• Korean Journal of Materials Research
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• v.3 no.3
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• pp.292-299
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• 1993

In this paper the effects of the length of carbon fiber on the wear properties of carboni carbon composites were investigated. Carbon/carbon composites were fabricated by the liquid impregnation method using the resol-type phenolic resin as a matrix precursor and PAN-based, non-surface treated carbon fiber as a reinforcement. The measured values of the friction coefficient of carbon/carbon composites against AlSl 304 stainless steel ranged from 0.2 to 0.3 under the operating condition used in this study. The effect of the length of carbon fiber on the friction coefficient of carbon/carbon composites were not found. But, it was realized that the wear rate of carbon/carbon composites tends to increase, as the length of carbon fiber increases.

• Ceramist
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• v.22 no.3
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• pp.316-327
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• 2019

Carbon nitride has drawn broad interdisciplinary attention in diverse fields such as catalyst, energy storage, gas adsorption, biomedical sensing and even imaging. Intensive studies on carbon dioxide (CO₂) capture using carbon nitride materials with various nanostructures have been reported since it is needed to actively remove CO₂ from the atmosphere against climate change. This is mainly due to its tunable structural features, excellent physicochemical properties, and basic surface functionalities based on the presence of a large number of -NH or -NH₂ groups so that the nanostructured carbon nitrides are considered as suitable materials for CO₂ capture for future utilization as well. In this review, we summarize and highlight the recent progress in synthesis strategies of carbon nitride nanomaterials. Their superior CO₂ adsorption capabilities are also discussed with the structural and textural features. An outlook on possible further advances in carbon nitride is also included.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.1
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• pp.10-15
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• 2023

The carbonaceous materials have attracted much attention for utilization of anode materials for lithium-ion batteries. Among them, hollow carbon spheres have great advantages (high specific capacity and good rate capability) to replace currently used graphite anode materials, due to their unique features such as high surface areas, high electrical conductivities, and outstanding chemical and thermal stability. Herein, we have synthesized various sizes of hollow carbon spheres by a facile hardtemplate method and investigated the anode properties for lithium-ion batteries. The obtained hollow carbon spheres have uniform diameters of 350 ~ 600 nm by varying the template condition, and they do not have any cracks after the optimization of the process. Increasing the diameter of hollow carbon spheres decreases their specific capacities, since the larger hollow carbon spheres have more useless spaces inside that could have a disadvantage for lithium storage. The hollow carbon spheres have outstanding rate and cyclic performance, which is originated from the high surface area and high electrical properties of the hollow carbon spheres. Therefore, hollow carbon spheres with smaller diameters are expected to have higher specific capacities, and the noble channel structures through various doping approaches can give the great possibility of high lithium storage properties.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.6 no.4
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• pp.96-100
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• 1997

Tensile properties of carbon fiber reinforce composite laminates with non-woven carbon mat are evaluated in this paper. Composite laminates are made by inserting non-wovon carbon mat between layers, The specimens were cut and polished according to ASTM standard . Longitudinal and Transverse Young's modulus are obtained by tensile test. Young's moduli without non-woven carbon mat are compared with those with non-woven carbon mat. Longitudinal and Transverse tensile strength are also investigated. Experimental results show that the transverse Young's modulus of composite materials with non-woven carbon mat is about 10% higher than that of composite materials without non-woven carbon mat. Longitudinal tensile strength of composite materials with non-woven carbon mat is about 24% higher than that of composite materials without non-woven carbon mat. Transverse tensile strength and torughness also increase by inserting non-woven carbon mat between layers.

• Journal of the Korean Ceramic Society
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• v.40 no.10
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• pp.1021-1026
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• 2003

Resin impregnation of carbon materials was affected by surface of carbon materials. The surface of carbon materials with coupling treatment improved comparability and wettability with resin, and that increased impregnation efficiency and properties of carbon materials. As a results of FT-IR, The silanol was coated on carbon surface with one layer. Coupling treatment of carbon materials increased impregnation efficiency, which improved porosity, mechanical strength, density and friction behavior.

• Korean Journal of Metals and Materials
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• v.49 no.10
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• pp.780-789
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• 2011

The effects of alloyed carbon on the pitting corrosion, the general corrosion, and the passivity behavior of Fe18Cr10Mn0.4NxC (x=0~0.38 wt%) alloys were investigated by various electrochemical methods and XPS analysis. The alloyed carbon increased the general corrosion resistance of the FeCrMnN matrix. Carbon enhanced the corrosion potential, reduced the metal dissolution rate, and accelerated the hydrogen evolution reaction rate in various acidic solutions. In addition, carbon promoted the pitting corrosion resistance of the matrix in a chloride solution. The alloyed carbon in the matrix increased the chromium content in the passive film, and thus the passive film became more protective.

• Composites Research
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• v.29 no.4
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• pp.138-144
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• 2016

Recently, electromagnetic interference (EMI) shielding materials have been extensively developed and significantly considered to protect electronic systems from harmful electromagnetic waves. Although, metal-based materials show high electrical conductivity and EMI shielding effectiveness, they have several challenging problems such as high density and corrosion. Carbon-based materials have been acclaimed as alternative EMI materials due to light weight, high mechanical properties, resistance to corrosion and excellent electrical conductivity. Here, we introduce 1-phase and 2-phase carbon materials as well as 3-phase hybrid carbon materials. The 3-phase hybrid carbon materials composed of metal nanoparticles, carbon nanotubes and graphene can be used as a promising EMI shielding material.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.224-224
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• 2012

For decades, carbon fiber has expanded their application fields from reinforced composites to energy storage and transfer technologies such as electrodes for super-capacitors and lithium ion batteries and gas diffusion layers for proton exchange membrane fuel cell. Especially in fuel cell, water repellency of gas diffusion layer has become very important property for preventing flooding which is induced by condensed water could damage the fuel cell performance. In this work, we fabricated superhydrophobic network of carbon fiber with high aspect ratio hair-like nanostructure by preferential oxygen plasma etching. Superhydrophobic carbon fiber surfaces were achieved by hydrophobic material coating with a siloxane-based hydrocarbon film, which increased the water contact angle from $147^{\circ}$ to $163^{\circ}$ and decreased the contact angle hysteresis from $71^{\circ}$ to below $5^{\circ}$, sufficient to cause droplet roll-off from the surface in millimeter scale water droplet deposition test. Also, we have explored that the condensation behavior (nucleation and growth) of water droplet on the superhydrophobic carbon fiber were significantly retarded due to the high-aspect-ratio nanostructures under super-saturated vapor conditions. It is implied that superhydrophobic carbon fiber can provide a passage for vapor or gas flow in wet environments such as a gas diffusion layer requiring the effective water removal in the operation of proton exchange membrane fuel cell. Moreover, such nanostructuring of carbon-based materials can be extended to carbon fiber, carbon black or carbon films for applications as a cathode in lithium batteries or carbon fiber composites.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.25 no.6
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• pp.290-293
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• 2015

Recently, a lot of interest has been shown in structural maintenance managements of civil infrastructures. Many researchers have been conducted on various maintenance techniques and repair materials. Among other fiber materials the carbon fiber materials are especially focused on maintenance management of Highway Bridges. Extensive work has been done on Carbon Fiber Sheet (CFS). Nevertheless, Carbon Fiber Strand Sheet (CFSS) is a newly developed material, on which limited work has been done until now. Therefore, in this study bonding the CFSS to RC slab specimen and fatigue resistance evaluation has been conducted. The results demonstrated an increase of 25.3 times more reinforcement of RC slab compared to non-reinforced RC slab. Moreover, compared to CFS-bonded RC slab, The CFSS-bonded RC slab showed 1.2 times greater reinforcement.

• Applied Chemistry for Engineering
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• v.20 no.5
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• pp.465-472
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• 2009

The technologies for improving the capacity of hydrogen storage were investigated and the recent data of hydrogen storage by using various porous carbon materials were summarized. As the media of hydrogen storage, activated carbon, carbon nanotube, expanded graphite and activated carbon fiber were mainly investigated. The hydrogen storage in the carbon materials increased with controlled pore size about 0.6~0.7 nm. In case of catalyst, transition metal and their metal oxide were mainly applied on the surface of carbon materials by doping. Activated carbon is relatively cheap because of its production on a large scale. Carbon nanotube has a space inside and outside of tube for hydrogen storage. In case of graphite, the distance between layers can be extended by intercalation of alkali metals providing the space for hydrogen adsorption. Activated carbon fiber has the high specific surface area and micro pore volume which are useful for hydrogen storage. Above consideration of research, porous carbon materials still can be one of the promising materials for reaching the DOE target of hydrogen storage.