• Applied Chemistry for Engineering
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• v.32 no.4
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• pp.403-408
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• 2021

In this study, a thin and flexible planar supercapacitor (PSC) was fabricated by coating polyaniline (PANI) on a screen-printed carbon electrode. Carbon ink was coated onto the flexible polyethylene terephthalate using a screen-printing method; subsequently, a thin film of PANI was coated onto the carbon surface using a dilute polymerization method. A thin flexible PANI electrode in an interdigitated structure was assembled with a polymer gel electrolyte that resulted in planar-shaped supercapacitor (PSC) devices. The as-obtained PANI/PSC was very thin and flexible, exhibiting a high areal capacitance of 409 µF/cm was obtained at a rate of 10 mV/s. This capacitance retains 46% of its original value at 500 mV/s. The flexible PANI/PSC exhibited an excellent capacitance retention of 82% even under bent states of 180° and 100 repetitive bent cycles.

• Journal of Korea Multimedia Society
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• v.20 no.6
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• pp.882-892
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• 2017

Locally Likely Arrangement Hashing (LLAH) is a method that describes image features based on the geometry between their neighbors. Thus, it has been preferred to implement augmented reality on poorly-textured objects such as text documents. However, LLAH strongly requires that image features be detected with high repeatability and located at a distance from one another. To fulfill the requirement for text document, this paper proposes a method that facilitates the word detection in infrared (IR) range by adjusting the IR-reflectance of words. Specifically, the words are printed out with two different black inks: one is using the K(carbon black) ink only, the other is mixing the C(cyan), M(magenta), Y(yellow) inks. Since only the words printed out with the K ink is visible in IR range, a part of words are selected in advance to be used as features and printed out the K ink. The selected words can be robustly detected with high repeatability in IR range and this enables to implement augmented reality on text documents with high fidelity. The validity of the proposed method was verified through experiments.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.40.1-40.1
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• 2011

Single-walled carbon nanotubes are one among the most promising carbonaceous materials to be used as the electrodes in the devices like micro batteries, supercapacitors, etc. In this study, single-walled carbon nanotube thin films have been fabricated through electrospray deposition technique which is one of the attractive direct printing methods in the field of printed electronics. Single-walled carbon nanotube ink (water dispersed, 3wt %) has been used to fabricate thin films through electrospray deposition technique. The as-deposited SWCNT thin films have been characterized using the appropriate characterization techniques and the results are presented.

• Particle and aerosol research
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• v.17 no.2
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• pp.21-27
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• 2021

We developed non-metallic electrodes that can replace metallic electrodes of the electrostatic precipitator(ESP) for the purpose of light weight, corrosion resistance, cost reduction. We manufactured three types of collection electrodes made of stainless steel (M), Carbon ink coating layer-Plastic sheet-Carbon ink coating layer (CPC), and Plastic sheet-Carbon ink coating layer-Plastic sheet (PCP). We studied the collection efficiency of a two-stage ESP using oil mist particles with and without collection stage by changing the flow rate, the material of collection electrode, and the applied voltage of the pre-charger module and the collection module. Here we measured concentrations of particles at diameters of 0.45 ㎛ (CMD; count median diameter) and 3.0 ㎛ (MMD : mass median diameter), as well as PM_2.5 and PM₁₀. As a result of the experiment, two-stage ESP had 22~25% higher collection efficiency in PM_2.5 than one-stage ESP at the same applied voltage. The difference in collection efficiency by varying the materials of collection electrodes was less than 5%. The weight of the non-metallic electrode was only one eighth the weight of the metal electrode. CPC electrode had a thickness of 0.27 mm, which was 1.5 times thinner than a thickness of PCP electrode, so when the flow rate increased, the CPC electrodes couldn't be kept at equal intervals due to the fluttering unlike PCP electrodes. In addition, the PCP-CPC collection module of the present experiment followed the theoretical efficiency based on Deutsch equation and Cochet's charging theory.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.12
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• pp.82-90
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• 2019

This analysis demonstrates the effective removal of heat generated from a solar panel's output degradation factor solar cells (the solar panel's output deterioration factor), and solves the problems of oxidation and corrosion in existing metal heat sinks. The heat-dissipating test specimen was prepared using carbon materials; then, its thermal conductivity and its effectiveness in reducing temperatures were studied using heat transfer numerical analysis. As a result, the test specimen of the 30g/㎡ basis weight containing 80% of carbon fiber impregnated with carbon ink showed the highest thermal conductivity 6.96 W/(m K). This is because the surface that directly contacted the solar panel had almost no pores, and the conduction of heat to the panels appeared to be active. In addition, a large surface area was exposed to the atmosphere, which is considered advantageous in heat dissipation. Finally, numerical analysis confirmed the temperature reduction effectiveness of 2.18℃ in a solar panel and 1.08℃ in a solar cell, depending on the application of heat dissipating materials.

• Journal of the Korean Graphic Arts Communication Society
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• v.16 no.1
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• pp.39-53
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• 1998

The extraction rate of ginger from Korean-grown ginger root with supercritical carbon dioxide was measured as a function of flow rate of supercritical carbon dioxide, particle size, temperature and pressure. the extraction rate increased as the particle size decreased due to a decrease in the diffusion path. The extraction rate were independent of flow rate of supercritical carbon dioxide in a plot of ginger oil yield versus extraction time. This indicated that the extraction process is controlled by intraparticle diffusion within a particle of ginger root. In the case of temperature and pressure effect, the experimental results showed that the extraction rate decreased with an increase in temperature and increased with an increase in pressure.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.4
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• pp.716-722
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• 2017

In this paper, a fully printed NFC tag operating at 13.56 MHz was designed and fabricated using silver nano-paste and carbon ink. The proposed NFC tag has a printed coil with an inductance of $2.74{\mu}H$ on a PI film for application to an NFC tag IC with an internal capacitance of 50 pF. Screen printing technology used in this paper has advantages such as large area printing for mass production, low cost and eco-friendly process compared to conventional PCB manufacturing process. The proposed structure consists of a circular coil implemented as a single layer using silver nano-paste and carbon ink, a jumper pattern for chip mounting between the outer edge and the center of the coil, and an insulation pattern between the coil and the jumper pattern. In order to verify the performance of the proposed NFC tag, we performed the measurements of the printing line width, thickness, line resistance, adhesion and environmental reliability, and confirmed the suitability of the NFC tag based on the full-printed manufacturing method.

• Analytical Science and Technology
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• v.32 no.3
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• pp.77-87
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• 2019

High viscosity carbon black dispersions are used in various industrial fields such as color cosmetics, rubber, tire, plastic and color filter ink. However, carbon black particles are unstable to heat due to inherent characteristics, and it is very difficult to keep the quality of the product constant due to agglomeration of particles. In general, particle size analysis is performed by dynamic light scattering (DLS) during the dispersion process in order to select the optimum dispersant in the carbon black dispersion process. However, the existing low viscosity analysis provides reproducible particle distribution analysis results, but it is difficult to select the optimum dispersant because it is difficult to analyze the reproducible particle distribution at high viscosity. In this study, dynamic light scattering (DLS) and asymmetrical flow field-flow fractionation (AsFlFFF) analysis methods were compared for reproducible particle size analysis of high viscosity carbon black. First, the stability of carbon black dispersion was investigated by particle size analysis by DLS and AsFlFFF according to milling time, and the validity of analytical method for the selection of the optimum dispersant useful for carbon black dispersion was confirmed. The correlation between color and particle size of particles in high viscosity carbon black dispersion was investigated by using colorimeter. The particle size distribution from AsFlFFF was consistent with the colorimetric results. As a result, the correlation between AsFlFFF and colorimetric results confirmed the possibility of a strong analytical method for determining the appropriate dispersant and milling time in high viscosity carbon black dispersions. In addition, for nanoparticles with relatively broad particle size distributions such as carbon black, AsFlFFF has been found to provide a more accurate particle size distribution than DLS. This is because AsFlFFF, unlike DLS, can analyze each fraction by separating particles by size.

• Korean Journal of Materials Research
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• v.14 no.11
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• pp.807-812
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• 2004

The uniformity of emission mage and field emission properties of carbon nanotube(CNT) cathodes dependence on CNT particle dispersion were investigated for field emission displays. We used multi-walled carbon nanotubes (MWNTs) synthesized by CVD method as the field emitter materials. CNT dispersion in CNT ink was carried out by ultrasonication and shaking methods. According to CNT dispersion conditions, the uniformity of emission image and field emission properties of CNT cathodes were greatly affected. The smaller particles of filler materials and CNT powders provide the better properties of the CNT cathodes.

• Journal of Electrochemical Science and Technology
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• v.13 no.1
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• pp.100-111
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• 2022

This paper presents a simple and inexpensive method to fabricate chemically and mechanically resistant hot electron-emitting composite electrodes on reusable substrates. In this study, the hot electron emitting composite electrodes were manufactured by doping a polymer, nylon 6,6, with few different brands of carbon particles (graphite, carbon black) and by coating metal substrates with the aforementioned composite ink layers with different carbon-polymer mass fractions. The optimal mass fractions in these composite layers allowed to fabricate composite electrodes that can inject hot electrons into aqueous electrolyte solutions and clearly generate hot electron- induced electrochemiluminescence (HECL). An aromatic terbium (III) chelate was used as a probe that is known not to be excited on the basis of traditional electrochemistry but to be efficiently electrically excited in the presence of hydrated electrons and during injection of hot electrons into aqueous solution. Thus, the presence of hot, pre-hydrated or hydrated electrons at the close vicinity of the composite electrode surface were monitored by HECL. The study shows that the extreme pH conditions could not damage the present composite electrodes. These low-cost, simplified and robust composite electrodes thus demonstrate that they can be used in HECL bioaffinity assays and other applications of hot electron electrochemistry.