• Korean Chemical Engineering Research
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• v.50 no.4
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• pp.614-620
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• 2012

Polyurethane prepolymers were prepared from poly (carbonate diol), isophrone diisocyanate and dimethylol propionic acid. Then, aniline terminated waterborne polyurethane dispersion (ATPUD) was synthesized by capping the NCO group of the prepolymer with aniline monomer. Subsequently, ATPUD and waterborne polyurethane dispersion (PUD), respectively, were blended with conducting polymer, poly (3,4-ethylenedioxythiophene)/polystyrene sulfonate [PEDOT/PSS], to yield antistatic coating solutions, and the mixture was coated on the polycarbonate substrates. At adequate addition amounts of PEDOT/PSS less than or equal to 2.5 g, the surface resistances ($1.0{\times}10^{11}{\sim}2.5{\times}10^8{\Omega}/cm^2$) of coating films from ATPUD showed better electronic conductivities than those ($5.0{\times}10^{11}{\sim}6.3{\times}10^9{\Omega}/cm^2$) from PUD. However, at excess amount of PEDOT/PSS of 3.0 g, the surface resistance from ATPUD showed similar electronic conductivity with that from PUD.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.11a
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• pp.125-128
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• 1998

Electroluminescent(EL) devices based on organic thin films have attracted lots of interests in large-area light-emitting display. One of the problems of such device is a lifetime, where a degradation of the cell is possibly due to an organic layer's thickness, morphology and interface with electrode. In this study, light-emitting organic electroluminescent devices were fabricated using Alq$_3$(8-hydroxyquinolinate aluminum) and TPD(N,N'-diphenyl-N,N'-bis(3-methylphenyl)-[1-1'-biphenyl]-4,4'-diamine).Where Alq$_3$ is an electron-transport and emissive layer, TPD is a hole-transport layer. The cell structure is ITO/TPD/Alq$_3$/Al and the cell is fabricated by vacuum evaporation method. In a measurement of current-voltage characteristics, we obtained a turn-on voltage at about 9 V. And we used other buffer layer of PPy(Polypyrrole) with ITO/PPy/TPD/Alq$_3$/Al structure. We observed a surface morphology by AFM(Atomic Force Microscopy), UV/visible absorption spectrum, and PL(Photoluminescence) spectrum. We obtained the UV/visible absorption peak at 358nm in TPD and at 359nm in Alq$_3$, and at 225nm and the PL peaks at 410nm in TPD and at 510nm in Alq$_3$ and at 350nm. We also studied EL spectrum in the cell structure of ITO/TPD/Alq$_3$/Al and ITO/PPy/TPD/Alq$_3$/Al and we observed the EL spectrum peak at 510nm from our cell

• Bulletin of the Korean Chemical Society
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• v.31 no.11
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• pp.3109-3114
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• 2010

Flexible composite films of $V_2O_5$ and conductive polypyrrole ($V_2O_5$/PPy) were grown by facile electrochemical polymerization, wherein an anodization potential was applied to the substrate electrode in an electrolyte solution containing pyrrole monomer and dispersed $V_2O_5$ particles. The coating of polypyrrole (PPy) on the surface of $V_2O_5$ particles was induced by the oxidative catalytic action of $V_2O_5$ during the electrochemical polymerization of pyrrole. PPy in the composite film connects the isolated $V_2O_5$ particles. This results in the formation of conductive networks in the composite film cathode, thereby enhancing the Li+ ion diffusion to the surface of the isolated $V_2O_5$ particles and thus increasing the accessibility of the $Li^+$ ions. The specific capacity tests of the Li rechargeable batteries revealed that the discharge capacity of this composite film cathode was higher, i.e., $497\;mAhg^{-1}$, than that of $V_2O_5$/PPy powder or pristine $V_2O_5$.

• Composites Research
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• v.24 no.6
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• pp.1-6
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• 2011

A new water-soluble and self-doped poly(styrenesulfonic acid-graft-aniline), PSSA-g-PANI, for dispersing carbon nanotubes (CNTs) in water was synthesized and its ability to stabilize aqueous CNT dispersions was examined. It was observed that the PANI in PSSA-g-PANI, which has benzoid and quinoid structure, was strongly adsorbed onto the nanotube surface via a strong ${\pi}-{\pi}$ interaction, and thus only gentle sonication causes exfoliation of CNT ropes to small bundles and the long-term stability of their resulting dispersions was much better than commercial surfactants. Furthermore, when thin films of PSSA-g-PANI/CNT are prepared from aqueous dispersion and their electrical conductivities are measured by the four probe technique, it is observed that their conductivities are in the range of 1.5-2.5 S/cm.

• Polymer(Korea)
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• v.36 no.4
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• pp.525-530
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• 2012

In this study, silane-crosslinked organic/inorganic composite membranes were prepared by simultaneous irradiation grafting of binary monomer mixtures (styrene and 3-(trimethoxysilyl)propyl methacrylate (TMSPM)) with various compositions onto a poly(ethylene-alt-tetraethylene) (ETFE) film and followed by sol-gel processing and sulfonation to provide a silane-crosslinked structure and a proton conducting ability, respectively. The Fourier transform infrared spectroscopy (FTIR) and thermo gravimetric analysis (TGA) were utilized to confirm the crosslinking of ETFE-g-PS/PTMSPM films. The prepared membranes with similar ion exchange capacity but a different TMSPM content were selected and their membrane properties were compared. The ETFE-g-PSSA/PTMSPM membranes were characterized by water uptake, dimensional stability, and proton conductivity after sulfonation. The membrane electrode assemblies (MEA) of the prepared membranes were fabricated and their single cell performances were measured.

• Industry Promotion Research
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• v.9 no.1
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• pp.21-29
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• 2024

In the rapidly advancing information society, electronic devices, including smartphones and tablets, are increasingly digitized and equipped with high-performance features such as flexible displays. This study focused on optimizing the manufacturing process for Transparent Conductive Films (TCF) by using the cost-effective conductive polymer PEDOT and transparent substrate PET as alternatives to expensive materials in flexible display technology. The variables considered are production speed (m/min), coating maximum temperature (℃), and PEDOT supply speed (rpm), with surface resistivity (Ω/□) as the response parameter, using Response Surface Methodology (RSM). Optimization results indicate the ideal conditions for production: a speed of 22.16 m/min, coating temperature of 125.28℃, and PEDOT supply at 522.79 rpm. Statistical analysis validates the reliability of the results (F value: 18.37, P-value: < 0.0001, R²: 0.9430). Under optimal conditions, the predicted surface resistivity is 145.75 Ω/□, closely aligned with the experimental value of 142.97 Ω/□. Applying these findings to mass production processes is expected to enhance production yields and decrease defect rates compared to current practices. This research provides valuable insights for the advancement of flexible display manufacturing.

• Korean Chemical Engineering Research
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• v.40 no.6
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• pp.729-734
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• 2002

In this study, the polyaniline films of emeraldine base(EB) and lucoemeraldine base(LEB) form chemically doping with poly(sodium-4 styrenesulfonate, PSS) were prepared by casting the mixed solution of chloroform and m-cresol on ITO(indium tin oxide) electrode. By analyzing UV-vis spectra of the mixed solutions, the effects of the secondary doping by m-cresol were obtained. And the conductivity of polyaniline film was increased with increasing m-cresol content. The results suggest that the improvement of conductivity obtained by secondary doping results primarily from interaction of polyaniline and m-cresol. As the results of analyzing cyclic voltammograms, it was known that the redox peak currents of polyaniline electrode prepared from LEB were larger and more reversible than those of polyaniline electrodes prepared from EB. The charge transfer resistances($R_{ct}$) of polyaniline electrodes were reduced with increasing m-cresol content, and LEB/PSS electrodes were smaller than EB/PSS electrodes. This result agrees to the analysis of the redox peak current of cyclic voltammograms. The solution resistance and the capacity of electrical double layer almost unchanged in all prepared polyaniline electrodes. It was confirmed that solution resistance was independent of frequency factor in AC impedance spectra. Also the polyaniline film doping with PSS was revealed pseudo n-type characteristics of conducting polymer.