• Journal of Ceramic Processing Research
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• 제19권6호
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• pp.467-471
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• 2018

Diatomite powder, a naturally occurring porous raw material, was used to make ceramic materials with porosity and high strength. The sintering behavior of the diatomite powder at various sintering temperatures suggests that diatomite monoliths with a high porosity and strength can be prepared at $1100^{\circ}C$. The compressive strength of the sintered diatomite monoliths increased as the sintering temperature increased, and the molding pressure of 2 MPa and the binder of 18.6 wt.% were excellent. When the sintering temperature rises, the diatomite powder is melted, and its pores gradually disappear. SEM images show that strengthening begins with the formation of inter-particle bonds at a low sintering temperature.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2004년도 High Temperature Superconductivity Vol.XIV
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• pp.17-17
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• 2004

• Korean Chemical Engineering Research
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• 제43권1호
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• pp.21-26
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• 2005

초임계 이산화탄소를 이용하여 다공성 고분자 모노리스를 제조하는 실험적 연구를 행하여, 단량체의 종류와 중합반응 조건들이 생성되는 고분자 모노리스의 물성에 미치는 영향을 실험적으로 조사하였다. 중합반응은 반응이 진행되는 동안 반응물의 상변화를 관찰할 수 있도록 사파이어 창을 부착한 고압 반응기 내에서 진행되었으며, 단량체의 농도가 매우 낮은 경우를 제외하고는 반응기 내부형태와 동일한 형상의 건조하고 다공성인 고분자 모노리스를 얻었을 수 있었다. 생성되는 고분자 모노리스의 비 표면적은 반응혼합물 중의 단량체 농도와 중합반응 압력에 따라 증가하였으며, 기계적 강도는 경도 보강제 MMA를 첨가하여 증대시킬 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제23권7호
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• pp.942-952
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• 2013

Monoliths are functional porous materials with a three-dimensional continuous interconnected pore structure in a single piece. A monolith with uniform shape based on poly(${\gamma}$-glutamic acid) (PGA) has been prepared via a thermally induced phase separation technique using a mixture of dimethyl sulfoxide, water, and ethanol as solvent. The morphology of the obtained monolith was observed by scanning electron microscopy and the surface area of the monolith was evaluated by the Brunauer Emmett Teller method. The effects of fabrication parameters such as the concentration and molecular mass of PGA and the solvent composition have been systematically investigated. The PGA monolith was cross-linked with hexamethylene diisocyanate to produce the water-insoluble monolith. The addition of sodium chloride to the phase separation solvent affected the properties of the cross-linked monolith. The swelling ratio of the cross-linked monolith toward aqueous solutions depended on the buffer pH as well as the monolith fabrication condition. Copper(II) ion was efficiently adsorbed on the cross-linked PGA monolith, and the obtained copper-immobilized monolith showed strong antibacterial activity for Escherichia coli. By combination of the characteristic properties of PGA (e.g., high biocompatibility and biodegradability) and the unique features of monoliths (e.g., through-pore structure, large surface area, and high porosity with small pore size), the PGA monolith possesses large potentials for various industrial applications in the biomedical, environmental, analytical, and separation fields.

• 한국응용과학기술학회지
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• 제31권1호
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• pp.83-91
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• 2014

본 연구에서는 졸-겔, 용매치환, 표면개질, 상압건조 공정과 계면활성제에 의한 템플레이팅(templating) 공법 및 소결 공정을 이용하여 실리카 에어로겔 모노리스와 메조포러스 실리카 모노리스를 각각 합성하였다. 제조된 두 종류의 실리카 모노리스는 균열이 없이 비교적 투명하였으며, 매우 높은 기공율(92-94%) 및 비표면적($800-840m^2/g$)과 수 십 nm 수준의 기공 크기를 갖는 것으로 확인되었다. 표면개질을 적용한 실리카 에어로겔 샘플이 스피링백 효과로 인하여 메조포러스 실리카 모노리스에 비해 더욱 미세하고 균질한 나노 기공 구조를 보였을 뿐만 아니라, 그 단열 성능도 더욱 우수한 것으로 나타났다. 본 연구를 통해 합성된 두 종류의 실리카 모노리스를 중간층으로 적용한 복층 창유리의 단열 성능을 측정된 모노리스의 열전도도와 이론식을 근거로 조사한 결과, 기존의 상업적으로 응용되는 공기층 삽입 복층 창유리에 비해 우수한 단열 성능을 보이는 것으로 나타났다.

• 한국재료학회지
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• 제3권3호
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• pp.207-214
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• 1993

$Li_2O-Al_2O_3-SiO_3$계 결정화유리의 저온합성을 위하여 출방원료로서 각 해당 금속 알콕시드를 사용하였다. 알코올을 용매로 충분히 첨가하고, drying control chemical additive로 dimethy1 formamide를 적당량 첨가한 혼합용용액을 과잉의 물로 충분히 가수분해시킨 습윤겔을 저온으로 건고하여 균열이 없는 건조된 monolith겔을 합성하였다. 건조겔로부터 750-$950^{\circ}C$로 10시간 이상 소결하여 저열팽창성을 나타내는 ${\beta}$-eucrypytite(${\beta}$-quartz 고용체), $Li_2O\cdot Al_2O_3\cdot 3SiO_2$및 ${\beta}$-spodumene등의결정상을 석출시켰다.

• The Korean Journal of Ceramics
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• 제6권2호
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• pp.120-123
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• 2000

The geopolymer technique may be a future-oriented technology for saving energies and resources. This technique requires 3 fundamental elements so-called filler, hardener and geopolymer liquor being generally an alkaline silicate solution. Quartz powder, water quenched granulated blast furnace slag and sodium silicate solution prepared from $Na_2O\cdot2SiO_2$were chosen for these three elements. After mixing these starting materials in appropriate proportions, monoliths were prepared by casting at room temperature. Strength tests showed the following results for 28d age speciment: 7.9-12.7 MPa in flexural strength and 20.2-32.8 MPa in compressive strength, depending on geopolymer liquor/solid ratio, P/S and fineness of the quartz powders used.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 봄 학술발표회 논문집
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• pp.386-387
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• 2003

Titania-silica hybrid inorganic materials are interesting subjects and many researchers have been studying.$\^$1-3)/ In general, the titania-silica hybrid materials are used as film and catalyst. Sol-gel method has widely been used as an alternative technology to prepare a wide variety of applications including monoliths, powders, coatings, and fibers.$\^$4-6)/ The typical sol-gel method is hydrolysis and condensation of tetraethyl orthosilicate (TEOS), Si(OCH$_2$CH$_3$)$_4$. (omitted)

• 한국자동차공학회논문집
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• 제10권1호
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• pp.115-124
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• 2002

The optimum design of auto-catalyst needs a good compromise between the pressure drop and flow distribution in the monolith. One of the effective methods to achieve this goal is to use the concept of radially variable cell density. However, there has been no study of evaluating the usefulness of this method on light-off catalyst. We have computationally investigated the effectiveness of variable cell density technique applied to the light-off catalyst using a three-dimensional integrated CFD model. in which transient chemical reacting calculations are involved. Computed results show that variable cell density technique can reduce the accumulated emissions of CO and HC during the early 100sec of FTP cycle by 86.78 and 80.87%, respectively, The effect of air-gap between the monoliths has been also examined. It is found that air-gap has a beneficial effect on reducing pressure drop and cold-start emissions.

• 한국환경과학회지
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• 제13권3호
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• pp.319-325
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• 2004

An experimental study on the preparation of monolithic porous polymers by environmentally friend process in supercritical carbon dioxide has been carried out. Polymerization mixture composed of a cross-linking monomer, initiator and functional co-polymer was charged in the reactor with sapphire window. After the system was purged with a flow of $CO_2$ for 15 min, the reactor was pressurized with liquid $CO_2$ up to 100 bars. The reactor was isolated from and placed back to the system via quick connector for shaking until the mixture had become fully homogeneous. The reactor was then heated and pressurized to the required reaction conditions and left overnight. After cooling and $CO_2$ evacuation, the polymer was removed from the reactor as dry, white, continuous monoliths. The effect of experimental conditions on the physical properties of porous polymer was systematically examined, and it was found that monomer content had a major effect on the physical properties of the polymers.