• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.313-314
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• 2003

분할형 극세사 직물은 서로 상용성을 가지지 않는 nylon/polyester의 용융고분자물을 복합방사법에 의하여 filament 형태로 방사한 후 이를 제직, 편성의 방법으로 포를 제조하고 알칼리 용액에 처리함으로써 생산되어 진다. 따라서 극세사 직물은 일반적으로 소수성의 합성섬유로 이루어졌음에도 불구하고 알칼리 가수분해에 의하여 분할된 섬유 사이의 수많은 모세관에 의하여 높은 흡수성과 수분전이능력을 갖게 된다. 이러한 이유로 극세사 직물은 일반적인 와이퍼의 용도뿐만이 아니라 food service, medicine, 반도체를 제조하는 clean room등으로 그 응용범위를 넓혀 가고 있다. (중략)

• 한국연소학회:학술대회논문집
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• 2015.12a
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• pp.329-330
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• 2015

• Textile Coloration and Finishing
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• v.17 no.3 s.82
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• pp.1-7
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• 2005

Cationic dyeable polyester(CDP) was produced through melt blending of cationic chips having $2mol\%$ of sodium salt of dimethyl ester of 5-sulfoisophthalic acid(DMS salt) and normal polyester chips in different proportions to obtain yarns having varying amount of comonomer in the fiber. The modified polyesters showed increased moisture regain, decreased viscosity, lower softening point and improved antistatic characteristics, according to the amount of modifier. In dyeing at $100^{\circ}C$ the dyeing rate of cationic dyes with CDP fiber increased slowly than that of disperse dyes. In dyeing at $120^{\circ}C$ cationic dyes reached to equilibrium at 30min and disperse dyes at 10min. Cationic dyes in dyeing of CDP fabric have a better wash fastness compared with disperse dyes, also rubbing fastness of cationic dyes is better than that of disperse dyes. The light fastness of CDP fabric for cationic and disperse dyes is not good. The fastness of 75d/36f CDP fabric is higher than 75d/72f fabric. Solvent wicking fastness of CDP with cationic dyes is better than that of disperse dyes.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.719-724
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• 2001

The objective of this investigation was to separate silicon and silica for recycling by the liquid-liquid separation technique. In the preparation of silicon (Si) single crystal, a small amount of silicon is fixed on the surface of silica (quartz, $SiO_2$) crucible. The used crucible is crushed for recycling both silicon and silica in a high purity from the mixed powder. Zeta-potential of silicon and silica are almost the same at pH higher than 3. Their separation by simple flotation is ruled out. However, their hydrophobic characteristics are different in several different organic solvent from the measurement of contact angle. Therefore, the liquid-liquid extraction is employed to separate silicon and silica. The result indicates that the organic solvent mixed with dodecyl ammonium acetate could extracted the silicon powder at high purity (97-100%) with high recovery from the silica powder in the water phase.

• Macromolecular Research
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• v.11 no.3
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• pp.163-171
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• 2003

For the pervaporation of water-ethanol mixtures, new composite membranes having poly(acrylic acid)-poly (butyl methacrylate-co-methyl methacrylate) interpenetrati ng polymer network [PAA-P(BMA-co-MMA) IPN] skin layer supported on porous and crosslinked poly(BMA-co-MMA) were prepared. The morphology of the sub-layer of the composite membrane prepared in the presence of 60 wt% solvent showed cellular structure, on the other hand that of sublayer prepared in the presence of 70 wt% solvent presented very porous interconnected pore structure with macrovoids. Permeation rates of the composite membranes were largely influenced by the morphology of the sublayer. Separation factors increased with the increase of the degree of crosslinking of the PAA network. It was found that permeation rates could be increased by introducing anionic charges on carboxyl groups of the PAA. The permeation rate changes of the PAA-P(BMA-co-MMA) IPN composite membranes according to the feed compositions showed quite similar pattern with the swelling behavior in water-ethanol mixtures.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1523_1524
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• 2009

Inkjet technology has various merits as a direct patterning process in plenty of industrial applications, but critical issue such as coffee ring effect should be overcome for the application to an industrial manufacturing process. In this paper, we introduced the morphological analysis of inkjet printed pattrerns on the characristics of inks and substrates. In case of Triethlene Glycol Monoethly Ether based ink, the coffee ring effect was observed. However, an ethanol based ink showed the round shaped morphology under the same printing conditions and surface conditions. An ink consisted of the solvent with high boiling point results in coffee ring effect. This experimental results showed that the morphological change of the printed droplet is caused by the main solvent of ink, rather than the metal content, viscosity and surface tension.

• Journal of environmental and Sanitary engineering
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• v.22 no.3
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• pp.77-87
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• 2007

The ion exchange resins have been synthesized from chlormethyl styrene - 1,4 - divinylbenzene(DVB) with 1%, 3%, and 5%-crosslinking and macro cyclic ligand of OenNen-$H_4$ by copolymerization method and the adsorption characteristics of uranium(VI), iron(II) and samarium(III) metallic ions have been investigated in various experimental conditions. The synthesis of these resins was confirmed by content of chlorine, element analysis, and IR-spectrum. The effects of pH, time, dielectric constant of solvent and crosslink on adsorption of metallic ions were investigated. The uranium ion was showed fast adsorption on the resins above pH 3. The optimum equilibrium time for adsorption of metallic ions was about two hours. The adsorption selectivity determined in ethanol was in increasing order uranium ${UO_2}^{2+}>Fe^{2+}>Sm^{3+}$ ion. The adsorption was in order of 1%, 3%, and 5% crosslink resin and adsorption of resin decreased in proportion to order of dielectric constant of solvent.

• KSBB Journal
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• v.22 no.3
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• pp.146-150
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• 2007

Poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] microspheres were prepared using solvent evaporation technique. P(3HB-co-4HB) with 3.9 mol% 4HB was synthesized by fed-batch culture of Ralstonia eutropha. The effects of concentration and type of surfactant (Tween 80, sodium dodecylsulfate, and polyvinyl alcohol), addition of dispersion stabilizer (Acacia), concentration of polymer and model drug (bovine serum albumin) on particle size of the microspheres and their in vitro drug release characteristics were investigated. The average particle size of the microspheres decreased with the addition of dispersion stabilizer and increased with the concentration of surfactant, drug and polymer. Amount of drug release increased with decreasing particle size of the microspheres.

• Membrane and Water Treatment
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• v.13 no.4
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• pp.173-181
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• 2022

Polyvinylidene fluoride (PVDF) flat sheet hydrophobic membranes were prepared using 16 wt% PVDF in Dimethyl acetamide (DMAc) by phase inversion technique for desalination application using Membrane Distillation (MD). In this work, the effect of coagulation mediums such as ethanol and water as well their synergistic behavior on the fabricated PVDF membrane morphology was studied using SEM. Moreover, other characteristics required for the membrane distillation applications namely porosity, hydrophobicity and tensile strength were measured using the gravimetric method, sessile drop method and universal testing machine respectively. It was observed that the membrane morphology paradigm shifted from the finger-like structure to the sponge-like structure on increasing the ethanol concentration in coagulant. The porosity of the fabricated membrane was under the required MD range and found to be 57.3% at 16 weight % of PVDF in DMAc solvent under a pure ethanol coagulant bath. Moreover, the top surface contact angle ranges from 85° to 115° on increasing the bath concentration from CBC 0 to CBC 100 at 16 weight % of PVDF in DMAc solvent.

• Bulletin of the Korean Chemical Society
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• v.27 no.1
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• pp.82-86
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• 2006

Propylene Carbonate (PC) has the interesting properties of being able to dissolve and dissociate lithium salts, thus leading to highly conducting electrolytes even at low temperatures. Moreover, electrolytes that contain PC are stable against oxidation at voltages up to ~5 V. However, it is known that, when lithium is intercalated into graphite in pure PC based electrolytes, solvent co-intercalation occurs, leading to the destruction of the graphite structure. (i.e., exfoliation). The objective of this study was to suppress PC decomposition and prevent exfoliation of the graphite anode by co-intercalation. Electrochemical characteristics were studied using Kawasaki mesophase fine carbon (KMFC) in different 1 M $LiPF_6$/PC-based electrolytes. Electrochemical experiments were completed using chronopotentiometry, cyclic voltammetry, impedance spectroscopy, X-ray diffraction, and scanning electron microscopy. From the observed results, we conclude that the MA and $Li_2CO_3$ additive suppressed co-intercalation of the PC electrolyte into the graphite anode. The use of additives, for reducing the extent of solvent decomposition before exfoliation of the graphite anode, could therefore enhance the stability of a KMFC electrode.