• 한국수소및신에너지학회논문집
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• 제33권6호
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• pp.715-722
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• 2022

Pt-Fe/carbon black nanocatalysts were prepared by spontaneous reduction reaction of Platinum(II) acetylacetonate and Iron(II) acetylacetonate in a nucleophilic solvent and they were characterized by scanning electron microscopy (SEM), energy dispersive X-ray analyzer (EDS), thermogravimetric analyzer (TGA), transmission electron microscopy (TEM), Brunauer, Emmett and Teller (BET) surface area analysis and anion exchange membrane (AEM) water electrolysis test station. The distribution of the Pt and Fe nanoparticles on carbon black was observed by TEM, and the loading weight of Pt-Fe nanocatalysts on the carbon black was measured by TGA. Elemental ratio of Fe:Pt was estimated by EDS and it was found that elemental ratio of Pt and Fe was changed in the range of 1:0 to 0:1, and the loading weight of Pt-Fe nanoparticles on the carbon black was 5.95-6.78 wt%. Specific surface area was greatly reduced because Pt-Fe nanocatalysts blocked the pores. I-V characteristics were estimated.

• 한국대기환경학회지
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• 제26권4호
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• pp.392-402
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• 2010

Black carbon (BC) concentrations were measured with an aethalometer (AE-16, 880 nm) at time interval of 5-min at an urban site of Gwangju over a year 2008. 24-hr filter-based integrated measurements of $PM_{2.5}$ particles were also made at the same site during the winter and summer intensive periods to test any optical loading bias in the raw BC data measured by aethalometer. BC concentration was higher in winter than in summer, possibly due to increase in emissions from energy consumption and poor dispersion with reduction of boundary layer in winter. Also temporal cycles of BC indicate that short-term transient spikes were common, occurring primarily during the rush-hour periods. A similar feature was also observed in diurnal concentration cycle of CO, mainly emitted from motor vehicles. When both low wind speed and weather patterns such as mist, haze and etc were combined, high BC concentrations frequently occurred. The amount of optical loading effect described by the "k" factor showed the seasonal variation, ranging from 0.0003 to 0.0036. This implies that optical loading effect is not seen at all times. From the comparison between the filter-based elemental carbon (EC) and aethalometer BC data, it was found that the loading compensated BC values were more reasonable than the raw BC ones reported from the aethalometer.

• 한국정밀공학회지
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• 제23권8호
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• pp.100-107
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• 2006

The objective of this research is to investigate the electromagnetic interference(EMI) shielding characteristics of fiber reinforced composites. We fabricated glass and carbon fiber reinforced composites filled with metal powder and nano carbon black. The measurements of shielding effectiveness(SE) were carried out frequency range 300MHz - 1GHz for commercial purposes such as electric or telecommunication devices. The return loss and loss due to absorption were also measured as a function of frequency in the micro wave(300MHz-1GHz) region. It is observed that the SE of the composites is the frequency dependent, increase with the increases in filler loading. The Mg metal powder filled composite showed higher SE compared to that of carbon black. The Mg metal powder/epoxy composite was shown to exhibit up to 40dB of SE. The results indicates that the composite having higher filler loading can be used for the purpose of EMI shielding as well as for some microwave applications.

• 한국수소및신에너지학회논문집
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• 제32권5호
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• pp.285-292
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• 2021

To study the effect of the mixture ratio of Ni-Pt nanocatalysts on water electrolysis characteristics in anion exchange membrane system, Ni-Pt nanocatalysts were loaded on carbon black by using a spontaneous reduction reaction of acetylacetonate compounds. The loading weight of Ni-Pt nanocatalysts on the carbon black was measured by thermogravimetric analyzer and the elemental ratio of Ni and Pt was estimated by energy dispersive x-ray analyzer. It was found that the loading weight of Ni-Pt nanoparticles was 5.36-5.95 wt%, and the loading weight increased with increasing Pt wt%. As the Ni-Pt loading weight increased, the specific surface area decreased, because Ni-Pt nanoparticles block the pores of carbon black. It was confirmed by BET analysis and dynamic vapor sorption analysis. I-V characteristics were estimated.

• Macromolecular Research
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• 제8권6호
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• pp.268-275
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• 2000

After imposing a large pre-strain, anisotropy increases with increasing residual extension ratio. Gums have very low residual extension ratio and exhibit little anisotropy, while black filled SBR and especially sulfur-cured carbon black filled NR have large set and anisotropy. For carbon black filled rubber, samples subjected to tensile loading in perpendicular to the pre-strain direction have the same stress-strain curves shape as the sample without pre-strain (=isotropic samples), but slightly lower modulus. However, compared to isotropic or perpendicular directional samples to pre-strain direction, samples subjected to tensile loading in parallel to the pre-strain direction show low stress at low deformation, but have high stiffness at high deformation. Normalized anisotropy changes with strain. The normalized anisotropy for various deformations is a linear function of residual extension ratio.

• 전기화학회지
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• 제23권2호
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• pp.47-55
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• 2020

고에너지 밀도의 리튬이온 이차전지를 구성하기 위하여 고로딩 LiCoO₂ 양극을 구성하였으며, 이의 전극설계를 다르게 하며 전기화학적 특성을 비교하였다. 기준로딩을 적용한 전극의 경우 약 2.2 mAh/㎠의 로딩값을 가지도록 하고, 고로딩 전극의 경우 약 4.4 mAh/㎠의 로딩값을 가지도록 전극을 제조하였다. 이때 도전재인 카본블랙의 함량과 전극의 기공도를 다르게 구성하여 전극 내의 전자전도도와 이온전도도가 고로딩 전극의 성능에 주는 영향을 비교하였다. 도전재의 함량이 증가할수록 전기화학적 성능이 향상될 것으로 기대하였으나, 도전재의 함량이 7.5 질량%까지 증가하게 되면 오히려 성능의 저하가 발생하였다. 이는 도전재가 충분히 제공된 경우에는, 동일한 로딩의 전극구성에서 활물질인 LiCoO₂ 구성비의 감소로 인해 전극두께가 증가하기 때문에 이로 인한 분극증가가 원인으로 판단된다. 그리고 전극의 기공도를 증가시키게 되면 이온전달의 경로는 확장될 수 있으나, 입자들 간의 접촉이 저하되고 전극의 두께가 증가하기 때문에 전극 내 전자전달은 불리하게 된다. 따라서, 전극의 압착을 강하게 하여 기공도를 낮출수록 전자전달이 개선되어 전지의 성능이 향상되었다. 고로딩 전극의 제조에 있어서는 전자전달의 경로를 충분히 확보하면서 전극두께를 감소시키는 전극설계가 필요하다.

• Elastomers and Composites
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• 제20권3호
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• pp.189-204
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• 1985

The purpose of this study is to examine the dynamic properties, especially the damping and fatigue properites, of NR vulcanizates and to find out the vulcanizate which can be used as damping materials in industry. The results of this study can be summarized as follows: 1. In the ODR test, the S-2 vulcanizate was the fastest one in terms of having reached to optimum cure times($t_{90}$) and, with the same formula, when 50phr of HAF carbon black loaded, the shortest optimum cure times has shown. 2. The S - 2 vulcanizate was the best than the others in the physical properties. In aging properties, however, the E - 1 vulcanizate appeared to be better than the other vulcanizates. 3. The results of the RDS test for the NR vulcanization system under the condition of 0.1% strain amplitude and 1 Hz frequency showed no connection between Tg and the the nature of the crosslinking system, but 50phr loading of HAF carbon black increased Tg. The damping values of vulcanizates in the elastic region showed a strong relations the damping values and the crosslinking system. The S - 2 vulcanizate with higher crosslink density had lower damping values than other vulcanizates, and furthermore, the SH - 2 vulcanizates with 50phr loading of HAF carbon black increased the damping values. 4. The Goodrich Flexometer test showed that the heat buildup for the gum NR vulcanizates was less than for those which contained 50phr of HAF carbon black. In particular, the fatigue life of the vulcanizate with lower damping values appeared to be longer than that of the vulcanizates with higher damping values. In the fatigue test, the increasment of the loading or the temperature, applied to the vulcanizates, appeared to be shorten their fatigue life.

• 공업화학
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• 제20권6호
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• pp.622-627
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• 2009

알칼리 수용액에 현상이 가능한 감광성 수지재료와 전도성 카본블랙 필러를 이용하여 포토 패터닝이 가능한 폴리머 후막 저항 페이스트를 제조하고 평가하였다. 감광성 수지로는 인쇄회로기판의 보호층으로 주로 사용되는 photo solder resist(PSR)를 사용하여 자외선에 의한 노광 및 알칼리 수용액에의 현상이 가능하게 하였다. 감광성 폴리머 저항 페이스트를 제작한 후, PCB 테스트 보드를 이용하여 후막저항체의 전기적 특성을 평가하였다. 카본블랙의 첨가량에 따라 시트저항은 감소하였으나, 과량 첨가시에는 현상성에 한계를 나타내었다. 재경화에 따라서 시트저항이 감소하였으며, 카본블랙의 첨가량이 많을수록 그 변화율은 작게 나타났다. 포토공정을 적용하여, 미세 패터닝된 meander형 후막저항체를 제조할 수 있었고, 이 방법을 통하여 적은 면적에도 시트저항의 수십 배에 달하는 큰 저항값을 구현할 수 있었다.

• Elastomers and Composites
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• 제38권3호
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• pp.273-280
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• 2003

본 연구에서는 분자량이 다른 순수 천연고무 용융체와 다양한 유형의 카본블랙을 혼합한 배합고무 용융체의 탄성반응을 조사하였다. 또한 카본블랙과 고무 분자와의 상호작용과 이들 탄성반응이 갖는 상관성을 규명키 위해 입자의 크기와 구조가 다른 카본블랙을 대상으로 결합고무를 측정하였다. 카본블랙의 함량이 증가할수록 결합고무는 증가하였고 특히 카본블랙 입자의 크기가 작아 비표면적이 넓고 구조가 발달될수록 증가하였다. 카본블랙을 혼합한 배합고무 용융체의 탄성반응은 순수고무 경우에 비해 크게 향상되었으며 특히 결합고무가 큰 경우에 보다 현저하였다. 순수고무 용융체의 분자량이 증가할수록, 그리고 고무에 혼합된 카본블랙 입자의 크기가 작을수록 응력이완 거동은 지연되었으며 복원거동은 보다 탄성적으로 변하였다. 영구변형 거동에 있어서는 고무 분자량이 감소하고 카본블랙 입자 크기가 증가할수록 그 변형정도가 커졌다.

• Bulletin of the Korean Chemical Society
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• 제31권11호
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• pp.3221-3224
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• 2010

This study investigates the requirements of lithium-air cathodes, which directly influence discharge capacity. The cathodes of Li-air cell are made by using five different carbon materials, such as Ketjen black EC600JD, Super P, Ketjen black EC300JD, Denka black, and Ensaco 250G. The Ketjen black EC600JD provides discharge capacity of 2600 mAh/g per carbon weight, while that of Ensaco 250G shows only 579 mAh/g. To figure out the differences of discharge capacity from carbon materials, their surface area and pore volume are analyzed. These are found out to be the critical factors in determining discharge capacity. Furthermore, carbon loading on Ni foam and amounts of electrolyte are significant factors that affect discharge capacity. In order to investigate catalyst effect, electrolytic manganese dioxide (EMD) is incorporated and delivered 4307 mAh/g per carbon weight. This infers that EMD facilitates to break $O_2$ interactions and leads to enhance discharge capacity.