• Ceramist
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• v.21 no.3
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• pp.283-292
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• 2018

Here, we introduce various type of inorganic nanostructure synthesized with functional nanoparticles and silica. From two decades ago, functional inorganic nanoparticles have been synthesized and highlighted, now we moved to next level of wet-chemical synthesis. By integrating functional nanoparticles with silica, we were able to synthesize multi-functional nanostructure, which expand the applications of nanoparticles to catalyst, drug carrier, sensors. In this context, silica has been spotlighted due to its versatility. Silica has highly biocompatible, relatively transparent and stable under harsh conditions. Thus it can be used as good supporter to synthesize complex multi-functional nanostructure when mixed with other functional nanoparticles. A various shape of complex nanostructures have been synthesized including core-shell type, yolk-shell type and janus type etc. In this paper, we have described the purposes of synthesizing silica noncomplex and various case studies for biomedical applications and self-assembly.

• Journal of Korean Society for Atmospheric Environment
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• v.17 no.4
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• pp.363-370
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• 2001

In this study, TiO$_2$, the popular photocatalyst, was used to decompose ethanol. TiO$_2$was prepared by the sol -gel method and coated on pyrex stick. A 15W, UV-A lamp was used as the UV light source and il gas chromatography (HP 5890) was used to confirm the concentrations of ethanol, $CO_2$and the intermediates. Variation of preparation parameters and calcination temperature for TiO$_2$photocatalysts in the sol -gel method caused changes of ethanol decomposition activity. The best ethanol photodecomposition activity was obtained on the sample when prepared with 0.14 mol of HCI, a mol of ethanol and 1.3 mol of TTIP ware mixed in sol-gel process and calcinated at 50$0^{\circ}C$ for 3 hours. Acetaldehyde was detected as an intermediate and decomposed to carbon dioxide and water at the end of the reaction.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.262-262
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• 2010

To investigate the effect of the amount of hydrogen on CVD grown-graphene, the flow rate of hydrogen was changed, while other process parameters were kept constant during CVD synthesis. Substrate which consists of 300nm-nickel/$SiO_2$/Si substrate, and methane gas mixed with hydrogen and argon were used for CVD growth. Graphene was synthesized at $950^{\circ}C$. The thickness and the defect of graphene were analyzed using raman spectroscopy. The synthesized graphene shows non-uniform and more defective below a certain amount of hydrogen.

• Journal of Contemporary Eastern Asia
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• v.13 no.2
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• pp.69-85
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• 2014

This paper explores the convergence process by focusing on the massively multiplayer online game(MMOG) industry and the online broadcasting industry in South Korea. In doing so, the paper seeks to establish the concept of Hidden catalysts for the integration process between the two industries and explore the roles of the Hidden catalysts in triggering the industry's transition. Further, the modified multi-level socio-technical model we applied in our research allows us both to understand each industry's development towards convergence in various dimensions and also to focus on the activities of the Hidden catalysts. In assessing the role of Hidden catalysts in industry convergence, we found that Hidden catalysts depend on two essential features: first, appropriate technology leading to the new industry dominance; and second, managerial capabilities to deal with conflicts among other new interest groups, to harmonise with government initiatives for industry development and to create new value in the integrated market to please the demand of mixed customers.

• Particle and aerosol research
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• v.8 no.2
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• pp.69-74
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• 2012

This study describes how successfully a conventional flame aerosol synthesis was used to continuously synthesize Pt-Ru catalysts supported by carbon agglomerates. Nearly spherical catalysts produced in the flame were mainly composed of metallic Pt and Ru with the molar ratio of 1:1 and those sizes were controllable from ~1.5 nm to ~2.0 nm. Nevertheless, only Pt peaks were found from X-ray diffraction experiments, suggesting that amorphous-like Ru was well mixed in the crystalline Pt lattices. It was found from Cyclo-voltamograms and CO stripping experiments that the electrochemical properties of the catalysts are at least comparable to that of a conventional commercial sample.

• Elastomers and Composites
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• v.26 no.4
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• pp.296-303
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• 1991

Surface of crystalline silica was sequentially reacted with silane(A 187), liquid $rubber(CTBN{\times}8)$, and vinyl monomer(GMA) in existence of TEA(triethylamine) or BPO(benzoyl peroxide). It was mixed with epoxy resin at a ratio $0{\times}60%$ (vol. % ) of total component. For mixtures, viscous properties were investigated experimentally. 1) Coating ratio depended on pH of mixture and quantity of catalyst. 2) Treated silica represented lower viscosity than untreated. 3) Thixotropic index represented best at silica_content $15{\sim}23%$ and showed more large deviation over $120^{\circ}C$. 4) Relative viscosity followed kernel's at $0{\times}10%$ of silica content and get out of Mooney's at more than 15%.

• Elastomers and Composites
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• v.27 no.4
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• pp.255-261
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• 1992

Chlorosulfonated polyethylene(CSM) was moisture-cure after treating them with silane coupling agents such as ${\gamma}-mercapto$ propyl trimethoxy silane, ${\gamma}-glycidoxy$ propyl triethoxy silane and methyl triethoxy silane, 3-(trimethoxy silyl) propyl methacrylate and 3-thiocyanopropyl triethoxy silane. The cure reaction is composed two steps. The first is the reaction between chlorosulfonyl groups of CSM and silane coupling agents. The second is the formation of cross-links which are siloxane linkage. The linkage is formed by the condensation of silanol groups which are produced by the hydrolysis of alkoxysilyl groups. CSM was mixed with MPS etc., and dilaurate dilaurate as catalyst on two open mill and the compounds were lured in hot water at $70^{\circ}C$ Physical properties of moisture-cured CSM was measured. CSM was effectively moisture-cured and r-mercapto propyl trimethoxy silane and r-glycidoxy propyl trimethoxy silane were capable of the vulcanizing agents.

• Bulletin of the Korean Chemical Society
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• v.23 no.8
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• pp.1103-1105
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• 2002

H-ZSM-5 and γ-alumina were treated with formaldehyde and sodium carbonate. The treatment increased the amounts of weak acid sites, removing strong acid sites. The maximum temperature of weak acid sites in their ammonia TPD spectra shifted in the direction of high temperature. The modified H-ZSM-5 and g-alumina were mixed with the methanol synthesis catalyst to perform dimethyl ether synthesis from syn-gas. The modified catalysts showed better selectivity to dimethyl ether, minimizing the reforming reaction to carbon dioxide. The maximum yield of 53.3% to dimethyl ether was achieved under the reaction conditions of 54.4 atm, 523 K, and the feed rate of 4500 Lhr-1 .gcat-1.

• Journal of the Korean Ceramic Society
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• v.33 no.9
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• pp.961-968
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• 1996

The aluminum nitride was synthesized by the self-propagating high-temperature synthesis(SHS). The synthe-sis was used aluminum powder mixed with AlN powder as reactant and the control factors affected to synthesis were considered compact density pressure of reaction gas AlN diluent content and aluminum powder size. The SHS reaction conducted with a reactant containing 50% AlN diluent under 0.8MPa nitrogen gas pressure yielded a complete conversion of aluminum powder to AlN powders. The size and purity of AlN produced were found to be comparable with that of AlN produced by the carbothermal nitrogen method.

• Bulletin of the Korean Chemical Society
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• v.30 no.7
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• pp.1563-1566
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• 2009

One-dimensional aluminum nitride (AlN) nanostructures were synthesized by calcining an Al(OH)(succinate) complex, which contained a very small amount of iron as a catalyst, under a mixed gas flow of nitrogen and CO (1 vol%). The complex decomposed into a homogeneous mixture of alumina and carbon at the molecular level, resulting in the lowering of the formation temperature of the AlN nanostructures. The morphology of the nanostructures such as nanocone, nanoneedle, nanowire, and nanobamboo was controlled by varying the reaction conditions, including the reaction atmosphere, reaction temperature, duration time, and ramping rate. Iron droplets were observed on the tips of the AlN nanostructures, strongly supporting that the nanostructures grow through the vapor-liquid-solid mechanism. The variation in the morphology of the nanostructures was well explained in terms of the relationship between the diffusion rate of AlN vapor into the iron droplets and the growth rate of the nanostructures.