• Journal of the Korean Ceramic Society
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• v.37 no.1
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• pp.26-32
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• 2000

Preparation and characteristics of a matrix retaining electrolyte using SiC whisker, PES binder, and NMP(n-methyl-2-pyrrolidone) as a non-volatile solvent for a phosphoric acid fuel cell were investigated. The conditions of binder and plasticizer, and the effects of substituting a volatile solvent by a non-volatile solvent were also studied. The minimum amount of the binder was about 17 wt% for the proper bubble pressure and surrounding SiC whiskers. And the maximum amount of the plasticizer was about 10wt% to be fitted into the polymer chain of the binder. The matrix prepared by using a non-volatile solvent needed longer time to dry, and its pore size was smaller compared with that of the matrix prepared by using volatile solvent. The small pore size resulted in decrease of the overall pore volume. The ionic conductivity in the condition of the same thickness was decreased due to decrease of phosphoric acid absorbancy. As the internal resistance of the electrolyte increased, the fuel cell performance slightly decreased.

• Applied Chemistry for Engineering
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• v.24 no.2
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• pp.171-176
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• 2013

The need of volatile organic compound (VOC) free coating material has been increased to solve environmental problems such as the global warming. Nowadays, about 70~80% of coating materials used in the worldwide are a liquid type. Therefore, the development of non-solvent coating material that can minimize VOCs emissions is necessary to solve the global warming problem. In this study, acrylic monomers were added to develop non-solvent paints in order to improve disadvantages of the poor adhesion of a conventional phenolic resin caused by acidification. As a result, the blend resins of 2.818 Mpa phenol- formaldehyde resin/poly methyl methacrylate (PE/PMMA) has the best properties and performances for the adhesives.

• JSTS:Journal of Semiconductor Technology and Science
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• v.8 no.1
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• pp.46-50
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• 2008

The effect of physicochemical properties of solvents on the microstructure of polyvinyl carbazole (PVK) film for non-volatile polymer memory was investigated. For the solubilization of PVK molecules and the preparation of PVK films, four solvents with different physicochemical properties of the Hildebrand solubility parameter and vapor pressure were considered: chloroform, tetrahydrofuran (THF), 1,1,2,2-tetrachloroethane (TCE), and N,N-dimehtylformamide (DMF). The solubility of PVK molecules in the solvents was observed by ultravioletvisible spectroscopy. PVK molecules were observed to be more soluble in chloroform, with a low Hildebrand solubility parameter, than solvents with higher values. The aggregated size and micro-/nano-topographical properties of PVK films were characterized using optical and atomic force microscopes. The PVK film cast from chloroform exhibited enhanced surface roughness compared to that from TCE and DMF. It was also confirmed that the microstructure of PVK film has an effect on the performance of non-volatile polymer memory.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.320-320
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• 2010

The dye-sensitized solar cells (DSSCs) have achieved so far the highest validated efficiency over 11%. However, the cells with the best performance utilize volatile solvent as a electrolyte, which can cause some practical limitations for the long-term operation. This is one of the most substantial problems to be resolved for the commercialization of DSSCs. In order to improve the long-term stability, many research groups have reported new electrolyte system, to replace the liquid type electrolyte by non-volatile ones. In this work, we studied long-term stability of the DSSCs with various types of electrolytes such as (PVDF HFP) based polymer, eutectic melts of ionic liquids, and liquid based solvent. The cells with various electrolytes have been exposed to the condition under thermal stress and illumination over 1000 hours. We will report the change of photovoltaic properties with time and investigate the degradation mechanism with the impedance spectroscopic analysis.

• Analytical Science and Technology
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• v.33 no.1
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• pp.11-22
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• 2020

When extracting semi-volatile components of herbal medicines using hot water vapor, some substances may react with water vapor or oxygen, and some volatile substances may be lost, when using an organic solvent extraction method has the disadvantage that it may contain a non-volatile material and residual organic solvent. In addition, it is inefficient to separate semi-volatile substances from herbal medicines into each single component and conduct biological activity research for each component to determine the effective ingredient, and some components may be lost in the separation process. In this study, semi-volatile substances evaporated under two pressure-reduced conditions in Chinese herbal medicines such as Cnidii Rhizoma, Aucklandiae Radix and Amomum Fructus were separated by cooling with liquid nitrogen. Those were analyzed by gas chromatography-mass spectrometry (GC-MS) to identify the components, and this method may be used to study biological activities at the cellular level. The substances separated under reduced pressure, essential oil obtained by simultaneous distillation extraction (SDE) method and substances by using solid phase micro-extraction (SPME) from Cnidii Rhizoma, Aucklandiae Radix and Amomum Fructus were analyzed by GC-MS. In the case of Cnidii Rhizoma and Aucklandiae Radix, there were some differences among the essential oil components obtained by SDE and those identified by low temperature capture (CT) and SPME method, these were believed to be produced by some volatiles reacting with water or oxygen at the boiling point temperature of water.

• Journal of the Korean Society of Tobacco Science
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• v.7 no.1
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• pp.85-92
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• 1985

Extraction efficienties of volatile organic acids in tobacco leaves according to several extraction methods were investigated and contents of volatile organic acids in 16 kinds of tobacco leaf varieties were compared. Extraction efficiency according to simultaneous distillation and extraction was 5 to 10 times higher than that according to solvent extraction, steam distillation, essential oil extraction or continuous extraction and distillation. Total contents of volatile organic acids were 1.62 to 12.94mg per l00g of sample in aromatic tobacco varieties,0.12 to 2.08mg in flue-cured tobacco leaves, and trace in burleys. Among the Korean aromatic tobacco varieties, total contents of volatile organic acids in ST374-3 were the highest, 4.66mg per l00g of sample, and those in Sohyang and Hyangcho were low, 1.69mg and 1.62mg, respectively. Among flue-cured tobacco varieties, those in NC2326 were the highest, 2.08mg per 100g of sample, but those in the other varieties were not more than 0.80mg per 1 00g of sample. Total contents of volatile organic acids in acidic hydrolysis with 0.1 M tartaric acid were higher than in non-acidic condition in all kinds of tobacco varieties.

• Journal of Environmental Science International
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• v.21 no.2
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• pp.165-179
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• 2012

Indirect $CO_2$ effect due to non-methane volatile organic compound (NMVOC) emissions from solvent and product use and fugitive NMVOC emissions from fuels in the Republic of Korea and 13 Annex I countries under United Nations Framework on Climate Change were estimated and the proportions of them to total greenhouse gas (GHG) emissions ranged from 0.092% to 0.45% in 2006. Indirect greenhouse effect ($CO_2$, $CH_4$, and $O_3$) were estimated at 13 photochemical assessment monitoring sites in the Republic of Korea using concentrations of 8 NMVOCs of which indirect global warming potential (GWP) were available. The contribution of toluene to mixing ratio was highest at 11 sites and however, the contribution of toluene to indirect greenhouse effect was highest at nine sites. In contrast to toluene, the contributions of ethane, butane, and ethylene were enhanced. The indirect greenhouse effects of ethane and propane, of which ozone formation potentials are the lowest and the third lowest respectively among targeted 10 NMVOCs, ranked first and fourth highest respectively. Acetaldehyde has relatively higher maximum incremental reactivity and is classified as probable human carcinogen however, its indirect GWP ranked second lowest.

• Clean Technology
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• v.22 no.3
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• pp.203-207
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• 2016

Here, we report a novel fabrication technique for patchable organic lasing sheet based on non-volatile liquid organic semiconductors and freestanding polymeric film with high flexibility and patchability. For this work, we have fabricated the second-order DFB grating structure, which leads to surface emission, embedded in the freestanding polymeric film. Using an ultra-violet (UV) curable polyurethaneacrylate (PUA) mixture, the periodic DFB grating structure can be easily prepared on the freestanding polymeric film via a simple UV curing process. Due to unsaturated acrylate remained in the PUA mixture after UV curing, the freestanding PUA film provides adhesive properties, which enable mounting of the patchable organic lasing sheet onto non-flat surfaces with conformal contact. To achieve laser actions in the freestanding resonator structure, a composite material of liquid 9-(2-ethylhexyl)carbazole (EHCz) and organic laser dyes was used as the laser medium. Since the degraded active materials can be easily refreshed by a simple injection of the liquid composite, such a non-volatile liquid organic semiconducting medium has degradation-free and recyclable characteristics in addition to other strong advantages including tunable optoelectronic responses, solvent-free processing, and ultimate mechanical flexibility and uniformity. Lasing properties of the patchable organic lasing sheet were also investigated after mounting onto non-flat surfaces, showing a mechanical tunability of laser emission under variable surface curvature. It is anticipated that these results will be applied to the development of various patchable optoelectronic applications for light-emitting displays, sensors and data communications.

• KSBB Journal
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• v.17 no.2
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• pp.148-152
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• 2002

The extraction of volatile essential oil using supercritical carbon dioxide with 2%(v/v) ethanol and non-ethanol was performed in a semi-continuous flow extractor at the range of pressures and temperatures 6.9 to 17.2 MPa and 30 to 45$^{\circ}C$, respectively. When ethanol was added to the co-solvent, the solubility of volatile essential oils was increased up to 90% over the neat CO$_2$ value. The most efficiency of extraction of the voilatile essential oils was achieved at 13.8㎫ and 40$^{\circ}C$ by supercritical carbon dioxide with entrainer from Citrus junos peel.

• Korean Chemical Engineering Research
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• v.55 no.2
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• pp.214-219
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• 2017

In this work, we fabricated PS-b-P4VP block copolymer membranes from self-assembly and non-solvent induced phase separation (SNIPS), which combines the block copolymer self-assembly and conventional NIPS process. While previous studies mostly focused on the fabrication of well-defined structures, we systematically examined various processing parameters such as polymer concentration, solvent evaporation duration, solvent composition, and humidity, to optimized the membrane structures. As a result, the morphology of PS-b-P4VP membranes was optimized at a certain polymer concentration in solution and composition of volatile solvent at low humidity conditions, resulting in SNIPS separation membranes with well-defined nanopores on the surface, 75% of membrane porosity, and 18% of surface porosity.