• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.7
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• pp.462-466
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• 2015

In this paper, we investigated the relations between dispersion of CNTs (carbon nanotubes) and electrical conductivity in the CNT/PVDF (polyvinylidene fluoride) composite film. By adding hydrophobic CNTs as filler into the PVDF matrix, we fabricated hydrophobic and electrically conducting polymer coating film. Dispersion of CNTs in the CNT/PVDF composite film plays a significant role in terms of electrical conductivity and wetting property. Spray coating method was used to form the CNT/PVDF composite films by injecting the dispersed CNTs in the PVDF solution with different weight ratios from 0.7 wt% to 7 wt%. We investigated the electrical properties and contact angles of the CNT/PVDF composite films with the CNT concentration. Finally we discussed the conducting mechanism and feasibility of the CNT/PVDF composite film for the conducting polymer films.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.917-919
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• 2003

The effect of conducting carbon layer on the performance of AC thin film EL display was examined. It was found that incorporation of small amount of carbon nano-tube and conducting additive greatly improve the luminance of the inorganic EL compared to the one with only conducting carbon black.

• Transactions on Electrical and Electronic Materials
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• v.13 no.5
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• pp.237-240
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• 2012

A conducting polymer, poly 3-hexylthiophene (P3HT) is characterized with the metal-insulator-semiconductor (MIS) measurement method and the high frequency planar circuit method. From the MIS measurement method, the relative dielectric constant of the P3HT film is estimated to be 4.4. For the high frequency planar circuit method, a coplanar waveguide is fabricated on the P3HT film. When applying +20 V to the CPW on P3HT film, the P3HT film is in accumulation mode and becomes lossy. The CPW on P3HT film is 1.5 dB lossier than the CPW on $SiO_2$ film without P3HT film at 50 GHz.

• Analytical Science and Technology
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• v.7 no.2
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• pp.181-186
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• 1994

Using poly(3-methylthiophene) conducting polymer film electrodes, feasiblity for Ag determination by stripping voltammetry has been studied. Ag ions accumulated by complexation with 18-crown-6, which are existing on the surface of the polymer film electrode, migrate inside of polymer film through potential scanning within limited potential range, and then are reduced and oxidized on the glassy carbon substrate. Therefore, the polymer film must have proper thickness and porosity for easy penetration of Ag ions. On the basis of these experimental results, $5.0{\times}10^{-6}M$ Ag(I) in aqueous solution could be determined.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.3
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• pp.528-531
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• 1994

Digitalization in electronic system is required the capacitor which have a large capacitance with small size, low impedance at high frequency, and high reliability. The fabrication and its properties of aluminum solid electrolytic capacitor are investigated. Employing conduction polymer film such as, polypyrrole as solid electroylte, solid type aluminum electrolytic capacitors were made. The surface of insulationg oxide is covered with conducting polymer layer prepared by chemical oxidative polymerization. Thereafter this conducting layer is covered with conducting polymer prepared by electrochemical polymerization. The dielectric properties of these capacitors were also measured and discussed. Regarding on frequency characteristics of the trial made capacitor, impedance and ESR at high frequency is lower than those of the stacked type film capacitor. It is alo confirmed that temperature coefficient of capacitance and dissipation factor of the capacitor are lower than those of film capacitor and liquid type aluminum electrolytic capacitor.

• Polymer(Korea)
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• v.31 no.4
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• pp.308-314
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• 2007

A composite film of polyurethane(PU)-graft-poly(acrylic acid) (PAAc)/polyaniline (PU-g-AAc/PANI) was successfully fabricated for the purpose of adding conductivity on the surface of a general purpose polymer and improving adhesive property between the general purpose polymer and conducting polymer layer. The results from ATR-FTIR and XPS analyses also supported the successful synthesis of the composite film by showing characteristic peaks for every step. A low surface resistivity of $2{\times}10^3\;ohm/sq$ proved the surface conductivity of synthesized PU-g-AAc/PANI film and the surface resistance decreased with increasing the amount of grafted AAc, which acted as a dopant for PANI film.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.1039-1042
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• 2001

A method for designing antireflection (AR) and antistatic (AS) films by the use of conducting polymer as an electrically conductive transparent layer is proposed. The conducting AR film is composed of four-layer with alternating high and low refractive index layer: silicon dioxide (n=1.44) and titanium dioxide (n=2.02) prepared at low temperature by sol-gel method are used as the low and high refractive index layer, respectively. The 3,4-polyethylenedioxythiophene (PEDOT) which has the sheet resistance of 10$^4$$\Omega$/$\square$ is used as a conductive layer. Optical constant of ARAS film was measured by the spectroscopic ellipsometer and from the measured optical constants the spectral properties such as reflectance and transmittance were simulated in the visible region. The reflectance of ARAS films on glass substrate was below 0.8 %R and the transmittance was higher than 95 % in the visible wavelength (400-700 nm). The measured AR spectral properties was very similar to its simulated results.

• JSTS:Journal of Semiconductor Technology and Science
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• v.8 no.1
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• pp.46-50
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• 2008

The effect of physicochemical properties of solvents on the microstructure of polyvinyl carbazole (PVK) film for non-volatile polymer memory was investigated. For the solubilization of PVK molecules and the preparation of PVK films, four solvents with different physicochemical properties of the Hildebrand solubility parameter and vapor pressure were considered: chloroform, tetrahydrofuran (THF), 1,1,2,2-tetrachloroethane (TCE), and N,N-dimehtylformamide (DMF). The solubility of PVK molecules in the solvents was observed by ultravioletvisible spectroscopy. PVK molecules were observed to be more soluble in chloroform, with a low Hildebrand solubility parameter, than solvents with higher values. The aggregated size and micro-/nano-topographical properties of PVK films were characterized using optical and atomic force microscopes. The PVK film cast from chloroform exhibited enhanced surface roughness compared to that from TCE and DMF. It was also confirmed that the microstructure of PVK film has an effect on the performance of non-volatile polymer memory.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.7.1-7.1
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• 2011

Nanoporous templates have been widely used for the development of new functional nanostructured materials suitable for electronics, optics, magnetism, and energy storage materials. We have prepared nanoporous templates by using thin films of mixtures of polystyrene-block-poly (methyl methacrylate) (PS-b-PMMA) and PMMA homopolymers. These templates have cylindrical nanoholes spanning the entire thickness of the film. Some applications of nanoporous templates are introduced: a) anti-reflective coating, b) the preparation of conducting polymer nanowires of poly (pyrrole), poly (3,4-ethylenedioxy-thiopene) onto a glass coated with indium-tin-oxide, and c) the separation membranes for biomaterials. We found that when the pore fraction of nanoholes in the film was ~0.68, almost zero reflectance at a specific wavelength, which can be changed with film thickness, was achieved at visible wavelengths Furthermore, ultra high density array of conducting nanowires was successfully prepared onto various substrates including flexible polymer. Due to highly alignment of polymer chain along the nanowire direction, the conductivity was much increased. Furthermore, these nanoporous films were found to be very effective for the separation of human Rhinovirus type 14 (HRV 14), major pathogen of a common cold in humans, from the buffer solution. We also found that when the pore size was effectively controlled down to 6 nm, a single file diffusion was observed.

• Applied Chemistry for Engineering
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• v.10 no.6
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• pp.902-906
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• 1999

Electrically conducting composite films were prepared by a vapor phase in situ polymerization of pyrrole in the methyl cellulose film containing a copper(II) perchlorate. Methylcellulose had high affinity to pyrrole and was used as a matrix polymer. Conducting polypyrrole was embedded in the methylcellulose film forming a conducting network and the conductivity of the composite films ranged $10^{-1}$ to $10^{-7}S/cm$. The conductivities of conducting composite films were dependent on the nature of the matrix polymers, concentration of oxidant and polymerization time. In situ polymerization of pyrrole was observed in the matrix polymer and confirmed by UV-vis spectra. From the results of the thermogravimetric analysis, the chemical oxidative polymerization of pyrrole in the matrix polymers did not give any negative effects on the thermal stability of the composite films. Electron micrograph of composites indicated good penetration of PPy in the matrix polymer. DMA suggested a certain degree of incompatibility of the polypyrrole in the composites.