• Bulletin of the Korean Chemical Society
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• v.34 no.8
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• pp.2321-2324
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• 2013

An improved hybrid solar cell was obtained by focusing on the effects of ligand for CdSe nanoparticles, in the active layers. The performance was compared by mixing nanoparticles capped with pyridine or oleic acid for the acceptor material into poly(3-hexylthiophene):[6,6]-phenyl C61 butyric acid methyl ester based active layer. The solar cells with pyridine capped CdSe nanoparticles showed a power conversion efficiency of 2.96% while oleic acid capped CdSe nanoparticles showed 2.85%, under AM 1.5G illumination. Formation of percolation pathways for carrier transport and a reduction in the hopping event resulted in better performance of pyridine capped nanoparticles.

• Applied Chemistry for Engineering
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• v.22 no.2
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• pp.173-177
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• 2011

In this study, the formation of $AlPO_4$-type porous materials from alum sludge was investigated. The materials were synthesized by the reaction of aluminum hydroxide and phosphoric acid with an organic template. Cationic surfactant, natural humic acid, and amino acids were used for the organic template. The residual organic templates were removed by calcination at $600^{\circ}C$ in the air. Powder X-ray diffraction patterns showed the charicteristic patterns of the $AlPO_4$-type porous materials. The morphology of the material was examined using a scanning electron microscopy. The coordination environment of $Al^{3+}$ ion was investigated by $^{27}Al$ MAS NMR technique. Both tetrahedrally and octahedrally coordinated$Al^{3+}$ ions were found in the as-synthesized samples while all $Al^{3+}$ ions were tetrahedrally coordinated in the calcined products. The development of mesopore in the solid material was confirmed by the measurement of BET specific surface area. Finally, they were used for removal of toxic formaldehyde from the air and the formaldehyde molecules were adsorbed on the surface of pores. In conclusion, $AlPO_4$-type porous materials from alum sludge might be applicable in the removal of toxic volatile organic compounds from the air.

• Journal of Soil and Groundwater Environment
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• v.16 no.2
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• pp.52-60
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• 2011

Although facilities for the passive treatment of AMD (Acid Mine Drainage) are currently operating in Korea, their removal efficiency for heavy metals is relatively low in average (only 80%). Passive treatment system is composed of oxidation tank, SAPS (Successive Alkalinity Producing System), and wetland. In the treatment system adopted in korea, SAPS (Successive Alkalinity Producing System) plays a major role to remove about 65% of heavy metals through a precipitation. However, the efficiency of SAPS is limited due to the use of mushroom compost (MC) as a organic material and of limestone as a neutralizer. Therefore, this research was performed to search for alternative organic materials through the field test. We tested two types of mixed organic materials: 1) cow manure and spent oak (herein, CO) and 2) cow manure and sawdust (herein, CS). For comparison mushroom compost (herein, MC) was also tested. The result showed that the average Fe removal efficiency was 91.38% with CO, 85.19% with CS, and 91.58% with MC. Thus, CO can be effectively used as an alternative of MC in the SAPS system for heavy metals removal.

• Bulletin of the Korean Chemical Society
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• v.33 no.9
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• pp.3111-3114
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• 2012

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.11a
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• pp.35-35
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• 2011

Phase change material(PCM) has thermal energy storage and been attracted attention. Latent heat of the organic PCM can keep maintaining temperature when the change of outside energy conditions influence to PCM. Thus, many researchers have interested to thermal energy storage ability and investigated to applications such as thermal storage of solar energy, bioclimatic building, icebank, medical application, clothing industry and so on. Among the many applications, investigation of the PCM in clothing industry is also important because the people has interest functional factor called health-care in the clothing. In addition, PCM can give them mild environment condition such suitable temperature control or humidity. To fabrics, the PCM has various methods such as microcapsule, padding and modified cross-section formation(Sheath/core). Sheath core PCM fabric has a better benefit of durability than other method. However, PCM sheath/core spinning is difficult. In addition, dyeing property is important to use clothing industry due to visual images. In this study, we investigated dyeing properties of Nylon/PCM sheath/core fabrics. Especially, we observed the relation between dyeing property and PCM including ratio. Various temperature and pH conditions were also studied to optimize dyeing properties as acid dye.

• Journal of the Semiconductor & Display Technology
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• v.8 no.3
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• pp.1-5
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• 2009

In this study, we have shown the power conversion efficiency of organic thin film photovoltaic devices utilizing a conjugated polymer/fullerene bulk-hetero junction structure. We use MDMO-PPV(Poly[2-methoxy-5-(3,7-dimethyloctyloxy -1,4-phenylenevinylene) as an electron donor, PCBM([6,6]-Phenyl C61 butyric acid methyl ester) as an electron accepter, and PEDOT:PSS used as a HTL(Hole Transport Layer). We have fabricated OPV(Organic Photovoltaic) devices as a function of the MDMO-PPV/PCBM concentration from 1:1 to 1:5. The electrical characteristics of the fabricated devices were investigated by means of I-V, P-V, F·F(Fill Factor) and PCE(power conversion efficiency). The power conversion efficiency was gradually increased until 1:4 ratio, also the highest efficiency of 0.4996% was obtained at the ratio.

• Applied Chemistry for Engineering
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• v.22 no.2
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• pp.230-234
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• 2011

In this work, the primary material for a single layered hardmask which can afford a spin-on process was prepared by the minture of organic and inorganic sources. The preparation of hybrid polymer was attempted by esterification from silanol terminated siloxane compounds and acetonide-2,2-bis(methoxy)propionic acid. The optical, thermal and morphological properties of the test hardmask film was examined in terms of cross-linking agent and additives. In addition, the etch rate of hardmask film and photo resist layer were compared. The hybrid polymer prepared from organic and inorganic materials was found to be useful for hardmask film to form the nano-patterns.

• Textile Coloration and Finishing
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• v.28 no.2
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• pp.92-100
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• 2016

To chemically prepare polypyrrole(pPy) coated fabrics(silk, cotton and nylon fabrics), the fabrics were first soaked in 0.4M oxidant $FeCl_3$/0.06M dopant anthraquinone-2-sulfonic acid solution for 5min at room temperature, and subsequently soaked in a 0.4M monomer pyrrole aqueous solution for 5min at room temperature. The content(wt%) of coated pPy in the coated fabrics was controlled by the number of treatments(these two steps). This study examined the effect of the number of treatments/pPy content on the sheet resistance, mechanical/bending properties and color behaviors of pPy coated fabrics. The coated pPy content, sheet resistance(${\Omega}$/square) and color strength(K/S) of pPy coated fabrics increased sharply with increasing number of treatments up to 20 times, while the increase slowed down afterward. The tensile strength, elongation at break and lightness($L^*$) decreased with increasing number of treatments. The tensile modulus and bending rigidity of coated fabrics increased significantly with increasing number of treatments/coated pPy content. This indicated that the flexibility of coated fabrics decreased considerably.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.277-277
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• 2012

PCDTBT (Poly[N-9''-hepta-decanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)]) is an attractive material as a semiconducting polymer for organic thin film transistor (OTFT) and organic solar cell (OSC). High power conversion efficiency (~6%) under simulated AM 1.5G solar illumination of bulk-heterojunction solar cell with PCDTBT and [6,6]-phenyl C60 butyric acid methyl ester (PC61BM) blend was reported. In OSC, it is known that the band alignment at the interface between donor and acceptor is critical. Therefore, we studied the interfacial electronic structures of PCDTBT and PC61BM. The polymers are deposited by electro-spray on gold and In-situ x-ray and ultraviolet photoelectron spectroscopy measurements revealed the interfacial electronic structures. We obtained the energy level alignment between two materials and the different interface formation was observed with different deposition order.

• Resources Recycling
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• v.14 no.6 s.68
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• pp.28-36
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• 2005

A hydrometallurgical process to leach cobalt from the waste cathodic active material, $LiCoO_{2}$, and subsequently to separate it by solvent extraction was developed. The optimum leaching conditions for high recovery of colbalt and lithium were obtained: 2.0 M sulfuric acid, 5 $vol.\%$ hydrogen peroxide, $75^{\circ}C$ leaching temperature, 30 minutes leaching time and an initial pulp density of 100 g/L. The respective leaching efficiencies for Co and Li were $93\%$ and $94.5\%$. About $85\%$ Co was extracted from the sulfuric acid leach liquor containing 44.72 g/L Co and 5.43 g/L Li, using 1.5 M Cyanex272 as an extractant at the initial pH 5.0 and in organic to aqueous phase ratio of 1.6:1 under the single stage extraction conditions. The Co in the raraffinate was completely extracted by 0.5 M Na-Cyanex272 at the inital pH 5.0, and an organic to aqueous phase ratio of 1;1. The cobalt sulfate solution of higher than $99.99\%$ purity could be recovered from waste $LiCoO_{2}$, using a series of hydrometallurgical processes: sulfuric acid leaching of waste $LiCoO_{2}$- solvent extraction of Co by Na-Cyanex 271 - scrubbing of Li by sodium carbonate solution - stripping of Co by sulfuric acid solution.