• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.211-214
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• 2001

The undesirable phase transformation of zirconium dioxide at high temperatures can be eliminated by stabilization of the cubic phase with an addition of a selected alkaline earth or rare-earth oxide. In this paper the ionic conductivity of cubic solid solutions in the stabilized ZrO$_2$ by CaO-Y$_2$O$_3$ system was examined. The higher ionic conductivity appears to be related to lower activation energy rather than to the number of oxygen vacancies dictated by composition. Those compositions of highest conductivity lie close to the cubic-monoclinic solid-solution phase boundary. Conductivity temperature data are presented that indicate a reversible order-disorder transition for Zr$_2$2-Y$_2$O$_3$cubic solid solutions containing 20 and 25 mole % $Y_2$O$_3$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.04a
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• pp.23-26
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• 1997

This work presents the TMAH/IPA anisotropic etching characteristics with addition of Pyrazine. (100) Si etching rate of 0.747 ${\mu}{\textrm}{m}$/min at 8$0^{\circ}C$ was obtained using TMAH 25 wt.% / IPA 17 vol.% / pyrazine 0.1 g. The etching rate of (100) Si is increased about 52% compare to pure TMAH 25 wt.%. But etching rate of (100) Si is decreased with increasing Pyrazine additive. Activation energy of TMAH/IPA/pyrazine is much lower than TMAH and TMAH/IPA solutions. Addition of Pyrazine does not effect on surface flatness and decreases undercutting ratio about 20 %. Therefore, TMAH/IPA/pyrazine is an attractive anisotropic etchant because of alkaline-ion free.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.64-69
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• 1999

Slags are by-products of the metallurgical industry. The most important slag from the standpoint of the quantity used as building material is iron blastfurnace slag. Slags are either crystalline stable solid used as aggregates or glassy material used as hydraulic binder. Slag cements are low heat of hydration cements. Slags react more slowly with than portland cement but they can be activated chemically. Activatiors can be either alkaline activators such as soda, lime, sodium carbonate, sodium silicate or sulphate activators such as calcium sulphate or phosphogypsum. So, in this study slaked lime was used as an activator that the compressive strength of this modified cement(M1 type) is high range in early age. And initial setting time of M1 type cement was shorter than conventional cements.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.10
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• pp.1114-1119
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• 2004

The photodepositioned tungsten film by laser CVD has been carried out the taping test with scotch tape over 10 times. As a result, it exhibited strong adhesion to the under-film such as ITO and SiNx patterned on the LCD substrate. However, it was seriously attacked by alkaline solution used for removing polyimide. And a thickness of laser CVD tungsten film had a close relation to a speed of laser scanning. Also we have improved the success rate of a laser CVD repair with making two pairs of contact hole structure and decreasing laser scanning speed.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.201-201
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• 2011

Recently, mussel-inspired surface modification, called polydopamine coating has been extensively implemented to many areas, due to its material versatility and ease to use. In particular, incubation of substrates in an alkaline dopamine solution resulted in self-polymerization of dopamine and modified variety of material surfaces, including noble metals, metal oxides, ceramics, and synthetic polymers. However, the polydopamine coating has a drawback to practical use; it takes more than 12 hrs to introduce sufficient polydopamine layers to solid substrates. Here, we investigated the rate-enhanced polydopamine coating by varying reaction conditions: pH, concentration, and the addition of the oxidizing agent. As a result, the optimum condition for fast polydopamine coating was found, and solid substrates were efficiently coated with polydopamine layers in just few minutes using the condition. The polydopamine-modified surface was characterized by XPS and contact angle goniometry, and the biocompatibility of the modified surface was also proved by cell attachment test.

• Resources Recycling
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• v.10 no.6
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• pp.3-8
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• 2001

This study was examed about leaching behavior in order to separate plasticizer selectively before dechlorination from flexible PVC material in alkali solutions at $80~120^{\circ}C$. The dechlorination of that was not almost occurred below $100^{\circ}C$. But the yield of elution of plasticizer was 100% above 5M NaOH. Therefore, by controlling alkali concentration and reaction temperature, it is possible to extract the plasticizer selectively without taking dechlorination.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.475-476
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• 2005

Efficient electron injection is essential to achieve bright and efficient organic light-emitting diodes (OLEDs). In spite of high work function of Al, it is a common cathode because of its stability. In this paper, to overcome the poor electron injection in OLEDs with Al cathode, OLEDs with various composite cathodes were fabricated and investigated using a conventional OLEDs structure of indium tin oxide ITO/NPB(40 nm)/$Alq_3$(50 nm)/Al. composite cathodes were composed of alkaline materials such as Ca and Li, Al deposition or codeposited with AI. We showed best performance at the device with composite cathode (LiF/Al).

• Journal of the Korean institute of surface engineering
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• v.32 no.3
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• pp.363-365
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• 1999

The improved method comprises electrochemically deposition of nickel hydroxide into the sintered nickel plaque cathode from nickel aqueous electrolyte at acid pH in a treating zone containing an anode. The electrochemical impregnation was examined under various conditions. Deposition condition of fine active material was obtained from the impregnation of a high temperature and also high current density. This method also could be decreased swelling and buckling of the plaque. A nickel electrode prepared by electrochemical impregnation is useful as the positive in nickel-cadmium cells. The utilization of the active material indicated almost 100% based on a one electron charge.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.11a
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• pp.343-346
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• 1995

In this paper, the effect of alkaline oxides on the humidity sensitivity of $V_2O_{5}$(2mol%)-doped $TiO_2$(98mol%) was investigated as functions of $Li_{2}Co_{3}$, $Na_{2}Co_{3}$. III-1. Measurement of Density. When the mole% of $Li_2$O is varied 0,1,2,5mol%, the more the mole% of additives is increased, the more difference of bulk and apparent density is largely narrowed. The difference of two densities of sample containing 2mol% $Na_2O$ was large all the moat. The sample containing 1mol% $Na_2O$ was small most. III-2. Observation of porosity. The porosity and total intrusion volume according to various amounts of $Li_2O$ was reduced and those of sample containing 2mol% $Na_2O$ as 31.13%, 0.1155mL/g was the highest and 1mol% $Na_2O$ was lowed most and 5, 10mol% $Na_2O$ was more high compare with sample without alkaline oxides. III-3. Characteristic of humidity sensitivity. 1. Impedance of samples containing $Li_2O$ was high compare with sample without alkaline oxides, so we thought it showed Poor sensitivity because it have no impedance changing rapidly as function of relative humidity. 2. When the humidity was increasing from 30RH% to 90RH%, the impedance of sample containing 2mol% $Na_2O$ at 120HZ changed exponential rapidly from 6${\times}$$10^{7}$$\Omega$) to 1.25${\times}$$10^4$$\Omega$. At under 50RH% and over 50RH%, the humidity sensitivity of samples containing 2mol% $Na_2O$ was best especially in the range of the low humidity. III-4. Characteristic of TG curves. When algal me oxide $M_{2}CO_{3}$(M=Li, Na) were added into $V_{2}O_{5}$-doped $TiO_2$, the stability of humidity sensitivity of samples containing amounts of $Li_2O$ was unstable. The samples containing 1mol% $Na_2O$ was unstable.

• Membrane Journal
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• v.27 no.5
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• pp.425-433
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• 2017

As the problems related to the environmental pollution such as carbon dioxide emission are emerging, the need for the renewable energy and environmentally friendly energy is getting intense. Fuel cells are eco-friendly energy generation devices that generate electrical energy and produce water as a sole by-product. Compared to the traditional proton exchange membrane fuel cell (PEMFC), anion exchange membrane alkaline fuel cell (AEMAFC) has a main advantage of possibility to use low cost metal catalysts due to its faster kinetics. The AEM, which conducts $OH^-$ ions, should possess high ion conductivity as well as high chemical stability at high pH conditions. We hereby introduce a crosslinked poly(2,6-dimethyl-1,4-phenylene oxide) having a spacer-type conducting group as novel AEM, and report a high ion conductivity ($67.9mScm^{-1}$ at $80^{\circ}C$) and mechanical properties (Young's modulus : 0.53 GPa) as well as chemical stability (6.8% IEC loss at $80^{\circ}C$ for 1,000 h,) for the developed membrane.