• Bulletin of the Korean Chemical Society
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• v.34 no.2
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• pp.379-383
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• 2013

For the production of ethanol from freshwater cyanobacteria, a new pretreatment method using supercritical fluid was introduced. In this study, it was found that the supercritical fluid could penetrate inside the cell wall and help to liberate starch from cyanobacterial cells which resulted in the increase of the efficiency of ethanol production. For Microcystis aeruginosa, supercritical fluid pretreatment increased the amount of ethanol produced from cyanobacteria from 1.53 g/L to 2.66 g/L. For Anabaena variabilis, the amount of ethanol was increased from 1.25 g/L to 2.28 g/L. With use of supercritical fluid pretreatment, the efficiency of the process to obtain higher ethanol yields from freshwater cyanobacteria was improved upto 80%. The optimum temperature and pressure conditions for supercritical fluid pretreatment were determined as the temperature of $40^{\circ}C$ and the pressure of 120 atm. This study demonstrates the feasibility of using supercritical fluid pretreatment for ethanol production using freshwater cyanobacteria.

• Textile Coloration and Finishing
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• v.32 no.2
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• pp.80-88
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• 2020

Supercritical fluid dyeing is a new alternative to the conventional aqueous process because of its environmental benefits. In this study, dyeing properties of Nylon 6 fabrics were investigated depending on dyeing temperature and pressure in supercritical CO₂ fluid dyeing system. In order to select the optimal condition for supercritical fluid dyeing of Nylon 6 fabrics, dyeing temperature and pressure were varied from 100, 110, 120℃, 200, 230, 260bar, respectively. The results of K/S values and levelling properties showed that the optimal dyeing condition for Nylon 6 fabrics was 110℃ and 230bar in the supercritical CO₂ fluid dyeing system. The washing fastness ratings of the dyed Nylon 6 fabrics under supercritical medium were good for both fading and staining except for staining on nylon.

• Textile Coloration and Finishing
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• v.15 no.2
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• pp.93-101
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• 2003

To acquire dyeing ability on aramid(Nomex) spun yarn in supercritical fluid dyeing, supercritical fluid dying(SFD) machine of 3L scale was designed. C. I. Disperse Red 60 and Red 360 were used in this work. It was possible to increase dyeing ability and to get level dyeing of fiber by attaching assistance devices(controlling device of supercritical fluid, nozzle, cover of carrier, etc.) to SFD machine. Physical properties(tensile strength, elongation, shrinkage) of Nomex spun yam treated by SFD were not changed. K/S values of dyed Nomex spun yam with Red 360 were higher than that with Red 60 and color fastness of dyed Nomex spun yam by SFD was similar to that by conventional dyeing method.

• Proceedings of the KAIS Fall Conference
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• 2011.05a
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• pp.489-492
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• 2011

Supercritical fluid technology has been an alternative for purification and separation of biological compounds in cosmetic, food, and pharmaceutical products. Solubility information of biological compounds in supercritical fluids is essential for choosing a supercritical fluid processes. The equilibrium solubility of hinokitiol was measured in supercritical carbon dioxide with a static method in the pressure range from 8 to 40 MPa and at temperatures equal to 313.2, 323.2 and 333.2 K. The experimental data were correlated well by Peng.Robinson equation of state and quasi-chemical nonrandom lattice fluid model.

• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.605-614
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• 2022

In this study, oregano was extracted by supercritical extraction and hydrothermal extraction method. In vitro experiments such as antimicrobial and antioxidant activity test were performed. As a result of the disc diffusion method, only the supercritical extracts formed a clear zone. The MIC for S. aureus was found only in the supercritical fluid extracts and it was 1000 ㎍/mL. The hydrothermal extract's MIC is 125 ㎍/mL for C. acnes. Through biofilm inhibition assay, we found that the supercritical fluid oregano extracts inhibit the biofilm of S. aureus by more than 70% even at low concentrations of 125 ㎍/mL. On the other hand, the antioxidant ability of the hydrothermal extract was better than that of the supercritical fluid extracts. Furthermore, we tried to make a skincare ingredient for atopic dermatitis by utilizing the S. aureus biofilm inhibitory ability of oregano supercritical fluid extracts. Liposome was used to overcome the low solubility of the oregano supercritical fluid extracts and increase stability.

• KSBB Journal
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• v.23 no.2
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• pp.147-152
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• 2008

The variety of functional plants has an attention for new natural food preservation and natural antiseptic development. The extracts from functional plants with various methods (ethanol extraction, hot water extraction and supercritical fluid extraction) tested antimicrobial activity against 10 strains including the pathogenic and food poisoning bacteria, the yeast and fungi. The antimicrobial activities of supercritical fluid extracts were shown higher than ethanol extract and hot water extract when tested with disc-diffusion method and minimum inhibitory concentration (MIC). Antimicrobial activity of supercritical fluid extract was two times higher than ethanol extract in Cinnaonomum cassia. In addition, the supercritical fluid extractions of Chamaecyparis obtuas and the C. cassia showed the higher yield than Origanum vulgare and Scutellariae baicalensis. The supercritical fluid extract of C. cassia showed an antimicrobial activity against all strains tested. The supercritical fluid extract of S. baicalensis showed strong antimicrobial activity on Listeria monocytogenes. Supercritical fluid extraction of O. vulgare and C. obtuas showed strong antimicrobial activity on Salmonella typhimuriium. In MIC test, C. obtuas was shown the best natural material for the preparation of natural antimicrobial agent by supercritical fluid extraction. In conclusion, these results suggest that supercritical fluid extraction technique was effective to obtain functional ingredient with higher antimicrobial activity in the development of new antimicrobial reagent from natural materials.

• KSBB Journal
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• v.20 no.5 s.94
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• pp.329-337
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• 2005

Because of their unique properties, supercritical fluids have been known as one of the most promising materials for the future technology. Supercritical fluid technologies have been widely applied to various operations such as extraction, impregnation, nano-particle generation, oxidation, reaction etc. Industrial applications, especially their successful usage of supercritical fluid, have been reviewed. A special case for the first successful industrial application of supercritical $CO_2$ extraction in Korea was reviewed. Its unique characteristics of enriched antioxidant, $'\grmma-tocopherol'$ enabled this industrial application in Korea in spite of its low market price. Also its size and operation conditions were known as world records.

• Bulletin of the Korean Chemical Society
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• v.18 no.6
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• pp.584-588
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• 1997

A new device to accurately deliver small amount of modifier into supercritical carbon dioxide fluid is described. Carbon dioxide, the most widely used mobile phase in supercritical fluid chromatography, is a relatively non-polar fluid, and hence the addition of small amount of polar modifiers could be necessary to migrate polar solutes. In this work, supercritical CO₂and modifier are delivered from the pump to a 100 μL mixing chamber in which a small magnetic bar is rotating. After passing through the mixing chamber, supercritical CO₂is changed to a new mobile phase with different polarity. The amount of modifier added into supercritical CO₂is measured by an amperometric microsensor, which is prepared from a thin film of perfluorosulfonate ionomer.

• Proceedings of the PSK Conference
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• 2001.04a
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• pp.233.2-234
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• 2001

• KSBB Journal
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• v.14 no.5
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• pp.633-637
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• 1999

Supercritical fluid of carbon dioxide was used to investigate the effects of its temperature and density on the distribuion coefficients of fatty-acid esters composing fish oil. The distribution coefficient of fatty acid ester was greatly different from each other according to the temperature and density of the supercritical fluid. The possibility of separation of a certain fatty acid from the mixture of fatty acids was tested. The density of the supercritical fluid showing the great differences ofthe distribution coefficients among the fatty acid esters ranged from 0.3 g/mL to 0.4 g/mL. The retrograde condensation took place at high densities of the supercritical fluid.