• Proceedings of the Membrane Society of Korea Conference
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• 1999.10b
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• pp.63-66
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• 1999

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2004.04a
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• pp.180-185
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• 2004

• Applied Chemistry for Engineering
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• v.24 no.4
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• pp.391-395
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• 2013

In this study, zinc oxide (ZnO) nano powder, well known as an UV absorbing material, was synthesized with three synthetic conditions by the hydrothermal method. After ZnO nano powder was surface-modified with various silane coupling agents to improve dispersion property, a dispersion sol was prepared with dispersant for 72 h by the ball-milling of surface-modified ZnO nano powder. The dispersion sol, prepared by modifying the surface of the ZnO nano powder with an average size of about 30 nm using 3-chloropropyl trimethoxy silane, showed an excellent dispersion stability with a high UV-shielding and visible trnasparency.

• Elastomers and Composites
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• v.45 no.3
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• pp.217-222
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• 2010

Paved roads are suffered from the permanent plastic deformation in hot summer and cracks in cold winter, which are detrimental to safe driving. This leads to necessity of modification of asphalt to resist those deformation. In this study, two kinds of modifiers were examined; organic polymers and a photoinitiator which is activated by ultraviolet lay. The mechanical and rheololgical properties of modified asphalts were examined using UTM and rheometer. Results showed that the properties were varied depending on the types of polymer and irradiation time. UV irradiation increased the tensile strength and storage modulus of thermoplastic polymer-modified asphalt, however UV was not effective on thermoset polymer. According to long term ultraviolet curing test, properties of the polymer/photoinitiator-modified asphalt did not decrease, but rather increase for 20 years. This indicates that the useful life of the asphalt could be extended by addition of photoinitiator.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.5
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• pp.332-339
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• 2011

Effects of powdered activated carbon impregnated by iron oxide nano particle (Impregnated PAC) on the microfiltration (MF) membrane system performance in NOM removal from water were investigated in this study. A fluidized bed column was employed as a pretreatment of MF membrane process. The Impregnated PAC bed was stably maintained at an upflow rate of 63 m/d without leakage of the Impregnated PAC particles, which provided a contact time of 29 minutes. A magnetic ring at the upper part of the column could effectively hold the overflowing discrete particles. The Impregnated PAC column demonstrated a significant enhancement in the MF membrane performance in terms of fouling prevention and natural organic matter (NOM) removal. Trans-membrane pressure of the MF membrane increased to 41 kPa in 98 hours of operation, while it could be maintained at 12 kPa with the Impregnated PAC pretreatment. Removal of NOM determined by dissolved organic carbon and UV254 was also enhanced from 46% and 51% to 75% and 84%, respectively, by the pretreatment. It was found that the Impregnated PAC effectively removed a wide range of different molecular-sized organic compounds from size exclusion analysis.

• Journal of Industrial Technology
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• v.23 no.A
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• pp.187-191
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• 2003

A hollow-fiber type polysulfone UF membrane was surface-coated with hydroxyethylmethacrylate (HEMA). The effect of various coating parameters on permeation flux, such as concentration ratio of AIBN/HEMA, solvent(water or methanol), and UV irradiation time, was investigated. The water permeation flux of oil-emulsion increased with concentration ratio of AIBN/HEMA, and increased with UV irradiation time. The flux of the membrane coated in solution using methanol as a solvent was greater than that of the membrane coated in solution using water as a solvent. The flux of both the coated and the uncoated membrane declined with the operation. The flux decline means that the membrane fouling by oil-emulsion occurs. However, the fouling of the coated membrane was much less than that of the uncoated membrane.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2008.10a
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• pp.279-284
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• 2008

• Textile Coloration and Finishing
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• v.16 no.1
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• pp.10-17
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• 2004

Wool fabrics were treated with deep UV for 10 to 30min and then dyed with C.I. Acid Yellow 99, C.I, Acid Red 57 and C.I. Acid Blue 62. FT-IR and XPS have been used to prove the chemical composition of wool fiber surfaces. The mechanical property and colorfastness were also studied. The intencities of the peaks of C=O group at $1700^cm^{-1}$ were increased with increasing irradiation time. Relative $O_{1s},\; N_{1s}\; and\; S_{2p}$ intensities increased considerably and oxygen was incorporated in the form of CO and COO on the fiber surface. The dye uptakes of wool fabrics dyed with three acid dyes were proportional to irradiation times and in inversely proportional to irradiation distances. It was found that the tensile strength of wool fabrics were gradually deteriorated with the UV irradiation times. The colorfastness, such as washing, light and rubbing, of UV irradiated wool fabrics dyed with acid dyes were good.

• Applied Chemistry for Engineering
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• v.21 no.2
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• pp.200-204
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• 2010

Surface properties are important for determining the functions and uses of materials. So modification of materials with polymer thin films has emerged as an important method to control the physical and chemical properties of the surface layer. We report a simple and effective method to photochemically attach thin polymeric layers to solid surface without chemical derivatization of the substrate and/or the polymer. The system is based on a photoreactive poly(4-vinylpyridine) (P4VP) thin film which is formed on the $SiO_{2}$ surface via spin coating. This substrate is then covered with another polymer film that is reacted with the benzyl radical moieties by UV irradiation. As a result of photochemical reaction, a thin layer of the later polymer is covalently bound to the surface of P4VP. Unbounded polymer is removed by sonication. The thickness of the attached film is a function of the irradiation time and the molecular weight of the polymer. Spatially defined polymer thin films can be fabricated by way of photolithography.

• Polymer(Korea)
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• v.26 no.3
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• pp.389-399
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• 2002

Poly (ethylene terephthalate) (PET) fibers were modified by deep UV irradiation which was produced by a low pressure mercury lamp. FT-IR and XPS analyses were used to elucidate the surface chemical composition of PET fibers treated with UV. Relative $O_{1s}$ intensity increased considerably and it was found that oxygen was incorporated in the form of COO on the fiber surface. FT-IR and XPS analyses proved the existence of carboxylic groups on the surfaces and the adsorption test of cationic compound further supported these results. The concentration of carboxylic acid group on the surface increased remarkably with Increasing irradiation time. XPS analysis and adsorption experiments proved that the surface structure of the UV-irradiated PET fibers were stable for 12 months. Antibacterial property and the deodorization rate of UV-irradiated PET fibers adsorbed with the berberine compound were investigated. Reduction rates of bacteria increased by about 21 to 99% compared to unradiated PET fiber. Deodorization rates of 23% for unradiated PET fiber increased to about 75% for 30 min irradiated samples.s.