• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2000년도 춘계학술발표대회 논문집
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• pp.26-30
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• 2000

• Carbon letters
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• 제3권2호
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• pp.80-84
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• 2002

The surface treatment of C-type isotropic pitch-based carbon fiber was carried out by anodic oxidation in 5 wt% $NH_4NO_3$ electrolyte. The changes of fiber surface and carbon fiber/ABS resin composites were characterized by SEM, XPS and mechanical properties test. The oxygen functional groups on the surface, such as hydroxyl (-C-OH), carboxyl (-COOH) groups etc., increased after oxidation. Tensile strength, flexural strength and modulus of carbon fiber/ABS composites were also enhanced. However, the impact strength decreased with the improvement of the surface adhesion between CF and matrix.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2003년도 춘계학술발표대회 논문집
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• pp.50-52
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• 2003

본 연구에서는 비교계측법을 이용하여 탄소/페놀릭 주자직 복합재료에 대한 열전도도를 계측하였다.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2000년도 춘계학술발표대회 논문집
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• pp.43-48
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• 2000

Composite materials have been increasingly used in automotive and aircraft industries, naturally leading to active researches on the materials. The carbon-epoxy composite is selected to study its thermal characteristics. During multiple thermal cycles composed of repeated cooling and heating variations of elastic constants are investigated to understand thermal effects on the carbon-epoxy composite. In this investigation longitudinal resonance method and flexural resonance method was used to characterize. The values of $E_1$ show small amount of increases depending on number of cycles of the thermal fatigue processes whereas values of $G_13$ do not indicate noticeable changes. Also, in cases of $E_2$ and $G_23$ their values decrease to a certain extend in initial stages after applications of thermal fatigue processes. However, the number of cycles of the applied thermal fatigue processes does not seem to affect their values.

• Advances in nano research
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• 제2권4호
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• pp.199-210
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• 2014

Carbon nanotubes have exceptional mechanical, thermal and electrical properties, and are considered for high performance structural and multifunctional composites. In the present study, the natural frequencies of aligned single walled carbon nanotube (CNT) reinforced composite beams are obtained using shear deformable composite beam theories. The Ritz method with algebraic polynomial displacement functions is used to solve the free vibration problem of composite beams. The Mori-Tanaka method is applied to find the composite beam mechanical properties. The continuity conditions are satisfied among the layers by modifying the displacement field. Results are found for different CNT diameters, length to thickness ratio of the composite beam and different boundary conditions. It is found that the use of smaller CNT diameter in the reinforcement element gives higher fundamental frequency for the composite beam.

• 마이크로전자및패키징학회지
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• 제28권4호
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• pp.73-77
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• 2021

신체 착용 및 부착이 가능한 웨어러블 기기용 유연 전극은 외력에 대한 기계적/전기적 내구성을 확보하고 동시에, 다양한 기능성을 부여하는 방향으로 연구가 활발히 진행되고 있다. 본 연구는 Carbon black를 전도성 필러로 적용하여 Carbon/PDMS 기반 유연 복합체를 제조하고 carbon black의 함량에 따른 복합체의 유연전극, 온도 센서 및 히터용 소재로서의 적용 가능성에 대해 고찰해 보았다. Carbon black의 함량 증가에 따른 비저항 감소를 관찰하였고, 반복인장에 따른 전기저항 변화율 실험을 통해 유연전극으로서의 적용 가능성을 확인하였다. 온도 변화에 따른 carbon/PDMS 복합체의 전기적 특성 평가를 통해 온도센서로서 적용이 가능한 정온도계수 특성을 관찰하였고, carbon black 함량에 따라 정온도계수 특성 조절이 가능함을 확인할 수 있었다. 전압 인가에 따른 Carbon/PDMS 복합체의 발열 특성 관찰을 통해 히터용 소재로서의 적용가능성 역시 확인할 수 있었다.

• Carbon letters
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• 제22권
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• pp.25-35
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• 2017

The aim of the work was to investigate the thermo-electrical properties of low cost and rapidly produced randomly oriented carbon/carbon (C/C) composite. The composite body was fabricated by combining the high-pressure hot-pressing (HP) method with the low-pressure impregnation thermosetting carbonization (ITC) method. After the ITC method step selected samples were graphitized at $3000^{\circ}C$. Detailed characterization of the samples' physical properties and thermal properties, including thermal diffusivity, thermal conductivity, specific heat and coefficient of thermal expansion, was carried out. Additionally, direct current (DC) electrical conductivity in both the in-plane and through-plane directions was evaluated. The results indicated that after graphitization the specimens had excellent carbon purity (99.9 %) as compared to that after carbonization (98.1). The results further showed an increasing trend in thermal conductivity with temperature for the carbonized samples and a decreasing trend in thermal conductivity with temperature for graphitized samples. The influence of the thickness of the test specimen on the thermal conductivity was found to be negligible. Further, all of the specimens after graphitization displayed an enormous increase in electrical conductivity (from 190 to 565 and 595 to 1180 S/cm in the through-plane and in-plane directions, respectively).

• Carbon letters
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• 제16권3호
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• pp.203-210
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• 2015

This study fabricated low thermal conductive polyacrylonitrile (PAN)-based carbon fibers containing cellulose particles while maintaining their mechanical properties. The high thermal conductivity of carbon fibers limits their application as a high temperature insulator in various systems such as an insulator for propulsion parts in aerospace or missile systems. By controlling process parameters such as the heat treatment temperature of the cellulose particles and the amount of cellulose added, the thermal and mechanical properties of the PAN-based carbon fibers were investigated. The results show that it is possible to manufacture composite carbon fibers with low thermal conductivity. That is, thermal conductivities were reduced by the cellulose particles in the PAN based carbon fibers while at the same time, the tensile strength loss was minimized, and the tensile modulus increased.

• 한국재료학회지
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• 제20권2호
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• pp.104-110
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• 2010

The characteristics of all polymer composites containing carbon materials are determined by four factors: component properties, composition, structure and interfacial interactions. The most important filler characteristics are particle size, size distribution, specific surface area and particle shape. As a consequence, in this paper we discuss the aspects of the mechanical, electrical and thermal properties of composites with different fillers of carbon black, carbon nanotube (CNT), graphene and graphite and focus on the relationship between factors and properties, as mentioned above. Accordingly, we fabricate rubber composites that contain various carbon materials in carbon black-based and silica based-SBR matrixes with dual phase fillers and use scanning electron microscopy, Raman spectroscopy, a rhometer, an Instron tensile machine, and a thermal conductivity analyzer to evaluate composites' mechanical, fatigue, thermal, and electronic properties. In mechanical properties, hardness and 300%-modulus of graphene-composite are sharply increased in all cases due to the larger specific surface. Also, it has been found that the thermal conductivity of the CNT-composite is higher than that of any of the other composites and that the composite with graphene has the best electrical properties.

• Composites Research
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• 제32권3호
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• pp.127-133
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• 2019

탄소나노튜브는 이론적인 기계적, 전기적 물성이 우수함에도 불구하고 아직까지 그 수준에 도달하고 있지 않다. 특히나 인장 강도는 10% 미만의 수준 정도에 그치고 있어 이를 보안하기 위한 연구가 활발히 진행되고 있다. 기계적 강도를 향상하기 위한 방법으로는 긴 탄소나노튜브의 합성, 배향 외에 화학적 가교, 수소결합, 고분자 함침 등의 방법이 연구되고 있다. 본 총설 논문에서는 탄소소재의 전구체인 폴리아크릴로니트릴(PAN), 폴리도파민(PDA)을 탄소나노튜브 섬유에 코팅 또는 함침하여 탄화 공정을 거쳐 고강도 고전도성 탄소나노튜브 섬유/탄소 복합소재를 제조하는 연구를 소개하고자 한다.