• Polymer(Korea)
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• v.24 no.6
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• pp.763-769
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• 2000

The multifunctional cation exchangers, sulfonated polypropylene-g-(acrylic acid/styrene) [PP-g-(AAc/Sty)] were synthesized by the irradiational grafting of AAc and Sty onto PP staple fabric with electron beam accelerator and its subsequent sulfonation. The highest degree of grafting obtained was 190% at a monomer mixture of 30 vol% AAc: 70 vol% Sty and a solvent mixture of 30 vol% water : 70 vol% methanol and the degree of grafting decreased with an increase of the AAc content in the monomer mixture at constant solvent content. Maximum ion exchange capacity of the copolymer was 4.6 meq/g. The Li$^{+}$ adsorption ability of the copolymer synthesized in the study was the best among PP-g- AAc, sulfonated PP-g-Sty, and sulfonated PP-g-(AAc/Sty).).

• 한국가시화정보학회:학술대회논문집
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• 2004.12a
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• pp.65-74
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• 2004

Measurement of concentration distributions of suspended particles in a micro-channel is out of the most crucial necessities in the area of Lab-on-a-chip to be used for various bio-chemical applications. One most feasible way to measure the concentration field in the micro-channel is using micro-LIF(Laser Induced Fluorescence) method. However, an accurate concentration field at a given cross plane in a micro-channel has not been successfully achieved so far due to various limitations in the light illumination and fluorescence signal detection. The present study demonstrates a novel method to provide an ultra thin laser sheet beam having five(5) microns thickness by use of a micro focus laser line generator. The laser sheet beam illuminates an exact plane of concentration measurement field to increase the signal to noise ratio and considerably reduce the depth uncertainty. Nile Blue A was used as fluorescent dye for the present LIF measurement. The enhancement of the fluorescent intensity signals was performed by a solvent mixture of water $(95\%)$ and ethanol (EtOH)/methanol (MeOH) $(5\%)$ mixture. To reduce the rms errors resulted from the CCD electronic noise and other sources, an expansion of grid size was attempted from $1\times1\;to\;3\times3\;or\;5\times5$ pixel data windows and the pertinent signal-to-noise level has been noticeably increased accordingly.

• Journal of the Korean Ceramic Society
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• v.51 no.4
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• pp.324-331
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• 2014

The dispersion characteristics of AlN-4.5 wt% $Y_2O_3$ powder mixture by various dispersants were investigated in ethanol and methyethly-ketone (MEK) solvents. In general, the cationic polymer dispersants demonstrated superior dispersion of the powder as compared to the non-ionic ester-type dispersants or anionic phosphate-ester-based ones. The dispersion performance of the cationic polymer dispersants was sensitive to the type of solvent. An anhydric maleic-acid-based graft copolymer dispersant, AFB-1521, demonstrated a very good dispersion capability in ethanol but exhibited a much inferior dispersion in MEK. On the other hand, the dispersion of the powder mixture was very good with a phosphate-ester-based block polymer dispersant, BYK-111, in MEK solvent, while dispersionwas much degraded in ethanol.

• Proceedings of the Membrane Society of Korea Conference
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• 1999.07a
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• pp.93-94
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• 1999

• Resources Recycling
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• v.9 no.4
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• pp.28-36
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• 2000

This study describes to analyze the characteristics for separation and recovery of both the dried particles and the purified solvent from the waste solvent through the vaporization process by the continuous and instantaneous vacuum drying system. The vacuum drying system for the waste solvents recovery consists of a feeding pump, a double pipe heat exchanger, a vacuum spray chamber, and a condenser. The vacuum drying system heats the waste solvent to the vapor in the double pipe heat exchanger and the expanded vapor is sprayed at the end of the tube. The vaporized solvent in the condenser are recovered. The particles in the waste solvent are separated and dried from the vapor in the vacuum spray chamber. Performance evaluation of the vacuum drying system was conducted using the mixture of the dried pigment particles and benzene or alkylbenzene as test samples. For the mixture of 10 wt% pigment particles an 90% benzene, the recovery efficiency of benzene was 88% with the purity of 99% and the recovery efficiency of dried particles was 94% with the moisture of 1.1 wt%. The size of pigment particles was decreased from $6.5\mu\textrm{m}$ to $5.6\mu\textrm{m}$ in diameter due to high speed spraying and dispersion in the vacuum drying system during drying process. Therefore, the vacuum drying system showed to be an effective method for separating particles and solvent in the waste solvent.

• Korean Journal of Food Science and Technology
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• v.15 no.1
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• pp.70-76
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• 1983

Separation of fructose from glucose-fructose mixture was studied by utilizing the solubility differences of both sugars in the mixed solvents of water and alcohols with or without the presence of NaCl and $CaCl_2$. Better separation of fructose was obtained in ethanol-water solvent than other solvent-water systems. The addition of NaCl to the ethanol-water solvent system improved the separation factor based on the relative composition of two sugars in the supernatant by twice. The change in feed composition from 50-50 mixture of glucose and fructose resulted in a worse separation factor. It was found in the present studies that the best separation of fructose (fructose 75%, glucose 25%) was achieved when NaCl and ethanol was slowly added to the solution containing 20% water, 40% fructose and 40% glucose to make up the final solution with the parts of ethanol 36 ml, water 4 ml, glucose 8 gm, fructose 8 gm and NaCl 0.25gm.

• Resources Recycling
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• v.22 no.6
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• pp.19-25
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• 2013

Solvent extraction experiments have been conducted to separate Zr(IV) and Hf(IV) from chloride solutions by using LIX63 and Cyanex301. Zr and Hf were extracted by cation exchange reaction in the pH range from 1 to 4 by the extratants. Since the extraction percentage of the two metals was similar to each other, it was difficult to separate the two metals by using LIX63 or Cyanex301. Use of a mixture of LIX63/TBP or Cyanex301/TBP resulted in antagonism in our experimental ranges. Our data showed that there is some possibility of separating the two metals by the mixture of Cyanex301 and TBP because the extraction percentage of Hf decreased more rapidly than that of Zr as HCl concentration was decreased. The mixture of LIX63 and Cyanex301 had little effect on the separation of the two metals.

• Journal of Pharmaceutical Investigation
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• v.20 no.4
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• pp.193-198
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• 1990

To increase the dissolution rate of furosemide, cogrinding or coprecipitating of furosemide with povidone was carried out. The ground mixture of furosemide with povidone was prepared by cogrinding in a ceramic ball mill and the coprecipitate was prepared by solvent method using methanol. The povidone ground mixture and the coprecipitate showed a faster and more enhanced dissolution rate than the physical mixture or intact furosemide. The IR, DTA and TGA studies showed the physicochemical modifications of furosemide from the ground mixture and the coprecipitate. An interaction, in the ground mixture and in the coprecipitate, such as association between the functional groups of furosemide and povidone might occur in the molecular level. The coprecipitating and cogrinding techniques with povidone provided a promising way to increase the dissolution rate of poorly soluble drugs.

• International Journal of Highway Engineering
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• v.18 no.6
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• pp.97-104
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• 2016

OBJECTIVES : The objective of this research is to develop additives for the modification of Solvent DeAsphalting Residue (SDAR) to be used as pavement materials, and evaluate the performance of asphalt mixture manufactured using the SDAR modified by developed additives. METHODS : The SDAR generally consists of more asphaltenes and less oil components compared to the conventional asphalt binder, and hence, the chemical/physical properties of SDAR are different from that of conventional asphalt binder. In this research, the additives are developed using the low molecular oil-based plasticizer to improve the properties of SDAR. First, the chemical property of two SDARs is analyzed using SARA (saturate, aromatic, resin, and asphaltene) method. The physical/rheological properties of SDARs and SDARs containing additives are also evaluated based on PG-grade method and dynamic shear-modulus master curve. Second, various laboratory tests are conducted for the asphalt mixture manufactured using the SDAR modified with additives. The laboratory tests conducted in this study include the mix design, compactibility analysis, indirect tensile test for moisture susceptibility, dynamic modulus test for rheological property, wheel-tracking test for rutting performance, and direct tension fatigue test for cracking performance. RESULTS : The PG-grade of SDARs is higher than PG 76 in high temperature grades and immeasurable in low temperature grades. The dynamic shear modulus of SDARs is much higher than that of conventional asphalt, but the modified SDARs with additives show similar modulus compared to that of conventional asphalt. The moisture susceptibility of asphalt mixture with modified SDARs is good if, the anti-stripping agent is included. The performance (dynamic modulus, rutting resistance, and fatigue resistance) of asphalt mixture with modified SDARs is comparable to that of conventional asphalt mixture when appropriate amount of additives is added. CONCLUSIONS : The saturate component of SDARs is much less than that of conventional asphalt, and hence, it is too hard and brittle to be used as pavement materials. However, the modified SDARs with developed additives show comparable or better rheological/physical properties compared to that of conventional asphalt depending on the type of SDAR and the amount of additives used.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.504-507
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• 2002

A separation/purification process for enzymatic sugar ester production was investigated The crude reaction mixture contained sugar ester and unreacted fatty acid in acetone. The reaction mixture was mixed with KOH/phosphate buffer. Hexane was then added to enhance phase separation. Three phases formed: a lower aqueous phase containing nothing of interest, a polar organic solvent middle phase that contained mostly fatty acid soaps, and a hexane-rich upper phase that contained mostly sugar ester. Distribution coefficient of each component was measured.