• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.555-558
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• 2004

In this paper, the variable producing conditions of YBCO superconducting powder by use of sol-gel method was investigated. YBCO superconducting powder which was prepared by sol-gel method was shown the characteristic gel formation, particle size and its properties under variable preparation conditions, such as pH, drying and processing time, and powder heat treatment, etc.

• Journal of the Korean Ceramic Society
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• v.26 no.5
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• pp.677-681
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• 1989

On the preparation of silica glass by sol-gel process, we used fine powder of silica gel to prevent cracking. In this case, the best condition of silica glass preparation is the contents of 10~40wt% seed and the gelation time of solution in contract. The dried gels conversed to silica glass by heat treatment up to 125$0^{\circ}C$.

• Journal of the Korean Ceramic Society
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• v.34 no.6
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• pp.611-619
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• 1997

Optimal Mullite sol was synthesized by sol-gel process using Aluminium sec-butoxide(ASB), Tetraethoxysilane(TEOS) and then, Mullite films were dip-coated with various holding time in sol bath and heat-treated at 130$0^{\circ}C$ above for crystallization. The thickness of coated film increased linearly with holding time in sol bath and average pore size was controllable within 20~30$\AA$.

• Journal of the Korean Ceramic Society
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• v.30 no.7
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• pp.535-542
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• 1993

It was investigated in this study that a preparation method, activation energy, surface area, pore volume, pore size distribution and DTA analysis of the dry gel in process of producing monolithic porous gel in Li2O-Al2O3-TiO2-SiO2 system by the sol-gel technique using metal alkoxides. Activation energy for gellation according to the variation of water concentration and the kind of catalysts ranged from 10 to 20kcal/mole. Monolithic dry gels were prepared after drying at 9$0^{\circ}C$ when the amount of water for gellation was 4~8 times more than the stoichiometric amount, that was necessary for the full hydrolysis of the mixed metal alkoxide. The specific surface area, the pore volume, the average pore radius of the dried gel at 18$0^{\circ}C$ according to the various kinds of catalyst were about 348~734$m^2$/g, 0.35~0.70ml/g and 10~35$\AA$, respectively. It showed that the dry gels were porous body. As a result ofthe analysis of DTA, it was confirmed that the exothermaic peaks at 715$^{\circ}C$ and 77$0^{\circ}C$ was clue to the crystallization of dried gel.

• 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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• 2006.11a
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• pp.245-246
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• 2006

A propyl alcohol based sol-gel method was used as to replace the 2-methoxyethanol with 1,1,1 tris (hydroxymethyl) ethane for preparation of pzt piezoelectric ceramic. The powder obtained by this sol-gel process were calcined at $900^{\circ}C$ and followed by the sintering at $1100^{\circ}C$ for ca2 hrs as to reach a pyrochlore-free crystal phase. The characterization of synthesized material was carried out by the XRD analysis and the surface morphology were determined by high resolution scanning electronmicroscopy. Further, the prepared small sized pzt thin powders are likely to be used m various applications.

• Polymer Science and Technology
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• v.4 no.6
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• pp.444-451
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• 1993

• Proceedings of the Materials Research Society of Korea Conference
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• 2007.11a
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• pp.135.1-135.1
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• 2007

• Journal of the Korean Ceramic Society
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• v.33 no.10
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• pp.1124-1130
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• 1996

• Proceedings of the Korean Ceranic Society Conference
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• 2000.10a
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• pp.45.2-45
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• 2000