• Journal of the Korean Vacuum Society
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• v.2 no.4
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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%.

• Journal of the Korea Concrete Institute
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• v.15 no.2
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• pp.345-351
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• 2003

The transport characteristics of deleterious ions such as chlorides depend on the pore structures of concrete and are the major factors in the durability of concrete structures in subjected to chloride attack such as in marine environments. In this paper, the effect of the pore structure on compressive strength and chloride diffusivity of concrete was investigated. Six types of concretes were tested. The pore volume of concrete containing mineral admixtures increased in the range of 3∼30nm due to micro filling effect of hydrates of the mineral admixtures. There was a good correlation between the median pore diameter, the pore volume above 50nm and compressive strength of concrete, but there was not a significant correlation between the total pore volume and compressive strength. The relationship between compressive strength and chloride diffusivity were not well correlated, however, pore volume above 50nm were closely related to the chloride diffusion coefficient.

• Textile Coloration and Finishing
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• v.11 no.6
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• pp.1-6
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• 1999

The porosities of PET fibers were investigated using a nitrogen porosimeter according to oxygen plasma treatment and dyeing with a disperse dye, and they were discussed in terms of the change of internal micro-structure of the PET fiber. The total pore volume, surface area and average pore size of the plasma treated PET fibers increased expectably compared with the untreated sample. The PET fibers treated with oxygen plasma and then dyed with a disperse dye were increased significantly in the surface area and the total pore volume comparing with those of plasma treated only, but decreased in the average pore size. The increase of the surface area, after dyeing, of the plasma treated PET fibers was due to addition of the surface area of the dye itself to that of the PET fiber. The increase of the total pore volume of the plasma treated PET fibers by dyeing, which is the opposite result to the general idea that the pore volume of fibers would be reduced by occupation of dye molecules in the pores, could be explained by the free-volume model. This is that the amorphous region in the fiber expanded by occupation of dye molecules, and the marginal space surrounding dyes was generated as many smaller pores, and the decrease of the average pore size of the dyed sample also could be explained The decrease of the average pore size was caused by the splitting of a larger pore into smaller pores.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.39 no.4
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• pp.7-13
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• 2007

Effects of pulp type, refining and filler type on the pore characteristics and physical properties of paper were investigated. HwBKP, SwBKP and BCTMP are used to study the effect of pulp type in this study. The effects of each filler (PCC, GCC and talc) and the combination of PCC/GCC were also studied. Highest bulk, pore volume and light scattering are obtained from BCTMP and PCC. It was found that the pore size and pore volume are important in light scattering in paper structure. It was found that PCC was the most effective filler for the improvement of the bulk and light scattering because of the increase in pore volume which can scatter light, but the increase of PCC content was not so effective in the improvement of bulk.

• Journal of Environmental Science International
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• v.9 no.4
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• pp.345-349
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• 2000

Activated carbons were prepared from Korean coal by steam activation in this study. The variation of pore structure of the activated carbons were investigated according to different carbonization temperatures. Yield, surface area, pore volume and pore structure of this activated carbon were compared with those of activated carbon prepared without carbonization. The investigated carbonization temperature ranged from 700${\circ}C$ to 1,000${\circ}C$. Carbonization was carried out in nitrogen atmosphere for 70 minutes and activation was performed by steam at 950${\circ}C$ for 210 minutes. Surface area and pore volume of the resulting activated carbons increased with carbonization temperature. Also pore volume increased by 20% compared to the activated carbon without carbonization. Especially, in mesopore region, the activated carbon carbonized at 900${\circ}C$ had more pores by 60% than that of activated carbon carbonized at other temperature.

• Journal of the Korean Society of Tobacco Science
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• v.16 no.2
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• pp.191-197
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• 1994

Relationships between surface structure and adsorption properties of smoke components were investigated in surface-modified and un-modified activated carbon filter cigarettes. Commercially available activated carbon was treated with nitric acid and hydrogen peroxide as oxidant, and their pore volume, surface structure, BET surface area, pore type and size were studied. BET surface area and pore volume were decreased by nitric acid treatment, but median pore diameter was 8.1 $\AA$, which showed better development of pore compared with that of un-modified activated carbon, 6.9 $\AA$. In case of hydrogen peroxide treatment, BET surface area and pore volume were increased. Their pore was found to be a slit type based on V-t plot analysis. Neutralization capacities for bases of different strength (NaHCO3, Na2CO3, NaOEt and NaOH) showed that the majority of the acidic surface groups are of weak acidity. Modification of the activated carbon surface led to a slight change in adsorption properties when analyzing the smoke of triple-filter cigarette with surface-modified activated carbon.

• Particle and aerosol research
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• v.12 no.3
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• pp.65-72
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• 2016

Nanoporous $SiO_2$ particles containing different pore volume and size were prepared from silicic acid by a spray pyrolysis. The pore size, pore volume and particle size could be controlled with varying the precursor concentration, reaction temperature, and amount of organic templates such as Urea and poly ethylene glycol (PEG). The pore size distribution, pore volume and specific surface area of as-prepared particles were analyzed by BET and BJH methods, and the average particle sizes were measured by a laser diffraction method. The nanoporous $SiO_2$ particles ranged $0.6-0.9{\mu}m$ in diameter were successfully synthesized and the average particle size increased as the silicic acid concentration increased. The morphology of nanoporous $SiO_2$ particles was spherical and pores ranged 1 - 40 nm in diameter were measured in the particles. In case of Urea added into silicic acid, it showed no much difference in the morphology, pore size and pore volume at different Urea concentration. On the other hand, when PEG was added, it was clearly observed that pore diameter and pore volume of the particles surface increased with respect to PEG concentration.

• Journal of Powder Materials
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• v.6 no.1
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• pp.81-87
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• 1999

Based on the pore filling theory, the microstructure evolution during liquid-phase sintering has been analyzed in terms of interrelationship between average grain size and relative density. For constant liquid volume fraction, the microsturucture trajectories reduced to a single curve in a grain size(x)-density(y) map, regardless of grain growth constant. The slope of curves in the map was inversely proportional to average pore size, while it increased fapidly with liquid volume fraction. Increase in pore volume fraction retarded the densification considerably, but showed marginal effect on the slope. The activation energy of densification was predicted to be the same as that of grain growth as long as the liquid volume fraction is constant for any temperature range studied. The present analyses on microstricture evolution may demonstrate the usefulness of pore filling theory and provide a guideline for process optimization of liquid-phase sintering.

• Korean Journal of Materials Research
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• v.28 no.1
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• pp.62-67
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• 2018

Active clay, bentonite and zeolite were used as porous materials for humidity controlling ceramic boards. The specific area and the pore volume of active clay were higher than bentonite and zeolite. The flexible strength of the gypsum board decreased with an increasing amount of porous material, and the flexible strength was lowest when active clay with a higher specific surface area than others porous materials was added. The specific surface area and total pore volume of ceramic boards containing porous material were highest at $102.25m^2/g$, $0.142cm^3/g$, respectively, when the active clay was added. In addition, as the amount of added porous materials increased, the specific surface area and total pore volume of the ceramic board increased, but the average pore diameter decreased. The addition of s porous materials with a high specific area and a large pore volume improved the moisture absorptive and desorptive performance of the ceramic board. Therefore, in this experiment, the moisture absorptive and desorptive properties were the best when active clay was added. Furthermore, as the amount of added porous materials increased, the moisture absorptive and desorptive properties improved. When 70 mass% of active clay was added to ${\alpha}$-type gypsum, the hygroscopicity was the highest, about $300g/m^2$, in this experiment.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.711-714
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• 2003

Factors causing deterioration of concrete structures under marine environment are various, especially penetration and diffusion of chloride ion, carbon dioxide, and water through pore effects on the durability of concrete as well as mechanical properties of concrete. Pore of porous materials like concrete can be classified as micro-, meso-, and macro-pore. And pore of cement matrix is classified as pore which occupied by water, air void, and ITZ between cement paste and aggregates. In this study, to verify the relationship between pore of cement matrix and the property of chloride ion diffusivity, the regression analysis is producted. From the result of regression analysis, the average pore diameter more than total pore volume effects on the diffusivity of chloride ion.