• Korean Chemical Engineering Research
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• 제62권1호
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• pp.13-18
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• 2024

웨어러블 디바이스용 유연 전극 소재 개발을 위해 탄소섬유 토우(carbon fibers tow)의 전처리에 따른 전기화학적 특성을 조사하고, 이를 활용하여 포도당을 타겟으로 전기화학적 비효소 센서를 제작하였다. 탄소섬유 토우는 탈사이징(desizing)과 활성화(activation) 공정을 통해 전처리 되었으며, 활성화는 화학적 산화와 전기화학적 산화의 두 가지 방법으로 이루어졌다. 전처리된 샘플은 주사전자 현미경(SEM)을 이용하여 표면 분석되었으며, 전기화학적 특성 및 센싱성능 분석은 시간대전류법와 순환전압 전류법, 전기화학 임피던스 분석법을 이용하여 수행되었다. 탄소섬유 토우는 전처리를 통해 감소된 R_et와 ΔE_p, 증가된 I_p 등 향상된 전기화학적 특성을 보였으며, 두 활성화 방법에서는 유사한 전기화학적 특성이 얻어졌다. 본 연구에서는 전기화학센서 적용을 위해 전기화학적으로 활성화된 탄소섬유 토우를 최종 전극 물질로 선정하였다. 이 전극을 기반으로 제작된 비효소적 포도당 검출 센서는 0.09899~3.754 mM과 3.754~50 mM의 선형 구간에서 각각 0.744 mA/mM과 0.330 mA/mM 정도의 향상된 감도를 보였다. 본 연구를 통해 탄소섬유 토우의 전극 소재로서 사용 가능성을 확인했으며, 고성능 유연 전극 소재 개발에 기초 연구로 활용 가능할 것으로 기대된다.

• Carbon letters
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• 제11권1호
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• pp.28-33
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• 2010

In this study, $TiO_2$-Activated carbon (AC) complex fibers were prepared by electrospinning for the synergetic effect of adsorption and degradation of organic pollutant. The average diameter of these fibers increased with increasing the amount of AC added, except for 1AC-TOF (AC$/TiO_2$ =1/40 mass ratio). After calcinations at $500^{\circ}C$, long as-spun fibers were broken and their average diameter was slightly decreased. The resultant fibers after calcination had rough surface and sphere shapes like a peanut. From XRD results, it was confirmed that as-spun fibers were changed to anatase $Ti_O2$ fiber after calcinations at $500^{\circ}C$. The prepared $TiO_2$-AC complex fibers could remove procian blue dyes by solar light irradiation with high removal property of 94~99%. The PB dye was rapidly removed by adsorption during the initial 5 minutes. But after 5 minutes, dye removal was occurred by photodegradation. In this study, the most efficient AC/$TiO_2$ ratio of $TiO_2$-AC complex fibers was 5/40, showing the synergetic effect of adsorption and photodegradation. It is expected that the $TiO_2$-AC complex fibers can be used to remove of organic pollutants in water system.

• 한국재료학회지
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• 제19권10호
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• pp.562-568
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• 2009

Electrospinning is a technique that produces sub-micron sized continuous fibers by electric force from polymer solutions or melts. Due to its versatile manufacturability and the cost effectiveness, this method has been recently adopted for the fabrication of one-dimensional materials. Here, we fabricated polyacrylonitrile (PAN) polymer fibers, from which uniform carbon fibers with diameters of 100-200 nm were obtained after carbonization at 800 $^{\circ}C$ in N$_2$. Special emphasis was directed to the influence of the phase separated polymer solution on the morphology and the microstructure of the resulting carbon fiber. The addition of poly(stylene-co-acrylonitile) (SAN) makes the polymer solution phase separated, which allows for the formation of internal pores by its selective elimination after electrospinning. XPS and Raman Spectroscopy were used to confirm the surface composition and the degree of carbonization. At the PAN:SAN = 50:50 in vol%, the uniform carbon fibers with diameters of 300$\sim$500 nm and surface area of 131.6 m$^2$g$^{-1}$ were obtained.

• Carbon letters
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• 제12권1호
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• pp.16-20
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• 2011

Commercial PAN fibers were thermally stabilized at 220 or $240^{\circ}C$ for 30 min. Those fibers were further stabilized using radio-frequency (RF) capacitive plasma discharge during 5 or 15 min. From Fourier transform infrared spectroscopy results, it was observed that an additional plasma treatment led to further stabilization of PAN fibers. After stabilization, carbonization was performed to investigate the final tensile properties of the fabricated carbon fibers (CFs). The results revealed that a combination of thermal and plasma treatment is a possible stabilization process for manufacturing CFs. Morphology of CFs was investigated using scanning electron microscopy. The morphology shows that the plasma stabilization performed by the RF large gap plasma discharge may damage the surface of the CF, so it is necessary to select a proper process condition to minimize the damage.

• 한국세라믹학회지
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• 제42권7호
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• pp.469-474
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• 2005

Activated Carbon Fibers (ACFs) are widely used as adsorbents in technologies related to pollution abatement due to their highly porous structure and large adsorption capacity. The porous structure and surface area of ACFs depends strongly on both the activation processes arid the nature .of the precursors. The chemical activation with hydroxides has recently been, of great interest as it permits the preparation of activated carbon fibers with highly developed porosity. In this work, OXI-PAN fiber used as precursor for the preparation of activated carbon fibers by chemical activation with KOH and NaOH. The affects of several activation conditions on the surface properties, pore size distribution and adsorption capacity of Ag ion and Iodine ion on ACFs studied.

• Carbon letters
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• 제1권2호
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• pp.82-86
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• 2000

The present research was undertaken to evaluate the possibility of water purification filter with activated carbon fibers (ACFs) using a very low cost precursor consisting of phenolic resin coated on glass fibers. The simplified procedure involving coating, curing and activation and a very low cost glass fiber as a raw material were adopted in order to reduce manufacturing cost. The breakthrough curves of the manufactured ACFs and the commercial activated carbon (AC, Calgon F-200) were investigated in the initial concentration range from 19 to 49 ppm for benzene, toluene and ethylbenzene. From breakthrough profiles, the manufactured ACFs had significantly faster adsorption kinetics than the AC. Especially the benzene breakthrough curves, the manufactured ACF (13 g of ACF with 32% of carbon on the glass) was over the limited level (5 ppb) after flowing of 32 l at initial concentration of 15 ppm, while the commercial AC was shown about 3 ppm in initial adsorption.

• Carbon letters
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• 제5권3호
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• pp.103-107
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• 2004

The atmospheric pressure plasma treatments ($Ar/O_2$ and $Ar/N_2$) of activated carbon fibers (ACFs) were carried out to introduce hydrophilic functional groups on carbon surfaces in order to enhance the hydrogen chloride gas (HCl) adsorption. Surface properties of the ACFs were determined by XPS and SEM. $N_2$/77 K adsorption isotherms were investigated by BET and D-R (Dubinin-Radushkevich) plot methods. The HCl removal efficiency was confirmed by HCl detecting tubes (range:1~40 or 40~1000 ppm). As experimental results, it was found that all plasma-treated ACFs showed the decrease in the pore volume, but the HCl removal efficiency showed higher level than that of the untreated ACFs. This result indicated that the plasma treatments led to the conformation of hydrophilic functional groups on the carbon surfaces, resulting in the increase of the interaction between the ACFs and HCl gas.

• 폴리머
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• 제31권5호
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• pp.436-441
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• 2007

In this work, the multiwalled carbon nanotubes(MWNTs) were functionalized with sodium dodecylbenzene sulfonate(SDBS) and then MWNTs/Lyocell composite fibers were prepared. The properties of MWNTs, the functionlization on the surface of MWNTs and their dispersion in the cellulose matrix were characterized by TEM, SEM, WAXD and FT-IR. The results showed that SDBS has been coated successfully onto the surface of the MWNTs by functionlization. This can improve effectively the dispersion uniformity of MWNTs in NMMO aqueous solution and is helpful to prepare a spinnable spinning dope. Moreover, the resultant MWNTs/Lyocell composite fibers still have cellulose II crystal structure, and their tensile strength and initial modulus increased with the increasing draw ratio and reached the optimal value with adding 1 wt% MWNTs. The thermal stability of the composite fiber was also improved by the addition of the MWNTs.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2001년도 춘계학술발표대회 논문집
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• pp.122-125
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• 2001

The objective of this research is to develop hybridized yarns for thermoplastic composites, and to examine tile effect of cooling rate on mechanical properties of the composites. The co-braided yarn utilizing carbon fibers as reinforcements and Nylon 66 fibers as matrix materials has been fabricated. Thermoplastic composites have been manufactured by the hot-press forming process. For the processing conditions, cooling rates of $-2.5^{\circ}C$/min and $-60^{\circ}C$/min have been considered. Three-point bending test and losipescu shear test were performed to investigate the effect of the cooling rate and the surface treatment of carbon fibers. SEM photographs were used to investigate the fracture surfaces of the tested samples. The cooling rate of $-60^{\circ}C$/min resulted in the higher strength and elastic modulus for bending and shear tests. The composites of the epoxy-sized carbon fibers showed the lowest strength due to the degradation of the sizing material during the thermoforming process.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.445-450
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• 2006

It is proposed that the electromechanical relation of the conductive materials with high electrical resistance may be used to estimate the current stress of prestressing tendons. To choose the best conductive material to this end, we studied the electromechanical relations of carbon fibers and metalic heat wires experimentally. It is found that the relation of carbon fibers can be modelled by a parabolic(or hyperbolic) function in the early stage of deformation. However because the relation is not consistent when it is unloaded and reload, carbon fibers are not suitable for this purpose. Metallic heat wires show a consistent linear relation during loading and unloading in the elastic deformation and are suitable for this purpose. To estimate the electromechanics relation of metallic wires, we developed a simple formula based on the rigid plasticity. We propose a new kind of prestressing tendons whose stress can be monitored.