• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.04a
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• pp.141-145
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• 1997

스퍼터링법으로 제조한 CoNbZr/Cu/CoNbZr 다층막에 대해 습식 식각법으로 패턴을 형성하기 위해 새로운 식각 용액을 제조하여 이 용액의 최적의 식각 조건에 대해 연구하였다. 염기성 수용액은 농도에 관계없이 Cu만을 선택적으로 식각하며 CoNbZr 비정질 박막은 식각하지 않았다. 그러나, 본 연구에서 제조 한 17.5 mol%의 염기성 수용액에 HF를 20 mol% 혼합한 식각 용액으로 CoNbZr/Cu/CoNbZr 다층막을 동시에 식각할 수 있었다. 또한 이 식각 용액은 CoNbZr/Cu/CoNbZr 다층막을 3단계로 식각하고 식각된 단면은 이방성 구조를 가지며, 매우 우수한 식각 특성을 나타내었다.

• Korean Journal of Food Science and Technology
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• v.50 no.2
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• pp.191-197
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• 2018

This study investigated the influence of starch extraction (ST-EX) solutions on the extraction yield and characteristics of Chinese yam (CY) starches from domestic Dioscorea batatas. Ascorbic acid (VitC), $Na_2S_2O_3$, $NaHCO_3$, and $Na_2CO_3$ were used as ST-EX solutions (0.4%, w/v). The extracted CY starches were examined for ST-EX yield, chemical composition, size distribution, X-ray diffraction, solubility, swelling power, gelatinization, and pasting viscosity. The highest ST-EX yield was obtained from $NaHCO_3$, followed by VitC. Lower protein content, relative crystallinity, and gelatinization enthalpy were found in CY starches from alkaline ST-EX solutions ($NaHCO_3$ and $Na_2CO_3$). Size distribution and gelatinization temperature did not generally differ for CY starches from the different ST-EX solutions. Pasting viscosities increased in the order from $Na_2CO_3$ > $Na_2S_2O_3$ > $NaHCO_3$ > VitC ST-EX solutions. Thus, VitC may be most appropriate to extract CY starch from Dioscorea rhizomes, considering its ST-EX yield, total starch content, and variation in pasting viscosity.

• Journal of the Korean Chemical Society
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• v.20 no.1
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• pp.56-58
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• 1976

A new mechanism is proposed for the reduction of nitrobenzene in basic solution that does not involve hydroxylamine as an intermediate. This paper presents evidence that the azoxybenzene is not formed from the hydroxylamine, but formed instead from the dimerization of nitrosobenzene.

• The Korean Journal of Rheology
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• v.2 no.1
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• pp.53-59
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• 1990

물량 및 촉매를 변화시키며 TEOS 용액에 대하여 점도를 측정하였다. 염기성 촉매 를 사용한 TEOS 용액은 구형 입자를 갖는 것으로 나타났다. 적은 초기 물량과 산성 촉매 를 사용한 TEOS 용액은 환원 점도의 실험결과로 미루어 선형의 고분자를 갖고 있는 것으 로 보인다. 반면 많은 물량과 산성폭매를 사용한 TEOS 용액은 많은 가지 사슬을 갖는 비 선형 입자를 형성하는 것으로 사료된다. 적은 물량의 산성촉매에서 생성하는 선형고분자 구 조느 삼중규소연쇄의 리본형태로 생각된다.

• Journal of the Korean Chemical Society
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• v.16 no.3
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• pp.149-156
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• 1972

The responsive characteristics of hydrogen-responsive glass electrode in various buffer solutions of methanol, N,N-dimethylformamide and acetonitrile were examined. The potentials were attained more rapidly with an electrode stored in the same solvent medium than that stored in water before use. However, the time to be required for a stable potential increased with the basicity of buffer solution, and it was not provide a constant potential in the strong basic solution of these solvent. Even in acidic solution, the potential was varied according to the past usage of the electrode.

• Korean Chemical Engineering Research
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• v.40 no.6
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• pp.735-740
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• 2002

In order to improve the anti-fogging property of polymer films, organic-inorganic hybrid coating solutions which have good hydrophilic property and transmission in the range of visible light were synthesized by the sol-gel method. The coating solutions were prepared by adding glycidoxypropyl trimethoxysilane(GPS) to a colloidal silica(15 nm) suspension(Ludox). GPS as silane coupling agent forms strong bonds to the colloidal silica and surrounding polymer matrix and links two different materials together. Solutions prepared by addition of GPS at the acidic condition resulted in coatings that were less prone to cracking, while those at the basic condition caused coatings with more cracking. These resulted in better hydrophilic property and transmission in the range of visible light for the solution prepared at the acidic condition(pH 2). Compared with coatings under acidic conditions, coatings prepared at basic conditions showed worse hydrophilic property and transmission in the range of visible light.

• 한국전기화학회:학술대회논문집
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• 2000.04a
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• pp.25-25
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• 2000

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2005.05a
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• pp.301-305
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• 2005

3-메틸-1-페닐-2-피라졸린-5-은과 N,N-디에틸-1,4-페닐렌디아민의 반응에서 마젠타 아조메틴색소(M)를 합성하였다. 마젠타 아조메틴 색소는 에탄올, 아세톤, 그리고 클로로포름에 잘 녹는다. 원소분석, 핵자기공명스펙트럼, 적외선 홉수 스펙트럼, 그리고 GC/MS 스펙트럼에서부터 마젠타 아·조메틴 색소임을 확인하였다. 마젠타 아조메틴 색소는 염기성용액에서 분해된다. 에탄을 수용액에서 염기에 의한 마젠타 아조메틴 색소의 퇴색반응을 분광학적인 방법으로 540 nm에서 측정하였다. 그리고 OH$^-$와 H$_{2}$O(11${\sim}$40 M의 범위)의 농도가 증가함에 따라 퇴색반응속도는 증가하였다. 이 반응에 대한 실험속도 식은 다음과 같다. -d[D]/dt = {k$_{OH}$[OH$^-$][H$_{2}$O]}[D] 이 속도식과 일치하는 메커니즘을 제시하였다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2003.10a
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• pp.78-79
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• 2003

• Applied Chemistry for Engineering
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• v.9 no.6
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• pp.920-923
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• 1998

In this work, the adsorption characteristics of the activated carbon treated with 30 wt. %HCl and 30 wt. % NaOH were investigated. The acid and base values were determined by Boehm's method and the surface area and porosity was measured by BET-method with $N_2$-adsorption. Also, the adsorption characteristics of the activated carbons treated with acid and base chemical solutions were investigated with $CO_2$ and $NH_3$-adsorption. From which, relatively different adsorption behaviors of the modified activated carbons were observed in the amounts of $CO_2$ and $NH_3$ adsorptions, even though the physical surface structures of the activated carbons, such as specific surface area, pore size and pore volume, were not significantly changed.