• Clean Technology
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• v.13 no.1 s.36
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• pp.34-45
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• 2007

Phase behavior of the ternary systems of water-insoluble simvastatin drug, which is well known to be effective drugs for hypercholesterolemia therapy, in solvent mixtures of dichloromethane and supercritical carbon dioxide was investigated to present a guideline of establishing operating conditions in the particle formation of the drugs by a supercritical anti-solvent recrystallization process utilizing dichloromethane as a solvent and carbon dioxide as an anti-solvent. The solubilities of simvastatin in the mixtures of dichloromethane and carbon dioxide were determined as functions of temperature, pressure and solvent composition by measuring the cloud points of the ternary mixtures at various conditions using a high-pressure phase equilibrium apparatus equipped with a variable-volume view cell. The solubility of the drug increased as the dichloromethane composition in solution and the system pressure increases at a fixed temperature. A lower solubility of the drug was obtained at a higher temperature. The second half of this work is focused on the particle formation of the simvastatin drug by a supercritical anti-solvent recrystallization process in a cylindrical high-pressure vessel equipped with an impeller. Microparticles of the simvastatin drug were prepared as functions of pressure (8 MPa to 12 MPa), temperature (303.15 K, 313,15 K), feed flow rate of carbon dioxide, and stirring speed (up to 3000 rpm), in order to observe the effect of those process parameters on the size and shape of the drug microparticles recrystallized.

• Korean Chemical Engineering Research
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• v.53 no.2
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• pp.193-198
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• 2015

The high-pressure phase behavior of a polycaprolactone (Mw=56,145 g/mol, polydispersity 1.2), dichloromethane, and carbon dioxide ternary system was measured using a variable-volume view cell. The experimental temperatures and pressures ranged from 313.15 K to 353.15 K and up to 300 bar as functions of the $CO_2$/dichloromethane mass ratio and temperature, at poly(D-lactic acid) weight fractions of 1.0, 2.0, and 3.0%. The correlation results were obtained from the hybrid equation of state (Peng-Robinson equation of state + SAFT equation of state) for the $CO_2$-polymer system using the van der Waals one-fluid mixing rule. The three binary interaction parameters were optimized by the simplex method algorithm.

• Journal of the Korean Wood Science and Technology
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• v.41 no.5
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• pp.447-455
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• 2013

Hemicellulose extract obtained by pre-pulping extraction of woodchips, is very diluted acidic in nature. The major component responsible for this weak acidity is acetic acid, present in levels up to 5~10 g/L. Here, we report an exploratory study on the extract upgrading by reactive solvent extraction of acetic acid as well as ASPEN simulation. In this study, liquid-liquid equilibria for the ternary systems (water + acetic acid + ethyl acetate) were measured at the temperature of 298.15 K and 10 (pH = 2.02), 5 (pH = 2.17), and 1 (pH = 2.48) percent of acetic acid samples were used to carry out liquid-liquid extraction studies using ethyl acetate. In a one-stage batch experiment, 96.0% of acetic acid could be extracted for the solvent when the ratio of organic-to-aqueous phases is 4:1. For simulation results, they were used to estimate the interaction parameters between each of the three compounds of the systems studied for the NRTL and UNIQUAC models. The estimated interaction parameters were successfully used to predict the equilibrium compositions by the two models.

• Membrane Journal
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• v.22 no.2
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• pp.128-134
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• 2012

In this study, hydroxy polyimide (HPI) was prepared for non-porous membrane by solvent evaporation method. As the result of gas permeance properties measurement, $CO_2$ permeability was 85 Barrer and the $CO_2/N_2$ selectivity was 23 at $30^{\circ}C$. Flat sheet membrane and hollow fiber membrane were prepared by using ternary system of polymer, solvent and non-solvent additive. Morphologies and gas permeance properties were measured by FE-SEM and bubble flow meter. Each $CO_2$ permeability of 18.28 GPU, 70 GPU and $CO_2/N_2$ selectivity of 6.72, 8.63 at $30^{\circ}C$ in the flat sheet membrane and hollow fiber membrane. Hollow fiber membrane has gas permeance property better than flat sheet membrane.

• Journal of the Korean Society of Safety
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• v.20 no.3 s.71
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• pp.91-97
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• 2005

The research on the explosive limits is one of fundamental fields of combustion process, and information on the explosive limits of mixture of fuel and oxidant, with or without additives, is very important for the prevention in industrial fire and explosion accidents. Explosive limits of all compounds and solvent mixtures can be calculated with the appropriate use of the fundamental laws of Raoult, Batten, Le Chatelier and MRSM(modified response surface methodology) model. In this study, the reference values of lower explosive limits(LEL) of the ethanol+toluene+ethylacetate system were compared with the calculated values by using the solution thermodynamics and the MRSM model, respectively. The values calculated by the proposed equations were a good agreement with literature data within a few percent. By means of this methodology, it is possible to evaluate reliability of experimental data of the lower explosive limits of the flammable mixtures. Also, from given results, it is possible to predict explosive limits of the other flammable liquid mixtures used in the chemical process by the use of the proposed equations.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.41 no.3
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• pp.201-208
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• 2015

Organogels are semi-solid systems that consist of an apolar solvent as the liquid phase within a three-dimensional networked structure. In this study, we developed a stable and skin penetration-enhanced Lecithin Organogel (LO) containing genistein, which is one of the poorly soluble active ingredients in both polar and apolar phase. After screening of various components (type of gelators, organic and aqueous phase), hydrogenated lecithin (HL), sunflower oil (SO), dipropylene glycol (DPG), and polyethylene glycol (PEG) were mainly used in this formulation. Phase ternary diagram was employed for optimization of the composition in the LO. The formulated LO were evaluated for its organoleptic characteristics, stability, pH, rheology, phase transition temperatures, microscopic analysis and skin penetration. The optimized stable LO system can be utilized as an effective and stable cosmetic formulation that can carry poorly soluble active ingredients at high concentration for topical dermal delivery.

• Fire Science and Engineering
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• v.15 no.3
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• pp.14-20
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• 2001

The flash points are one of the most important fundamental properties used to determine the potential for fire and explosion hazards of flammable substances. A classification of the flash points is important for the safe handling of flammable liquids which constitute the solvent mixtures. Basic to all flash points behavior are vapor pressure and explosive limits(lower explosive limit and upper explosive limit). The flash points of flammable solvent mixtures can be calculated with the appropriate use of the fundamental laws of Raoult, Dalton, Le Chatelier and activity coefficient models. In this study, the reference values of lower flash points were compared with the calculated values by using Raoult's law and MRSM(modified response surface methodology) model. The lower flash points were in agreement with the predicted by Raoult's law and MRSM model. By means of this methodology, it is possible to evaluate reliability of experimental data of the flash points of the flammable mixtures.

• Membrane Journal
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• v.22 no.1
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• pp.62-71
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• 2012

In this study, for preparation of gas separation membrane with high permeability, hydroxy polyimide was synthesized using 6FDA and APAF. Synthesis of HPI was confirmed by H-NMR and FT-IR, thermal property of membrane was characterized by Differential scanning calorimetric (DSC) and thermogravimetric analyzer (TGA). Especially, the synthesized HPI can possible to search conversion to PBO at $450^{\circ}C$. To obtain the membrane having high permeability, ternary system consist of polymer, solvent and non-solvent additive was introduced, asymmetric HPI flat sheet membrane was prepared by phase inversion method. Finally, the change of morphology with each component was observed through FE-SEM.

• Journal of Pharmaceutical Investigation
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• v.32 no.4
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• pp.299-303
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• 2002

The oral bioavailability of itraconazole is variable and low in fasting state. This is mainly due to the low solubility of this drug. Bioavailability can be improved by changing the formulation and it is general that the liquid preparations show greater bioavailability than the solid dosage forms such as tablets and capsules do. Benzyl alcohol-water binary mixture showed the excellent solubilizing capacity for itraconazole but the release of the drug from the preparation needs to be enhanced. In this study, various nonionic surfactants and hydrophilic polymers, poloxamers, were screened to investigate their effects on the releasε of itraconazole from the liquid preparations. Poloxamer 407 showed the most enhancing effect on the drug release and the release rate was proportional to thε amount of poloxamer 407 added. A liquid preparation of itraconazole, consisting of benzyl alcohol/water/poloxamer 407 ternary solvent system, releasεd more than 80% of the total drug amount at 5 min and showεd the possibility of a new formulation development.

• Korean Chemical Engineering Research
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• v.44 no.6
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• pp.669-675
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• 2006

Toluene of aromatic compounds, MEK of ketones and IPA of alcohols were extremely used as VOCs (Volatile Organic Compounds) on the getting into step with industrial process. The adsorption characteristics of three component solvent vapors (Toluene-MEK-IPA) on the activated carbonaceous adsorbents such as AC, ACF and AC+ACF were investigated in a stainless steel fixed bed adsorption experimental apparatus in order to identify those carbons for eliminating and recovering solvent vapors from industrial emission sources. The used activated carbonaceous adsorbents were pelletized commercial activated carbon and activated carbon fiber. The breakthrough curves and adsorption capacity have been obtained at atmospheric pressure in a adsorption fixed bed. It has been found that non-polar and larger molecules have been adsorbed better than polar and smaller molecules. Especially, alcohols and ketones were poorly adsorbed due to competitive adsorbability in ternary mixture system. However, it could be overcome by employment of activated carbonaceous adsorbent which have different porosity distribution appropriately.