• Elastomers and Composites
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• 제54권3호
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• pp.188-200
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• 2019

Rubber articles contain various organic additives such as antidegradants, curing agents, and processing aids. It is important to extract and analyze these organic additives. In this paper, various extraction methods of organic additives present in rubber composites were introduced (solvent extraction, Soxhlet extraction, headspace extraction, and solid-phase microextraction), and the extracts were characterized using gas chromatography/mass spectrometry (GC/MS). Solvent and Soxhlet extractions are easy-to-perform and commonly used methods. Efficiency of solvent extraction varies according to the type of solvent used and the extraction conditions. Soxhlet extraction requires a large volume of solvent. Headspace sampling is suitable for extracting volatile organic compounds, while solid-phase extraction is suitable for extracting specific chemicals. GC/MS is generally used for characterizing the extract of a rubber composite because most components of the extract are volatile and have low molecular weights. Identification methods of chemical structures of the components separated by GC column were also introduced.

• KSBB Journal
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• 제29권2호
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• pp.98-105
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• 2014

Three different types of extraction processes, which used supercritical carbon dioxide ($SCCO_2$) and organic solvent, were attempted to improve the extraction yield of oil from Chlorella vulgaris: cosolvent-modified $SCCO_2$ extraction, $SCCO_2$ extraction with ultrasonic sample treatment in organic solvent, and static extraction with organic solvent followed by dynamic $SCCO_2$ extraction. Among these, the last $SCCO_2$ extraction process was found to be most effective in the extraction of oil. Compared with pure $SCCO_2$ extraction, the extraction yield of oil was observed to increase about 7 times.

• Journal of Korean Society for Atmospheric Environment
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• 제14권E호
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• pp.27-40
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• 1998

The solubility characteristics of organic compounds were studied in terms of the extraction efficiency as a function of the polarity of the organic solvent, and the acidity of water in urban aerosol samples collected in University of East Anglia (UEA), Norwich, England. The extraction efficiency of organic compounds were evaluated with respect to the organic carbon, -nitrogen and -hydrogen by means of a wide range of solvent which include polar and nonpolar organic solvents as well as acids and alkaline water. In addition, after being dissolved in aqueous solution, the aqueous chemistry of organic compounds were studied in terms of the organic metal complexes in aerosol, which were studied with oxalic acid, copper, and zinc. The results of this study indicate that solubility characteristics of organic compounds depend on the polarity of the solvents and the acidity of the solvents. In particular, some organic compounds are water soluble, even though they are much smaller than acetone soluble fractions. In the comparison between polar organic solvent extraction and non- polar organic solvent extraction, it can be thought that significant fraction of organic compounds analysed in the aerosol samples, are polar organic compounds because of the higher extraction efficiencies of organic compounds in polar organic solvent extraction than in nonpolar organic solvent extraction. Regarding the study of the oxalic -metal complexes, it can be thought that most oxalic acids are present in the form of oxalic -copper complexes in the aerosols collected at UEA.

• KSBB Journal
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• 제26권5호
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• pp.453-458
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• 2011

In this study, two different extraction techniques, organic solvent extraction and supercritical carbon dioxide ($SCCO_2$) extraction, were employed to evaluate the extraction efficiency of oil from Chlorella vulgaris. In the organic solvent extraction, the effects of various organic solvent on the extraction yield were investigated. The $SCCO_2$ extraction was carried out while varying such operating parameters as temperature, pressure, $SCCO_2$ flow rate, and cosolvent. About 4.9 wt% of oil was extracted from ground Chrollera vulgaris for 18 h when dichloromethane/methanol (2：1, v/v) was used as an extraction solvent. The oil yield of the $SCCO_2$ extraction was found to be very low (0.53 wt%) and to increase up to about 0.86 wt% with the addition of cosolvent.

• 펄프종이기술
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• 제44권6호
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• pp.50-57
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• 2012

In this study, the beeswax extraction methods using organic solvents were examined to develop a optimal dewaxing technology for beeswax-treated Hanji. Thermally-aged beeswax-treated Hanji was dewaxed using four types of extraction methods including dipping, Soxhlet extraction, ultrasonic washing and shaking methods. Then, the aging stability of the dewaxed Hanji was evaluated in terms of variations in paper strength and in the color of the printed area with muk. The experimental results suggested that the dewaxing methods allowing solvent to flow during extraction showed superior extraction efficiency. The dipping method in which the organic solvent does not flow showed the slowest extraction rate of beeswax compared to three other methods. In terms of variations in tensile strength and folding endurance, however, no obvious differences in the aging stability were observed amongst these four extraction methods. Regarding the aging stability in terms of the color of the printed area with muk, Soxhlet extraction method showed the best performance of dewaxing.

• 한국산학기술학회논문지
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• 제5권2호
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• pp.174-185
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• 2004

미세기공 중공사형 모듈을 이용한 비분산 막-용매 추출에 의하여 유기오염물을 페수로부터 분리하였다. 시스템은 향류 및 병류로 각각 진행되었으며, 분배계수의 비교로부터 MIBK가 분리용 용매로 선정되었다. 향류의 분리도가 병류보다 우수하였으며, 총괄물질전달계수도 구하였다.

• 공업화학
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• 제7권1호
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• pp.203-213
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• 1996

평형 추출장치를 사용하여 유기산의 물리추출과 반응추출에서 추출도에 미치는 추출제의 종류와 농도, 용매의 영향을 조사하였다. 사용된 유기산은 아크릴산과 메타크릴산이었고, 추출제로는 n-octylamine(OA)과 di-n-octylamine(DOA), tri-n-octylamine(TOA)및 tri-octylmetyl ammonium chloride(TOMAC ; Aliquat 336)을 사용하였다. 실험결과 반응추출에서 추출도는 물리추출의 경우보다 2~9배 정도 증가 되었으며, 유기산의 추출도에 미치는 추출제의 영향은 OA, TOMAC, DOA 및 TOA의 순서로 추출도가 증가하였으며, 또한 추출제의 농도가 증가할수록 추출도가 증가하였다. 용매의 영향은 종래의 용매의 유전상수보다는 용해도인자에 의한 용매선택 방법이 신뢰성이 있었고, 용질과 용매의 용해도인자의 차이가 작을수록 추출도가 증가하여 케로진, 크실렌, 클로로포롬, MIBK 및 n-BAc의 순서로 좋아졌다.

• Journal of Microbiology and Biotechnology
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• 제14권5호
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• pp.932-937
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• 2004

In situ extraction by organic solvent was studied in order to improve the recovery yield of hydrocarbon from the culture of Botryococcus braunii, a green colonial microalga. When the solvent mixture of octanol as an extractive solvent and n-octane as a biocompatible solvent was added to a two-phase column, the algal growth was seriously inhibited, even at a low concentration of polar octanol. Therefore, a two-stage cell-recycle extraction process was proposed to improve the contact area between the organic phase and the aqueous phase. The hydrocarbon recovery with in situ cell-recycle extraction showed a three-fold increase (57% of cell) in yield over that with two-phase extraction. In addition, over 60% of the hydrocarbon could be recovered without serious cell damage by downstream separation when this process was applied to the culture broth after batch fermentation.

• Bulletin of the Korean Chemical Society
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• 제33권10호
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• pp.3196-3202
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• 2012

Post-synthesis is used to synthesize organic hybrid inorganic mesoporous sieves. In this method, the activity and structure of the base sieve are crucial to obtain the definable hybrid materials. The chemical and physical properties of the base can be largely changed either by the final step of its synthesizing processes, by template removal which is accomplished with the oxidative thermal decomposition (burning) method or by solvent extraction method. In this paper we compared two methods for the post-synthesis of organic hybrid MCM-48. When the template was extracted with HCl/alcohol mixture, the final product showed larger pore size, larger pore volume and better crystallinity compared to the case of the thermal decomposition. The reactivity of the surface silanol group of template free MCM-48 was also checked with an alkylsilylation reagent $CH_2=CHSi(OC_2H_5)_3$. Raman and $^{29}Si$ NMR spectra of MCM-48 in the test reaction indicated that more of the organic group was grafted to the surface of the sample after the template was removed with the solvent extraction method. Direct synthesis of vinyl-MCM-48 was also investigated and its characteristics were compared with the case of post-synthesis. From the results, it was suggested that the structure and chemical reactivity can be maintained in the solvent extraction method and that organic grafting after the solvent extraction can be a good candidate to synthesize a definable hybrid porous material.

• 대한화학회지
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• 제53권4호
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• pp.427-431
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• 2009

대두 잔기로부터 유기용매를 사용하여 이소플라본을 추출하는 열역학적 메카니즘을 조사하였다. 대두 잔기로부터 유기용매를 사용한 이소플라본 추출과정에서의 분배 계수를 결정하기 위한 간단한 모델을 설정하고 $K,\;{\Delta}H^0,\;{\Delta}S^0\;and\;{\Delta}G^0$ 간에 열역학적 함수를 계산하였다. 그 결과 대두 이소플라본 추출은 흡열과정이며 엔트로피 증가과정임을 발견하였다. 온도가 증가할수록 ${\Delta}G^0$가 감소하였다.