• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.165-166
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• 2014

The Composite waterproofing began to rise gradually 2000s in domestic. However, the sheet-membrane composite waterproofing method also acts as an abutment vulnerability that was a problem in a single method, and had the problem of damage to the formation of leakage paths. The existing non-overlap method, through vigorous research abutting sheet shall or could be developed to improve the seal performance of this method with the I-type joint coating material. Nevertheless, it has an integral top coat paint membrane and a sheet abutment limitation, damage to the upper membrane is damaged junction coating membranes has been generated. In this study, a method that has a layer of insulation on the joint bond breaker concept development, and to determine the physical properties with insulated joints to determine the breaking off of the upper joint is damaged coating membrane and tensile performance.

• Membrane Journal
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• v.19 no.1
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• pp.54-62
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• 2009

Pervaporation membrane for butanol separation was prepared by hybrid process. Plasma treatment of commercial poly(dimethylsiloxane) (PDMS) membrane was attempted and combination of plasma treatment and PDMS solution coating on polysulfone, poly(ether imide) supports were also performed. Plasma treatment of PDMS membrane with hexane and silane group compounds was performed to increase the hydrophobicity of the surface, which enhanced the separation factor upto 12.5 at the expense of flux decrease down to $1.15kg/m^2{\cdot}hr$. Contact angle and relative sorption ratio were also related with hydrophobicity of the memrbane. Increase of PDMS prepolymer composition resulted in dense structure of coating layer with better separation factor. Effects of sequence of PDMS coating vs. plasma treatment were examined. It was found that plasma treatment with butanol and n-hexane plasma followed by PDMS coating showed better performance and vice versa for plasma treatment with hexamethyldisilane and hexamethyldisilazane.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.29 no.2
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• pp.77-81
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• 2019

Recently, as the problem of environmental pollution emerges, various methods of eco-friendly water treatment method are being developed. Polymer membranes, which are currently leading the market, are inexpensive, but have many problems in terms of chemical resistance and durability. Thus, ceramic membrane has been attracted great attention as high-efficiency water treatment due to excellent durability and chemical resistant. In this study, ceramic membranes were developed via pore structure, size control, and surface treatment. The pore size of the membrane was controlled through the formation of $ZrO_2$ and $TiO_2$ coating films. Tape casting and sol-gel process were used to form a ceramic coating film with nanopores on the surface of the membrane. Microstructure analysis of ceramic membrane and pore size analysis of the coating film were conducted and the change of water treatment characteristics was observed.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.28 no.1
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• pp.38-43
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• 2018

Ceramic membrane has been widely used for water treatment due to its advantages of eco-friendly property and low energy consumption. However, high porosity of ceramic membrane higher than 40 % may cause a problem of strength, when it is applied to a water treatment module. In order to solve this problem, the strength of the membrane edge was improved by using the ceramic glaze. Four different glaze compositions for low temperature sintering was selected to minimize the deformation of the membrane microstructure. After coating with low temperature glaze, cracks were observed due to differences in thermal expansion coefficient between the membrane and glaze. Thus, the thermal expansion coefficient of glaze was controlled by addition of cordierite and petalite. As a results, the compressive strength of the ceramic membrane, which was coated with the optimized glaze composition, was increased from $27N/m^2$ to $117N/m^2$, indicating that the glaze coating can improve the disadvantages of the fragile ceramic membrane.

• Membrane Journal
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• v.15 no.1
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• pp.34-43
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• 2005

The poly(vinyl alcohol) (PVA)-based thin film composite nanofiltration (NF) membranes were prepared by coating polysulfone ultrafiltration membranes, sulfonated polyethersulfone and polyamide NF membranes with aqueous PVA solution by a pressurizing method. The PVA was cross-linked with aqueous glutaraldehyde solution. The NF membranes coated with a very low concentration of PVA on all the support membranes was successfully prepared. With increasing the hydrophilicity of the support membranes, the water flux increased. Especially, ζ-potential of negatively charged polyamide NF membrane was reduced by coating the membrane with PVA. A fouling experiment was carried out with positively charged surfactant, humic acid, complex of humic acid and calcium ion and bovine serum albumin. A non-coated polyamide NF membrane was significantly fouled by various foulants. The fouling process when using humic acid and protein occurred at the isoelectric point. There was severe fouling when using humic acid and adding bivalent cations. By coating the polyamide NF membrane with aqueous PVA solution, fouling was reduced. The polyamide NF membrane coated with PVA was resistant to the acidic and basic solution.

• Membrane and Water Treatment
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• v.10 no.4
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• pp.287-298
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• 2019

Lotus leaf has a special dual micro and nano surface structure which gives its highly hydrophobic surface characteristics and so-called self cleaning effect. In order to endow PVDF hollow fiber membrane with this special structure and improve the hydrophobicity of membrane surface, PVDF hollow fiber composite membranes was obtained through the immersion coating of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) dilute solution on the outside surface of PVDF support membrane. The prepared PVDF composite membranes were used in the vacuum membrane distillation (VMD) for the desalination. The effects of PVDF-HFP dilute solution concentration in the dope solution and coating time on VMD separation performance was studied. Membranes were characterized by SEM, WCA measurement, porosity, and liquid entry pressure of water. VMD test was carried out using $35g{\cdot}L^{-1}$ NaCl aqueous solution as the feed solution at feed temperature of $30^{\circ}C$ and the permeate pressure of 31.3 kPa. The vapour flux reached a maximum when PVDF-HFP concentration in the dilute solution was 5 wt% and the coating time was kept in the range of 10-60 s. This was attributed to the well configuration of micro-nano rods which was similar with the dual micro-nano structure on the lotus leaf. Compared with the original PVDF membrane, the salt rejection can be well maintained which was greater than 99.99 % meanwhile permeation water conductivity was kept at a low value of $7-9{\mu}S{\cdot}cm^{-1}$ during the continuous testing for 360 h.

• Journal of the Korean Wood Science and Technology
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• v.49 no.6
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• pp.658-666
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• 2021

A novel flame retardant and antibacterial composite membrane coating for wood surfaces was prepared by adding POSS-based phosphorous nitrogen flame retardant (later referred to as NH₂-POSS) and silver nanoparticles (Ag NPs) to chitosan (CS). The effects of NH₂-POSS content (mass fractions of CS 0%, 0.5%, 1%, 3%, 5%, and 7%) on the structure and properties of the composite membrane coating on wood were investigated. The composite film was prepared by the method of blending and ducting. Contact angle, tensile property and antibacterial effects of the composite film were measured, and infrared spectroscopy was used. The results show that the addition of NH₂-POSS can not only improve the toughness of the membrane, but also the flame retardancy of the membrane, which improves the application of the membrane in wood products. However, with the addition of NH₂-POSS, the transparency of the composite membrane was weakened. The inhibitory effect of the composite membrane on the growth of Escherichia coli was enhanced with the increase in Ag NPs. This research provides a foundation for the application of functional wood.

• Journal of the Korean Ceramic Society
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• v.30 no.3
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• pp.189-198
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• 1993

A new pressurized sol-gel coating technique forming membrane layers inside pores of the porous support by the simple operation has been developed. Crack-free and reproducible nanoparticulate silica membranes supported on the porous $\alpha$-alumina tube are synthesized by pressurized coating at 600kPa for 2hr. The pore radius and N2 gas permiability at the room temperature of silica membrane layers are 8$\AA$ and 7.0$\times$10-7mol/$m^2$.s.Pa, respectively. The mechanism of N2 gas transfer through synthesized membrane layers is the perfect Knudeen flow, and the thermal stability of the silica composite membranes is excellent upto 40$0^{\circ}C$.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.161-162
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• 2014

The subject of this study, Eco-friendly Polyurethane Waterproofing Membrane Coating of Exposed Type is manufactured by replacing environmental hazardous substance such as Toluene, Dioctyl Phthalate with Dimethyl Carbonate, waste-soybean oil. As part of existing filler is also replaced with waste-rubber chip and waste-soybean oil. As a result of environment friendly tests, in test of detection of VOCs case was contented with the Ministry of Environment standards at 5% below. Testing methods for heavy metal extracted was contented with standards for official wastes test method. So it is judged that environment friendly is secured.

• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.771-777
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• 1999

The structural function of three egg membrane layers and cuticle layer, and the effectiveness of 5 film coatings (chitosan, starch, gelatin, dextrin, mineral oil) on the prevention of Salmonella enteritidis penetration was investigated using confocal scanning laser microscopy (CSLM). Diameters of outer membrane fibers, inner membrane fibers and limiting membrane particles in eggshell were $1.5{\sim}7.2$, $0.8{\sim}2.0$ and $0.1{\sim}1.4\;{\mu}m$, respectively and average thicknesses were 10.0, 3.5, $3.6\;{\mu}m$, respectively. Average thickness of cuticle layer was $6.0\;{\mu}m$ and cuticle layer covered $40{\sim}80%$ of total eggshell surface. Average coating films thickness for chitosan, starch, gelatin, dextrin and mineral oil were 2.2, 2.5, 3.9, 3.6 and $5.0\;{\mu}m$, respectively. After immersion process eggshell surface was almost completely covered by coating films. Chitosan coating was most effective among 5 film coatings in inhibiting growth of Salmonella enteritidis. Penetration process of Salmonella enteritidis through eggshell was investigated by multicolor imaging using CSLM and plate counting. Cuticle layer was the most important structure in blocking the penetration. Among 5 film coatings, chitosan showed the best and similar effectiveness with cuticle layer.