• 한국세라믹학회지
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• 제26권5호
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• pp.593-600
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• 1989

Fine spinel powder was prepared from the Mg-Al double alkoxide synthesized using magnesium powder, aluminum foil and sec-butyl alcohol. This powder was compared with powder prepared by mixing two commercial alkoxides. The spinelization was started at 50$0^{\circ}C$ and was almost completed at 100$0^{\circ}C$ with a good crystallinity in the double alkoxide system. In mixed alkoxide system, homogeneous spinel powder was not obtained and MgO existed as a second phase because of solubility and hydrolysis rate differences of two alkoxides. The relative density of specimen prepared by double alkoxide was 99% and specimen prepared by mixed alkoxide was 95%. The modulus of rupture of specimens prepared by double alkoxide and mixed alkoxide was 49.9kg/$\textrm{mm}^2$ and 41.6kg/$\textrm{mm}^2$, respectively.

• 한국세라믹학회지
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• 제28권12호
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• pp.975-980
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• 1991

Chelated titanium alkoxides are hydrolysed showly and stable enough to prepare multicomponent gels of titania without its precipitation due to the fast hydrolysis of Ti alkoxide. The alkoxy groups of chelated titanium alkoxide are hydrolysed as fast as that of titanium alkoxide but the chelating groups are stable even in aqueous solution. The chelating groups showed different rates of hydrolysis in aqueous ammonia solution and water added one. Those rates were monitored with UV-VIS spectrophotometer by using their unique absorption bands before and after hydrolysis.

• 한국세라믹학회지
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• 제25권6호
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• pp.585-592
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• 1988

Aluminum sec-butoxide was synthesized from aluminum foil and alcohol. The characteristics of the alumina powder prepared from the synthesized alkoxide by the Yoldas method were studied. As a result of measuring the synthesized aluminum sec-butoxide by GC, the purity of the synthesized alkoxide was 98.7% on the basis of commercial alkoxide and the yield was 78.5%. A127-MASNMR analysis shows that powders dried at 9$0^{\circ}C$ and $\alpha$-Al2O3 have 6-cordinated structure and ${\gamma}$-Al2O3 has 4-coordinated structure. The characteristics of alumina powder prepared from the synthisized alkoxide showed the same characteristics with the alumina powder prepared from the commercial alkoxide.

• 공업화학
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• 제9권2호
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• pp.273-277
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• 1998

본 연구는 metal alkoxide, 크라운에테르, 4급 onium염 등을 촉매로 사용하여 프로필렌카보네이트(PC)와 알콜 개시제로부터 hydroxy-terminated poly(propylene carbonate) (HTPPC)를 합성하는데 관한 것이다. 촉매의 종류와 골격구조, 알콜의 종류와 농도, 그리고 용매가 반응에 미치는 영향을 고찰하였다. Metal alkoxide의 Lewis acidity가 크고 alkoxide 음이온의 친핵성이 클수록 높은 반응활성을 나타내었다. Metal alkoxide와 크라운에테르의 혼합촉매는 metal alkoxide 단독 촉매보다 높은 프로필렌 카보네이트 전화율을 보였고, 4급 onium염 촉매의 경우 양이온의 크기가 크고 음이온의 친핵성이 클수록 높은 활성을 나타내었다. 또한 용매의 극성이 높고 [PC]/[Initiator]의 농도 비가 낮을수록 HTPPC의 수율이 높게 나타났다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1994년도 춘계 학술발표 강연 및 논문 개요집
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• pp.70-70
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• 1994

• 한국재료학회:학술대회논문집
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• 한국재료학회 2002년도 추계학술발표강연 및 논문개요집
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• pp.74-74
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• 2002

• 한국세라믹학회지
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• 제32권11호
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• pp.1233-1240
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• 1995

LAS system, which is difficult to be sintered, was densified by using the powder synthesized from metal alkoxides. Sinterability, thermal and mechanical properties were improved through synthesizing the complex oxide powder from the addition of Ge as an alkoxide. As a result, the synthesizing and sintering temperature of the LAS system lowered by about 10$0^{\circ}C$ and its modulus of rupture (MOR) increased twice higher compared to the sample from the oxide by the direct method.

• 한국세라믹학회지
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• 제30권12호
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• pp.987-992
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• 1993

In order to synthesize the heat resistance ceramics of LAS system, we studied on preparing the fine powder with homogeneity by sol-gel method using metal alkoxide. Various results were obtained depending on the composition and process. When the amount of H2O added at initial stage is higher than 10mol/$\ell$, and when the amount of catalyst is 0.1mol/$\ell$, the particle size of synthesized hydrate becomes finer. On condition that partial prehydrolysis time of TEOS is more than 50 hours, the monosized fine powder is obtained(below 1${\mu}{\textrm}{m}$).

• 한국세라믹학회지
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• 제21권2호
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• pp.127-134
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• 1984

Basic research on the formation of monolithic glasses from metal alkoxide has been done concerning gelling of silicon alkoxides and dehydration of those gells. The felling time were increased with increasing of Carbon number of alkyl radical of alkoxide and am-ount of water and the lower pH value of water. Large portions of water and organic materials were rem-oved below 25$0^{\circ}C$ and shrinkage of glass took place above 80$0^{\circ}C$ Therefore heating up to 25$0^{\circ}C$ and above 75$0^{\circ}C$ must be done gradually with rate of 0.5$^{\circ}C$/min.

• 한국결정성장학회지
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• 제5권4호
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• pp.332-342
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• 1995

실리콘 알콕사이드 용액의 졸-겔 전이에 있어서 반응조건에 중요한 영향을 미치는 인자에 대하여 Raman 분광분석을 기초로 해서 고찰해 보았다. 촉매의 종류, 용매, 건조제어용 화학첨가제 및 물의 양과 같은 여러 가지 인자가 졸-겔 과정에 있어 전이메카니즘에 영향을 주었다.