• Applied Chemistry for Engineering
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• v.25 no.2
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• pp.193-197
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• 2014

The electrode for gas sensor was prepared by using pitch-based activated carbon fibers and polyvinyl alcohol (PVA) to investigate the toxic gas sensing characteristics. The physicochemical properties of activated carbon fibers electrode for gas sensor were analyzed with SEM and BET. Toxic gases sensing property of the electrode was also identified by different toxic gases such as $NH_3$, NO and $CO_2$. The specific surface area of activated carbon fibers electrode for gas sensor was decreased by 33% owing to PVA used as a binder compared with the activated carbon fibers. However, its pore size distribution of the ACF electrode was not greatly influenced by PVA. The activated carbon fibers electrode for gas sensor responded to toxic gases by electron hopping unlike semiconductor based gas sensors. In this study, activated carbon fibers electrode was decreased to 7.5% in resistance for the NH3 gas of the 100 ppm concentration and its $NH_3$ gas sensing property was confirmed the most excellent compared with other toxic gases.

• Composites Research
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• v.29 no.5
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• pp.256-261
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• 2016

In this work, we have prepared the filter papers with the pitch-based activated carbon fibers and the binder fibers using wet-laid process. The influence of the binder fiber on the porosity of the filter papers has been investigated by using nitrogen adsorption isotherms at 77 K and a scanning electron microscope (SEM). As a result, the specific surface area has increased with an decrease in the content of binder fiber. It has been shown that the optimum ratio of pitch-based activated carbon fibers and the binder fibers is 70:30, resulting in high porosity, excellent bonding strength, large specific surface area ($650.4m^2/g$) and high noxious gas removal efficiency (86.9%). In addition, it has been observed that the mean pore size distribution of the fiber papers has not been affected by the binder fiber.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10b
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• pp.134-137
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• 2003

탄소섬유나 활성탄소섬유(activated carbon fiber, ACF)는 일반적으로 출발물질에 따라 polyacrylonitrile(PAN)계, 아크릴(acryl)계, 피치(pitch)계, 페놀(phenol)계 등으로 분류할 수 있다. 보통 습식, 용융 혹은 용융분사(melt-blown) 방사 방법에 의해 섬유 형태로 형성한 다음 산화성 가스 분위기에서 불융화 과정을 거쳐 열에 대한 안정성을 부여하여 불활성 분위기에서 탄소화하여 탄소섬유를 제조하거나, 수증기나 이산화 탄소와 같은 산화성 분위기에서 활성화하여 활성탄소섬유를 제조한다. (중략)

• Korean Journal of Materials Research
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• v.8 no.2
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• pp.114-119
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• 1998

등방성 피치계 탄소섬유를 Co$_{2}$gas중에서 등온산화시켜 활성탄소섬유를 제조하였다. 산화된 섬유의 비표면적은 BET장치를 이용하여 측정하였다. Burn-off가 증가하여도 반응속도는 크게 감소하지 않았으며, 80$0^{\circ}C$와 90$0^{\circ}C$에서 산화된 섬유의 비표면적은 40%-60%의 burn-off에서 급격히 증가하다가 60%이상에서 감소하였다. 110$0^{\circ}C$에서 산화된 시편은 40%이상 burn-off되어도 비표면적은 크게 증가하지 않고 60%를 지나서도 계속해서 표면적이 증가하는 현상을 나타내었다. 100$0^{\circ}C$에서 60.4%의 burn-off가 일어난 산화섬유의 비표면적은 3,614$m^2$/g로 가장 큰 값이 얻어졌다. 등방성 탄소섬유는 미세한 흑연결정립들이 무질서한 배향을 하고 있으며, 미세기공벽으로 작용할 수 있는 결정립층이 많기 때문에 활성탄소섬유 제조를 위한 원료로 적합하다고 판단된다.

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.95-97
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• 2003

전기방사는 submicron 이하 크기의 섬유를 부직포형태인 3차원으로 적층된 웹상으로 얻을 수 있는 방법으로 최근 많은 연구가 되고 있다[1-3]. 전통적인 방사방법인 용융방사와 melt blown 방사 방법으로 제조되는 피치계 탄소섬유는 우수한 방사성을 갖는 프리커서 피치를 이용해야 하고 이러한 방법으로 제조되는 탄소섬유나 활성탄소 섬유는 주로 직경 10-15 um 내외의 것이 대부분이어서 상대적으로 직경이 크기 때문에 굽힘 강도가 낮아 압축가공이 취약하다. (중략)

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.240-240
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• 2003

탄소재료의 가스화속도는 근본적으로 활성자리의 수와 관련되어 있으며, 또한 가스화속도는 활성자리 뿐 아니라 확산제한에 따라 달라진다. 대부분의 탄소재료의 활성화 초기단계는 제한된 활성자리 때문에 반응속도는 느리고, 다음 단계는 총 활성자리가 증가하여 반응속도는 급격히 증가하고, 마지막으로 활성자리가 감소하여 활성화 속도는 감소한다. 이러한 sigmoidal특성을 나타내는 활성화 단계를 기공발달과정으로 설명하면, 활성화 초기에 탄소재료 내부에 이미 존재하는 닫힌 기공이 열리고, 일단 기공이 열리면 성장하게 된다. 이렇게 기공 수가 증가하는 것 뿐 아니라 기공 직경이 증가하여 활성화 과정이 진행될수록 비 표면적 및 기공부피는 증가하는데 이런 일련의 과정을 통하여 활성자리 수는 증가하고 또는 감소한다. 이렇게 기공이 발달하는 과정은 각각의 활성화 단계에서 탄소재료의 비 표면적 측정으로 알 수 있으며, 전반적인 산화속도 변화를 측정하여 반응단계를 추정하게 된다. 대부분의 연구자들은 반응 전체의 평균 산화속도를 측정한 후 활성화 에너지를 구하여 반응조절단계로 활성화 기구를 설명한다. 이 연구에서는 활성화 과정 중에 발생하는 중량감소 단계, 즉 각각의 활성화 단계에 따라 달라지는 반응속도상수를 측정하고, 반응단계별 활성화 에너지를 비교 해석하여 피치계 탄소섬유의 기공발달에 영향을 미치는 활성화 기구를 고찰하고자 하였다.

• 한국전기화학회:학술대회논문집
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• 2005.04a
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• pp.9-9
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• 2005

• Korean Chemical Engineering Research
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• v.46 no.5
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• pp.863-867
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• 2008

Pitch based activated carbon fiber(ACF) was prepared from reformed naphtha cracking bottom oil(NCB oil) by melt spinning. The fibers obtained were stabilized, carbonized, and then steam activated. The ACF was sensitized with Pd-Sn catalytic nuclei via a single-step activation approach. This sensitized ACF was used as precursors for obtaining copper plated ACFs via electroless plating. ACFs uniformly decorated with metal particles were obtained with reduced copper plating in the reaction solution. Effects of the amount of copper on characteristics of ACF/Cu catalysts were investigated through BET surface area, X-ray diffraction, scanning emission microscopy, and ICP. The amount of copper increased with plating time, but the surface area as well as the pore volume decreased. NO conversion increased with reaction temperature. NO conversion decreased with increasing the amount of copper, which is seemed to be due to the reduction of surface area as well as the dispersion of copper.

• Applied Chemistry for Engineering
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• v.26 no.5
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• pp.598-603
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• 2015

In this study, electrochemical properties of pitch-based activated carbon fibers (ACFs) were investigated by different heat-treatment temperature of the pitch-based ACFs in order to improve the specific capacitance of electric double-layer capacitor (EDLC). The ACFs were prepared by different heat-treatment temperatures of 1050 and $1450^{\circ}C$, after activation with 4 M KOH at $800^{\circ}C$ using stabilized pitch fiber. The specific surface area of prepared ACFs increased from $828m^2/g$ to $987m^2/g$, also the micropore and mesopore volumes of prepared ACFs were increased. These results because pore was produced by desorbing oxygen and hydrogen elements within the ACFs, and pore size was increased by contraction ACFs by heat-treatment process. Because of the porous properties, the specific capacitance was increased from 73 F/g to 119 F/g using cyclic voltammetry with 1 M $H_2SO_4$ at scan rates of 5 mV/s.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.6_3
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• pp.1333-1339
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• 2023

To produce activated carbon fibers, the process is carried out through either physical activation method or chemical activation method. In this study, we present the results regarding the characteristics of activated carbon fibers manufactured under various conditions through the quantitative control of steam. The yield after activation indicates a decreasing trend with the increase in steam quantity and activation time. Additionally, specific surface area characteristics exhibit variations based on activation time and steam flow rate. The SEM analysis results reveal that higher steam flow rates lead to the presence of both mesopores and macropores on the surface of activated carbon fibers (ACF).