• Bulletin of the Korean Chemical Society
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• 제35권8호
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• pp.2533-2536
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• 2014

• 센서학회지
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• 제22권3호
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• pp.181-184
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• 2013

Highly ordered porous materials having mesopores in the walls of macropores showed improved adsorption dynamics results for VOC molecules, especially bulky molecules. These meso/macroporous mataerials were synthesized by the dual templating method, and mesopore and macropore size were controlled by adjusting the templates for each pore size regime. In the case of adsorption and desorption of small VOC molecules (toluene), although meso/macroporous MCM-41 with smaller mesopore size showed improved results, meso/macroporous SBA-15 with larger mesopore size was not improved regardless of the existence of macropores, since there was no limitation of movement through the larger mesopore. However, the adsorption dynamics of bulky VOC molecules (p-xylene) over meso/macroporous SBA-15 were drastically improved by increasing the macropore size.

• 한국전기전자재료학회논문지
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• 제30권2호
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• pp.67-73
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• 2017

Recently, macroporous ceramic materials with high electrical conductivity and mechanical strength are urgently needed for semiconductor and display manufacturing devices. In this work, we obtained electro-conducting macroporous aluminosilicate ceramics having surface resistivity of 108~1,010 ohm by dispersing electro-conducting carbon in ceramic matrix. By addition of 0.5~3.0 wt% frit glass, chemical bonding between grains was strengthened, and flexural strength was enhanced up to 160 MPa as a result. We evaluated the characteristics of present ceramics as vacuum chuck module for liquid crystal display display manufacturing devices.

• Bulletin of the Korean Chemical Society
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• 제31권12호
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• pp.3593-3599
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• 2010

In an original effort, this lab attempted to employ polystyrene nanoparticles as a template for the synthesis of ordered and highly porous macroporous $SiO_2$ thin films, utilizing their high combustion temperature and narrow size distribution. However, polystyrene nanoparticle thin films were not obtained due to the low interaction between individual particles and between the particle and silicon substrate. However, polystyrene-polyacrylic acid (PS-AA) colloidal particles of a core-shell structure were synthesized by a one-pot miniemulsion polymerization approach, with hydrophilic polyacrylic acid tails on the particle surface that improved interaction between individual particles and between the particle and silicon substrate. The PS-AA thin films were spin-coated in the thickness ranges from monolayer to approximately $1.0\;{\mu}m$. Using the PS-AA thin films as sacrificial templates, macroporous $SiO_2$ thin films were successfully synthesized by vapor deposition or conventional solution sol-gel infiltration methods. Inspection with field emission scanning electron microscopy (FE-SEM) showed that the macroporous $SiO_2$ thin films consist of interconnected air balls (~100 nm). Typical macroporous $SiO_2$ thin films showed ultralow refractive indices ranging from 1.098 to 1.138 at 633 nm, according to the infiltration conditions, which were confirmed by spectroscopy ellipsometry (SE) measurements. This research shows how the synthetic control of the macromolecule such as hydrophilic polystyrene nanopaticles and silicate sol precursors innovates the optical properties and processabilities for actual applications.

• 한국분말재료학회지
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• 제25권3호
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• pp.203-207
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• 2018

Plastic pollution is threatening human health and ecosystems, resulting in one of the biggest challenges that humanity has ever faced. Therefore, this study focuses on the preparation of macroporous carbon from biowaste (MC)-supported manganese oxide ($MnO_2$) as an efficient, reusable, and robust catalyst for the recycling of poly(ethylene terephthalate) (PET) waste. As-prepared $MnO_2/MC$ composites have a hierarchical pore network and a large surface area ($376.16m^2/g$) with a narrow size distribution. $MnO_2/MC$ shows a maximum yield (98%) of bis(2-hydroxyethyl)terephthalate (BHET) after glycolysis reaction for 120 min. Furthermore, $MnO_2/MC$ can be reused at least nine times with a negligible decrease in BHET yield. Based on this remarkable catalytic performance, we expect that $MnO_2$-based heterogeneous catalysts have the potential to be introduced into the PET recycling industry.

• Carbon letters
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• 제13권2호
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• pp.94-98
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• 2012

Herein, macroporous carbon foams were successfully prepared with phenol and formaldehyde as carbon precursors and an ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate ($BMIPF_6$), as a pore generator by employing a polymerization-induced phase separation method. During the polycondensation reaction of phenol and formaldehyde, $BMIPF_6$ forms a clustered structure which in turn yields macropores upon carbonization. The morphology, pore structure, electrical conductivity of carbon foams were investigated in terms of the amount of the ionic liquid. The as-prepared macroporous carbon foams had around 100-150 ${\mu}m$-sized pores. More importantly, the electrical conductivity of the carbon foams was linearly improved by the addition of $BMIPF_6$. To the best of the author's knowledge, this is the first result reporting the possibility of the use of an ionic liquid to prepare porous carbon materials.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 D
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• pp.1558-1560
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• 1998

Macroporous silicon diaphragms 20 to $200{\mu}m$ thick have been formed on p-type silicon by anistropic etching in TMAH solution and then by electrochemical etching in HF-ethanol-water solution with an applied current. The pores have a pore diameter of $1.5{\sim}2{\mu}m$, with a depth of $20{\sim}30{\mu}m$ and are not interconnected, which are in sharp contrast to the porous silicon reported previouly for similarly doped p-Si. The fabrication of macroporous silicon and free-standing diaphragms is expected to offer new applications for microsensors, micro-machining, and separators.

• Bulletin of the Korean Chemical Society
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• 제34권5호
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• pp.1388-1390
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• 2013

Macroporous $SnO_2$ foam was successfully synthesized via a simple soft-chemical route by hybridization between alkylamine and tin(IV) oxide. According to X-ray diffraction (XRD) analysis, the as-prepared $SnO_2$ foam had a highly ordered lamella structure along the crystallographic c-axis, which transformed to a rutile phase after thermal treatment at $300^{\circ}C$. X-ray absorption spectroscopy (XAS) at the Sn K-edge revealed that $SnO_2$ particles in the hybrid material maintained their nanosized structure after hybridization with alkylamine. Scanning electron microscope (SEM) images clearly showed that the as-prepared $SnO_2$ foam had a macroporous structure. This synthetic route can be extended to the development of open frameworks with good electrochemical properties in battery applications.

• Bulletin of the Korean Chemical Society
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• 제31권8호
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• pp.2395-2398
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• 2010

• 한국토양비료학회지
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• 제42권4호
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• pp.239-248
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• 2009

본 실험은 지하수에 포함된 중금속을 제거하기 위한 투수성반응벽체를 개발하기 위하여 대공극 형성물질로 분쇄한 폐지와 식물섬유를 그리고 구조형성소재로 Na와 Ca-벤토나이트를 사용하여 소성 후 소성된 소재의 표면 구조와 공극발달 특성을 조사하였다. 그러나 소성은 중금속 제거율을 급격히 감소시키는 양이온교환용량에 영향을 미치므로 2:1 점토광물 중에서 양이온교환용량이 큰 점토광물과 일반 산업물질을 소재를 선정하였다. 연구 결과는 살펴보면 소성온도가 증가함에 따라 소성에 사용된 소재의 기존 CEC의 10 % 이하로 급격히 감소되는 경향을 보여주었다. 일축 압축 시험 결과 처리간 용적밀도는 큰 차이가 없었지만 Na와 Ca-벤토나이트를 소성소재 모두 폐지가 5 % 정도 처리하였을 때 압축강도가 가장 높은 것으로 나타났다. 그리고 소성온도와 기간 모두 공극 형성에 영향을 미친 것으로 조사되었다. 이러한 연구 결과로부터 다공체 내에 형성된 공극은 수분 투수 특성과 중금속 제거에 모두 영향을 미칠 것이라 추정하였다.