• Applied Chemistry for Engineering
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• v.22 no.4
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• pp.376-383
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• 2011

The CMCs of LA and LA3 nonionic surfactants obtained from the reaction between glycidol and lauryl alcohol were found to be $0.97{\times}10^{-3}mol/L$ and $1.02{\times}10^{-3}mol/L$ respectively and the surface tensions for 1 wt% surfactant were 26.99 and 27.48 mN/m respectively. Dynamic surface tension measurements using a maximum bubble pressure tensiometer showed that the adsorption rate of surfactant molecules at the interface between the air and the surfactant solution was found to be relatively fast in both surfactant systems, presumably due to the high mobility of surfactant molecules. The contact angles of LA and LA3 nonionic surfactants were 27.8 and $20.9^{\circ}$ respectively and the dynamic interfacial tension measurement by a spinning drop tensiometer showed that interfacial tensions at equilibrium condition in both systems were almost the same. Also both surfactant systems reached equilibrium in 2~3 min. Both surfactant solutions showed high stability when evaluated by conductometric method and the LA nonionic surfactant system provided the higher foam stability than the LA3 nonionic surfactant system. The phase behavior experiments showed a lower phase or oil in water (O/W) microemulsion in equilibrium with an excess oil phase at all temperatures studied. No three-phase region was observed including a middle-phase microemulsion or a lamellar liquid crystalline phase.

• Journal of the Korean Applied Science and Technology
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• v.32 no.2
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• pp.290-295
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• 2015

The purpose of this study is to separate nitrocellulose from 175 mm ammunition propellant by environmentally responsible recovery method. Recovery of nitrocellulose from obsolete ammunition is much more desirable than destruction since it can be reused in the several purpose. In spite of durable demilitarization of obsolete ammunition, the current holding amount of obsolete ammunition is gradually increasing and accumulated. The existing demilitarization methods, such as incineration and priming are strictly restricted for the noise, dust, oscillation and air and soil pollution. This study is focused on the separation of nitrocellulose by environmentally responsible recovery method by the solubility difference of nitrocellulose in nonpolar solvent. The purity of an extracted nitrocellulose was analysed by IR and TLC method and was clarified as very high.

• Applied Chemistry for Engineering
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• v.22 no.4
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• pp.416-422
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• 2011

In this study, the effect of cosurfactant on the phase equilibrium and dynamic behavior was studied in systems containing NP7 nonionic surfactant solutions and nonpolar hydrocarbon oils. All cosurfactants used during this study such as n-pentanol, n-octanol and n-decanol acted as a hydrophobic additive and thus promoted the transition from an oil in water (O/W) microemulsion (${\mu}E$) in equilibrium with an excess oil phase to a three-phase region containing excess water, excess oil, and a middle-phase microemulsion and further to a water in oil (W/O) ${\mu}E$ in equilibrium with the excess water phase. The transition temperature was found to decrease with both increases in the chain length and amount of addition of a cosurfactant. Dynamic behavior studies under O/W ${\mu}E$ conditions showed that an oil drop size decreased with time due to the solubilization into micelles. On the other hand, both the spontaneous emulsification of water into the oil phase and the expansion of oil drop were observed under W/O ${\mu}E$ conditions because of the diffusion of surfactant and water into the oil phase. Under conditions of a three-phase region including a middle-phase ${\mu}E$, both the rapid solubilization and emulsification of the oil into aqueous solutions were found mainly due to the existence of ultra-low interfacial tension. Dynamic interfacial tension measurements have been found to be in a good agreement with dynamic behavior results.

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.5-8
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• 2003

요오드화 아연과 수소화 요오드에 의해 개시되는 비닐에테르류 단량체의 양이온 리빙 중합이 보고$^{(1)}$ 된 이래 리빙 중합 개시계에 대한 연구가 많이 진행되어 왔다. 본 연구자들은 광양이온중합 개시제인 요오드화 디페닐요드늄과 할로젠화 아연 존재 하에서 비닐에테르 단량체의 광양이온중합을 실시하여 비극성 용매 하에서 연쇄이동이나 정지반응이 존재하지 않는 리빙중합을 보고한$^{(2-4)}$ 바 있는데 이 중합에서 비닐에테르 단량체와 프로톤산에 의하여 생성된 단량체 adduct의 C-I 결합이 안정한 공유결합을 형성하나 요오드화아연에 의해 C-I 결합의 분극화되어 활성화됨으로서 개시와 성장반응이 가능한 것으로 설명되었다. (중략)

• KSBB Journal
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• v.15 no.4
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• pp.408-410
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• 2000

The supercritical fluid extraction(SFE) technique was applied for the isolation and purification of nonpolar physiologically acitve mateials from Agaricus blazei fruiting bodies. the qualitative analysis of extract was accomplished by gas chromatography-mass spectrometer(GC-MS) and extract was determined as linoleic acid(cis-9 cis-12-octadecadienoic acid) In order to obtain the optimum operating conditions of supercritical fluid extraction process the various temperatures and pressures were applied for process operation. From the comparison of exraction efficiencies $50^{\circ}C and 200 kg_f/cm^2$ were determined as optimum conditions.

• Korean Journal of Pharmacognosy
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• v.48 no.4
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• pp.280-284
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• 2017

Lion's Mane Mushroom, Hericium erinaceum, is a traditional edible mushroom widely used in culinary applications. It has been also used as a medicine in East Asian countries due to its various biological activities. Chemical investigation of fruiting bodies of this mushroom afforded many aromatic compounds, which were mostly isolated from polar fraction of its extracts. Herein we tried to investigate non-polar compounds from the extracts of this mushroom. $CHCl_3$-soluble fraction of the extracts was subjected to chemical investigation, which resulted in isolation of four compounds. Their chemical structures were elucidated as ircicerebroside (1), cortenuamide A (2), 1-D-arabinitol-monolinoleate (3), and cinnamic acid (4) on the basis of spectroscopic data. To the best of our knowledge, this is the first report of compounds 1, 2, and 4 from Hericium erinaceum.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.8
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• pp.611-617
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• 2001

The non-polar optical phonon scattering in the valence band depends on the masses, ratios, and types of mixtures of constituent atoms. Therefore, the random distribution of atoms in alloy semiconductors should be considered in the analysis of scattering mechanisms. For this purpose, the force equations of n atoms in a unit cell are expressed in a n x n matrix form to obtain the angular frequencies due to the acoustic and non-polar optical phonons. And, n is then assumed to be infinity. When this work is compared with other results published elsewhere, it is concluded that the independence of atomic displacement or amplitude of oscillation as ell as the infinite number of atoms in a unit cell must be taken into account for the random distribution of atoms in alloy semiconductors.

• Journal of the Korean Chemical Society
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• v.40 no.5
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• pp.302-307
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• 1996

Diethanolamine dithiocarbamate is known to react with dichlorobis(ethylenediamine)cohalt(Ⅲ) chloride to form [Co(dtc)3](dtc=diethanolamine dithiocarbamate) in which two sulfur atoms of the dithiocarbamate are bound to cobalt. The complex is moderately soluble in acetone, but sparingly soluble in carbon disulfide. Kinetics and mechanisms of the reaction of dichlorobis(ethylenediamine)cobalt(Ⅲ) chloride with diethanolamine dithiocarbamate have been studied in aqueous solution. Activation parameters have been calculated from the kinetic data for the reaction and from these results a possible mechanism for the reaction has been proposed.

• Journal of the Korean Chemical Society
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• v.28 no.5
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• pp.323-327
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• 1984

Nicotine was reacted with an equimolar amount of ozone in methylene chloride and distilled water. The reaction mixture was separated by column chromatography or thin layer chromatography and then purified by vacuum distillation. The six compounds obtained from this reaction were characterized by NMR, IR and Mass spectrometry. These were identified as unchanged nicotine, nornicotine, anabasine, ${\beta}$-nicotyrine, cotinine and nicotine-N-oxide. From these results, reaction mechanism for the ozonolysis ofon nicotine was proposed; the pyrrolidine ring is attacked by ozone at the 1'-position followed by further transformation.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.10
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• pp.784-789
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• 2011

A linear spring model, where the interactions among atoms are assumed to be isotropic and elastic, is employed for the study of non-polar optical phonon scattering in the valence band of alloy semiconductors. The force equations of n atoms are used in the spring model for the consideration of the random distribution of constituent atoms in an alloy semiconductor. When the number of atoms in a unit cell is assumed to be two based on the experimental result, the optical deformation potent is valid for compound semiconductors as well as alloy semiconductors.