• Textile Coloration and Finishing
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• v.21 no.4
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• pp.57-62
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• 2009

N-Halamines are compounds which have covalent bonding between nitrogen and halogen. N-Halamine materials possess strong antimicrobial properties against wide spectrum of bacteria. The aim of this study is to prepare N-halamine membranes using m-aramid and poly(vinyl alcohol) (PVA). Surface characteristics using scanning electron microscope (SEM), pore size distribution, liquid permeability and mean pore size were measured to confirm feasibility as membrane. The results indicated that increased PYA portion up to 15% in the m-aramid/PVA blend resulted in improved pore size distribution, liquid permeability as well as mean pore size. Furthermore, antibacterial efficacy of the membranes after chlorination was confirmed and the results showed that bacteria in water were inactivated.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.15 no.1
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• pp.25-32
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• 2009

It is now widely recognized that the disposal of packaging waste is an increasing environmental concern. Recent interest in polymer waste management of packaging materials has added incentive to the research. Poly(vinyl alcohol) is a readily biodegradable water-soluble polymer. However, this polymer cannot be processed by conventional extrusion technologies because the melting point of PVA is close to its decomposition temperature. Therefore, PVA films have been mostly prepared by solvent casting from water. Applications of PVA include sizing, binders, fibers, and films for agricultural chemicals and hospital laundry bags. A better understanding of PVA films, which also play important roles in the degradation of plastics, will expand the usage of PVA. Composite films based on PVA generally exhibit better mechanical and thermal properties than pure PVA. The aim of this review article is to review types, formation, and properties of PVA films and PVA based composite films used in packaging related researches.

• Membrane Journal
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• v.13 no.1
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• pp.29-36
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• 2003

A characterization of the permeation and separation using single salt solution was carried out with charged composite membranes. Various charged composite membranes were fabricated by blending an ionic polymer with a nonionic polymer in different ratios. In this study, sodium alginate, chitosan and poly(vinyl alcohol) were employed as anionic, cationic and nonionic polymers, respectively. The permeation and separation behaviors of the aqueous salt solutions have been investigated through the charged composite membranes with various charge densities. As the content of the ionic polymer increased in the membrane, the hydrophilicity of the membrane increased, and pure water flux and the solution flux increased correspondingly, indicating that the permeation performance through the membrane is determined mainly by its hydrophilicity. Electrostatic interaction between the charged membrane and ionic solute molecules, that is, Donnan exclusion, was observed to be attributed to salt rejection to a greater extent, and molecular sieve mechanism was effective for the separation of salts under a similar electrostatic circumstance of solutes.

• Macromolecular Research
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• v.13 no.5
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• pp.385-390
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• 2005

The electrospinning process is a fascinating method to fabricate small nanosized fibers of diameter several hundred nanometers. Surfactant-polymer solutions were prepared by adding poly(vinyl alcohol) (PVOH) to distilled water with cationic, anionic, amphoteric, and non-ionic surfactants. Average diameter of the electrospun PVOH fibers prepared from PVOH solution was over 300 nm, and was decreased to 150 nm for the mixture of PVOH/amphoteric surfactant. To explain the formation of ultra fine fiber, the characteristic properties in a mixture of PVOH/surfactant such as surface tension, viscosity, and conductivity were determined. In this paper, the effect of interactions between polymers with different classes of surfactants on the morphological and mechanical properties of electrospun PVOH nonwoven mats was broadly investigated.

• Korean Membrane Journal
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• v.1 no.1
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• pp.86-92
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• 1999

The nanofiltration (NF) membranes based on poly(vinyl alcohol) (PVA) and sodium alginate (SA) were prespared. Homogeneous PVA/SA blend membranes were prepared by casting a PVA/SA (95/5 in wi%) mixture solution on an acryl plate followed by drying at a room temperature and by cros-slinking with glutaraldehyde (GA) for 20 minutes PVA/SA blend composite membranes were also prepared by coating a PVA/SA (95/5 in wi%) mixture solution on microporous polysulfone(PSF) supports. The PVA/SA active layer of the composite membrane was crosslinked at room temperature by using an membranes were characterized with a scanning electron microscopy (SEM) a fourier transform infrared spectroscopy (FTIR) and permeation tests. The permeation properties of the composite membrane were as follows: 1.3{{{{ {m }^{2 } }}}}/{{{{ {m }^{2 } }}}}day of flux and >95% of rejection at 200 psi for a 1000 ppm PEG600 solution.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.8
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• pp.720-727
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• 2004

In the process of ice-slurry making, the phenomenon of ice adhesion influences extremely to ice making system. In this study, the effect on the ice adhesion by thermal storage material with additives is investigated quantitatively. Various solutions of 300 g in a stainless vessel were frozen under stirring. Through the experiment the ice adhesion between cooling wall and ice-slurry was compared with each other by measuring the stirring power. From the experiment, the stirring power in EG, SCA solution was smaller than those in the solution containing functional materials, such as poly-vinyl-alcohol or kitchen detergent.

• Proceedings of the Korean Fiber Society Conference
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• 2001.10a
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• pp.29-32
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• 2001

Conductive polymers(CPs) are a relatively new class of organic materials displaying as their foremost property a high conductivity combined with very light weight, flexibility and reasonably facile processability[1]. Due to their high conductivity/weight ratio, they have recently evinced much interest in potential application as EMI shielding screens, coatings or jackets for flexible conductors, rechargeable batteries and as possible substitutes for metallic conductors or semiconductors in wide variety of electrical devices[2]. (omitted)

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1459-1461
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• 2009

In this study, we prepared the multi-refraction film thin by ink-jet technique with sol-gel precursor. The precursors were prepared by using some transition metal alk-oxide and the tetraethylorthosilicate (TEOS) mixed separately with n-Butyl Alcohol and PVB (Poly(vinyl butyral)).The structure and morphology of the resulting films were investigated by atomic force microscope (AFM). It is shown that the shape of the pattern of the films would affect the refraction proportion.

• Proceedings of the Membrane Society of Korea Conference
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• 1999.07a
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• pp.35-38
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• 1999

Nanofiltration (NF) composite membranes based of poly (vinyl alcohol) (PVA) and sodium alginate (SA) were prepared by coating PVA/SA (95/5 in wt %) mixture solutions on the microporous polysulfone (PS) supports, followed by the crosslinking with glutaraldehyed. The composite membranes prepared were characterized with a scanning electron microscopy (SEM), a fourier transform infrared spectroscopy(FTIR), an elecrtokinetic analyzer (EKA) and permeation tests.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.661-664
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• 2006

Recently, various concrete reinforcing fibers have been used to reduce the plastic shrinkage cracking which occurs before the concrete hardens. In this study, the physical properties of nylon fiber reinforced concrete such as slump, air content, compressive strength and tensile strength were investigated. In addition, the performance of nylon fiber in the plastic shrinkage cracking reduction of concrete has been estimated in comparison with polypropylene, poly vinyl alcohol fiber and cellulose fiber. Nylon fiber showed considerable advantages in terms of the workability of concrete and the plastic shrinkage cracking reduction of concrete compared with polypropylene fiber and cellulose fiber.