• 대한토목학회논문집
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• 제42권6호
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• pp.787-792
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• 2022

겨울철 제설염의 사용은 콘크리트의 미세조직을 손상시기게 되고 이는 내구성을 감소시켜 콘크리트의 수명 단축으로 이어진다. 이러한 단점을 개선하기 위해 상변화물질(Phase Change Material, PCM)의 잠열을 콘크리트에 적용함으로써 손상을 완화하고 제설염의 수요를 감소시킬 수 있는 융설 PCM 함침 경량골재(Phase Change Material Impregnated Light Weight Aggregate, PCM-LWA) 콘크리트를 개발하고자 한다. 콘크리트를 제작할 때, PCM을 함침하고 캡슐화한 팽창점토(Expanded Clay)는 일반골재의 50 %를 대체하여 사용되었으며, 열적 성능을 향상시키기 위해 사용된 다중벽 탄소나노튜브(Multi-walled Carbon Nano Tube, MWCNT)는 바인더 중량 대비 0.10 %, 0.15 % 및 0.20 %의 비율로 첨가되었다. PCM-LWA를 적용한 시편들의 압축강도 시험 결과 약 54 %의 강도 감소를 보였지만 MWCNT의 첨가를 통하여 PCM-LWA 콘크리트의 열적 성능을 크게 향상시켰다. 열 사이클링 시험에서 모든 시편은 15℃ ~ -5℃의 온도에서 시험하였다. 주변 온도가 0℃ 미만으로 내려갈 때, 다른 시편들의 내부 온도는 0℃ 미만으로 내려가거나 조금 웃도는 경향을 보였지만, CNT를 0.10 % 첨가한 시편의 내부 온도는 2℃로 유의미한 차이를 보였다. 0.15CNT와 0.20CNT의 경우 CNT의 함유로 인하여 과냉각이 발생하였고 열효율이 떨어지게 되어 시편 내부의 온도가 0℃ 이하로 떨어지는 것을 확인할 수 있었다. 융설 시험에서 열 사이클링 시험의 결과와 유사하게 50PCM-LWA와 0.10CNT는 얼음을 녹이는 데에 가장 뛰어난 성능을 보였지만 시간이 흐름에 따라 열전도율이 높은 0.10CNT 시편이 가장 우수한 성능을 보였다.

• 한국산업융합학회 논문집
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• 제26권6_3호
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• pp.1297-1303
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• 2023

Research on enhancing the mechanical strength, lightweight properties, electrical conductivity, and thermal conductivity of composite materials by incorporating nano-materials is actively underway. Thermoplastic resins can change their form under heat, making them highly processable and recyclable. In this study, Polyamide-Nylon 6 (PA6), a thermoplastic resin, was utilized, and as reinforcing agents, fused carbon nano-materials (FCN) formed by structurally combining Carbon Nanotube(CNT) and Graphene were employed. Nano-materials often face challenges related to cohesion and dispersion. To address this issue, Silane functional groups were introduced to enhance the dispersion of FCN in PA6. The manufacturing conditions for the composite materials involved determining the use of a dispersant and varying FCN content at 0.05 wt%, 0.1 wt%, and 0.2 wt%. Tensile strength measurements were conducted, and FE-SEM analysis was performed on fracture surfaces. As a result of the tensile strength test, it was confirmed that compared to pure PA6, the strength of the polymer composite with a content of 0.05 wt% was improved by about 60%, for 0.1 wt%, about 65%, and for 0.2 wt%, the strength was improved by 50%. Also, when compared according to the content of FCN, the best strength value was shown when 0.1 wt% was added. The elastic modulus also showed an improvement of about 15% in the case of surface treatment compared to the case without surface treatment, and an improvement of about 70% compared to pure PA6. Through FE-SEM, it was confirmed that the matrix material and silane-modified nanomaterial improved the dispersibility and bonding strength of the interface, helping to support the load evenly and enabling effective stress transfer.

• Carbon letters
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• 제13권2호
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• pp.126-129
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• 2012

Nanocomposite films were made by a simple solution casting method in which multi-walled carbon nanotubes (MWCNT) and magnetite nanoparticles ($Fe_3O_4$) were used as dopant materials to enhance the electrical conductivity of chitosan nanocomposite films. The films contained fixed CNT concentrations (5, 8, and 10 wt%) and varying $Fe_3O_4$ content. It was determined that a 1:1 ratio of CNT to $Fe_3O_4$ provided optimal conductivity according to dopant material loading. X-ray diffraction patterns for the nanocomposite films, were determined to investigate their chemical and phase composition, revealed that nanoparticle agglomeration occurred at high $Fe_3O_4$ loadings, which hindered the synergistic effect of the doping materials on the conductivity of the films.

• Tribology and Lubricants
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• 제24권5호
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• pp.269-274
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• 2008

Carbon nanotube composite is considered to be a good candidate material for composite material because of its excellent mechanical property and low density under high temperature as well as good wear and frictional properties. In this study, tribological characteristics of carbon nanotube aluminum composite were evaluated using pin-on-disk wear tester. Spark Plasma Sintering method is more effective than Hot Pressing method in terms of wear and friction. The composite with 1% CNT has the lowest friction and wear characteristic.

• Steel and Composite Structures
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• 제25권6호
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• pp.649-661
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• 2017

This paper is motivated by the lack of studies in the technical literature concerning to the influence of carbon nanotubes (CNTs) waviness and aspect ratio on the vibrational behavior of functionally graded nanocomposite annular sector plates resting on two-parameter elastic foundations. The carbon nanotube-reinforced (CNTR) plate has smooth variation of CNT fraction based on the power-law distribution in the thickness direction, and the material properties are also estimated by the extended rule of mixture. In this study, the classical theory concerning the mechanical efficiency of a matrix embedding finite length fibers has been modified by introducing the tube-to-tube random contact, which explicitly accounts for the progressive reduction of the tubes' effective aspect ratio as the filler content increases. Parametric studies are carried out to highlight the influence of CNTs volume fraction, waviness and aspect ratio, boundary conditions and elastic foundation on vibrational behavior of FG-CNT thick sectorial plates. The study is carried out based on three-dimensional theory of elasticity and in contrary to two-dimensional theories, such as classical, the first- and the higher-order shear deformation plate theories, this approach does not neglect transverse normal deformations. The annular sector plate is assumed to be simply supported in the radial edges while any arbitrary boundary conditions are applied to the other two circular edges including simply supported, clamped and free. For an overall comprehension on 3-D vibration of annular sector plates, some mode shape contour plots are reported in this research work.

• 분석과학
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• 제21권3호
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• pp.229-236
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• 2008

본 연구에서 HCl을 처리하지 않고 혹은 HCl 처리한 표면 처리된 MWCNT 및 TNB를 이용하여 $C/TiO_2$ 복합체를 제조하였다. XRD 결과 값으로부터 모두 시료에 한 가지 결정 구조 즉 anatase형을 존재하고 있음을 알 수 있었다. SEM 사진으로부터 $TiO_2$ 입자와 CNT는 균일하게 분포하고 있음을 알 수 있었다. EDX 결과에서, 모두 시료에 C, O, Al와 Ti 피크를 볼 수 있으며, 특히 시료 CT에 있는 C와 Ti의 함량은 시료 HCT에 있는 것보다 많게 나타났다. 마지막으로, $C/TiO_2$ 복합체는 $TiO_2$보다 더 좋은 광촉매 특성을 가지고 있음을 알 수 있었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 춘계학술대회 논문집
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• pp.97-98
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• 2009

Here, we describe a versatile strategy for precise control of the optoelectrical properties of the single walled carbon nanotube (SWNT)/silane binder hybrid films by noncovalent hybridization. Stable SWNT/silane binder solutions were prepared by direct mixing of high concentration CNT solutions and silane sol solutions. The critical binder content was determined by varying the amount of binder in the SWNT/binder solutions. A binder content of 50 wt% was used to prepare the other SWNT/binder solutions. This study demonstrates how the intermolecular interactions between the SWNTs and the silanes can affect the conductivity of the CNT/binder network films by characterizing the optoelectrical and Raman spectroscopic properties of the SWNT/silane films containing silane binders with various functional groups. The use of the PTMS binder with phenyl groups was found to be most effective in the fabrication of transparent and conductive films on glass substrates. Such a precise control of the optoelectrical properties of SWNT/binder films can be useful to fabricate the high performance conductive thin films, with ramifications for understanding the fundamental intermolecular interaction in carbon materials science.

• Carbon letters
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• 제10권4호
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• pp.320-324
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• 2009

We investigated the effect of diameter and content of carbon nanotubes (CNTs) on the physical properties of styrenebutadiene rubber (SBR)/CNTs nanocomposites. CNTs-reinforced SBR nanocomposites were prepared by the melt mixing process. CNTs with different diameters were synthesized by the chemical vapor deposition method (CVD). In this work, the mechanical property and other physical properties of SBR/CNTS nanocomposites were discussed as a function of the content and diameter of CNTs.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.218-219
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• 2006

To Smoothness of semiconducting materials in power cable, we have investigated those of semiconducting materials showed by changing the content of carbon black and Carbon Nanotube. Then they were produced as sheets after pressing for 20 minutes at $180^[{\circ}C]$ with a pressure of $200[kg/cm^2]$. The content of conductive carbon black and Carbon Nanotube was the variable, and their contents were 20-40[wt%] and 2-6[wt%] respectively. The smoothness was measured by JSM-6400.

• 폴리머
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• 제36권5호
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• pp.579-585
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• 2012

고분자 발포체에 전도성을 부여하기 위하여 고내상 에멀젼 중합법을 활용하여 폴리스티렌/탄소나노튜브 미세기공 발포체를 제조하였다. 본 연구에서는 고내상 에멀젼의 안정성과 중합된 미세기공 발포체의 전기 전도도를 향상시키기 위하여 탄소나노튜브의 개질, 계면활성제의 함량 및 분산 시간에 따른 영향을 고찰하였다. 탄소나노튜브는 분산이 용이하도록, 분산상인 수상에는 산처리 및 계면활성제로 분산하여 사용하였고 연속상인 유상에는 유기 작용기로 표면 개질하여 사용하였다. 탄소나노튜브의 분산성은 제조한 발포체의 전기 전도도 차이로 확인할 수 있었다. 계면활성제로 분산한 미처리 탄소나노튜브를 수상에 첨가한 경우 전기 전도도 향상에는 효과적이었지만 약간 수축된 형상의 발포체가 제조되었다. 유기 개질한 탄소나노튜브를 유상에 첨가한 경우 안정한 발포체를 얻을 수 있었으나 전기 전도도 향상에는 한계가 있었다.