• Fibers and Polymers
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• 제5권4호
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• pp.280-288
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• 2004

Split-type nylon/polyester microfiber and polyester microfiber fabrics possess drapeability, softness, bulkiness, and smoothness, so that they can be applied in various industrial fields. In particular, these fabrics are able to absorb various organic solvents, and can be used as clean room materials. To investigate the chemical affinity between solvents and the compositional materials of these fabrics, the contact angle of thermally pressed film fabrics was measured with different solvents. The thermally pressed nylon/polyester fabric films showed a chemical attraction to formamide. The sorption properties of the microfiber fabrics were investigated using a real time testing device, and these tests showed that the sorption behavior was more influenced by the structure of the fibrous assembly than by any chemical attraction. The effect of the fabric density, specific weight, and sample structure on the sorption capacity and rate was examined for various organic solvents. The sorption capacity was influenced by the density and the specific weight of the fibrous assembly, and knitted fabric showed a higher sorption capacity than woven fabric. However, the sorption rate was less affected in lower viscosity solvents. On applying Poiseuille's Law, the lower viscosity solvents showed higher initial sorption rates, and more easily penetrated into the fibrous assembly.

• 정보학연구
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• 제7권2호
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• pp.1-5
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• 2004

본 연구는 산업적으로 중요한 필름 및 인화지 제조시 녹감 사진유제에 필수적으로 들어가는 분광증감색소인 benzoxazolo carbocyanine계를 선택하여 다양한 용매에 대해 경시변화에 대한 안정성이 있는가 또한 용매에 따른 흡수최대피크값이 어느 정도 변화되는가를 측정하여 사진유제에 잘 적용할 수 있는지를 연구 조사한다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권3호
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• pp.147-150
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• 2004

Permeabilization is known to overcome cell membrane barriers of whole cell biocatalysts. The use of organic solvents is advantageous in terms of cost, simplicity, and efficiency. In this study, Ochrobactrum anthropi SY509 was permeabilized with various organic solvents. Treatment with organic solvents resulted in lower permeability barriers due to falling out lipids of the cell membrane. Therefore, permeabilized cells showed higher enzyme activity with no cell viability. Among various organic solvents, 0.5% (v/v) chloroform was selected as the most efficient permeabilizing reagent. Changes in the cell membrane structure were observe d and the residual amounts of phospholipids of the cell membrane were measured to investigate the mechanism of the improved permeability.

• Bulletin of the Korean Chemical Society
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• 제23권5호
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• pp.708-714
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• 2002

The hexanuclear metallamacrocycles were observed repeatedly in various conditions including the presence of several different tricationic metal ions in the macrocyclic ring system and of the linear alkyl chains at the acyl site of N-acylsalicylhydrazide ligand, which contrasts to the formation of the decanuclear metallamacrocycle with bulkier side chains such as phenyl group at the acyl site of the ligand. We synthesized a series of metallamacrocycles in various solvents to find the relationship between the solvents and the nuclearity of the metallamacrocycles. Whether the solvents are sterically more demanding or not, the complexes formed kept the hexanuclear metallamacrocycle system.

• Journal of Photoscience
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• 제12권3호
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• pp.171-174
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• 2005

The relationship between porous surfaces and photoluminescence (PL) behavior of porous silicon carbide (PSC) in various solvents has been studied. The porous surfaces of p-type silicon carbide can be fabricated by electrochemical anodization from the 6H, 15R, 4H-${\alpha}$-SiC substrates in dark-current mode (DCM) condition. We have been investigated the dependence of the PL spectra of PSC under the medium having the different dielectric constants. It has been found that PL depends sensitively on the environment surrounding the surface. The extent of chemically stability on the surface of PSC due to the various solvents was confirmed by reflectance Fourier transform infrared (FTIR) spectroscopy. Detailed IR experiments on the PSC samples were carried out before and after various solvents immersion. These results will be offered important information on the origin of PL in porous structure.

• 한국응용과학기술학회지
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• 제14권2호
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• pp.65-70
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• 1997

The symmetric naphthothiazolo carbocyanine is of industrial importance as red-sensitizing dye in the spectral sensitization of emulsion microcrystals in negative film-making. The stability on the solvents of naphthothiazolo carbocyanine dye was measured by UV-Vis spectrophotometer, and then all of solvents were stabilized sensitizer. The maximum absorption peak range in various solvents was $600nm{\sim}612nm$. But it was identified that only methanol can be used to photographic emulsion.

• 한국포장학회지
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• 제9권1호
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• pp.1-6
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• 2003

The partitioning behavior of five printing ink solvents was studied in various cookie ingredients before and after baking which had different water content and different structure. Solvents were ethyl acetate, hexane, isopropanol, methyl ethyl ketone, and toluene which represent different characteristic functional groups. Gas chromatography (G.C.) was used to measure partitioning values at $25^{\circ}C$ on each raw and baked cookie ingredients. Baking condition of cookie ingredients was $260^{\circ}C$ for 10 min. In cookie ingredients, decreases in water content generally affected Kp of polar solvents, but did not affect that of the non-polar solvents. However, as water content decreased in the cookie ingredient, the Kp of the non-polar and polar solvents showed mixed results.

• 한국의류학회지
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• 제17권1호
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• pp.63-75
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• 1993

Partially oriented polyester yarn (PET POY) was treated in the unrestrained state using various solvents at different temperatures. Interactions between PET POY & solvents were estimated by the changes of microstructure, morphology and mechanical properties. The correlation between the changes of microstructure & morphology and the changes of mechanical properties was also studied. TCE, Dioxane, O-DCB, DMF, and BA were found to be active solvents, while Iso-AA and water were found to be weak solvents. PET POY was affected mainly by the solvents when treated with active solvents and affected mainly by heat when treated with weak solvents. Changes by the solvent treatment in microstructure and morphology were : an increase in crystallinity, a change in birefringence, a shrinkage in length, and a change in DSC curve. As for the changes in mechanical properties, findings in the PET POY when treated with solvents were : a decrease in stress-at-break, a change in yield stress, an increase in strain-at-break & yield strain, and a decrease in initial modulus. Changes in microstructure and morphology directly affected the mechanical properties.

• Bulletin of the Korean Chemical Society
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• 제28권9호
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• pp.1472-1476
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• 2007

Artificial neural networks (ANNs) are successfully developed for the modeling and prediction of normalized polarity parameter (ETN) of 216 various solvents with diverse chemical structures using a quantitative-structure property relationship. ANN with architecture 5-9-1 is generated using five molecular descriptors appearing in the multi-parameter linear regression (MLR) model. The most positive charge of a hydrogen atom (q+), total charge in molecule (qt), molecular volume of solvent (Vm), dipole moment (μ) and polarizability term (πI) are input descriptors and its output is ETN. It is found that properly selected and trained neural network with 192 solvents could fairly represent the dependence of normalized polarity parameter on molecular descriptors. For evaluation of the predictive power of the generated ANN, an optimized network is applied for prediction of the ETN values of 24 solvents in the prediction set, which are not used in the optimization procedure. Correlation coefficient (R) and root mean square error (RMSE) of 0.903 and 0.0887 for prediction set by MLR model should be compared with the values of 0.985 and 0.0375 by ANN model. These improvements are due to the fact that the ETN of solvents shows non-linear correlations with the molecular descriptors.

• 분석과학
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• 제22권2호
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• pp.159-165
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• 2009

기능성 염료의 일종인 fluoran계 염료의 열 변색현상으로부터 열역학적인 함수들을 구하였다. 양성자성 용매와 비양성자성 용매에서 온도변화에 따른 UV-Vis 스펙트럼을 측정함으로서 평형상수와 엔탈피 값을 측정하였다. 양성자성 용매에서는 락톤형으로만 존재하나 비양성자성 용매에서는 락톤형과 쯔비터 이온형이 같이 존재함을 확인하였다. 평형 상수를 결정하는 요인은 용매의 극성도가 아니라 수소결합 주게의 성질에 큰 영향을 받음을 확인하였다. 엔탈피 변화량도 측정하였다. 온도 변화에 따라 열 변색 현상이 잘 일어나므로 엔탈피 변화량은 약 -2.0 kJ/mol정도이며, 따라서 열린형이 닫힌형보다도 에너지가 안정함을 확인하였다. 산에 의한 엔탈피 변화량은 양성자성 용매에서는 거의 0 kJ/mol에 가까우며 비양성자성 용매에서는 일정한 경향성을 찾기 어려웠으며. 또한 엔트로피와 깁스 자유에너지도 일정한 경향성을 보이지 않았다. 이러한 열역학적인 분석 결과는 기능성 염료의 디자인이나 합성에서 중요한 정보를 제공할 수 있다.