• Journal of Electrochemical Science and Technology
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• v.5 no.3
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• pp.73-81
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• 2014

This paper describes the continuous flow operation of membraneless sodium perborate fuel cell using acid/alkaline bipolar electrolyte. Here, hydrazine is used as a fuel and sodium perborate is used as an oxidant under Alkaline-acid media configuration. Sodium perborate affords hydrogen peroxide in aqueous medium. In our operation, the laminar flow based microfluidic membranleless fuel cell achieved a maximum power density of $27.2mW\;cm^{-2}$ when using alkaline hydrazine as the anolyte and acidic perborate as the catholyte at room temperature with a fuel mixture flow rate of $0.3mL\;min^{-1}$. The simple planar structured membraneless sodium perborate fuel cell enables high design flexibility and easy integration of the microscale fuel cell into actual microfluidic systems and portable power applications.

• Carbon letters
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• v.11 no.4
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• pp.298-303
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• 2010

A method of functionalization of multi-walled carbon nanotube (MWNT) at room temperature using dry ozone gas is described. The resulting MWNT were characterized by Fourier transform infrared, x-ray photoelectron spectroscopy, and scanning electron microscopy. Combined to these analyses and solubility in liquids, it could be concluded that the dry ozone gas exposure introduces polar functional groups such as carboxylic groups to MWNT similar to acidic modification of MWNT. Particularly, the stable dispersion of MWNT in water after ozone treatment above a critical level could be obtained, implying potential bio-application. The hydrophilic functional groups on the MWNT introduced by ozone oxidation were helpful in improving the interaction with functional groups in PA6 such as $-NH_2$ and -CONH- resulting in improved mechanical properties.

• Corrosion Science and Technology
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• v.10 no.5
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• pp.162-166
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• 2011

Effects of chemical compositions and manufacturing conditions on mechanical properties and microstructures were investigated in order to obtain galvannealed high strength dual phase steel sheets with superior mechanical properties and coating properties. An intercritical annealing between Ac1 and Ac3 was conducted to produce the DP (dual phase) steel sheets, followed by quenching to room temperature. The purposes of Al addition are to reduce the iron oxidation with chemical composition (Si, Mn etc.) and to improve the wettability by liquid zinc. The present study will focus on the characterization for making dual phase steel sheets and enhancing the galvanizability of Al added DP steel sheets about continuous annealing line in CGL.

• Nuclear Engineering and Technology
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• v.32 no.6
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• pp.595-604
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• 2000

Flow-Accelerated Corrosion Behavior of SA106 Gr.C steel in room temperature alkaline solution simulating the CANDU primary water condition was studied using Rotating Cylinder Electrode. Systems of RCE were set up and electrochemical parameters were applied at various rotating speeds. Corrosion current density decreased up to pH 10.4 then it increased rapidly at higher pH. This is due to the increasing tendency of cathodic and anodic exchange half-cell current. Corrosion potential shifted slightly upward with rotating velocity. Passive film was formed from pH 9.8 by the mechanism of step oxidation and the subsequent precipitation of ferrous species into hydroxyl compound. Above pH 10.4, the film formation process was active and the film became stable. Corrosion current density showed increment in pH 6.98 with the rotating velocity, while it soon saturated from 1000 rpm above pH 9.8. This seems that activation process which represents formation of passive film on the bare metal surface controls the entire corrosion process

• Journal of Hydrogen and New Energy
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• v.25 no.4
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• pp.419-424
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• 2014

Direct ethanol fuel cell has been fabricated with ceramic membrane. A porous silicon carbide (SiC) membrane having approximately 30% porosity has been applied for a direct ethanol proton exchange membrane (DE-PEM) fuel cell. A horizontal type cell having Pt ($18mg/cm^2$) catalyst layer on both side of the ceramic membrane was used for the demonstration test. The ethanol oxidation based-fuel cell stack showed very high voltage (1.289V) and measurable current level (68mA) even though at room temperature.

• Journal of the Korean Ceramic Society
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• v.36 no.8
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• pp.863-870
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• 1999

SOI(silicon on insulafor) was fabricated through the direct bonding using (100) Si wafer and 4$^{\circ}$off (100) Si wafer to investigate the stacking faults in silicon at the Si/SiO2 oxidized and bonded interface. The treatment time of wafer surface using MSC-1 solution was varied in order to observe the effect of cleaning on bonding characteristics. As the MSC-1 treating time increased surface hydrophilicity was saturated and surface microroughness increased. A comparison of surface hydrophilicity and microroughness with MSC-1 treating time indicates that optimum surface modified condition for time was immersed in MSC-1 for 2 min. The SOI structure directly bonded using (100) Si wafer and 4$^{\circ}$off (100) Si wafer at the room temperature were annealed at 110$0^{\circ}C$ for 30 min. Then the stacking faults at the bonding and oxidation interface were examined after the debonding. The results show that there were anomalies in the gettering of the stacking faults at the bonded region.

• Journal of Radiation Industry
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• v.5 no.3
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• pp.237-242
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• 2011

In this research, the radiation resistance of ethylene propylene rubber (EPR) and chlorosulfonated polyethylene (CSPE) which can be used as a insulating materials of for electrical cable in the nuclear power plant were investigated. EPR and CSPE were irradiated by ${\gamma}$-ray at various doses ranging from 50 to 500 kGy at room temperature in air. The irradiated EPR and CSPE was investigated in terms of activation energy, mechanical properties, and oxidation stability. The experimental results revealed that CSPE exhibited the higher radiation resistance in comparison to that of EPR.

• Journal of Industrial and Engineering Chemistry
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• v.68
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• pp.168-172
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• 2018

This study first investigates the effect of the choice of cation on three different ionic-liquid-based gel polymer electrolytes (ILPEs) with polyimide membranes. The preparation of three ILPEs based on electrospun membranes of PI and incorporating a room-temperature ionic liquid, 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide complexed with lithium bis(trifluoromethylsulfonyl)imide, is described. ILPE-EMImTFSI has an ionic conductivity as high as $5.3{\times}10^{-3}S\;cm^{-1}$ at $30^{\circ}C$. Furthermore, it shows higher thermal stability and electrochemical oxidation stability compared to the other two ILPEs because of its stronger bonds. These results indicate that polyimide-based ILPE-EMImTFSI is a good candidate for use in high-safety rechargeable lithium metal batteries.

• Bulletin of the Korean Chemical Society
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• v.20 no.3
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• pp.333-336
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• 1999

The polyaniline films with various insoluble parts are fabricated. The oxidation state (1-y) of these polyaniline is 0.53 and 0.54, respectively. To control the interchain and intrachain interaction of the polymer, the polyaniline films are stretched with appropriate ratio. The insoluble part of polyaniline synthesized at room temperature (low molecular weight) is 12%-76% and that of polyaniline synthesized at 0 'IC (intermediate molecular weight) is 65%-89%. The low molecular weight polyaniline films with various drawing ratios have amorphous structure. In the intermediate weight polyaniline films, the crystallinity of films increases with drawing ratio as well as insoluble part. The difference of the insoluble part affects electrical conductivity which is increased dramatically with draw ratio. In particular, the higher insoluble part caused greater increase in electrical conductivity.

• Journal of Electrochemical Science and Technology
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• v.6 no.3
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• pp.95-105
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• 2015

In the present work, Carbon supported Pt₁₀₀, Pt₈₀Sn₂₀, Pt₈₀Ni₂₀ and Pt₈₀Sn₁₀Ni₁₀ electrocatalysts with different atomic ratios were prepared by ethylene glycol-reduction method to study the electro-oxidation of ethanol in membraneless fuel cell. The electrocatalysts were characterized in terms of structure, morphology and composition by using XRD, TEM and EDX techniques. Transmission electron microscopy measurements revealed a decrease in the mean particle size of the catalysts for the ternary compositions. The electrocatalytic activities of Pt₁₀₀/C, Pt₈₀Sn₂₀/C, Pt₈₀Ni₂₀/C and Pt₈₀Sn₁₀Ni₁₀/C catalysts for ethanol oxidation in an acid medium were investigated by cyclic voltammetry (CV) and chronoamperometry (CA). The electrochemical results showed that addition of Ni to Pt/C and Pt-Sn/C catalysts significantly shifted the onset of ethanol and CO oxidations toward lower potentials. The single membraneless ethanol fuel cell performances of the Pt₈₀Sn₁₀Ni₁₀/C, Pt₈₀Sn₂₀/C and Pt₈₀Ni₂₀/C anode catalysts were evaluated at room temperature. Among the catalysts investigated, the power density obtained for Pt₈₀Sn₁₀Ni₁₀/C (37.77 mW/cm² ) catalyst was higher than that of Pt₈₀Sn₂₀/C (22.89 mW/cm² ) and Pt₈₀Ni₂₀/C (16.77 mW/ cm² ), using 1.0 M ethanol + 0.5 M H₂SO₄ as anode feed and 0.1 M sodium percarbonate + 0.5 M H₂SO₄ as cathode feed.