• Journal of Adhesion and Interface
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• v.16 no.4
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• pp.152-155
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• 2015

Platinum (Pt) is an easily moldable, anti-corrosive and also good catalyst in a variety of chemical reactions. Platinum can be used in many fields, however, however, the low wettability of platinum substrate in many platinum-based devices has been made a problem when they contact with liquid state environment. In this study, we report a simple and effective self-assembled monolayer coating method which provides tremendously increased wettability on platinum substrate device by using Sodium 3-mercapto-1-propanesulfonic acid solution. After surface modifications, water contact angle of the surfaces displayed less than $10^{\circ}$, representing that surfaces are successfully coated to be super-hydrophilic surface by simple dip coating method.

• Macromolecular Research
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• v.17 no.11
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• pp.907-911
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• 2009

To improve the moisture stability of the $CaS:Eu^{2+}$ red phosphor, surface coatings with silica nanoparticles were performed using five different methods, i.e., $P_1$, $P_2$, $P_3$, $P_4$, and $P_5$. The phosphors were coated with silica nanoparticles using a dip coating method ($P_1$) and sol-gel method ($P_2$). The phosphors were coated using a solution containing silica nanoparticles and poly(1-vinyl-2-pyrrolidone), PVP, $(P_3$). The phosphors were also coated with silica nanoparticles by reacting with the 1-vinyl-2-pyrrolidone (VP) monomer ($P_4$) or by reacting with mixtures containing VP and tetraethylorthosilicate ($P_5$). A decrease in the photoluminescence (PL) intensity was observed regardless of the coating methods. However, the moisture stability of the phosphors was enhanced by the coating when aged in a temperature-controlled humidity chamber. Among these methods, the $P_4$ (or $P_5$) method exhibited the greatest increase in moisture stability of the phosphors. The coated phosphors showed a relatively constant intensity with aging time, whereas the uncoated phosphor showed a decrease.

• Polymer(Korea)
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• v.38 no.3
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• pp.391-396
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• 2014

Polymer microneedles can be fabricated by a micromolding method, an easy and cost-effective method. However, it is not easy to achieve uniform coating with an aqueous coating solution due to hydrophobic surface of polymer microneedles. 3-Dimensional coating polymer microneedles could deliver more than twice as much dose as in-plane metal microneedles by increasing coating area and the number of microneedles per unit area. A uniform coating was not obtained by addition of coating additives in the coating solution. The satisfied coating was achieved by treatment of surface of polymer microneedle with metal deposition and UV/ozone, and UV/ozone treatment was an ultimate surface treatment method based on biological safety. Calcein coating polymer microneedles were prepared by using UV/ozone treatment and followed dip-coating, and they delivered calcein in porcine skin successfully after 15 min of insertion.

• Korean Chemical Engineering Research
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• v.57 no.4
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• pp.525-530
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• 2019

The performance and stability of solid oxide fuel cells (SOFCs) depend on the microstructure of the electrode and electrolyte. In anode, porosity and pore distribution affect the active site and fuel gas transfer. In an electrolyte, density and thickness determine the ohmic resistance. To optimizing these conditions, using costly method cannot be a suitable research plan for aiming at commercialization. To solve these drawbacks, we made high performance unit cells with low cost and highly efficient ceramic processes. We selected the NiO-YSZ cermet that is a commercial anode material and used facile methods like die pressing and dip coating process. The porosity of anode was controlled by the amount of carbon black (CB) pore former from 10 wt% to 20 wt% and final sintering temperature from $1350^{\circ}C$ to $1450^{\circ}C$. To achieve a dense thin film electrolyte, the thickness and microstructure of electrolyte were controlled by changing the YSZ loading (vol%) of the slurry from 1 vol% to 5 vol. From results, we achieved the 40% porosity that is well known as an optimum value in Ni-YSZ anode, by adding 15wt% of CB and sintering at $1350^{\circ}C$. YSZ electrolyte thickness was controllable from $2{\mu}m$ to $28{\mu}m$ and dense microstructure is formed at 3vol% of YSZ loading via dip coating process. Finally, a unit cell composed of Ni-YSZ anode with 40% porosity, YSZ electrolyte with a $22{\mu}m$ thickness and LSM-YSZ cathode had a maximum power density of $1.426Wcm^{-2}$ at $800^{\circ}C$.

• Progress in Superconductivity
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• v.9 no.1
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• pp.85-90
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• 2007

Lanthanum aluminate($LaAlO_3$) film has been prepared on single crystal and metal substrates by dip coating method. Lanthanum acetate and aluminum were prepared via ligand exchange starting from lanthanum nitrate hexahydrate and aluminum nitrate hexahydrate in acetate glacial acetic acid solution after being refluxed. Coating solution was obtained by diluting the gel with methanol and 2-methoxyethanol to adjust the total cation concentration to 0.67 M. Precursor coated film was prepared by dip-coating with a speed of 25 mm/min on various substrates such as $LaAlO_3$ (001), MgO(001), $SrTiO_3$(001) single crystal, LMO/MgO/Ni-alloy. Thin films have been obtained by heat treating the precursor film at various temperatures from $600^{\circ}C{\sim}900^{\circ}C$ and various heating rate from $0.83^{\circ}C/min{\sim}1.25^{\circ}C/min$ under $Ar/O_2$ mixture containing 1000ppm oxygen. The films have been characterized by scanning electronic microscopy (SEM) and X-ray diffraction (XRD). XRD analysis for the prepared film showed that $LaAlO_3$ thin films with a preferred orientation of (100) plane parallel to substrate surface were obtained at $800^{\circ}C(1.11\;^{\circ}C/min)$ on LMO/MgO/Ni-alloy substrate, but the intensity decreased with the increase of heat treatment temperature.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.1
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• pp.57-66
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• 2003

TiO$_2$ sol was prepared by sol-gel method, and this sol was coated in ceramic and glass bead by dip-coating method. The coated catalyst was applied to degrade benzene in the gas phase by exposing to UV -lamp (365 nm) in a batch reactor. The removal efficiency of the benzene was compared by changing various conditions such as the kind of chemical additives, the coating beads (ceramic and glass), solution pH, the initial concentration of TiO$_2$ sol, UV intensity, and benzene concentration. The physical structure of TiO$_2$ sol used in this study was found to be pu-rely anatase type from XRD analysis. The results showed that ceramic bead was effective as the coating agent rath-er than glass bead. The significant change in the benzene removal efficiency of benzene did not occur with chang-ing coating frequency and the initial concentration of TiO$_2$ sol. The removal efficiency of benzene increased with increasing UV intensity, and with acidic treatment of TiO$_2$-coated ceramic bead.

• Membrane Journal
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• v.31 no.1
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• pp.80-85
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• 2021

In this study, we developed an evaporation-driven self-assembly coating method for an ceramic intermediate layer on an ultrapermeable ��-Al2O3 support with large pore size of ~1.5 ㎛. The method led to the formation of a ceramic intermediate layer with higher surface homogeneity and less surface roughness than the conventional dip-coating method. A mesoporous ��-Al2O3 layer was deposited on the support to evaluate support quality. A supported ��-Al2O3 membrane was defect-free even without repeated coating. Furthermore, the membrane showed 2.3 times higher nitrogen permeance than one prepared on a macroporous support with pore size range of 100~200 nm, which is widely used for ceramic membrane coating.

• Corrosion Science and Technology
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• v.21 no.2
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• pp.111-120
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• 2022

To solve the corrosion problem of industrial equipment and other constructions containing metals, corrosion protection can be performed by using coating which provides a barrier between the metal and its environment. Coatings play a significant role in protecting irons and steels in harsh marine and acid environments. This study was conducted to identify an anti-corrosive epoxy coating for carbon steel composite with 0.1, 0.3, and 0.5 wt% concentrations of nanoparticles of SiO₂ using the dip-coating method. The electrochemical behavior was analyzed with open circuit potential (OCP) technics and polarization curves (Tafle) in 3.5 wt% NaCl and 5 vol% H₂SO₄ media. The structure, composition, and morphology were characterized using different analytical techniques such as X-ray Diffraction (XRD), Fourier Transform Infrared spectrum (FT-IR), and Scanning Electron Microscopy (SEM). Results revealed that epoxynano SiO₂ coating demonstrated a lower corrosion rate of 2.51 × 10^-4 mm/year and the efficiency of corrosion protection was as high as 99.77%. The electrochemical measurement showed that the nano-SiO₂ / epoxy coating enhanced the anti-corrosive performance in both NaCl and H₂SO₄ media.

• Korean Chemical Engineering Research
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• v.45 no.5
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• pp.442-447
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• 2007

In order to improve the surface hardness of transparent plastic films, organic-inorganic hybrid coating solutions were synthesized by the sol-gel method. The coating solutions were prepared by adding GPTMS (glycidoxypropyl trimethoxysilane) to a colloidal silica (12 nm) suspension. PC(polycarbonate) substrates were dipped into the coating solutions and dried at room temperature for 10 min before being cured at $80^{\circ}C$ for 30 min. The effect of the solution pH and GPTMS content was investigated on the properties of coating films. The pencil hardness and adhesion to substrates of the coating films, prepared at acidic condition (pH 4), showed better properties than those at neutral or basic conditions. Also, the pencil hardness and adhesion to substrates of the coating films increased with increasing GPTMS content.

• Carbon letters
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• v.14 no.4
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• pp.255-258
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• 2013

Flexible transparent conducting films (TCFs) were fabricated by dip-coating single-wall carbon nanotubes (SWCNTs) onto a flexible polyethylene terephthalate (PET) film. The amount of coated SWCNTs was controlled simply by dipping number. Because the performance of SWCNT-based TCFs is influenced by both electrical conductance and optical transmittance, we evaluated the film performance by introducing a film property factor using both the number of interconnected SWCNT bundles at intersection points, and the coverage of SWCNTs on the PET substrate, in field emission scanning electron microscopic images. The microscopic film property factor was in an excellent agreement with the macroscopic one determined from electrical conductance and optical transmittance measurements, especially for a small number of dippings. Therefore, the most crucial factor governing the performance of the SWCNT-based TCFs is a SWCNT-network structure with a large number of intersection points for a minimum amount of deposited SWCNTs.