• Food Science and Biotechnology
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• v.18 no.5
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• pp.1161-1172
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• 2009

Food nanoemulsion systems consisting of water and oleoresin capsicum (OC), polyoxythylene sorbitan esters (Tween 20, 40, 60, and 80), propylene glycol (PG), sucrose monostearate (SM), and their corresponding mixtures were formulated to use as food vehicles. Tween 80 produced OC nanoemulsions with stable dispersions as one-phase systems, and the dertermined emulsification efficiencies clearly distinguished the ability of the various surfactants to emulsify OC. The nanoemulsions were prepared by both ultrasonication and self-assembly, and the nanoemulsion areas were determined using phase diagrams by measuring the sizes of the emulsions. One-phase nanoemulsions were presented, with a multiple cloudy region and phase separation that were dependent on the particle size of the emulsion. The OC nanoemulsions prepared by ultrasonication using systems of OC/Tween 80/water, OC/Tween 80/water+PG, and OC/Tween 80/water+SM, resulted in particle sizes ranging from 15 to 100 nm. Finally, the nanoemulsions maintained their initial sizes during storage, ranging from 65 to 92 nm.

• Journal of Powder Materials
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• v.25 no.4
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• pp.309-315
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• 2018

In the present work, we synthesize nano-sized ZnO, $SnO_2$, and $TiO_2$ powders by hydrothermal reaction using metal chlorides. We also examine the energy-storage characteristics of the resulting materials to evaluate the potential application of these powders to dye-sensitized solar cells. The control of processing parameters such as pressure, temperature, and the concentration of aqueous solution results in the formation of a variety of powder morphologies with different sizes. Nano-rod, nano-flower, and spherical powders are easily formed with the present method. Heat treatment after the hydrothermal reaction usually increases the size of the powder. At temperatures above $1000^{\circ}C$, a complete collapse of the shape occurs. With regard to the capacity of DSSC materials, the hydrothermally synthesized $TiO_2$ results in the highest current density of $9.1mA/cm^2$ among the examined oxides. This is attributed to the fine particle size and morphology with large specific surface area.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.8
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• pp.744-751
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• 2003

Co-Pd alloy thin films prepared by a DC-sputter that have self-organized nano structure(SONS), are promising for high-density information storage media in information era. We prepared the samples by varying Pd contents of 0~8.1 wt% at the substrate temperatures of room temperature (RT) and 200 $^{\circ}C$, respectively Microstructure and Pd contents of the Co$_{1-x}$ Pd$_{x}$ films are probed by a scanning electron microscope (SEM), a transmission electron microscope (TEM) and an energy dispersive spectrometer (EDS). We also investigated the saturation magnetization (Ms), remanence and coercivity of the Co$_{1-x}$ Pd$_{x}$ films. Surface roughness are measured by an atomic force microscope (AFM). We revealed that self-organized nano size Co-enriched phase and Pd-enriched phase existed with Pd contents at the substrate temperatures of RT and 20$0^{\circ}C$ through microstructure characterization. SONS helped to keep the saturation magnetization and enhance the perpendicular anisotropy with Pd contents. Out result implies that we may tune the perpendicular magnetic properties with keeping the saturation magnetization by varying substrate temperatures and Pd contents for high density magnetic recording.rding.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.37-40
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• 2004

Electrochromic displays offer the possibility of providing high brightness in reflective mode due to the fact that no polarization of the incident or reflected light is required. The use of appropriately roughened reflective layers can enable the diffuse or Lambertian reflection of light. truly imitating the optical nature of paper as a reading medium. Furthermore, the use of an electrochromic system, essentially an electrochemical device, allows for the integration of charge storage layers, endowing such devices with an on-state memory and associated low power consumption. In this paper we describe the $NanoChromics^{TM}$ system and overview the several strategies employed towards the migration of this technology to flexible display formats.

• Journal of Electrochemical Science and Technology
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• v.6 no.3
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• pp.81-87
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• 2015

This study introduces a facile strategy to prepare metal oxide/conducting polymer nanocomposites that may have promising applications in energy storage devices. Ploy aniline/nano wire manganese dioxide (PANI/NwMnO₂) was synthesized by cyclic voltammetry on glassy carbon electrode. Morphology and structure of the composite, pure PANI, MnO₂ nanowires were fully characterized using XRD and SEM analysis. Electrochemical studies shows excellent synergistic effect between PANI and MnO₂ nanowires which results in its capacitance increase and cycle stability against PANI electrode. Specific capacitances of PANI/NwMnO₂ and PANI were 456 and 190 F/g respectively. The electrochemical performance of electrodes studied using cyclic voltammetry, Galvanostatic charge/discharge and impedance spectroscopy.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.552-555
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• 2004

The reliability issue of the probe tip/recording media interface is one of the most crucial concerns in the Atomic Force Microscope (AFM)-based recording technology. In this work, the tribological characteristics of the probe/media interface were investigated by performing wear tests using an AFM. The ranges of applied normal load and sliding velocity for the wear test were 10 to 50nN and 2 to 20$\mu$m/s respectively. The damage of the probe tip was quantitatively as well as qualitatively characterized by Field Emission Scanning Probe Microscope (FESEM) analysis and calculated based on Archard s wear equation. It was shown that the wear coefficient of the probe tip was in the order of 10$^{-4}$ ~ 10$^{-3}$ , and significant contamination at the end of the probe tip was observed. Thus in order to implement the AFM-based recording technology, tribological optimization of the probe/media interface must be achieved.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1030-1035
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• 2003

The nanoimprint lithography technology makes higher density of semiconductor device and larger capacity of storage media. In this technology the induced damage while detaching polymer pattern from mold should be minimized. In order to analyze the problem, the basic knowledge of adhesion between the polymer and the mold is required. In this study a contact experiment of polyisobutylene specimen with spherical steel tip and polyisobutylene bead tip was conducted using nano indenter. During the contact experiment with various loading rate under load control the contact behavior of viscoelastic material was measured, i.e., the load and displacement between the tip and the specimen were measured. The data was analyzed by HBK model to obtain the stress intensity factor of contact edge and the contact radius as a function of time. Also the adhesion energies between steel/polyisobutylene and polyisobutylene/polyisobutylene were obtained employing the analysis of the crack of viscoelastic material by Schapery.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.107-108
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• 2005

Au and $Au/SiO_2$ nanoparticles(NPs) were synthesized by the colloidal method. The formation of Au and $Au/SiO_2$ NPs was confirmed using high resolution transmission electron microscopy (HRTEM). Synthesized solutions were deposited on Si wafer. The electrical properties of structures were measured using a semiconductor analyzer and a LCR meter. Capacitance versus voltage hysterisis curves showed the charge storage effect by Au and $Au/SiO_2$ NPs.

• Nano
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• v.13 no.12
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• pp.1850138.1-1850138.6
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• 2018

Two-dimensional (2D) or layered materials have a great potential for applications in energy storage, catalysis, optoelectronics and gas separation. Fabricating novel 2D or quasi-2D layered materials composed of relatively abundant and inexpensive atomic species is an important issue for practical usage in industry. Here, we suggest the layer-structured AlOOH (Boehmite) as a promising candidate for such applications. Boehmite is a well-known layer-structured material and a single-layer can be exfoliated from the bulk boehmite by breaking the interlayer hydrogen bonding. We study atomic and electronic band structures of both bulk and single-layer boehmite, and also obtain the single-layer exfoliation energy using first-principles calculations.

• Journal of the Korean Vacuum Society
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• v.15 no.2
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• pp.173-179
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• 2006

We have investigated structural and electrical properties of $PbZr_{0.3}Ti_{0.7}O_{3}$ (PZT) thin films deposited by pulsed laser deposition methods. PZT thin films have been deposited on $LaMnO_3$ (LMO) bottom electrodes with $LaAlO_3$ (LAO) substrates during different deposition times. High-resolution x-ray diffraction data have shown that all the PZT films and bottom electrodes are highly oriented. The thickness of each film is determined by field-emission scanning electron microscope. We have also observed root mean square roughness by using atomic force microscopy mode, and local polarization distribution and retention behavior of a ferroelectric domain by using piezoelectric force microscopy mode. A PZT/LMO structure has shown good ferroelectric and retention properties as the media for nano-storage devices.