• Clean Technology
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• v.14 no.3
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• pp.153-159
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• 2008

The solubility of triclosan, an anti-acne agent was measured in supercritical carbon dioxide ($scCO_2$) with a variable volume view cell at 313.15, 323.15, and 333.15 K and at pressures between 10 and 40 MPa. We successfully correlated triclosan solubility in $scCO_2$ using the quasi-chemical nonrandom lattice fluid (QLF) equation of state. Triclosan was micronized using the rapid expansion of supercritical solutions (RESS) process. The effects of temperature and pressure on particle size were investigated using phase behavior data and correlated results from the QLF model.

• KSBB Journal
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• v.17 no.1
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• pp.68-72
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• 2002

Supercritical Carbon Dioxide was evaluated and optimized for the enrichment and fractionation of the essential oil and the bitter principles of hops, both of which contribute to the flavor of beer, Selected conditions of extraction(pressure, temperature and co-solvent) influenced the composition, the olfactory results and the colour of the extract. Optimal extraction conditions were 30 min, 1800 psia and $ >45^{\circ}C $ with co-solvent. Under these conditions, yield was 65% from brewer's yeast. The bittering substances from brewer's yeasts almost were removed.

• Korean Chemical Engineering Research
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• v.44 no.3
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• pp.248-253
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• 2006

In order to develope an efficient drug delivery system, experimental researches on the supercritical impregnation of ibuprofen onto mesoporous silica, MCM-41,and its drug release characteristics were performed. Supercritical carbon dioxide was adapted as an alternative solvent as it is harmless and able to avoid defects of organic solvents in drug manufacturing processes. The procedure was composed of three steps, that is, as hydrothermal synthesis of MCM-41, supercritical impregnation of ibuprofen onto MCM-41 and release of impregnated ibuprofen. Supercritical impregnation reached equilibrium within 2 h for all cases of this research and the amount of equilibrium impregnation increased with solubility of ibuprofen in supercritical carbon dioxide. Release profiles of impregnated ibuprofen showed a similar behavior for all MCM-41 with different impregnated ibuprofen.

• Clean Technology
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• v.18 no.1
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• pp.38-42
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• 2012

Photonic crystals (PCs) are highly ordered porous materials which have been much attention because of its potential for controlling the light sauces. There are many methods for synthesizing this kind of materials among them we chose the supercritical deposition. With this method the reactants can easily infiltrate into the complex structure. In this paper, supercritical carbon dioxide ($scCO_2$) was used as a reaction medium, which is known as a sustainable solvent due to its nontoxic and noninflammable characteristics. We coated the colloidal template with metal alkoxide by using $scCO_2$ and then obtained macro-porous inverse opals. The reaction was carried out at $40^{\circ}C$ and 80 bar. We synthesized two different inverse opals which called silica and titania inverse opals by use of tetraethyl orthosilicate (TEOS) and titanium isopropoxide (TTIP) as a precursor, respectively.

• Textile Coloration and Finishing
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• v.31 no.1
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• pp.25-32
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• 2019

The influence of the contact amount of carbon dioxide per unit mass of dyestuff(${\alpha}$) on dyeing uniformity in supercritical fluid dyeing is analyzed in this study. The experiments using a 5L class Pilot Scale dyeing machine is carried out for this study purpose. For a fixed temperature and pressure, the amount of sample and the dyeing leveling time were considered as process variables. The results show that the increase in the amount of the sample causes a higher color difference than the reference sample, and it also increases the amount of residual dye. On the other hand, the color difference tended to decrease with the increase in dyeing time. Based on these results, the correlation between ${\alpha}$ value and dyeing uniformity in supercritical fluid dyeing is obtained.

• Bulletin of the Korean Chemical Society
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• v.35 no.10
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• pp.3107-3110
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• 2014

• KSBB Journal
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• v.18 no.5
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• pp.385-392
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• 2003

Biodegradable poly (L-lactide) (L-PLA) solution in methylene chloride was precipitated into microparticles by using supercritical carbon dioxide modified with polar cosolvents. The effects of the amount of polar cosolvents, solution concentration, temperature, and solution flow rate on the formation of microparticles were investigated. The mean particle size was found to increase with the increase of solution concentration and flow rate. It was also observed that the particle size not only increases but the size distribution also becomes less uniform as the temperature increases. The percent recovery of microparticles was found to be 30∼40% at all experimental conditions. The supercritical carbon dioxide modified with methanol and ethanol was employed to enhance the recovery, resulting in significant improvement up to about 80 and 70%, for methanol and ethanol, respectively. Furthermore, the mean diameter of L-PLA microparticles was found to be less than 1 $\mu\textrm{m}$ for both cosolvents.

• Clean Technology
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• v.11 no.3
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• pp.147-152
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• 2005

For estblishing the best technique for the micronization of Ibuprofen using supercritical fluids, the solubility should be known. The solubility of Ibuprofen in supercritical carbon dioxide was measured by observing the cloud point. The cloud point was observed using high pressure equipment equipped a variable volume view cell between temperature of 35, 40 and $45^{\circ}C$. The solubility data was correlated by the Peng-Robinson equation of state Solute physical properties, such as critical temperature (Tc), critical pressure (Pc) and acentric factor (${\omega}$) were estimated by the some group contribution method. As pressure was increased, the solubility increased at constant temperature. The retrograde phenomenon by a solute vapor pressure and a density of solvent was observed at the pressure of around 150bar. It was found that $CO_2$ can be used as a supercritical solvent in micronization of ibuprofen by RESS.

• Korean Journal of Food Science and Technology
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• v.25 no.3
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• pp.288-294
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• 1993

Solubilities of urea-crystallized tuna oil methyl esters in supercritical carbon dioxide were determined by a flow through extraction reactor. Experimental results obtained under a quasi-equlibrium condition showed that at 150 bar, solubilities of the esters in supercritical $CO_2$ were 0.075, 0.028 and 0.006(w/w) at $40^{\circ}C,\;60^{\circ}C\;and\;80^{\circ}C$, respectively. In the pressure and temperature ranges $(100{\sim}200bar\;and\;40{\sim}80^{\circ}C)$, the solubility increased with the density of $CO_2$. However, selectivity of supercritical carbon dioxide on the extracted compounds was much better at low density than at high density. Supercritical fractionation with a temperature gradient $(50{\sim}75^{\circ}C)$ resulted in concentrates of EPA and DHA in purities of 12% and 85%, respectively.

• 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.