• Korean Chemical Engineering Research
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• v.51 no.1
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• pp.73-79
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• 2013

Waterborne polyurethane dispersion (WPUD) was synthesized from polycarbonate diol (PCD), isophorone diisocyanate (IPDI) and dimethylol propionic acid (DMPA) as starting materials. Then, waterborne acrylic polyurethane dispersion (AUD) was synthesized by reacting the WPUD with an acrylate monomer, methyl methacrylate (MMA). Subsequently, the AUD was mixed with multi-walled carbon nanotube (MWCNT) to yield a conductive coating solution, and the mixture was coated on the polycarbonate substrate. With increasing the amount of MMA in the AUD, the pencil hardness, abrasion resistance and chemical resistance of the coating films were improved, but the electrical conductivity of the coating films was decreased. On the other hand, the pencil hardness, abrasion resistance and chemical resistance of coating films were decreased, but the electrical conductivity was enhanced with increasing the amount of MWCNT in the conductive coating solutions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.455-456
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• 2007

Optically transparent, highly conductive coating have been major theme of thin film science efforts for some years. In this work, t-MWNT(thin Multi-walled Carbon Nanotubes) are acid treated, then the stable dispersion of t-MWNTs in polar solvent such as alcohols, was achieved by sonication. The transparent conducting films are prepared using the one component solution of t-MWNT/epoxy binder via spray coating on glass substrate. The characterization of acid treated t-MWNTs was performed by Raman spectrometer. The opto-electrical properties of conducting films are analyzed by the binder concentration, and the effect of co-solvent on the compatibility and dispersibility of one component t-MWNT/epoxy binder solutions are discussed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.381-382
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• 2008

$TiO_2$ colloidal solution was electrosprayed for preparing a conductive thin film with high quality. Electrospray is a technique of liquid dispersion electrically and a good method of manufacturing nanoparticle, nanofiber, porous membrane, film preparation and coating. Water and ethanol were used as solvents and their mixing ratio was varied for studying the influence of solvent volatile on nanoparticle dispersion. Various nozzles to control the thru-put of solutions.were examined. Integrated analytical method and scanning electron microscope were used to analyze integrity and microscopic images.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.394-394
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• 2007

Transparent conductive films can serve as a critical component in displays, solar cells, lasers, optical communication devices, and solid state lighting. Carbon nanotube (CNT) based transparent conductive films are fabricated on glass and polymer substrates. CNTs typically exist in form of quasi-crystalline bundles or highly entangled bundles containing tens of individual nanotubes. To achieve full potential, CNTs must be dispersed in a solvent or other organic media. CNTs are acid treated with nitric acid then the stable dispersion of CNTs in polar solvent such as alcohols, DMF, etc. is achieved by sonication. The solubility of CNTs correlates well with the area ratio of the D and G bands from Raman spectrum. Thin films are formed from well dispersed CNT solutions using spray coating method. CNT thin films exhibit a sheet resistance ($R_s$) of nearby $10^3\;{\Omega}/sq$ with a transmittance of around 80% on the visible light range, which is attributed by excellent dispersion and interaction among CNTs, solvents and polymeric binders.

• Fashion & Textile Research Journal
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• v.22 no.2
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• pp.233-239
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• 2020

We proposed a simple process of fabricating electroconductive textiles by coating conductive polymer PEDOT:PSS (Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)) on biocompatible PLA (Poly Lactic Acid) nanofiber web for application to smart healthcare. Electroconductive textiles were obtained by a drop-coating process using different amounts of PEDOT:PSS solutions., DMSO (dimethyl sulfoxide) was then used as an additive in the post-treatment process to improve conductivity. The surface morphology of the specimens was observed by FE-SEM. The chemical structures of the specimens were characterized using FTIR. The electrical properties (linear and sheet resistance) of the specimens were measured. The effect of the bending angles on the electrical properties was also investigated to confirm their applicability as wearable smart textiles. FE-SEM and FTIR analysis confirmed that the deposition of PEDOT:PSS on the PLA nanofiber web surface was successful. The conductivity of the PEDOT:PSS/PLA nanofiber web was enhanced up to 1.5 ml with an increasing amount of PEDOT:PSS solutions, but there was no significant difference at 2.0 ml. The optimum condition of PEDOT:PSS deposition was established to 1.5 ml. Even when the specimen coated with 1.5 ml was bent every 30°, the change in the electrical resistance values was still low within 3.7 Ω. It confirmed that stable electrical performance was maintained and proved the applicability as a flexible textile sensor.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.4
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• pp.388-394
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• 2008

For purpose of anti-static film remaining unchanged in the condition of $160^{\circ}C$, organic solvent, acid and base solution $0.01\sim0.03{\mu}m$ particles of Sb doped tin oxide(ATO) were grafted by 3-Glycidyloxypropyltrimethoxysilane(GPTS) for improving interfere bonding force between ATO and epoxy resin. The particles were dispersed in 2-methoxyethanol with YD-I28(Bisphenol A type epoxy resin, Kukdo chemical) and 1-imidazole as hardener. The anti-static solutions were coated on PI film as thickness of $0.1{\mu}m$. Surface resistivity of anti-static film containing conductive polymer became $10^{12}\Omega/\Box$ after 32 hours in $160^{\circ}C$. The surface resistivity of ATO grafted by GPTS / Epoxy coating layer remained as $10^{7.6}\Omega/\Box$ in $160^{\circ}C$ for 7 days. ATO grafted by GPTS / Epoxy coating layer coated on PI film was dipped in acetone for 7 days. The surface resistivity remained unchanged as $10^{7.6}\Omega/\Box$. The anti-static layer dipped in water solutions containing each KOH 10 wt % and $H_2SO_4$ 2 wt% was ultra-sonicated for 10 minutes per once until 30th. The surface resistance of anti-static layer containing ATO grafted by GPTS remained unchanged.

• Korean Journal of Materials Research
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• v.22 no.3
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• pp.155-158
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• 2012

In this work, AlON-$Al_2O_3$ coatings were prepared on Al2021 alloy by the electrolytic plasma processing (EPP) method. The experimental electrolytes include: 2 g/l NaOH as the electrolytic conductive agent, 10 g/l $Na_2AlO_2$ as the alumina formative agent, and 0.5 g/l $NaNO_2$, $NaNO_3$, and $NH_4NO_3$ as the nitride inducing agents. The effects of different nitrogen inducing agents were studied by a combined compositional and structural analyses of the ceramic coatings carried out by Xray diffractometry (XRD) and scanning electron microscopy (SEM) for the specimens EPP-treated at room temperature for 15 min under a hybrid voltage of 260 DC along with an AC 50 Hz power supply (200 V). Microhardness tests and wear tests were carried out to correlate the evolution of the microstructure and the resulting mechanical properties. Potentiodynamic polarizations and immersion corrosion tests were carried out in 3.5wt% NaCl water solutions under static conditions in order to evaluate the corrosion behavior of the coated samples. The results demonstrate that $NaNO_2$ is proven to be a good nitrogen inducing agent to produce high quality AlON-$Al_2O_3$ ceramic coatings.

• Korean Journal of Materials Research
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• v.20 no.2
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• pp.51-54
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• 2010

Transparent conductive films of single wall carbon nanotube (SWCNT) were prepared by spray coating method. The effect of acid treatment on the SWCNT films was investigated. The field emission scanning electron microscope (FESEM) shows that acid treatment can remove dispersing agent. The electrical and optical properties of acid-treated films were enhanced compared with those of as deposited SWCNT films. Nitric acid ($HNO_3$), sulfuric acid ($H_2SO_4$), nitric acid:sulfuric acid (3:1) were used for post treatment. Although all solutions reduced sheet resistance of CNT films, nitric acid can improve electrical characteristics efficiently. During acid treatment, transmittance was increased continuously with time. But the sheet resistance was decreased for the first 20 minutes and then increased again. Post-treated SWCNT films were transparent (85%) in the visible range with sheet resistance of about $162{\Omega}/sq$. In this paper we discuss simple fabrication, which is suitable for different types of large-scale substrates and simple processes to improve properties of SWCNT films.

• Journal of the Microelectronics and Packaging Society
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• v.30 no.2
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• pp.21-32
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• 2023

CuNWs(Copper nanowires) are attracting attention as a transparent electrode material because of their excellent electrical conductivity, high mechanical flexibility, and cost-effectiveness. However, since copper nanowires are easily oxidized, there is a disadvantage that properties of the transparent electrode may be deteriorated due to this, and researches are being conducted to improve this. Accordingly, in this review, various methods and studies to prevent oxidation and improve stability of copper nanowire transparent electrodes by using coating materials such as carbon-based materials, metals, and conductive polymers are introduced. Through this, we intend to provide solutions to solve the problem of development and oxidation of copper nanowire-based technology.