• 공업화학
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• 제22권4호
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• pp.416-422
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• 2011

본 연구에서는 보조계면활성제 첨가가 NP7 비이온 계면활성제, 물, 탄화수소 오일의 3성분으로 이루어진 시스템의 평형 및 동적 거동에 미치는 영향을 살펴보았다. 실험에서 사용한 n-pentanol, n-octanol, n-decanol 등의 보조계면활성제는 모두 소수성 첨가제로 작용하여, 알코올 첨가에 따라 oil in water (O/W) microemulsion (${\mu}E$)이 excess 오일상과 평형을 이루는 2상 영역으로부터 middle-phase ${\mu}E$이 excess water, excess 오일상과 각각 평형을 이루는 3상 영역을 거쳐서 water in oil (W/O) ${\mu}E$이 excess 물상과 평형을 이루는 2상으로 전이되었다. 또한 알코올의 사슬 길이 증가 및 첨가량 증가에 따라 상전이 온도는 감소하였다. O/W ${\mu}E$이 존재하는 조건에서는 비극성 오일의 종류와 상관없이 오일이 계면활성제 마이셀에 의하여 가용화되어 시간에 따라 오일의 크기가 감소하였다. 한편 middle-phase ${\mu}E$를 포함한 3상이 형성되는 조건에서는 매우 낮은 계면장력으로 인하여 오일이 수용액 상에 빠른 속도로 가용화되었고 작은 drop 형태로 유화되었다. 반면에 W/O ${\mu}E$의 2상을 형성하는 조건에서는 과포화로 인하여 일어나는 자발적 유화 현상과 물과 계면활성제의 오일상으로의 확산으로 인한 오일의 크기 증가가 관찰되었다. 비극성 탄화수소 오일과 계면활성제 수용액 사이의 시간에 따른 계면장력 측정 결과는 동적 거동 실험결과와 일치하는 경향을 나타내었다.

• The Korean Journal of Pain
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• 제6권1호
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• pp.74-82
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• 1993

신선한 소의 대뇌피질로부터 synaptosomal plasma membrane vesicles(SPMV)를 분리하고 이 SPMV로부터 추출한 총지질(cholesterol과 각종 인지질 함유)로서 제제한 인공세포막(SPMVTL)에서의 n-alkanols 침투 정도를 형광 probe를 이용한 형광 소광법을 통하여 검색하였다. n-alkanols는 SPMVTL 외부 단층(outer monolayer)의 표면에 주로 분포하되 그 탄소수에 비례하여 소수성 부위에 분포되는 양이 증가되는 경향을 나타내었다(1-decanol은 예외). Methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-hepatnol, 1-cotanol, 1-nonanol 및 1-decanol은 SPMVTL 외부 단층 표면(친수성 부위)에 분포되는 것이 소수성 부위에 분포되는 것에 비하여 각각 650, 288, 151.6, 69.5, 36.8, 11.9, 4.8, 1.6, 0.74, 2.1배가 된다는 것을 확인하였다. 1-decanol은 $C_{10}$인데도 불구하고 $C_8$인 1-octanol에 비하여 적은 양이 소수성 부위에 침투 분포되는 것이 확인되었다. 또한 n-alkanols는 저자등이 이미 보고한 SPMV에서의 경우보다도 본 연구에서의 SPMVTL의 경우가 현저하게 많은 양이 소수성 부위로 침투 분포된다는 것이 확인되었다.

• Biomolecules & Therapeutics
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• 제8권4호
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• pp.332-337
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• 2000

Physicochemical properties of aspalatone (acetylsalicylic acid maltol ester, AM), which has been recently found to have an antithrombotic effect, were studied in terms of solubility, dissolution, partition coefficient (Pc) and stability. The solubility of AM at 37$^{\circ}C$ was about 1.2 mg/ml and the P$_{c}$ value for n-octanol/water and chloroform/water was 11.4 and 382.6, respectively. Dissolution rates of AM at pH 1.2 and 6.8 were more than 80% within 30 min. The degradation of AM followed apparent first-order kinetics, and was dependent on temperature, pH and ionic strength. From the pH-rate profile, the optimal pH was found to be at around 4.0. Half-lives at pH 1.2 and 6.8 were 33.5 and 44.4 hr, respectively. The degradation rate of AM at pH 1.2 was somewhat faster than that of aspirin, but at pH 7.0, the degradation rate of AM was slower than that of aspirin.n.

• Archives of Pharmacal Research
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• 제14권4호
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• pp.311-318
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• 1991

Corneal permeability of various n-alkyl p-hydroxybenzoates (parabens) was studied in vitro using excised rabbit corneas, and the effect of lipophilicity of parabens on the corneal permeability was also investigated. Permeability coefficients were obtained from the least-square linear regression after the steady state had been reached. Lipophilicity of parabens was calculated by distribution coefficients determined in octanol-S | $12{\phi}{\parallel}$) rensen's buffer solution (pH 5.0). The relationship between lipophilicity and corneal permeability of parabens was not linear, but the optimum lipophilicity for the maximum permeation was found. The influence of tween 80 on corneal permeability of methyl and butylparaben was not significant.

• International Journal of Safety
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• 제9권2호
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• pp.6-10
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• 2010

The flash point of liquid solution is one of the most important flammability properties that used in hazard and risk assessments. Minimum flash point behaviour (MFPB) is showed when the flash point of a liquid mixture is below the flash points of the individual components. In this paper, the lower flash points for the flammable binary system, n-decane+n-octanol, were measured by Pensky-Martens closed cup tester. This binary mixture exhibited MFPB. The measured flash points were compared with the values calculated by the Raoult's law and the optimization method using van Laar and UNIQUAC equations. The optimization method were found to be better than those based on the Raoult's law, and successfully estimated MFPB. The opimization method based on the van Laar equation described the experimentally-derived data more effectively than was the case when the prediction model was based upon the UNIQUAC.

• 약학회지
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• 제46권3호
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• pp.168-173
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• 2002

The physicochemical properties of aloesin, which has been recently found to reduce renal toxicity induced by cis-platin, were studied including solubility, partition coefficient ( $P_{c}$ ), osmolality, and stability. The solubility of aloesin was about 500 mg/mι, and the $P_{c}$ value for n-octanol/water was 1.01 $\pm$ 0.03. The degradation of aloesin followed the pseudo-first-order kinetics and was dependent on temperature, pH and ionic strength. From the pH-rate profile, the optimal pH was found to be 2.0~3.0. Some metal ions increased the degradation rate in the rank order of M $n^{2+}$ ＞ F $e^{3+}$ ＞ C $u^{2+}$ ＞ F $e^{2+}$. On the other hand, other metal ions such as B $i^{3+}$, $Ba^{2+}$, Z $n^{2+}$, N $i^{2+}$, $Co^{2+}$ and $Mg^{2+}$ did not show the unfavorable effects. After autoclaving, aloesin contents remaining were 81.8~98.8% of initial concentrations depending on pH. The most stable pH was 3.98 in the autoclaving. Osmolality increased linearly as concentration increased.sed.creased.sed.

• 설비공학논문집
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• 제17권4호
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• pp.312-317
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• 2005

The objectives of this paper are to study the absorption characteristics of $NH_3$ bubbles in the binary nanofluids and to quantify the effects of surfactants and nano-particles on the bubble absorption performance. 2-Ethyl-1-Hexanol, n-Octanol, and 2-Octanol are used as the surfactants and nano-sized $Al_{2}O_3$ and Cu particles are added to make the binary nanofluids into $NH_3/H_{2}O$ solution. The concentration of $NH_3$ solution ($x_s$), the concentration of surfactants ($x_{SA}$), and the mass fraction of nano-particles ($w_{np}$) are considered as key parameters. The experimented ranges of $x_s,\;x_{SA},\;and\;w_{np}$ are $0{\sim}17.92\%,\;0{\sim}1,500\;ppm\;and\;0{\sim}0.2\%$, respectively. The absorption rates are calculated by measuring initial and final weights of test section and exposed time. In addition, the bubble absorption processes are visualized using the shadow graphic method. The results show that the absorption performance is significantly enhanced up to 4 times by adding the surfactants and up to 3 times in the binary nanofluids.

• Preventive Nutrition and Food Science
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• 제8권4호
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• pp.306-314
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• 2003

Volatile flavor components, produced during the young (P-1), immature (P-2), mature (P-3) and old (P-4) growth stages, of shiitake mushrooms (Lentinus edodes), were extracted by simultaneous steam distillation and extraction (SDE), using a mixture of n-pentane and diethyl ether (1:1, v/v) as the extraction solvent. Analyses of the concentrates, by capillary gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS), led to the identification of 129, 129, 111 and 120 components in the P-1, 2, 3 and 4 stages, respectively. The major volatile compounds were l-octen-3-o1, 3-octanol, 3-octanone and 4-octen-3-one. Ethanol and ethyl acetate were also detected in large amounts. The characteristic volatile compounds found in shiitake mushrooms, such as dimethyl disulfide, dimethyl trisulfide and 1, 2, 4-thiolane, were at low concentrations in all samples. The amount of l-octen-3-o1 decreased as growth progressed, but concentrations of 3-octanone increased. The amount of 4-octen-3-ol decreased from P-1 to P-3, but was at a high concentrations in P-4. The concentration of 3-octanol gradually increased and reached its highest concentration in P-3, but decreased in P-4. The C8-compounds comprised 70.91, 64.09, 64.29 and 60.01 % in the P-1, 2, 3 and 4 stages, respectively, so decreased gradually with growth. The S-compounds were found in the highest concentrations in P-3.

• 대한약리학회지
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• 제29권1호
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• pp.157-163
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• 1993

n-Alkanols의 분자적 약리작용기전 탐구에 기초자료를 제공하기 위하여 소의 신선한 대뇌피질로부터 분리한 synaptosomal plasma membrane vesicles (SPMV) 지질 이중층의 측방확산운동에 미치는 n-alkanols의 영향을 형광 probe법으로 검색하였다. n-Alkanols는 SPMV 지질 이중층의 측방확산운동 범위와 속도를 농도 의존적으로 증가시켰고 1-nonanol까지는 탄소수가 두개 증가될 때마다 그 효력은 약 10배 가량 증가되었으나 탄소수 10개인 1-decanol의 효력은 오히려 감소되는 경향을 나타내었다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권6호
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• pp.454-458
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• 2004

A study of the POSE (predispersed solvent extraction) for succinic acid by colloidalliq­uid aphrons was conducted. The organic phase contaning TOA (tri-n-octylamine) and 1-octanol permits a selective extraction of succinic acid from its aqueous solution. There was no difference of the extractability of POSE and that of conventional mixer-settler type extraction. Taking into account the no mechanical mixing in POSE, it was concluded that the POSE process is more adaptive than the conventional mixer-settler type extraction process. From mass transfer analysis at the various concentration of TOA in counter-current continuous operation, the concentration of TOA had no influence on the mass transfer coefficient. The loading values in continuous POSE were almost same as those in batch operation.