• 한국염색가공학회지
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• 제28권2호
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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.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.49-49
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• 2009

Nanocomposites of gold nanoparticles and multi-walled carbon nanotubes (MWNTs) were prepared by electrostatic interaction. Gold nanopartic1es were stabilized by polyvinylpyrrolidone (PVP), sodium dodecyl sulfate (SDS) and poly(sodium-4-styrenesulfonate) (PSS) in aqueous medium, and MWNTs were modified by poly(diallyldimethylammonium)chloride (PDDA) in water. The as-perpared Au-MWNT nanocomposites were structurally and electrically characterized by transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), UV/Vis spectroscopy, X-ray photoelectron spectroscopy (XPS) and cyclo voltammetry (CV). UV/Vis spectra of Au-MWNT nanocomposites showed the characteristic surface plasmon bands in the range of ~515nm, depending on the stabilizers. There is only slight change on the band shape with variation of stabilizing agents for gold nanoparticles. Through FE-SEM and TEM images, the distribution of gold, nanoparticles on the sidewalls of MWNTs was deliberately investigated on Au-MWNT nanocomposites treated with different stabilizers. XPS and CV showed redistribution of electron densities and changes in the binding energy states of nanopartic1es in nanocomposite respectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.181-181
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• 2010

Few-walled carbon nanotubes (FWNTs)-based field emitters with long term stability are fabricated by using a spray method. Tetraethylorthosilicate (TEOS) sol as a binder was mixed with dispersed solution of FWNTs to enhance the adhesion of FWNTs on the cathode substrate. Due to the strong intermolecular interaction of TEOS to the functional groups attached on CNTs and substrate, CNTs are tightly adhered to the cathode electrode when heat treatment is performed at $150^{\circ}C$ for 1 hour, resulting in a stable electron emission of CNT emitters for long time. Excellent field emission characteristics were exhibited, with a large field enhancement factor and low turn-on voltage, comparable to those of CNT emitters fabricated by a screen printing of CNT paste. Therefore, FWNTs / TEOS hybrid films could be utilized as an alternative for the efficient and reliable field emitters.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.386.1-386.1
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• 2014

The ionic polymer-metal composite (IPMC), a type of electro-active polymer material, has received enormous interest in various fields such as robotics, medical sensors, artificial muscles because it has many advantages of flexibility, light weight, high displacement, and low voltage activation, compare to traditional mechanical actuators. Mostly noble metal materials such as gold or platinum were used to form the electrode of an IPMC by using electroless plating process. Furthermore, carbon-based materials, which are carbon nanotube (CNT) and reduced graphene-CNT composite, were used to alter the electrode of IPMC. To form the electrode of IPMC, we employ the synthesized graphene on copper foil by chemical vapor deposition method and use the transfer process by using a support of PET/silicone film. The properties of graphene were evaluated by Raman spectroscopy, UV/Vis spectroscopy, and 4-point probe. The structure and surface of IPMC were analyzed via field emission scanning electron microscope. The fabricated IPMC performance such as displacement and operating frequency was measured in underwater.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2010년도 춘계학술발표대회
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• pp.55.1-55.1
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• 2010

차세대 디스플레이용 전극 재료는 투명하면서도 낮은 저항값을 가져야 하는 투명 전극 재료로 금속, 금속산화물, 전도성 고분자, 탄소재료 등을 들 수 있다. 금속재료는 전도도는 우수하지만, 낮은 투과도로 투명전극 재료로 적절하지 않고, 대표적인 금속산화물 재료인 indium tin oxide (ITO)의 경우, 우수한 투과성과 낮은 면저항을 기반으로 차세대 디스플레이용 전극으로 현재 사용되고 있다. 하지만 ITO 박막은 휘거나 접을 때 기계적 안정성이 취약한 문제점을 나타내고 있다. 이러한 문제점을 극복하기 위해 전도성과 탄성계수가 높고, 저온에서 대면적 공정이 가능한 CNT을 투명 박막 전극 연구가 활발히 진행되고 있다. 하지만 투명전극 제조시, 탄소 나노튜브 간의 van der waals 인력에 의한 응집 현상으로 인한 분산의 불안정성과 분산제 사용으로 인하여 탄소 나노튜브 박막전극의 전기적, 광학적 특성이 저하를 야기한다. 이에 본 실험에서는 아크 방전 공정으로 합성한 SWCNT 분산액을 사용하여 spray coating 방법으로 glass 위에 박막을 형성하였다. SWCNT 투명 박막 전극 위에 DC sputtering을 이용하여 얇은Ni를 도포한 후, $450{\sim}500^{\circ}C$, ethylene gas 분위기의 thermal CVD방법으로 Carbon NanoFibers (CNFs)를 생성시킴과 동시에 분산제를 burning out하였다. CNF 성장 전후의 투명 박막의 전기적 특성은 four point probe를 이용하여 면저항과 UV-vis 장비를 이용하여 가시광선 영역에서의 광학적 투과도를 측정 비교하였다.

• Macromolecular Research
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• 제17권9호
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• pp.666-671
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• 2009

Water repellent elastomeric surfaces were fabricated successfully on SBS/MWNT nanocomposites films using the breath figure method and subsequent thermal treatment. The uniformly dispersed CNTs were found to play significant roles in tuning the size and ordering of the macroporous morphology at the nanocomposite surface as well as enhancing the mechanical properties of nanocomposites. In particular, the CNTs dispersed in a nanocomposite solution retarded the coarsening process of aqueous droplets during the breath figure process and decreased the pore size in the finally fabricated film. The water contact angle measurement showed that the double-scale structure comprised of self-organized macropores and surface the roughness induced by a thermal treatment produced a highly water-repellent nanocomposite surface.

• 한국전기전자재료학회논문지
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• 제32권5호
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• pp.432-436
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• 2019

In this study, we produced a light, flexible, wearable gas sensor by depositing MWCNTs (Multi-walled Carbon Nanotubes) into nylon. MWCNTs are widely used as a gas sensor material due to their excellent mechanical, electrical and physical characteristics. We produced a gas sensor to detect NOx gases by depositing nylon yarn in a MWCNT solution. The MWCNT solution was made by mixing 3 mg MWCNT in 5 ml of ethanol. Nylon yarn was placed in the manufactured solution and ultrasonic waves were applied using an ultrasonicator for 3 h, resulting in MCWNT deposition. The MWCNT-deposited nylon yarn was dried at room temperature for 24 h. The MWCNT-thin-film-coated nylon yarn was masked 1 mm apart, and gold was then deposited on the masked nylon yarn to create the gas sensor. The sensor then was installed in a chamber with a controlled atmospheric environment and exposed to NOx gas. The changing signal from the sensor was amplified to analyze its gas detection characteristics.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.215-216
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• 2007

Semiconducting layers are thin rubber film between electrical cable wire and insulating polymer layers having a volume resistivity of ${\sim}10^2{\Omega}cm$. A new semiconducting material was suggested in this study based on the carbon nanotube(CNT)-reinforced polymer nanocomposites. CNT-reinforced polymer nanocomposites were prepared by solution mixing with various polymer type and dual filler system. The mechanical, thermal and electrical properties were investigated as a function of polymer type and dual filler system based on CNT and carbon black. The volume resistivity of composites was strongly related with the crystallinity of polymer matrix. With decreased crystallinity, the volume resistivity decreased linearly until a critical point, and it remained constant with further decreasing the crystallinity. Dual filler system also affected the volume resistivity. The CNT-reinforced nanocomposite showed the lowest volume resistivity. When a small amount of carbon black(CB) was replaced the CNT, the crystallinity increased considerably leading to a higher volume resistivity.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2009년도 춘계학술발표대회
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• pp.31.1-31.1
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• 2009

Carbon nanotubes (CNTs) are attractive material because of their superior electrical, mechanical, and chemical properties. Furthermore, their geometric features such as a large aspect ratio and a small radius of curvature at tip make them ideal for low-voltage field emission devices including backlight units of liquid crystal display, lighting lamps, X-ray source, microwave amplifiers, electron microscopes, etc. In field emission devices for display applications, the phosphor anode is positioned against the CNT emitters. In most case, light generated from the phosphor by electron bombardment passes through the anode front plate to reach observers. However, light is produced in a narrow depth of the surface of the phosphor layer because phosphor particles are big as much as several micrometers, which means that it is necessary to transmit through the phosphor layer. Hence, a drop of light intensity is unavoidable during this process. In this study, we fabricated a transparent cathode back plate by depositing an ultra-thin film of single walled CNTs (SWCNTs) on an indium tin oxide (ITO)-coated glass substrate. Two types of phosphor anode plates were employed to our transparent cathode back plate: One is an ITO glass substrate with a phosphor layer and the other is a Cr-coated glass substrate with phosphor layer. For the former case, light was radiated from both the front and the back sides, where luminance on the back was ~30% higher than that on the front in our experiments. For the other case, however, light was emitted only from the cathode back side as the Cr layer on the anode glass rolled as a reflecting mirror, improving the light luminance as much as ~60% compared with that on the front of one. This study seems to be discussed about the morphologies and field emission characteristics of CNT emitters according to the experimental parameters in fabricating the lamps emitting light on the both sides or only on the cathode back side. The experimental procedures are as follows. First, a CNT aqueous solution was prepared by ultrasonically dispersing purified SWCNTs in deionized water with sodium dodecyl sulfate (SDS). A milliliter or even several tens of micro-liters of CNT solution was deposited onto a porous alumina membrane through vacuum filtration. Thereafter, the alumina membrane was solvated with the 3 M NaOH solution and the floating CNT film was easily transferred to an ITO glass substrate. It is required for CNT film to make standing CNTs up to serve as electron emitter through an adhesive roller activation.

• 한국정보전자통신기술학회논문지
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• 제16권1호
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• pp.8-17
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• 2023

기존 liquid crystal display(LCD) 공정에서 Indium Tin Oxide(ITO) 투명전극과 폴리이미드 배향막의 러빙 공정은 액정을 정렬하고 전계를 인가하기 위하여 필수적인 공정이다. 하지만 ITO의 증착은 높은 진공을 요구하며, 러빙 공정은 정전기에 의해 소자가 손상될 수 있는 단점이 존재한다. 본 논문에서는 기존 ITO 투명전극을 대체하기 위하여 PEDOT:PSS와 Multi-wall carbon nanotube(MWNT)를 혼합하여 PEDOT:PSS 나노복합체를 제조하고, 러빙 공정을 대체하기 위하여 나노 주름 구조 몰드를 통한 나노임프린팅을 통하여 박막을 형성함으로써 기존 액정 디스플레이의 투명전극과 배향막 두 가지 박막을 PEDOT:PSS/MWNT 나노복합체 박막 하나만으로 기능하게 하여 공정을 단순화 하였다. 전사된 나노 주름을 따라 액정이 잘 배향됨을 확인하였으며, 이를 기반으로 만들어진 액정 셀에서 박막 내 MWNT의 함량이 높아질수록 박막의 전기전도도가 증가하여 낮은 구동 전압과 빠른 응답 속도를 갖는다는 것을 확인하였다. 본 연구를 통해 공정 단순화와 용액공정에 의한 공정 단가 절감, 기존 러빙 공정의 단점을 해결하는데 기여 할 수 있을 것으로 기대된다.