• 대한환경공학회지
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• 제27권6호
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• pp.620-625
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• 2005

연속식 흡착장치를 사용하여 활성탄의 세공구조와 아세톤 중기의 흡착특성과의 상관관계를 고찰하였다. 실험에서 비교한 활성탄 중 젠체 세공구조에서 직경 $10{\AA}$ 이하의 세공이 가장 많이 발달한 Takeda의 ACT 활성탄이 가장 긴 파과시간을 가지고 있었다. 평형흡착량은 파과시간에는 비례했지만, BET 비표면적에는 비례한다고 볼 수 없었기 때문에 BET 비표면적 만으로 흡착능을 평가하는 것은 어려웠다. 누적표면적과 평형흡착량과의 상관관계는 $10{\AA}$ 이하에서 가장 컸고, 세공범위가 클수록 감소했다.

• 펄프종이기술
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• 제45권1호
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• pp.35-41
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• 2013

In this study, we investigated the effect of the number of passes through agrinder on the pore characteristics of nanofibrillated cellulose (NFC) mat. The beaten pulp suspension was used to make NFC suspension using a grinder. To evaluate the pore characteristics of a NFC mat, the surface morphology of the dried NFC mat was observed with FE-SEM and the specific surface area was analyzed with BET nitrogen gas adsorption. The structure of NFC mat was changed with the different number of passes and drying methods. The specific surface area of NFC mat increased with the increase in the number of passes. The 20-passed NFC mat had 20 times larger specific surface area ($141m^2/g$) compared to the 0-passed NFC mat. The specific surface area was strongly correlated with the average pore size in NFC mat. The average pore diameter in NFC mat was calculated from the gas sorption isotherms using BJH model. The value was 13 - 15 nm, indicating that the NFC mat had mesoporous structure.

• 약학회지
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• 제29권4호
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• pp.176-182
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• 1985

As a part of the studies on adsorptive properties of Korean halloysite clays, Hadong white clays of premium grade were examined for geometric pore structured by mercury porosimetry and for specific surface areas by nitrogen adsorption according to the BET procedure. Three size fractions of the native clay sample were derived from passage BS #100, #200 and #325 meshes, respectively. Several parameters lhus observed in relation to the pore structures are shown below: 1. The size fraction of BS #100, #200 and #325 show internal pore volumes of 25.3, 30.2 and $35.0m^2g^{-1}$, respectively. 2. In the distribution curves of the cumulative pore volume against pore diameter, it has been shown that the larticle sizes, the steeper the distribution over the larger ranges of pore diameters. The converse is true the smaller particles. 3. Internal pore areas increase with decrease in pore sizes. It follows that the pores having diameters of $\leq$0.1$\mu\textrm{m}$ are responsible for more than 90% of the total pore area. 4. The behaviour of nitrogen adsorption can be best described by BET type IV isotherm. Further, the hysteresis loops of the adsorptiondesorption curves become narrower with decresing particle sizes. 5. The specific surface areas observed for the fractions of BS #100, BS #200 and BS #325 are 34.6, 35.4 and 43.2m $^2g^{-1}$, respectively. and the calcined clay of BS #325 has a specific surface area near $30.4m^2g^{-1}$.

• 공업화학
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• 제9권7호
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• pp.1059-1064
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• 1998

본 연구는 리튬이온 이차전지용 탄소전극을 개발하기 위하여 다양한 종류의 흑연과 MCMB6-28을 대상으로 이루어졌다. 이들의 층간거리는 $3.358{\sim}3.363{\AA}$, BET 비 표면적은 $2.95{\sim}26.15m^2/g$이었다. 이들의 전기화학적 특성은 층간거리가 크고 적절한 크기의 BET 비 표면적을 가질 때 리튬의 삽입과 탈삽입 거동이 우수하였다. 다양한 결정성계 탄소전극 활물질에 도전재로 KJ-Black을 0, 3, 5wt% 첨가하였을 때 도전제의 함량이 많을수록 전극과 전해질의 계면저항은 작아지나 3wt%를 첨가하였을 때 우수한 가역성을 보였다. 정전류 충 방전 시 인가되는 전류밀도를 증가시킴에 따라 탄소부극의 방전용량은 작아졌다.

• Carbon letters
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• 제2권3_4호
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• pp.176-181
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• 2001

A series of activated carbons were prepared from coconut shells and coal-tar pitch binder by physical activation with steam in this study. The effect of variable processes such as activation temperature, activation time and ratio of mixing was investigated for optimizing those preparation parameters. The activation processes were carried out continuously. The nitrogen adsorption isotherms at 77 K on pellet-shaped activated carbons show the same trend of Type I by IUPAC classification. The average pore sizes were about 19-21${\AA}$. The specific surface areas ($S_{BET}$) of pellet typed ACs increased with increasing the activation temperature and time. Specific surface area of AC treated for 90 min at temperature $900^{\circ}C$ was 1082 $m^2/g$. The methylene blue numbers continuously increased with increasing the activation temperature and time. On the other hand, iodine numbers highly increased till activation time of 60 min, but the rate of increase of iodine numbers decreased after that time. This indicates that new micropores were created and the existing micropores turned into mesopores and macropores because of increased reactivity of carbon surface and $H_2O$.

• Carbon letters
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• 제10권4호
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• pp.339-344
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• 2009

Henequen fiber was air-stabilized, carbonized, and steam-activated to obtain high surface area activated henequen fiber (AHF). Thermal behavior of henequen fibers has been studied by TGA. The structural morphology and characteristics were observed by SEM and BET surface area measurement. The yield of AHF from natural henequen was in the range of 20~25 wt%. Mesopores (2~2.5 nm) were developed on the AHF as the activation temperature was raised up to $700^{\circ}C$, and the band of mesopore size distribution moved to 15~30 nm when the activation were carried out at $900^{\circ}C$ for 30 min. The specific surface area and the total pore volume were about $1394\;m^2/g$ and $1.30\;cm^3/g$, respectively at this activation conditions.

• 공업화학
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• 제9권5호
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• pp.729-733
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• 1998

은 침착된 활성탄의 표면 구조와 세공의 크기 분포등에 대하여 연구하였다. 침착물은 내부 표면에는 영향을 주지 않고 외부 표면에만 영향을 주는 것으로 나타났다. 또한 흡착 등온선은 침착되지 않은 활성탄이나 침착된 활성탄 모두 전형적인 BET 분류 type-I 임을 확인하였으며, 침착물 양이 증가할수록 흡착량이 감소하며 window blocking 현상이 나타남을 확인하였다. 침착물 양이 증가할수록 비 표면적 값은 감소하였으며, 미세세공 부피도 감소하였다. 은 침착된 활성탄의 평균 미세세공 반경은 침착물 양과는 무관하게 일정하였다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.64.2-64.2
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• 2010

In order to improve the overall power conversion efficiency in dye-sensitized solar cells (DSSCs), it is very important to secure the sufficient surface area of photocatalytic nanoparticles layer for absorbing dye molecules. It is because increasing the amount of dye absorbed generally results in increasing the amount of light harvesting. In this work, we proposed a new method for increasing the specific surface area of photocatalytic titanium oxide ($TiO_2$) nanoparticles by using an inorganic templating method. Salt-$TiO_2$ composite nanoparticles were synthesized in this approach by spray pyrolyzing both the titanium butoxide and sodium chloride solution. After aqueous removal of salt from salt-$TiO_2$ composite nanoparticles, mesoporous $TiO_2$ nanoparticles with pore size of 2~50 nm were formed and then the specific surface area of resulting porous $TiO_2$ nanoparticle was measured by Brunauer-Emmett-Teller (BET) method. Generally, commercially available P-25 with the average primary size of ~25 nm $TiO_2$ nanoparticles was used as an active layer for dye-sensitized solarcells, and the specific surface area of P-25 was found to be ~50 $m^2/g$. On the other hand, the specific surface area of mesoporous $TiO_2$ nanoparticles prepared in this approach was found to be ~286 $m^2/g$, which is 5 times higher than that of P-25. The increased specific surface area of $TiO_2$ nanoparticles will absorb relatively more dye molecules, which can increase the short curcuit current (Jsc) in DSSCs. The influence of nanoporous structures of $TiO_2$ on the performance of DSSCs will be discussed in terms of the amount of dye molecules absorbed, the fill factor, the short circuit current, and the power conversion efficiency.

• 한국진공학회지
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• 제2권4호
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• pp.491-500
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• 1993

The adsorption of nitrogen (77K) and carbon dioxide(273K) was performed on a series of activated carbon fiber. Theadsorption iotherm of nitrogen was typical type 1 and that of carbon dioxide was convex. As the specific surface area increases, there are linear increases in BET constant C mean pore diameter, the width of pore size distribution, wide micropore volume, total micropore volume, total pore volume and external surface area, however, narrow micropore volume was nealy constant . The total micorpore volume fraction in total pore volume is above 97%.

• Bulletin of the Korean Chemical Society
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• 제32권5호
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• pp.1507-1510
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• 2011

In this study, mercury vapor adsorption behaviors for some kinds of porous materials having various pore structures were investigated. The specific surface area and pore structures were studied by BET and D-R plot methods from $N_2$/77 K adsorption isotherms. It was found that the micropore materials (activated carbons, ACs) showed the highest mercury adsorption capacity. In a comparative study of mesoporous materials (SBA-15 and MCM-41), the adsorption capacity of the SBA-15 was higher than that of MCM-41. From the pore structure analysis, it was found that SBA-15 has a higher micropore fraction compared to MCM-41. This result indicates that the mercury vapor adsorptions can be determined by two factors. The first factor is the specific surface area of the adsorbent, and the second is the micropore fraction when the specific surface areas of the adsorbent are similar.