• Journal of Electrochemical Science and Technology
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• 제1권1호
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• pp.25-30
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• 2010

This study demonstrated the synthesis of high-surface-area metal-free carbonaceous electrodes (CE) from anodic aluminum oxide (AAO) templates, and their application as supercapacitors. Multi-walled Carbon nanotubes (MWCNTs) were interwoven into a porous network sheet that was attached to one side of AAO template through a vacuum filtration of the homogeneously dispersed MWCNT toluene solution. Subsequently, the conducting polymer was electrochemically grown into the porous MWCNT network and nanochannels of AAO, leading to the formation of a carbonaceous metal-free film electrode with a high surface area in the given geometrical surface area. Typical conducting polymers such as polypyrrole (PPY) and poly(3,4-ethylenedioxythiophene) (PEDOT) were examined as model systems, and the resulting electrodes were investigated as supercapacitors (SCs). These SCs exhibited stable, high capacitances, with values as high as 554 F/g, 1.08 F/$cm^2$ for PPY and 237 F/g, 0.98 F/$cm^2$ for PEDOT, that were normalized by both the mass and geometric area.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2018년도 춘계학술대회 논문집
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• pp.101-101
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• 2018

Quantitative measurement of chloride ion concentration has an important role in various fields of electrochemistry, medical science, biology, metallurgy, architecture, etc. Among them, its importance of architecture is ever-growing due to unexpected degradations of building structure. These situations are caused by corrosion of reinforced concrete (RC) structure of buildings. And chloride ions are the most powerful factors of RC structure corrosion. Therefore, precise inspection of chloride ion concentration must be required to increase the accuracy of durability monitoring. Multi-walled Carbon nanotubes (MWCNTs) have high chemical resistivity, large surface area and superior electrical property. Thus, it is suitable for the channels of electrical signals made by the sensor. Silver nanoparticles were added to giving the sensing property. CuBTC, one of the metal organic frameworks (MOFs), was employed as a material to improve the sensing property because of its hydrophilicity and high surface area to volume ratio. In this study, sensing element was synthesized by various chemical reaction procedures. At first, MWCNTs were functionalized with a mixture of sulfuric acid and nitric acid because of enhancement of solubility in solution and surface activation. And functionalized MWCNTs, silver nanoparticles, and CuBTC were synthesized on PTFE membrane, one by one. Electroless deposition process was performed to deposit the silver nanoparticles. CuBTC was produced by room temperature synthesis. Surface morphology and composition analysis were characterized by scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), respectively. X-ray photoelectron spectroscopy (XPS) was also performed to confirm the existence of sensing materials. The electrical properties of sensor were measured by semiconductor analyzer. The chloride ion sensing characteristics were confirmed with the variation of the resistance at 1 V.

• Korean Chemical Engineering Research
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• 제50권4호
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• pp.729-732
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• 2012

본 논문에서 이온성액체를 이용한 초음파화학을 통해서 칼코젠 나노입자를 in-situ로 합성하여서 다중벽 탄소나노튜브(MWCNT) 위에 도포하였다. 1-Butyl-3-methylimidazolium tetrafluoroborate ($BMimBF_4$) 이온성액체를 이용해서 MWCNT의 표면을 기능화하였다. 합성된 MWCNT/$BMimBF_4$/CdTe, MWCNT/$BMimBF_4$/ZnTe, MWCNT/$BMimBF_4$/ZnSe 나노복합체를 TEM과 EDS를 이용해서 분석하였다. 특히, MWCNT/$BMimBF_4$/CdTe, MWCNT/$BMimBF_4$/ZnTe, and MWCNT/$BMimBF_4$/ZnSe 나노복합체는 각각 요철과 같거나, 거칠거나 부드러운 코어-쉘 형태와 같은 특이한 구조를 보여주었다. 본 연구는 반응속도가 다른 전구체로부터 얻어진 이성분 반도체 나노입자를 합성과 동시에 탄소나노튜브에 도포할 수 있는 새로운 합성법을 제시한다.

• Advances in concrete construction
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• 제8권3호
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• pp.207-215
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• 2019

Application of nanotechnology can be used to tailor made cementitious composites owing to small dimension and physical behaviour of resulting hydration products. Because of high aspect ratio and extremely high strength, carbon nanotubes (CNTs) are perfect reinforcing materials. Hence, there is a great prospect to use CNTs in developing new generation cementitious materials. In the present paper, a parametric study has been conducted on cementitious composites reinforced by two types of multi walled carbon nanotubes (MWCNTs) designated as Type I CNT (10-20 nm outer dia.) and Type II CNT (30-50 nm outer dia.) with various concentrations ranging from 0.1% to 0.5% by weight of cement. To evaluate important properties such as flexural strength, strain to failure, elastic modulus and modulus of toughness of the CNT admixed specimens at different curing periods, flexural bending tests were performed. Results show that composites with Type II CNTs gave more strength as compared to Type I CNTs. The highest increase in strength (flexural and compressive) is of the order of 22% and 33%, respectively, compared to control samples. Modulus of toughness at 28 days showed highest improvement of 265% for Type II 0.3% CNT composites. It is obvious that an optimum percentage of CNT could exists for composites to achieve suitable reinforcement behaviour and desired strength properties. Based on the parametric study, a tentative optimum CNT concentration (0.3% by weight of cement) has been proposed. Scanning electron microscope image shows perfect crack bridging mechanism; several of the CNTs were shown to act as crack arrestors across fine cracks along with some CNTs breakage.

• 공업화학
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• 제27권5호
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• pp.502-507
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• 2016

본 연구에서는 탄소나노튜브, 니켈 및 산화아연의 항균특성 활용을 목적으로 새로운 항균 나노 복합 재료를 개발하였다. 니켈 코팅된 탄소나노튜브의 제조 및 그들의 동시발생 집중 및 비활성 세균에 대한 항균소재의 잠재적 응용성을 평가하였다. 제조된 니켈 도금 탄소나노튜브의 형상 및 니켈 도금은 전계 방출 주사전자현미경(FE-SEM) 및 X선 에너지 분산 분광기(EDS)를 사용하여 분석하였다. 나노복합소재의 항균 특성을 확인할 수 있는 타깃 세균은 황색포도상구균과 대장균으로 지정하였다. 니켈 도금된 탄소나노튜브와 산 처리된 탄소나노튜브로 각각 강화된 나노복합소재의 황색포도상구균 및 대장균에 대한 항균특성을 비교하였을 때, 니켈 도금된 탄소나노튜브/산화아연으로 강화된 나노복합소재의 항균 특성이 더 우수한 결과를 보이는 것을 확인할 수 있었다. 이러한 결과에 따라서, 탄소나노튜브 표면에 도금된 니켈이 복합소재 내에서 세균의 살균 작용에 중요한 역할을 하는 것으로 판단할 수 있다. 또한, 첨가된 산화아연은 나노복합소재의 항균특성 향상을 목적으로 제안되었다.

• Advances in nano research
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• 제11권6호
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• pp.581-593
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• 2021

This model is proposed to describe the buckling behavior of Carbon Nanotubes (CNTs) embedded in an elastic medium taking into account the combined effects of the magnetic field, the temperature, the nonlocal parameter, the number of walls. Using Eringen's nonlocal elasticity theory, thin cylindrical shell theory and Van der Waal force (VdW) interactions, we develop a system of partial differential equations governing the buckling response of CNTs embedded on Winkler, Pasternak, and Kerr foundations in a thermal-magnetic environment. The pre-buckling stresses are obtained by applying airy's stress function and an adjacent equilibrium criterion. To estimate the nonlocal critical buckling load of CNTs under the simultaneous effects of the magnetic field, the temperature change, and the number of walls, an optimization technique is proposed. Furthermore, analytical formulas are developed to obtain the buckling behavior of SWCNTs embedded in an elastic medium without taking into account the effects of the nonlocal parameter. These formulas take into account VdW interactions between adjacent tubes and the effect of terms involving differences in tube radii generally neglected in the derived expressions of the critical buckling load published in the literature. Most scientific research on modeling the effects of magnetic fields is based on beam theories, this motivation pushes me to develop a cylindrical shell model for studying the effect of the magnetic field on the static behavior of CNTs. The results show that the magnetic field has significant effects on the static behavior of CNTs and can lead to slow buckling. On the other hand, thermal effects reduce the critical buckling load. The findings in this work can help us design of CNTs for various applications (e.g. structural, electrical, mechanical and biological applications) in a thermal and magnetic environment.

• Composites Research
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• 제24권6호
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• pp.25-30
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• 2011

본 연구에서는 유리섬유, 탄소섬유 및 유리섬유-탄소섬유 복합재에 MWCNT층을 삽입하는 경우 복합재의 전자파차폐 물성에 대한 연구를 수행하였다. 유리섬유 복합재의 경우, $200mm{\times}200mm$ 면적에 0.1~0.2 g의 MWCNT를 도포했을 때 (1.8~3.6 ${\mu}m$ 두께) 전자파차폐효과가 현격히 증가함을 발견하였다. 아울러, 두개 이상의 MWCNT층을 삽입하는 경우, 이들을 분산배치 하는 것 보다는 복합재 중앙에 집중배치 하는 것이 더 효과적이었다. 반면, 탄소섬유 및 유리섬유-탄소섬유 복합재의 경우, MWCNT층이 전자파차폐효과에 영향을 미치지 않음을 알 수 있었다. MWCNT를 비롯한 탄소나노소재를 전자파차폐용 소재로 효과적으로 활용하기 위해서는, 탄소나노소재의 첨가에 의한 다양한 전자파차폐 메커니즘 간 상관관계를 이해하는 것이 중요하다.

• 한국산업융합학회 논문집
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• 제20권3호
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• pp.233-243
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• 2017

This paper proposes a structure of direct-printed flexible tactile-sensor. These flexible tactile sensors are based on pressure-sensing materials that allow pressure to be measured according to resistance change that in turn results from changes in material size because of compressive force. The sensing material consists of a mixture of multi walled carbon nanotubes (MWCNTs) and TangoPlus, which gives it flexibility and elasticity. The tactile sensors used in this study were designed in the form of array structures composed of many lines so that single pressure points can be measured. To evaluate the performance of the flexible tactile sensor, we used specially designed signal-processing electronics and tactile sensors to experimentally verify the sensors' linearity. To test object grasp, tactile sensors were attached to the surface of the fingers of grippers with three degrees of freedom to measure the pressure changes that occur during object grasp. The results of these experiments indicate that the flexible tactile sensor-based robotic gripper can grasp objects and hold them in a stable manner.

• 설비공학논문집
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• 제23권1호
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• pp.47-53
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• 2011

In this study, the characteristics of multi-walled carbon nanotubes added nanofluid were investigated. Sodium Dodecyl Sulfate, SDS, and Polyvinylpyrrolidone, PVP, were employed as the dispersant. SDS or PVP was added in pure water. And then, 0.0005, 0.001, 0.002, 0.003. 0.004, 0.005,0.01, and 0.02 vol% of CM-95 and CM-100 were dispersed respectively. The thermal conductivity and the viscosity were measured with a transient hot-wire instrument built for this study and the DV II+ Pro viscometer. The results showed that PVP had good thermal conductivity at 300 wt% and the thermal conductivity of CM-100 was better than that of CM-95. However, the viscosity of CM 100 was higher than that of CM 95.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.289-289
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• 2010

나노섬유는 지름이 수십에서 수백 나노미터(1나노미터=10억분의1m)에 불과한 초극세 물질로 비표면적이 매우 크고[1], 제작이 간편하여, 사용되어지는 고분자의 종류에 따라 에너지 환경 의료 관련 분야에서 전극소재 필터재 피복재 인공 피부등 다양한 분야에서의 활용이 가능하여 전 세계적으로 연구개발이 활발하게 이루어지고 있다. 그러나 그 자체만으로 응용하기에는 그 기계적 전기적 특성의 한계 때문에 응용의 다양성에 제약을 받고 있다. 그러나 그 자체만으로 응용하기에는 그 기계적 열적 전기적 특성을 가진 탄소나노튜브를 첨가한 복합나노섬유에 의해 그 응용영역의 한계를 넓혀가고 있다.[2] 본 연구에서는 전도성 고분자인 polymethyl methacrylate (PMMA)에 multi-walled carbon nanotubes (MWCNTs)를 첨가한 복합나노섬유를 전기방사법(electrospinning method)을 통해서 제조하였다. [2~3] CNTs 첨가농도에 따른 제조된 복합나노섬유의 형상변화와 섬유내의 CNTs 배열상태를 각각 주사전자 현미경(scanning electron microscope: SEM)과 투과전자현미경(transmission electron microscope: TEM)을 이용하여 관찰하였다. 또한, 복합나노섬유의 광학 특성 변화를 CNTs 첨가농도에 따라서 FT-IR과 Raman spectroscopy등을 이용하여 조사하였으며, 나노섬유의 tensile strength의 측정을 통해 CNTs 함량에 따른 기계적 특성 변화를 분석하였다.