• Journal of Pharmaceutical Investigation
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• v.35 no.2
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• pp.95-99
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• 2005

Mucoadhesive microspheres were prepared by interpolymer complexation of chitosan with poly(acrylic acid) (PAA) and solvent evaporation method to increase gastric residence time. The chitosan-PAA complex formation was confirmed by differential scanning calorimetry and swelling study. The DSC thermogram of chitosan-PAA microspheres showed two exothermic peaks for the decomposition of chitosan and PAA. The swelling ratio of the chitosan-PAA microspheres was dependent on the pH of the medium. The swelling ratio was higher at pH 2.0 than at neutral pH. The results indicated that the microspheres were formed by electrostatic interaction between the carboxyl groups of PAA and the amine groups of chitosan. The effect of various process parameters on the formation and morphology of microspheres was investigated. The best microspheres were obtained when 1.5% of the high molecular weight chitosan and 0.3% of PAA were used as an internal phase. The optimum internal phase volume was 7%. The com oil was used as the external phase of emulsion, and span 80 was used as the surfactant. The prepared microspheres had spherical shape.

• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.623-630
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• 2015

Prepared polyurethane resin for buffalo leather coating on surface was synthesized with addition reaction glycerol which had different mole ratio. Mechanical properties of the synthesized polyurethane resin were measured by the SEM, FT-IR, UTM. Growing concerns in the evnironment-friendly polymer resin, we have synthesized low late obtained solvent water dispersion resin to be coating on buffalo leather. The increase of aliphatic trihydric alcohol glycerol mole %, abrasion resistance and tensile strength had demonstrated reduce properties. On the contrary, elongation and flexibility properties had highly increased. In the result of toluene solvent resistance, there was no effect of increased or decreased by the ratio of glycerol mole %.

• Journal of the Korean Applied Science and Technology
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• v.32 no.1
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• pp.100-107
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• 2015

Prepared polyurethane resin for vegetable leather coating on surface was synthesized with glycerol which had different mole ratio. Mechanical properties of the synthesized polyurethane resin were measured by the SEM, FT-IR, UTM. Growing concerns in the evnironment-friendly polymer resin, we have synthesized low late obtained solvent water dispersion resin to be coating on vegetable leather. The increase of aliphatic trihydric alcohol glycerol mole %, abrasion resistance and tensile strength had highly stronger in intensity and longer durability. On the contrary, demonstrated reduce properties of elongation and flexibility. In the result of toluene solvent resistance, there was no effect of increased or decreased by the ratio of glycerol mole %.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2004.05a
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• pp.218-226
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• 2004

Solvent extraction and stripping experiments were conducted to separate iron from a spent $FeCl_3$ etching solution containing nickel. In the extraction, PC88A, MIBK and Alamine336 were tested as an extractant in various diluents. Alamine336 salt in toluene led to the highest extraction percentage of iron. Stripping percentage of iron from the loaded organic by Alamine336 increased with decreasing HCl conentration of stripping solution and with increasing volume ratio of aqueous to organic. In the operation of bench scale mixer-settler, 7 extraction stage with 1.0M Alamine336 salt in toluene and 10 stripping stage with 0.01M HCl solution resulted in a stripped solution with 133g/L of iron and in a raffinate with most of nickel together with a small amount of iron when the flow rate ratio of organic to aqueous was 7.

• Journal of Korean Society on Water Environment
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• v.22 no.2
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• pp.288-293
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• 2006

Basic investigations have been carried out for the solvent extraction of silver contained in the waste photographic fixing solution using D2EHPA as an extractant. Extraction experiments were conducted using artificial waste solution which was made by dissolving $AgNO_3$ in distilled water along with actual waste fixing solution. For artificial waste solution, the extraction of silver was found to occur very rapidly at the initial stage of extraction. In addition, more silver was extracted as the volumetric ratio between aqueous phase and organic phase was decreased. The volumetric ratio of organic extractant to diluent was also taken as an influential variable and the extracted amount of silver was observed to decrease with temperature. The characteristics of silver extraction for actual fixing solution was generally similar to that for artificial waste solution. Regarding the kinetic analysis, the extraction of silver contained in the actual solution was observed to follow a first order reaction.

• Textile Coloration and Finishing
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• v.19 no.6
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• pp.12-20
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• 2007

Four kinds of natural dying solutions (natural colorant extracts)were obtained by extraction from sappan wood, black tea, peony, and clove using water as extracting solvent at $90^{\circ}C$ for 90 min with liquor ratio (solid natural colorant material/solvent water, weight ratio) of 1/10. The dyeing, colour fastness and deodorizing properties of fabrics (cotton, silk, and wool fabrics) dyed with natural colorant extracts were compared. It was found that these properties were significantly dependent on the concentration of extracts, the structure of colorant, and the kind of fabrics. The K/S value of dyed cotton fabric increased in the order of peony < sappan wood < clove < black tea, however, the values of dyed silk and wool fabrics were in the order of peony < sappan wood < black tea < clove. Colour fastness (light, water, and perspiration fastness) was in the range of 3 - 5 grade except for sappan wood. The deodorizing performance of fabrics dyed with various natural colorants extracts was in the range of 56 - 99%. The deodorizing performance increased in the order of peony < black tea < sappan wood < clove. Especially, the deodorizing performance of all fabrics dyed with clove was found to be the highest at 98-99%.

• The Korean Journal of Ceramics
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• v.3 no.3
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• pp.187-190
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• 1997

The aluminum-magnesium (Al-Mg) aklloys have been proved to be an effective solvent for synthesis of cubic-phase boron nitride (cBN) from hexagonal-phase boron nitride (hBN) at the conditions of high pressures and high temperatures (HP/HT). Various kinds of hBN powders having different crystallinity have been tested for cBN synthesis with Al-Mg solvents. The conversion ratio from hBN to cBN and the shape of synthesized cBN crystals appeared to be affected strongly by chemical composition and added amount of Al-Mg solvents as well as crystallinity of BN powders. As the magnesium content increased in the Al-Mg solvents, the conversion ratio increased and the size of cBN crystals became larger. The crystal facets developed well in the specimens with solvents having high Mg content. It was observed that a hBNlongrightarrowcBN transformation occurred more easily in the specimens having well crystallized hBN powders. Amorphous BN having much $B_2O_3$ impurity exhibited a low threshold temperature for transformation to cBN, which was attributed to crystallization of amorphous BN to well crystallized hBN prior to transformation into cBN with help of $B_2O_3$.

• Journal of Adhesion and Interface
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• v.12 no.1
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• pp.11-15
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• 2011

In this study we synthesized low VOC-solvent soluble thermo plastic polyurethane, The effect of chain extender and NCO/OH ratio for properties of thermoplastic polyurethane was investigated. Also, we prepared low VOC-type primer by TPU and acrylic modified tackifier resin. When NCO/OH ratio was 2 or more, TPU was insoluble in low VOC solvent. And peel strength was higher value using polar type tackifier than non-ploar type tackifier.

• Resources Recycling
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• v.6 no.3
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• pp.9-14
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• 1997

A study has been made of the rccovery of copper (11) by solvent extraction with Alamine336 (Tri-n-oclylamine) as a extractant from hydrochloric etching solutions. The effect of extractant concentrations, hydrochloric acid, chloride Ion concentrations and phase ratio (organiclaqueaus) on copper extraction were studied. Experimental results showed that the concenl~atiano f extractant and the phase ratio strongly influenced the copper extraction, and the extraction percent of capper Increased at higher hydrochloric acid and chloride ion mncmhation. We proposed that the optimum extrachon stages of copper for continuous extraction process by analysidng thc McCabe-Thielc diagram. Stripping of copper from the loaded organic phases wn be accomplished by pure water (H, O) as a dripping reagent effectively. As the tcmpcrature is increased, thc stripping of copper is enhanced.

• Korean Journal of Pharmacognosy
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• v.53 no.4
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• pp.202-206
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• 2022

Salidroside is a major phenolic glycoside of Acer tegmentosum (Aceraceae) and known to be a hepatoprotective compound. Extraction conditions are one of the most important factors to save time and cost from an economic point of view. For this reason, this study was conducted to optimize the extraction condition for maximum yield of salidroside. For optimization, three extraction factors such as ethanol concentration (%), extraction temperature (℃), and solvent to material ratio (mg/mL) were tested and optimized for maximum yield of salidroside using response surface methodology (RSM). The optimal condition was obtained as an ethanol concentration of 53.4%, an extraction temperature at 67.11℃ and a solvent to material ratio (mg/mL), 195.55 mg/ml. The salidroside yield under optimal conditions was found to be 1.59 mg/g dried samples, which were well-matched with the predicted value of 1.56 mg/g dried samples. These results will provide useful information about optimized extraction conditions for the development of salidroside as hepatoprotective therapeutics.