• Bulletin of the Korean Chemical Society
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• v.24 no.9
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• pp.1329-1332
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• 2003

Stepwise dechlorination of 1,2,4-trichlorobenzene was observed at a glassy carbon electrode in dimethylformamide containing 0.1 M tetraethylammonium perchlorate. Especially, dechlorination to dichlorobenzene and further to monochlorobenzene or benzene was successfully demonstrated with a porous reticulated vitreous carbon electrode. Electrochemical dechlorination of polychlorobenzenes employing a flow cell with a reticulated vitreous carbon working electrode is also described. Preliminary experiments with a flow cell showed that dechlorination of trichlorobenzene to dichlorobenzene was partially completed while dechlorination to benzene or monochlorobenzene was not successful, suggesting that a flow rate and electrolysis time should be further optimized for the complete electrolysis.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.315-316
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• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.89-90
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• 2012

• Journal of the Korean Vacuum Society
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• v.9 no.2
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• pp.122-129
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• 2000

Field emission behavior from vitreous carbon powders deposited on Mo coated glass by electro-phoretic method was investigated. Although the vitreous carbon has only $sp^2$ hybridized carbon bond, we could observe an excellent field emission behavior. Reproducible electron emission was observed without initiation process which is known to be needed in most carbon cathode materials. Critical electric field for electron emission was in the range from 3 to 4 MV/m. The effective work function was estimated to be about 0.06 eV, as obtained from the slope of Fowler-Nordheim plot. The stability of the emission behavior characterized by repeated I-V measurements, was much superior to the Si tips. We observed the possibility of full area light emission in vitreous carbon materials. This results showed that the field emission is not intimately related to the $sp^3$ hybridization of carbon, but the electrical properties of cathod/electrode interface or the conductivity of the cathode materials which required for the electron transport to the cathode surface.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.02a
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• pp.86-86
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• 1999

• Bulletin of the Korean Chemical Society
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• v.29 no.1
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• pp.168-172
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• 2008

A microbial fuel cell is a noble green technology generating electricity from biomass and is expected to find applications in a real world. One of main hurdles to this purpose is the low power density. In this study, we constructed a prototype microbial fuel cell using Proteus vulgaris to study the effect of various reaction conditions on the performance. Main focus has been made on the modification of the anode with electropolymerized polypyrrole (Ppy). A dramatic power enhancement was resulted from the Ppy deposition onto the reticulated vitreous carbon (RVC) electrode. Our obtained maximum power density of 1.2 mW cm-3 is the highest value among the reported ones for the similar system. Further power enhancement was possible by increasing the ionic strength of the solution to decrease internal resistance of the cell. Other variables such as the deposition time, kinds of mediators, and amount of bacteria have also been examined.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.4
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• pp.120-129
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• 2003

The anodic alumina is synthesized using 0.3M oxalic acid and the barrier layers of the anodic alumina are removed using the 20wt% $H_2SO_4$ solution. The structure of the anodic alumina is analyzed by XRD and SEM. It is observed by SEM that the size of anodic alumina pore is about 60nm. And the uniformity of the anodic alumina surface under the 20wt% $H_2SO_4$ solution is poorer than the unifomity of the the normal anodic alumina surface. The anodic alumina and the carbon are used cathode and anode in$Cd(NO_3)_2{\cdot}4H_2O$, $Co(NO_3)_2{\cdot}6H_2O$ and $PbSO_4$ solutions. In this study, the constant D.C. electrical current is flowed in each solution for 24hours. It is found that the voltages so far as 4.6, 3.4 and 5.1V at $Cd(NO_3)_2{\cdot}4H_2O$, $Co(NO_3)_2{\cdot}6H_2O$ and $PbSO_4$ solutions increase with increasing the flowing current time and after the voltage does not change which values are 4.2, 2.7 and 2.4V, respectively. The amount of metal ions in solutions decrease with increasing the flowing current time until the flowing current time is 18hours and the metals are formed at the surface of anodic alumina. After the metal ions are removed using the anodic alumina, and $Cd^{2+}$, $Co^{2+}$ and $Pb^{2+}$ ions are removed again using flow cell with retriculate vitreous carbon(RVC) working electrode. The concentration of $Cd^{2+}$, and $Co^{2+}$ions decrease until the flowing time of the solutions is 20minutes and the concentration of $Pb^{2+}$ ion decreases until that time is 30minutes. In this case, the removal effects of $Cd^{2+}$, $Co^{2+}$ and $Pb^{2+}$ ions are 34.78, 28.79 and 86.38%, respectively. And it is possible that both $Cd^{2+}$ and $Co^{2+}$ions are adsorbed in pore of RVC at the same time and the removal effects of $Cd^{2+}$ and $Co^{2+}$ions are 32.30 and 31.37%.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.12
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• pp.1263-1269
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• 2005

Horseradish peroxidase, had the phenol degradation rate of 95% in aqueous phase, was covalently immobilized on the surface of reticulated vitreous carbon(RVC) and the degradation of phenol was performed with in situ generated $H_2O_2$-immobilized HRP complex in an electrochemical reactor. The incorporation of carboxylic group on the RVC surface was confirmed by FT/IR spectrometry and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride(EDC) was used for peptide bonds between the carboxylic groups on the RVC surface and amine groups from HRP. The optimal conditions of in situ $H_2O_2$ generation such as concentration($10{\sim}200$ mM) and pH($5.0{\sim}8.0$) of electrolyte, supply of $O_2(10{\sim}50$ mL/min) and applied voltage($-0.2{\sim}-0.8$ volt, vs. Ag/AgCl) from potentiostat/galvanostat were determined by concentration of hydrogen peroxide and current efficiency. It was observed that the RVC immobilized HRP was stable maintaining 89% of the initial activity during 4 weeks. The phenol degradation rate of 86% was attained under the optimal condition of in situ $H_2O_2$ generation.

• Applied Chemistry for Engineering
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• v.24 no.4
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• pp.382-390
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• 2013

Foaming process of waste soda lime glasses by just chemical composition control of vitreous feed materials was investigated to find a novel and efficient recycling process. For the chemical composition control of feed materials, 10 wt. parts of $SiO_2$, 0.5 wt. parts of $Na_2SO_4$, 3.0 wt. parts of $B_2O_3$, and 0.3 wt. parts of carbon black as the foaming agent were mixed with 100 wt. parts of soda-lime vitreous feed powder. Proper conditions for foaming process in tunnel kiln are the foaming temperature of $830{\sim}850^{\circ}C$, the foaming time of 30~35 min, and the vitreous feed powder particle size of -325 mesh. Properties of foamed glass blocks obtained under these foaming conditions showed the density of $0.17{\sim}0.21g/cm^3$, thermal conductivity of $0.06{\pm}0.005kcal/h{\cdot}m{\cdot}^{\circ}C$, moisture absorption of 1.1~1.5%, and compressive strength of $20{\sim}30kgf/mm^2$.

• Korean Journal of Optics and Photonics
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• v.8 no.4
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• pp.277-282
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• 1997

The complex refractive index of Diamond-like Carbon (DLC) thin films, which can be applied to optical devices or electrical devices, have been determined using optical methods. DLC thin films are grown on Si(100) substrates and vitreous silica substrates respectively, using the technique of plasma enhanced chemical vapor deposition (PECVD). The spectroscopic ellipsometry data($\psi$, $\Delta$) and the transmission spectra of these DLC films are obtained. These optical spectra are analyzed with the help of the Sellmeier dipersion relation and a quantum mechanically derived dispersion relation. Using spectroscopic ellipsometry data at their transparent region, the refractive index and the effective thickness of DLC films on vitreous silica are model calculated, Then the transmission spectra are inverted to yield the extinction coefficient spectra k(λ) at absorbing region. These spectra are fit to the quantum mechanical dispersion relation and the best fit dispersion constants are determined. The complex refractive indices are easily calculated with these constants. The spectroscopic ellipsometry data at the absorbing region in model calculated to give the packing densities and the degrees of surface microroughness of DLC films. Discussions are made in correlation with the growth condition of DLC films.