• 한국생물공학회:학술대회논문집
• /
• 2000.11a
• /
• pp.644-647
• /
• 2000

The properties of hydrogen bonding between poly(2-ethyl-2-oxazoline)[PEOx] and poly(acrylic acid)[PAA] were investigated. PEOx and PAA formed stable complex and precipitated due to hydrogen bonding between hydrogen of PAA and oxygen of PEOx in acidic condition(below pH 4.3). Optimum reaction ratio of PEOx and PAA was determined as mass ratio of 1:1.5 for applications in aqueous two phase system. The mixtures of the polymers formed aqueous two phase system with dextran solution after the breakage of hydrogen bondings. This properties can be used for the recovery of valuable products.

• Textile Coloration and Finishing
• /
• v.14 no.2
• /
• pp.109-109
• /
• 2002

A study has been made of the dry-jet-wet spinning of PAN copolymer fibers using 60% aqueous zinc chloride solution as solvent and 25∼40% aqueous zinc chloride solution as non-solvent. The technological characteristics of this method were that small streams of dope were extruded from the die and allowed to pass through a short distance of air gap(about 10mm) before entering the spinning bath for full coagulation. This work showed the importances which coagulation condition, stretch ratio and fiber tenacity up to 10.5 g/d could be obtained with elongation of 11∼16%. Individual fibers were evaluated on the basis of density and mechanical properties such as tenacity and elongation etc.

• Textile Coloration and Finishing
• /
• v.14 no.2
• /
• pp.33-39
• /
• 2002

A study has been made of the dry-jet-wet spinning of PAN copolymer fibers using 60% aqueous zinc chloride solution as solvent and 25∼40% aqueous zinc chloride solution as non-solvent. The technological characteristics of this method were that small streams of dope were extruded from the die and allowed to pass through a short distance of air gap(about 10mm) before entering the spinning bath for full coagulation. This work showed the importances which coagulation condition, stretch ratio and fiber tenacity up to 10.5 g/d could be obtained with elongation of 11∼16%. Individual fibers were evaluated on the basis of density and mechanical properties such as tenacity and elongation etc.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2003.04a
• /
• pp.405-408
• /
• 2003

The soild phase microextraction(SPME)fiber which contains 100${\mu}{\textrm}{m}$ polydimethyl siloxane of a stationary phase was used for the analysis of volatile organic compounds contained in aqueous solution. volatile organic compounds, which were spiked in blank water and extracted by the headspace SPME techique, were analyzed by gas chromatography/flame ionization detector(GC/FID). The optimu condition of SPME fiber is determined that the analytes were extracted for 40min from extracts by using PDAfS100${\mu}{\textrm}{m}$ fiber. This new method could have wide application for the analysis of VOCs in aqueous solution.

• Textile Coloration and Finishing
• /
• v.10 no.1
• /
• pp.33-37
• /
• 1998

It is rather important in the water and oil repellent finishing for wool fabric what kind of water-repellent agents will be used. In many cases, Fluorocarbon-based water-repellent agents(eg.Oleophobol-S), the surface tensions of which very low, were recom-mended on account of good water and oil repellencies. In repellent finishing, fabrics were padded in a bath which contained aqueous solution of water-repellent agents, and wetting agents, followed by drying and curing. The most suitable treating condition for excellent repellency was as follows Fabrics were padded at liquor pick-up ratio of 50%, with aqueous solution which contained $30g/\ell$ of water-repellent agents, and $40g/\ell$ of wetting agents. And the padded fabrics were dried at $110^\circ{C}$ for 1 minute, and cured at $160^\circ{C}$ for 2 minutes. For the fabrics, water and oil repellencies and durability to repeated dry-cleanings are observed.

• Textile Coloration and Finishing
• /
• v.16 no.2
• /
• pp.8-14
• /
• 2004

The purpose of this study was to investigate dyeing properties and antibacterial activities of cotton and silk fabrics treated with Ginkgo biloba leaf extracted with three kinds of aqueous solvents: distilled water, electrolytic reduction water and electrolytic oxidation water. The optimum dyeing condition of Ginkgo biloba leaf was 120 min at 8$0^{\circ}C$. Electrolytic reduction water had the highest dyeability to both cotton and silk compared with electrolytic oxidation water and distilled water. A color of extract by distilled water and electrolytic oxidation water showed yellowish Yellow Red, extract by electrolytic reduction water showed reddish Yellow Red. Irrespective of kinds of extraction solvents, appropriate acidity of medium was pH 9∼11 and pH 3 for cotton and silk fabrics, respectively. Colorfastness to laundering and Light fastness showed generally low but crocking fastness was excellent. Antibacterial activities of the treated fabrics above were 99.9%.

• Journal of the Korean Chemical Society
• /
• v.10 no.1
• /
• pp.4-10
• /
• 1966

A new method of cobalt determination has been developed by employing ethylenediamine tetrabutyl acetate(EDTA-butyl ester) synthesized from EDTA and Butyl alcohol. The synthesized EDTA ester dissolved in butyl alcohol extracts various metal ions from aqueous solutions. Cobaltous ion extracted into organic phase containing EDTA ester to form Co (II)-EDTA butyl ester complex is back extracted into alkaline aqueous phase forming a stable pink colored complex of Co (III). The optimum condition for spectrophotometric determination of cobalt via the new complex has been established. The absorption peak occurs at 540$m{\mu}$ and Beer's law was obeyed over the concentration range of 0∼50 ${\mu}g/ml$ of cobalt.

• Asian Journal of Turfgrass Science
• /
• v.13 no.4
• /
• pp.213-222
• /
• 1999

The toxic effects of four pesticides on the entomopathogenic nematodes. Heterorhabditis bacteriophora NC strain, Steinernema glaseri NC and Dongrae strain were tested by checking the mortality of infective juveniles(Ijs) in aqueous solution of pesticide. Mortality of Ijs was influenced by pesticide and concentration and soaking time. The herbicide alachlor and insecticide fenitrothion were toxic to Ijc of three entomopathogenic nematodes. But, the fungicides mepronil and tolclofos-methyl were nontoxic to Ijs. Tolclofos-methyl showed significantly very week toxicity at 28 days after soaking for S. glaseri NC strain. H. bacteriophora NC strain was more highly sensitive to high temperature condition then were the other nematodes.

• Textile Coloration and Finishing
• /
• v.14 no.5
• /
• pp.261-267
• /
• 2002

Cotton fabrics were immersed in aqueous solution of N-methylmorpholine N-oxide(NMMO) with various concentrations, padded by 300% of pick-up, concentrated at $90^\circ{C}$ for 30min under constant-length condition, washed, and dried, to examine a possibility of linen-like finishing by the solvent bonding between fibers. With increasing the concentration of NMMO, cross-sections of fibers changed to oval or polygonal shapes and not only the fibers but also the warp and weft were bonded each other, which produced linen-like effect on the fabrics in the aspects of appearance and mechanical properties such as the Increase of stiffness and shear properties. The thickness, moisture regain and dyeability were increased with the concentration of NMMO.

• Bulletin of the Korean Chemical Society
• /
• v.17 no.9
• /
• pp.854-857
• /
• 1996

Absorption and luminescence spectra of Eu3+ (aquo) and the two different 1: 3 Eu3+: ligand systems in aqueous solutions are measured under mild acidic pH condition. The oxydiacetate (ODA) and dipicolinate (DPA) ligands, forming the similar geometric complexes, are used in this work. The three intensity parameters, Ωλ (λ=2, 4, and 6) are empirically determined by applying the Judd-Ofelt theorem to the oscillator strengths of the six absorption bands arising from the ground 7F0 state. Among the three intensity parameters, the Ω2 is found to response markedly to a miner change in the ligand environment via the 7F0→5D0 transition. In addition, the relative oscillator strengths of the four luminescence bands in the visible region, assigned to the 5D0→7FJ (J=1, 2, 3 and 4) transitions are obtained to investigate their sensitivity to the ligand environment. Among the four bands, the 610 nm band, attributed to the 5D0→7F2 transition, shows hypersensitivity in the luminescence.