapors evaporated at 37C equal to the human body temperature to match real condition. As the result, the conductance was decreased with the increase of ethanol vol% diluted in water. The sensors showed good sensitivity and linearity.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2003년도 기술심포지움 논문집
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• pp.22-26
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• 2003

Electrical conductivity of the oxidized MWNT(Multi walled nanotubes)/polymer composites were investigated with respect to various oxidative conditions of acid concentration, treatment temperature, and treatment time. To remove the impurities existing in MWNT-deposites, liquid-phase oxidation was performed using the $HNO_3/HSO_4$ mixtures. Secondary effects occurred by the oxidation of MWNTs such as the damages of MWNTs and the introduction of functionalities were analyzed through measuring FT-IR, TEM, and zeta potential, All the oxidized NWNTs were functionalized with carboxylic groups and the conditions of oxidation of the MWNTs could have a certain influence on the degree of functionalization, damages, and dispersion of the MWNT. The electrical properties of MWNT composites strongly depend on the oxidative conditions of MWNTs. The conductivity of the composites filled with the proper oxidized MWNT showed the highest percolation threshold.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.73-76
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• 2005

Carbon nanotubes (CNTs) have attracted an increasing attention due to their superior mechanical properties and potential application in industries. The strength of CNT has been predicted or calculated through several simulation techniques but actual experiments on stress-strain behavior are rare due to its dimensional limit, nanoscale positioning/manipulation, and instrumental resolution. We have attempted to observe straining responses of a multi-walled carbon nanotube (MWNT) by performing an in-situ tensile testing in a scanning electron microscope. The carbon nanotube, having its both ends attached on a cantilever force sensor and Y-shaped support, was elongated by a computer-controlled nanomanipulator. Linear deformation and fracture behaviors of MWNT were successfully observed and its force-displacement curve was also measured from the bending stiffness and displacement of the force sensor and manipulator.

• Transactions on Electrical and Electronic Materials
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• 제14권3호
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• pp.125-129
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• 2013

Composites of platinum and multiwalled carbon nanotubes (MWNTs) were prepared in various reduction conditions and characterized using cyclic voltammetry. The MWNTs were functionalized with carboxylic acid and/or hydroxyl groups in acidic solutions prior to the formation of MWNT-Pt composites. Platinum nanoparticles were deposited onto the chemically-oxidized MWNTs in 1-propanol and 1,3-propanediol. The reduction of Pt precursors in other solutions could induce differences in their morphologies in composite thin films. The morphologies of MWNTs with Pt deposited were dependent on the reduction solutions, and the electrocatalytic activities on alcohols changed accordingly. The electrochemical activities of the as-prepared MWNT-Pt thin films on common alcohols such as methanol and ethanol were investigated.

• 폴리머
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• 제38권2호
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• pp.240-249
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• 2014

다중벽 탄소나노튜브(MWNT)로 보강된 폴리에스터(PET) 복합재료에 관한 연구를 수행하였다. PET와 MWNT간의 계면결합력을 향상시키기 위하여, MWNT 표면에 bishydroxyethylene-terephthalate(BHET)를 도입하였다. 이렇게 기능화된 MWNT를 0.5~2.0 wt% 범위에서 이축압출기를 이용하여 PET와 용융 혼합하였다. MWNT/PET 복합재료를 필라멘트로 방사하고, 이를 연신 및 열처리하여 특성 분석을 하였다. 이로부터 복합섬유의 결정화 온도와 열분해 온도가 MWNT로 인하여 증가함을 알 수 있었으며, 항복응력과 인성은 MWNT의 1 wt%의 첨가만으로도 30%이상 증가함을 알 수 있었다. 따라서 MWNT를 BHET로 기능화하는 방법은 폴리에스터에 탄소나노튜브를 효과적으로 분산시키고 계면결합력을 증가시키는데 매우 효과적임을 알 수 있었다.

• 한국유변학회:학술대회논문집
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• 한국유변학회 2006년도 춘계 학술발표회 논문집
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• pp.45-48
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• 2006

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.61-61
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• 2008

Nanocomposites of metal (gold and silver) nanoparticles and multi-walled carbon nanotubes (MWNTs) were prepared with the assistance of various stabilizers for metals and MWNTs. Especially common surfactants such as poly(4-vinylpyridine) (PVP), sodium dodecyl sulfate (SDS), poly(sodium 4-styrene sulfonate) (PSS), and poly(diallyldimethylammonium) chloride (PDDA) were used for the sample preparation. Metal/MWNT nanocomposites were structurally characterized in by transmission electron microscopy (TEM), x-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD), UV/Vis spectroscopy. In addition, the electrical properties of the nanocomposites were studied by cyclic voltammetry (CV).

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 춘계학술발표대회 논문집
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• pp.131-134
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• 2004

The object of this study is to design the Radar Absorbing Structures (RAS) having sandwich structures in the X-band $(8.2\~12.4GHz)$ frequencies. Glass fabric/epoxy composites containing conductive carbon blacks and carbon fabric/epoxy composites were used for the face sheets. Polyurethane (PU) foams containing multi­walled carbon nanotube (MWNT) were used for the core. Their permittivities in the X-band were measured using the transmission line technique. The reflection loss characteristics for multi-layered sandwich structures were calculated using the theory of transmission and reflection in a multi-layered medium. Three kinds of specimens were fabricated and their reflection losses in the X-band were measured using the free space technique. Experimental results were in good agreements with simulated ones in 10dB absorbing bandwidth.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1436-1437
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• 2006

탄소 나노튜브는 기계적인 강도가 크고, 표면적이 넘으며 전기전도도가 우수할 뿐만 아니라 화학적으로도 안정하기 때문에 최근 여러분야에 적용하려는 연구가 활발히 진행되고 있는 나노물질이다. 특히 바이오센서에서 탄소 나노튜브는 작업 전극의 활성을 증대시키는 물질로써, 안정적인 효소 고정화에 기여하는 reservior로써 그리고 반응에서 생성된 전자를 전극에 효과적으로 전달하는 매개체로써 이용되고 있다. 본 연구에서는 다중벽 탄소 나노튜브(multi-walled carbon nanotube ; MWNT)를 화학처리하여 작용기를 유도한 후 효소와 반응시킨 용액으로 스크린 프린팅 방법으로 제작된 탄소전극의 표면을 개질하는 방법으로 바이오센서를 제작하였다. 이렇게 제작된 바이오센서를 탄소 나노튜브를 이용하지 않은 바이오 센서와 전기화학적으로 분석한 결과 감도가 약 3배정도 증가하는 결과를 얻을 수 있었다. 이것은 효소반응 시 발생된 전자가 나노튜브를 통해서 전극에 효과적으로 전달됨을 의미한다.