• 한국염색가공학회지
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• 제2권1호
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• pp.21-30
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• 1990

In order to obtain high dye uptake initially, polyethylene terephthalate (PET) filaments were dyed with C.I.Disperse Orange 3 and Red 1 in mixed solvents of tetrachloroethylene acidic solvent, ethyl alcohol and tetrachloroethylene basic solvent, DMF. The dyeing behavior in the mixed solvent of tetrachloroethylene and basic solvent, DMF, the initial uptake of disperse dyes increased rapidly. The shrinkage of PET increased when the solubility parameter values of PET fiber and mixed solvent approached graduately.

• 한국환경보건학회지
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• 제20권4호
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• pp.10-16
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• 1994

A Study was performed in order to measure mixed organic solvent concentrations in air of painting operations during January 5-28, 1991. The mixed organic solvent concentrations were analyzed by the gas chromatography. The results were as follows: 1. The detection of organic solvent was highest in aromatic hydrocarbon(68%), and followed by aliphatic hydrocarbon (18%), and ketone (14%). 2. The detection of organic solvent by component category was highest in the grid class solvent (79.4%), and followed by the 3rd class solvent (20.6%). 3. Number of cases exceeding TLVS of mixed solvent level in air was highest on dipping operation (44%), and followed by spray operation (40%), dry and washing operation (33%), and adhensive operation (12%).

• 한국산업보건학회지
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• 제7권1호
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• pp.3-18
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• 1997

This study was conducted to evaluate desorption efficiencies by types of desorption solvent for polar and non-polar organic compounds collected on activated charcoal tubes. Analytes tested were toluene, m-xylene, isobutyl alcohol, n-butyl alcohol, cellosolve acetate, and butyl cellosolve. Three different concentration levels of spiked sample were made. Types of cosolvent mixed with the main solvent, $CS_2$, were methanol, pentanol, and dimethylformamide (DMF) and the cosolvent for methylenechloride was methanol. The amounts of cosolvent added to the main solvent were 1, 5, and 10% by volume (v/v%), respectively. The results were as follows: 1. For all mixed solvents except 1% methanol and 1% pentanol with $CS_2$, desorption efficiency significantly increased, compared with that of $CS_2$ alone. 2. Desorption efficiency increased by increasing analyte loading on charcoal tube regardless of mixed solvents used and the material polarity. 3. For all cosolvents mixed with $CS_2$ by 1% and 5% volume, desorption efficiency for non-polar compound was significantly higher than that of polar compound. For the 10% mixed solvents and the methylenechloride mixed with methanol, the results were opposite. 4. The lowest mean percent bias of 4.79% was obtained from the 5% DMF-$CS_2$ mixed solvent, followed by 4.82% from the 10% DMF-$CS_2$ solvent while the highest bias of 23.26% was from the solvent of $CS_2$ alone. Based on the results of this study, in order to increase desorption efficiency, it is recommended to add such cosolvents as methanol, pentanol, and DMF to $CS_2$, preferably 5% by volume for analyzing polar compounds collected in charcoal tubes.

• 약학회지
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• 제5권1호
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• pp.20-23
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• 1960

The study of the isolative determination of the mixed weak bases of INAH and NA-Pas potentimetrically considering the properties of solvents for the INAH and Na-PAS, dielectric constant and solvative properties of solvents are described. The methanol: dioxan (4:1) and glacial acetic acid: dioxan (4:1) are studied first as the mixed solvent, using the N/10 perchloric acid and glacial acetic acid solution as the titrant. The authors found that there is no inflection on INAH with the methanol: dioxan solvent system and on Na-PAS at glacial acetic acid dioxan solvent system. By applying methanol glacial acetic acid dioxan (1:1:1) solvent system, Na-PAS and INAH were successfully determined isolatively from the mixed sample, showing the distinguished inflections respectively as shown in the titration curves in figures 3 and 4. It is found that this method could save considerable time for the isolative determination of the mixed sample of week bases as Na PAS and INHA which were quite difficult to be determined by the present routine at control laboratory.

• 자연과학논문집
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• 제9권1호
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• pp.169-175
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• 1997

효과적인 캐리어로 알려진 벤질알콜, 벤즈알데히드, 아세트 페놀을 사용하여 PET섬유를 분산염료로 염색함에 있어 캐리어 종류에 따른 염색성 특히 혼합용매의 효과를 평가하고 아울러 일광견뢰도, 세탁견뢰도, 인장강도와 같은 염색후의 물성변화에 대해 연구 검토하였다. 실험결과 벤즈알데히드와 아세트페놀의 혼합용매에서 가장 우수한 염색성을 보였으며 효과적인 캐리어 작용은 일광견뢰도 및 인장강도와 같은 물성을 크게 떨어뜨리는 결과를 가져왔다.

• 대한안전경영과학회지
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• 제2권2호
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• pp.95-108
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• 2000

Electrochemical charateristics of activated carbon fiber cloth(ACFC) electrode were studied with propylene carbonate(PC), ${\gamma}$-butyrolactone(GBL) and N,N-dimethyl-formamide(DMF) as a solvent and tetraethylammoniumtetrafluoroborate(TEABF$_4$), tetraethylammoniumhexafluorophosphate(TEABF$_{6}$), tetrabutylammoniumtetrafluoroborate(TBABF$_4$) and tetrabutylammonium hexafluorophosphate(TBAPF$_6$) as an electrolytes(active material). The concentrations of electrolytes were in the range of 0.2~1.2 N, the volume ratios of PC and DMF as a mixed solvent system, were 90：10, 80：20, 70：30, 60：40, 50：50, and 40：60 vol%. Electrochemical characteristics such as electric conductivity, internal resistance, and electric capacitance of fabricated unit cells were measured after the moisture of activated material was removed with molecular sieve. Electrochemical characteristics were better in mixed solvents system than in mono solvent system. The mono solvent system of 1.0 N electrolyte of GBL/TEABF$_4$ with activated carbon cloth electrodes showed better result but the mixed solvent system with PC and DMF/TEABF$_4$(50：50 vol%) and the concentration of 1.0 N electrolyte showed the best characteristics. Internal resistance was 3.47 $\Omega$ and specific capacitance was 19.1 F/g respectively.y.

• 약학회지
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• 제20권1호
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• pp.41-43
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• 1976

The dissociation constant of phenol red indicator in mixed solvents was studied. Methanol and ethanol were employed as solvents and studied the changes of pK values of indicator according to the kind and concentration of organic solvent which is mixed into water solution. The effect of methanol solvent on pK is negligible at 40%, 60% and 80% mixing. While in the case of ethanol, the effect of above 40% mixing is not negligible.

• 폴리머
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• 제25권6호
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• pp.811-817
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• 2001

용매와 비용매의 다양한 비율에 따라서 bisphenol A polycarbonate(PC)의 무정형에서 결정성의 상변화를 확인하였다. 용매로 chloroform을, 비용매로 isopropanol을 사용하였다. 결정화된 PC는 광학현미경과 SEM, XRD, DSC를 이용하여 조사하였고, DSC와 XRD의 측정값은 PC의 결정화도를 판단하는데 이용하였다. 용해도 상수는 PC의 결정화도를 조절하는데 중요한 인자로 PC 결정화도 차이는 혼합용매의 용해도 상수 차이로 설명하였다. 용매와 비용매 비율이 75/25 wt%의 PC 용액에서 고결정화도를 가진 PC powder로 얻을 수 있었다. 이런 결과는 혼합용매의 용해도 상수(9.85)가 PC의 용해도 상수(9.9)와 유사하였기 때문이라고 판단된다.

• Bulletin of the Korean Chemical Society
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• 제21권3호
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• pp.351-352
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• 2000

• 한국산림과학회지
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• 제110권3호
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• pp.431-439
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• 2021

본 연구에서 잣 구과피의 3가지 추출법(에탄올 추출, 초임계 추출, 에탄올과 초임계 추출물의 혼합)에 따른 항산화 활성, 주름개선 그리고 미백활성의 차이를 확인하였다. 그 결과, 총 폴리페놀 함량은 초임계 추출물이 11.03 mg/g GAE, 70% 에탄올 추출물이 33.79 mg/g GAE이었다. 전자공여능의 경우 1,000 ㎍/mL 농도에서 초임계 추출물은 13.60%, 70% 에탄올 추출물은 91.37%, 혼합물은 71.62%이었다. SOD 유사활성은 100 ㎍/mL 농도에서 초임계 추출물은 16.49%, 에탄올 추출물은 21.84%, 혼합물은 10.7%이었다. ABTS⁺ radical 소거능은 1,000 ㎍/mL 농도에서 초임계 추출물은 38.19%, 70% 에탄올 추출물은 80.23%, 혼합물은 78.72% 이었다. Tyrosinase 저해활성은 1,000 ㎍/mL 농도에서 초임계 추출물은 24.54%, 70% 에탄올 추출물은 36.55%, 혼합물은 15.23%이었다. Elastase 저해활성 측정은 1,000 ㎍/mL 농도에서 초임계 추출물은 15.62%, 70% 에탄올 추출물은 22.56%, 혼합물은 26.64%이었다. 피부수렴활성 결과는 70% 에탄올 추출물이 5000 ㎍/mL에서 81.23%이었고, 초임계 추출물과 혼합물은 활성을 나타내지 않았다. 본 연구에서 분석한 활성 결과는 잣구과피 70% 에탄올 추출물, 혼합물, 초임계 추출물 순으로 우수하게 측정되어 총 폴리페놀 함량 및 항산화 활성 모두 초임계 추출물이 높을 것으로 판단한 가설과 정반대의 결과를 나타내었다.