• The Korean Journal of Ceramics
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• 제7권2호
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• pp.80-84
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• 2001

The anisotropic CdS platelets were synthesized in the lamellar bilayer phase region of the octylamine-water binary system. The influence of the synthesis conditions of the system components on morphology and size of the platelets was examined. Atomic force microscopy (AFM) and high-resolution transmission electron microscopy (HRTEM) studies have shown thickness and face size of the synthesized particles. Platelets with face sizes ranging from 50 to 250 nm and thickness from 10 to 30 nm have been synthesized at room temperature. In addition, HRTEM micrographs show that the synthesized platelets are poly crystal.

• Bulletin of the Korean Chemical Society
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• 제20권1호
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• pp.69-75
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• 1999

The silica-pillared H-kenyaites were prepared by interlarmellar base-catalyzed reaction of tetraethylorthosilicate [TEOS, Si(OC2H5)4] intercalated into the interlayer of H-kenyaite. The intercalation of TEOS was conducted by the octylamine preswelling process, resulting in a dramatic increase in gallery height to 24.7 Å. The interlamellar hydrolysis of octylamine-TEOS/H-kenyaite paste were conducted between 10 min and 40 min in 0.00%, 0.05% and 0.10% NH3-water solution respectively, and resulting in siloxane-pillared H-kenyajte with gallery height of 28.2-31.8 Å. The calcination of samples at 538 ℃ resulted in silica-pillared H-kenyaites with a large surface areas between 411 m2/g and 885 m2/g, depending on the aging time and NH3 concentration. Samples with optimum specific surface areas and well ordered-basal spacing were obtained by reaction between 10 min and 40 min in pure water and 0.05% NH3-water solution. Mesoporous samples with narrow pore size distribution were also prepared by reaction for 10-40 min in 0.05% NH3 solution. Rapid interlamellar reaction of TEOS in pure water showed that intercalated octylamine itself could act as a base catalyst during interlamellar polycondensation of TEOS.

• 한국안전학회지
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• 제4권1호
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• pp.15-24
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• 1989

The transport of Chromium(Vl) ion from waste water throughl the liquid surfactant membrane containing tri-n-octylamine as a carrier, was analyzed by a slab model and was investigated through experiments. For the experiment of membrane stability, concentrations of surfactant and liquid parafnn oil were analyzed. Extraction euperiments were carried out to observe the effect of system variables, such as stirring speed, concentration of carrier, and NaOH in internal aqueous phase, and concentrations of H$_2$SO$_4$and initial chromium(VI) ion in external aqueous phase at $25^{\circ}C$. It is concluded that the most stable formation of liquid membrane emulsion was obtained when surfactant concentration is above 3 wt. ％ and liquid parafnn oil concentration is 50 vol. ％. The transport of chromium(VI) ion in bacth extractor increased with increasing carrier concentration, the volume ratio of emulsion to external aqueous phases, and initial concentration of chromium(VI) ion under the optimum stirring speed of chromium(VI) ion below 2 ppm. The theoretical equation on the transport of chromium(Vl) ion agreed well with the experimental results.

• Elastomers and Composites
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• 제23권1호
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• pp.11-17
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• 1988

The transport of chromium(VI) ion from waste water through the liquid surfactant membrane containing tri-n-octylamine as a carrier, was analyzed by a slab model and was investigated through experiments. For the experiment of membrane stability, concentrations of surfactant and liquid paraffin oil were analyzed. Extraction experiments were carried out to observe the effect of system variables, such as concentrations of carrier, and initial chromium(VI) ion in external aqueous phase at $25^{\circ}C$. It is concluded that the most stable formation of liquid membrane emulsion was obtained when surfactant concentration is above 3 wt.% and liquid paraffin oil concentration is 50 vol.%. The theoretical equation on the transport of chromium(VI) ion agreed well with the experimental results.

• 자원리싸이클링
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• 제6권3호
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• pp.9-14
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• 1997

염산계 에칭폐액으로부터 추출제로 Alamine336(Tri-n-octylamine)을 이용하여 용매추출법에 의해 구리를 회수하기 위한 연구를 행하였다. 주요 실험변수로는 염산농도 및 염소이온농도, 추출제의 농도, 유기상과 수용액상(폐액상)의 상비 등 구리이온의 추출에 영향을 미칠 수 있는 인자들에 대하여 실험을 하엿는데, 이 실험결과 추출제의 농도 및 상비가 구리의 추출에 큰영향을 미침을 알 수 있었고 또한 수용액상의 염산 및 염소이온의 농도가 증가할수록 구리의 추출률이 증가하였다. 한편 McCabe-Thiele diagram으로부터 구리성분의 연속추출공정에 필요한 이론적인 추출단수를 결정하였다. 유기상으로 추출된 구리성분은 탈거제로 물($H_2$O)을 사용함으로써 효율적으로 탈거가 가능하였고 탈거제의 온도가 증가할수록 구리성분의 탈거율은 증가하였다.

• Journal of Pharmaceutical Investigation
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• 제35권2호
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• pp.123-127
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• 2005

An HPLC method was employed for the determination of ethambutol in human plasma. After addition of internal standard (IS, octylamine, $2\;{\mu}g/mL$) and alkalinization of the plasma with 5 M sodium hydroxide, the drug and IS were extracted into the mixture of chloroform and diethyl ether (40:60, v/v). Following a 15-min vortex-mixing and a 10min centrifugation, the organic phase was spiked with $100{\mu}L$ of phenylethylisocyanate $(2000{\mu}g/mL)$ for chemical derivatization, mixed for 5 min and evaporated to dryness under a stream of nitrogen. The residue was reconstituted with $100{\mu}L$ of mobile phase and $20{\mu}L$ was injected into C18 column with a mobile phase consisting of methanol:water (70:30, v/v). The samples were detected utilizing an ultraviolet detector at 200 nm. The method was specific and validated with a limit of $0.15\;{\mu}g/mL$. Intra- and inter-day precision and accuracy were acceptable for all quality control samples including the lower limit of quantification. The applicability of this method was demonstrated by analysis of human plasma after oral administration of a single 1200-mg dose to 20 healthy subjects. From the plasma ethambutol concentration vs. time curves, the mean AUC was $9.61{\pm}1.64\;{\mu}g{\cdot}hr/mL$ and Cmax of $2.68\;{\mu}g/mL$ reached 2.73 hr after administration. The mean biological half-life of ethambutol was $3.46{\pm}1.21$ hr. Based on the results, this simple and validated assay could readily be used in any pharmacokinetic studies using humans.