• Journal of Information Display
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• v.8 no.1
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• pp.14-17
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• 2007

The toner type paper-like display (PLD) has been developed with two polymer particles having opposite polarity composed of polymer, colorant and external additives (nano-sized silica). Nano-sized silica with triboelectric charge was used for the charge control agent (CCA) and influenced on the electrostatic properties of the silica-coated polymer particles. The surface morphology and the cohesiveness of silica-coated polymer particles were changed with the silica coating time. From these results, it was verified that the PLD cell using silica-coated particles (200 seconds) shows a good white appearance and low driving voltage.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.05b
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• pp.5-9
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• 2005

$LiFePO_4$ is a potential candidate for the cathode material of the lithium polymer batteries. $LiFePO_4$ cathode active materials were synthesized by coating on the $LiFePO_4$ was tried using $TiO_2$ and corbon in oreder to increase cyclic performance and electronic conductivity. Highly dispersed on the particles enhances the electronic conductivity and increases the capacity. For lithium polymer battery applications, $LiFePO_4$/SPE/Li and $LiFePO_4$-$TiO_2$/SPE/Li 'cells were characterized electrochemically by cyclic volatammetry and charge/discharge cycling. The $LiFePO_4$-carbon-$TiO_2$ cathode in PVDF-PC-EC-$LiCIO_4$ electrolyte showed high capacity at high current density.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.05b
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• pp.33-36
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• 2005

Colloidal Silica(CS)/silane sol solutions were prepared in variation with synthesizing parameters such as ratio of CS to silane and reaction time. In the case of LHSA CS/tetramethoxysilane(TMOS)/methyltrimethoxysilane(MTMS) CS/silane sol, coating film had stable contact angle with increasing reaction time excepting for 48hours. Also, the LHSA CS/TMOS/MTMS coating film had more enhanced flat surface with increasing the amount of MTMS and increasing reaction time. In the case of thermal stability, thermal dissociation of LHSA CS/MTMS sol did not occur up to $550^{\circ}C$.

• Corrosion Science and Technology
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• v.4 no.1
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• pp.15-18
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• 2005

Hydroxyapatite(HAp) was synthesized using the waste sludge from semiconductor process and used as an anticorrosive pigment. The water absorption of coating pigmented with anticorrosive pigment and the corrosion at interface between coating and substrate were monitored using AC impedance techniques. The anticorrosive performance of HAp was compared with those of red lead(RL) and zinc potassium chromate(ZPC), which have been known as representative anticorrosive pigments. The amount of absorbed water in ZPC- and HAp- pigmented coatings was much higher compared to that in RL-pigmented and unpigmented film. However, it seems that the water absorbed into HAp- or ZPC-pigmented film is beneficial to anticorrosive function. The anticorrosive performance of HAp is superior or at least comparable to those of ZPC and RL. The excellent anticorrosive properties of HAp can be explained by its passivating ability, caused by the reaction of the soluble component of HAp with Fe to form iron phosphate in the presence of water.

• KIEE International Transactions on Electrophysics and Applications
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• v.11C no.2
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• pp.18-22
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• 2001

The thin films of high permitivity in ferroelectric materials using a capacitor are applied to DRAMs and FRAMs. (Ba, Sr)TiO$_3$ thin as ferroelectric materials were prepared by the sol-gel method and made by spin-coating on the Pt/Sio$_2$/Si substrate at 4,000 [rpm] for 10 seconds. The structural characteristics of the surface were analyzed by fractal dimension. The thickness of BST ceramics thin films was about 260∼280 [nm]. The property of the leakage current was stable with 10-9∼10-11[A] when the applied voltage was 0∼3[V]. BST thin films ha low leakage current properties when fractal dimension was low and a coating area was high.

• Journal of Surface Science and Engineering
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• v.30 no.6
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• pp.365-373
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• 1997

316L and 420 Stainless steels were deposited onto AZ9ID commercial magnesium alloy by plasma spray process with various gas flow rate of, TEX>$H_2$ secondary gas. And hardness as well as were track volume, coefficient of friction also had been measured. wear and hardness were measured by using reciprocal configuration tribometer and microghardness tester, respectively. Also, the microstructure of the coatings surface the cross sectional area of coating surface and cross sectional area of coaing/Substrate interface had been analyzed with Scanning Electron Microscope(SEM) and Optical microscope(OM). Finally, optimal process parameters for the improvement of coating efficiency such as mechanical property and wear behavior were examined.

• Journal of Surface Science and Engineering
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• v.39 no.2
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• pp.70-75
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• 2006

As technology advances, there is a demand for development of hard, solid lubricant coating. (Ti,Cr)N-$MoS_2$, films were deposited on SKD 11 tool steel substrate by co-deposition of $MoS_2$, with (Ti,Cr)N using a D.C. magnetron sputtering process. The influence of the $N_2/Ar$ gas ratio, the deposition temperature, the amount of $MoS_2$ in the films, and the bias voltage on the mechanical and the structural properties of the films were investigated. Wear tests were performed on the films deposited in various conditions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.200-201
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• 2008

태양전지 제작 시 반사방지막(Anti-reflection Coating)이 태양전지 효율에 미치는 영향을 알아보기 위한 실험으로 최적의 가스비를 알아보기 위하여 Plasma Enhanced Chemical Vapor Deposition(PECVD)를 이용한 Silicon nitride 증착 실험이다. SiH4 가스를 45 sccm으로 고정시킨 상태에서 NH3를 25,45,60,90,135 sccm으로 가변하여 Carrier Lifetime과 Refractive index를 측정하였다. PECVD의 조건은 기판온도 $450^{\circ}C$, Chamber 압력 1 Torr, 증착두께 $1000\AA$으로 고정하였다. 증착 후 500, 600, 700, $800^{\circ}C$로 열처리를 하고나서 Carrier Lifetime을 측정하여 열처리에 대한 효과도 알아보았다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.83-86
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• 1998

Ferroelectric PZT(40/67)/PZT(60/40)heterolayered thin films were Prepared by the alkoxide-based Sol-Gel method. PZT(40/60) and PZT(60/40) stock solutions were made and spin-coated on the P7Ti/Si02/Si substrate alternately. These PZT(40/60) and PZT(60/40) films were dried at 300$^{\circ}C$ for 30min to remove organic materials and were sintered at 650$^{\circ}C$ for 1 hour to crystalize into a perovskite structure. The coating and heating procedure were repeated 6 times to form heterolayered films. Increasing the number of coating, coercive field was decreased. The relative dielectric constant, loss, remanent polarization and coercive field of the 4-coated PZT heterolayered were 1200, 4.1[%], 30.794[${\mu}$C/㎡] and 147.22[kV/cm], respectively.

• Journal of the Korean Society of Marine Environment & Safety
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• v.3 no.2
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• pp.85-92
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• 1997

To determine an operational condition of an adhesion-type oil skimmer, it is important to estimate the withdrawal rate for a given driving velocity of the skimmer and material properties of the oil. As a theoretical model for this problem the formation of an oil film on a vertically driven flat plate is investigated. The previous steady-state analysis made in the field of coating industry are reviewed. These studies have been made under the assumptions of small Reynolds and capillary number, which is adequate for coating process but not for oil skimming. An alternative analysis based on the linear stability theory is made. Comparisons with the experimental results reveal that the stability analysis gives a correct estimation of the withdrawal rate for high capillary number at which the previous theory losses its validity.