• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2003년도 추계학술발표대회 논문집
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• pp.25-28
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• 2003

Carbon nanotubes(CNTs), since their first discovery, have been considered as new promising materials in various fields of applications including field emission displays, memory devices, electrodes, NEMS constituents, hydrogen storages and reinforcements in composites due to their extra-ordinary properties. The carbon nanotube reinforced nanocomposites have attracted attention owing to their outstanding mechanical and electrical properties and are expected to overcome the limit of conventional materials. Various application areas are possible for carbon nanotube reinforced nanocomposites through the functionalization of carbon nanotubes. Carbon nanotube reinforced polymer matrix nanocomposites have been fabricated by liquid phase process including surface functionalization and dispersion of CNTs within organic solvent. In case of carbon nanotube reinforced polymer matrix nanocomposites, the mechanical strength and electrical conducting can be improved by more than an order of magnitude. The carbon nanotube reinforced polymer matrix nanocomposites can be applied to high strength polymers, conductive polymers, optical limiters and EMI materials. In spite of successful development of carbon nanotube reinforced polymer matrix nanocomposites, the researches on carbon nanotube reinforced inorganic matrix nanocomposites show limitations due to a difficulty in homogeneous distribution of carbon nanotubes within inorganic matrix. Therefore, the enhancement of carbon nanotube reinforced inorganic nanocomposites is under investigation to maximize the excellent properties of carbon nanotubes. To overcome the current limitations, novel processes, including intensive milling process, sol-gel process, in-situ process and spark plasma sintering of nanocomposite powders are being investigated. In this presentation, current research status on carbon nanotube reinforced nanocomposites with various matrices are reviewed.

• Advances in nano research
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• 제14권5호
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• pp.443-450
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• 2023

Carbon nanotubes (CNTs) have received increased interest in reinforcing research for polymer matrix composites due to their exceptional mechanical characteristics. Its high surface area/volume ratio and aspect ratio enable polymer-based composites to make the most of its features. This study focuses on the experimental tensile testing and fabrication of carbon nanotube reinforced composite (CNTRC) beams, exploring various micromechanical models. By examining the performance of these models alongside experimental results, the research aims to better understand and optimize the mechanical properties of CNTRC materials. Tensile properties of neat epoxy and 0.3%; 0.4% and 0.5% by CNT reinforced laminated single layer (0°/90°) carbon fiber composite beams were investigated. The composite plates were produced in accordance with ASTM D7264 standard. The tensile test was performed in order to see the mechanical properties of the composite beams. The results showed that the optimum amount of CNT was 0.3% based on the tensile capacity. The capacity was significantly reduced when 0.4% CNT was utilized. Moreover, the experimental results are compared with Finite Element Models using ABAQUS. Hashin Failure Criteria was utilized to predict the tensile capacity. Good conformance was observed between experimental and numerical models. More importantly is that Young' Moduli of the specimens is compared with the prediction Halpin-Tsai and Mixture-Rule. Although Halpin-Tsai can accurately predict the Young's Moduli of the specimens, the accuracy of Mixture-Rule was significantly low.

• Carbon letters
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• 제15권4호
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• pp.255-261
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• 2014

Multi-walled carbon nanotube reinforced epoxy composites were fabricated using shear mixing and sonication. The mechanical, viscoelastic, thermal, and electrical properties of the fabricated specimens were measured and evaluated. From the images and the results of the measurements of tensile strengths, the specimens having 0.6 wt% nanotube content showed better dispersion and higher strength than those of the other specimens. The Young's moduli of the specimens increased as the nanotube filler content was increased in the matrix. As the concentrations of nanotubes filler were increased in the composite specimens, their storage and loss moduli also tended to increase. The specimen having a nanotube filler content of 0.6 wt% showed higher thermal conductivity than that of the other specimens. On the other hand, in the measurement of thermal expansion, specimens having 0.4 and 0.6 wt% filler contents showed a lower value than that of the other specimens. The electrical conductivities also increased with increasing content of nanotube filler. Based on the measured and evaluated properties of the composites, it is believed that the simple and efficient fabrication process used in this study was sufficient to obtain improved properties in the specimens.

• Bulletin of the Korean Chemical Society
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• 제35권2호
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• pp.597-600
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• 2014

In this work, the electromagnetic interference shielding effectiveness (EMI-SE) of carbon nanotube/carbon fiber-reinforced HDPE matrix composites are investigated with various preparation conditions, such as the carbon fiber and carbon nanotube content, the presence of metal additives, as well as mixing speed and time. It was found that the EMI-SE of the composites increased with filler contents and metal additives. These results indicate that the content and length of carbonaceous fillers determine the electric networks in the composites, resulting in the control of the EMI-SE of the composites.

• 한국표면공학회지
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• 제46권5호
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• pp.223-228
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• 2013

In this work, the grow of carbon nanotube (CNT) on carbon fiber was introduced on PAN-based carbon fibers for the enhancement of mechanical interfacial strength of carbon fibers-reinforced composites. The surface properties of carbon fibers were determined by scanning electron microscopy (SEM) and mechanical interfacial properties of the composites were studied by interlaminar shear strength (ILSS). From the results, it was found that the mechanical interfacial properties of CNT-carbon fibers-reinforced composites (CNT-CFRPs) enhanced with decreasing the CNT content. The excessive CNT content can lead the failure due to the interfacial separation between fibers and matrices in this system. In conclusion, the optimum CNT content on carbon fiber surfaces can be a key factor to determine the mechanical interfacial properties of the CNT-CFRPs.

• Advances in nano research
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• 제12권4호
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• pp.353-363
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• 2022

This paper presents an investigation about superharmonic and subharmonic resonances of a carbon nanotube reinforced composite beam subjected to lateral harmonic load with damping effect based on the modified couple stress theory. As reinforcing phase, three different types of single walled carbon nanotubes (CNTs) distribution are considered through the thickness in polymeric matrix. The governing nonlinear dynamic equation is derived based on the von Kármán nonlinearity with using of Hamilton's principle. The Galerkin's decomposition technique is utilized to discretize the governing nonlinear partial differential equation to nonlinear ordinary differential equation and then is solved by using of multiple time scale method. Effects of different patterns of reinforcement, volume fraction, excitation force and the length scale parameter on the frequency-response curves of the carbon nanotube reinforced composite beam are investigated. The results show that volume fraction and the distribution of CNTs play an important role on superharmonic and subharmonic resonances of the carbon nanotube reinforced composite beams.

• Composites Research
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• 제17권6호
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• pp.1-7
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• 2004

입자강화복합재료에 관한 연구는 오래 전부터 수행되어왔다. 최근 활발한 연구가 이루어지고 있는 나노복합재료도 역시 입자강화복합재료의 한 종류라 할 수 있다. 본 연구에서는 섬유강화 복합재료의 모재로서 사용되어질 수 있는 다중벽탄소나노튜브/에폭시 복합재료를 제작하고 그 물성을 고찰하였다. 본 연구에서 정립한 제작 공정을 사용하여 제작 된 다중벽 탄소나노튜브/에폭시 복합재료의 인장 물성을 MWNT의 첨가량에 따라 고찰하였다 0.5wt%의 MWNT를 첨가 하였을 때, 인장강성은 19%, 인장강토에서는 12%의 증가를 보였다. 또한 경화시 발생하는 재응집 현상을 관찰하고, 기계적 물성을 더 높이 항상시키기 위해서는 이 현상을 억제해야 함을 확인하였다.

• Coupled systems mechanics
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• 제6권1호
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• pp.1-15
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• 2017

Despite the exceptional mechanical properties of individual carbon nanotubes (CNTs), the effective properties of CNT-reinforced composites remain below expectations. The composite's microstructure has been identified as a key factor in explaining this discrepancy. In this contribution, a method for generating representative volume elements of aligned CNT sheets is presented. The model captures material characteristics such as random waviness and entanglement of individual nanotubes. Thus it allows studying microstructural effects on the composite's effective properties. Simulations investigating the strengthening effect of the application of a pre-stretch on the CNTs are carried out and found to be in very good agreement with experimental values. They highlight the importance of the nanotube's waviness and entanglement for the mechanical behavior of the composite. The presented representative volume elements are the first to accurately capture the waviness and entanglement of CNT sheets for realistically high volume fractions.

• 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.