• KSBB Journal
• /
• v.14 no.1
• /
• pp.109-113
• /
• 1999

Supercritical $CO_2$ chromatography was applied for purification of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from fish oil. Various supercritical $CO_2$ pressures were tested to find out the pressure effects on solubility and selectivity of low fatty acids in the silver nitrate column. The solubility of low fatty acids was increased as the supercntical $CO_2$ Pressure increased. However, the selectiviy between low fatty acids and EPA waw decreased. Stepwise density gradient method was applied to increase the purification efficiency of EPA. Low fatty acids were easily separated at the early elution steps with low $CO_2$ densities. Successive fractions containing 92.1~97.8% of EPA were collected. The average concentration of three purified fractions was 95.6% with the recovery rate of 30%.

• Journal of the Korean Ceramic Society
• /
• v.40 no.12
• /
• pp.1220-1223
• /
• 2003

TiO$_2$ and TiO$_2$-CdS which were expected to be highly activated photocatalysts with semiconductor properties, were prepared using supercritical fluid method. The powders prepared by supercritical fluid were agglomerate foam in 2-3 ${\mu}{\textrm}{m}$ size and the primary particles of 20 nm were arranged in the powders. The powders which were prepared by supercritical fluid method were anatase phase without any heat treatment.

• Korean Journal of Medicinal Crop Science
• /
• v.14 no.3
• /
• pp.168-172
• /
• 2006

Curcuma longa L. of Zingiberaceae family, has been reported to have radical scavenging activity and antiinflammatory effect. On these facts, biological activity and whitening effect were examined to evaluate a bioactivity of the extracts of Curcumma longa L. by extraction conditions as a possible pharmaceutical material. When compared extraction methods, supercritical extraction was the best showing various biological activities and whitening effect. The highest electron donating ability $(89%\;at\;1,000{\mu}g/ml)$ were detected and SOD-like activity was inhibited up to $95%\;at\;500{\mu}g/ml$ in supercritical extraction. To evaluate the whitening effect, tyrosinase inhibitory activity was conducted 89% of tyrosinase inhibitory effect examined at $1,000\;{\mu}g/ml$. From these results, we suggest that the supercritical extracts from Curcuma longa L. is useful for cosmetic ingredients.

• Clean Technology
• /
• v.18 no.2
• /
• pp.155-161
• /
• 2012

The purpose of this study is to remove paraffin wax binder effectively from powder injection molded part using supercritical fluids in powder injection molding process. For a thin powder injection molded part about 1-2 mm thickness, paraffin wax binder can be removed rapidly without any defect by traditional supercritical extraction process which has fixed high temperature and pressure condition. But, for a thick powder injection molded part, there are limitations in removing paraffin wax binder by the fixed high process condition because crack occurs at the beginning step. Therefore, here we studied variable condition debinding process that starts with mild process condition at the beginning step and then increase the process conditions simultaneously at each step. To find out the initial process condition that has the highest extraction yield without any defect for each sample thickness, we investigated various supercritical debinding conditions using 1-4 mm thickness ceramic injection molded sample. By using the variable condition debinding process that starts with the initial process condition at the first step and then increasing process conditions simultaneously at each step (temperature from 333.15 to 343.15 K, pressure from 12 to 27 MPa, and $CO_2$ flow rate from 1.5 to 10 L/min), over 95% of paraffin wax binder was removed from the 4 mm thick (10 mm diameter) ceramic injection molded disk samples within 5 hours.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.35 no.10
• /
• pp.1439-1443
• /
• 2006

This study was performed on the effects of extraction temperature, pressure, time on apparent solubility and extraction yield of perilla oil and tocopherol, and color and fatty acid composition of the residue in supercritical carbon dioxide $(SC-CO_2)$ extraction. Apparent solubility of perilla oil and tocopherol increased with the increase of $CO_2$ density and was found to strongly depend on extraction pressure rather than extraction temperature. The extract yield of tocopherol in $SC-CO_2$ extraction increased with an increase of temperature and decreased with an increase of pressure and extraction time. The perilla oil apparent solubility of dried perilla powder for $60\sim180$ min at $40^{\circ}C/276$ bar increased with an extraction time, on the other hands, tocopherol apparent solubility decreased. As the increase of $CO_2$ density, less redness and yellowness increased. Fatty acid composition of perilla oil showed that perilla oil extracted by $SC-CO_2$ had better unsaturated fatty acid and decreased in saturated fatty acid. $SC-CO_2$ extraction offers a safe natural method for gaining perilla oil from dried perilla seeds powder.

• Journal of the Korean Applied Science and Technology
• /
• v.31 no.3
• /
• pp.486-491
• /
• 2014

We have been fabricated Thin-walled carbon nanotubes (TWNTs)/amine epoxy additives composite using Eco-friendly solvent system such as supercritical process and dry mixed process. TWNTs/amine epoxy additives composite has used as a curing agent for urethane based bisphenol A type epoxy resin. The thermo-mechanical property of the epoxy resin cured by TWNTs/amine epoxy additives composite is characterized by dynamic mechanical analysis(DMA) and dispersability of the nanotubes in the epoxy matrix is also confirmed by scanning electron microscope(SEM). As a results, the epoxy resin cured by TWNTs/amine epoxy additives composite with supercritical process shows enhanced dispersability of the TWNTs in the matrix and thermo-mechanical property when compare to dry mixed process.

• 에너지협의회보
• /
• s.30
• /
• pp.32-33
• /
• 1994

• Bulletin of Food Technology
• /
• v.8 no.3
• /
• pp.37-44
• /
• 1995

• Fiber Technology and Industry
• /
• v.5 no.3_4
• /
• pp.185-193
• /
• 2001

• Ceramist
• /
• v.16 no.4
• /
• pp.67-75
• /
• 2013