• 한국응용과학기술학회지
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• 제36권2호
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• pp.609-622
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• 2019

계면활성제가 수용액 중에 용해되면 용액 내에서 micelle (< 20 nm) 이라는 응집체를 형성하며, micelle은 그 내부에 활성물질을 담지하여 가용화 제형이 형성될 수 있다. Swollen micelle은 50~100 nm 정도로 일반 가용화 제형보다 더 많은 양의 활성물질을 담지할 수 있는 제형이다. Swollen micelle은 고압유화와 같은 별도의 공정이 필요한 liposome이나 nanoemulsion과는 달리 특별한 공정이 필요 없어 생산적인 면에서 좀 더 효율성 있는 가용화 및 입자형성 방법이라고 할 수 있다. 본 연구에서는 Poloxamer 407을 이용하여 swollen micelle 제형에 대한 안정화 실험을 진행한 후, Response Surface Methodology (RSM)을 이용하여 tocopheryl acetate 가용화에 대한 제형 최적화 실험을 진행하였다. 가용화에 영향을 주는 계면활성제와 활성물질인 tocopheryl acetate를 요인(factor)로 설정하고 서로 간의 상관관계를 확인하였다. 평가방법으로서 온도 및 시간에 따른 안정성과 입자 분포 및 크기를 확인하였으며, FIB를 통해 효능 물질을 담지한 swollen micelle의 입자 구조 및 모양을 확인하였다. 이러한 실험 결과들을 통하여 tocopheryl acetate를 안정화시킨 swollen micelle은 poloxamer 407 0.500%, octyldodeceth-16 0.387%, tocopheryl acetate 0.945%일 때 가장 최적화된 처방이라 할 수 있다.

• 대한화학회지
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• 제16권4호
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• pp.205-207
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• 1972

새로히 합성한 dodecylquinolinium bromide의 수용액에서 표면장력과 전기전도도 측정치로 부터 critical micelle concentration을 결정하였다. 표면장력법으로 결정한 c.m.c.의 값은 $3.34 {\times} 10^{-3}mole/l$이고 전기전도도법으로 결정한 값은 3.41 {\times} $10^{-3}$mole/l이었다. 이값들은 dodecylpyridinium bromide의 그것보다 작은데 이는 dodecylquinolinium bromide의 소수성 group이 큰데서 오는 것으로 생각된다.

• Bulletin of the Korean Chemical Society
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• 제24권1호
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• pp.32-36
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• 2003

Co nanoparticles were prepared by the reverse micelle technique (NaBH₄reduction of cobalt chloride in a reversed micelle solution of didodecyldimethylammoniumbromide (DDAB)/toluene). The size and the shape of Co nanoparticles could be easily controlled by changing the water contents and micelle concentrations, and the solubility of Co nanoparticles was systematically tuned by choosing appropriate surface capping organic ligand molecules. Furthermore, a novel nanofabrication process was clearly demonstrated, which generated oxide over-coated Co nanorods from Co nanoparticles in organic solution by slow oxidation with an external magnetic field.

• 대한화학회지
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• 제33권5호
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• pp.459-467
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• 1989

계면활성제가 수용액 중에 용해되면 용액내에서 micelle이라는 응집체를 형성하며, micelle은 그 내부에 oil를 용해시켜 swollen micelle을 형성하게 된다. 실제로 물-oil-계면활성계의 상평형도상에서 micelle과 swollen micelle은 동일영역에 존재하게 되나 일반적으로 micelle과 swollen micelle의 형성에 관해서는 서로 다른 관점으로 취급되어 왔다. 본 연구에서는 이러한 계면활성제 응집체의 형성에 관한 일관된 열역학적 모델을 제시하고자 한다. 모든 경우에 저농도 영역에서 이상용액 이론을 적용하였으며, micelle 형성에너지는 소수성 작용에너지와 계면에서의 표면에너지의 합으로 표시하였다. 이론식으로부터 임계마이셀농도, 평균응집분자수, 용해비 등을 예측하였으며 실험관측치와 비교하였다.

• Bulletin of the Korean Chemical Society
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• 제10권5호
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• pp.437-442
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• 1989

The cmc's of sodium dodecyl sulfate (SDS)/Triton X-100 surfactant mixtures were determined by surface tension measurement at various surfactant compositions. The cmc values were lower than those predicted from ideal mixture. The regular solution theory was applied to calculate the interaction parameter, micellar composition, and the activity coefficients of surfactants in the mixed micelle. The interaction parameter (${\beta}$) was - 2.1. The nonideality arised largely from decreased activity of SDS in the mixed micelle. The mean aggregation numbers (${\bar{n}}$) and micropolarity of hydrocarbon region of the mixed micelles were determined by luminescence probe techniques. The total aggregation number (${\bar{n}}_{SDS}+{\bar{n}}_{TX}$) in mixed micelles showed little dependency on the composition of the micelle. The apparent dielectric constant of the hydrocarbon region of the micelle vs micellar composition plot showed positive deviation from linearity. Emission and emission quenching of excited tris(2,2'-bipyridine)ruthenium(Ⅱ) cation, $(Ru(bpy)_3^{2+})$, by methylviologen ($MV^{2+}$) were also investigated in the mixed micellar solutions. The quenching rate was lowest when the mole fraction of SDS in the surfactant mixtures (${\alpha}_{SDS}$) is about 0.25 and highest at ${\alpha}_{SDS}$ = 0.85. This was explained in terms of combined effects of binding of the cations with the micelle and mobility of the bound cations on the surface of the micelles.

• 대한화학회지
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• 제10권4호
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• pp.161-165
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• 1966

The critical concentrations of ${\alpha}$-amino capric acid for micelle formation have been determined by the surface tension measurements in both acidic and alkaline solutions, and also by the dye titration using Rhodamine B in alkaline solutions. The critical micelle concentrations obtained by the two methods show the good agreements within experimental errors. Since ${\alpha}$-amino acid is an ampholyte, it may aggregate to form the micelles in both more acidic and basic media than its isoelectric point. It is found that the basic media are rather preferable for the micelle formation than the acidic media. The effect of gegen ions upon the critical concentration for micelle formation in alkaline media is similar to that expected from the salt effect on the CMC (Critical Micelle Concentration).

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2001년도 추계학술발표회요약집
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• pp.283.2-283
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• 2001

• Archives of Pharmacal Research
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• 제9권3호
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• pp.139-144
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• 1986

The solubilization sites of aniline and its derivatives in micelles were investigated with fluorescence probe technique. The fluorescence probes employed in this study are 12-(9-anthroyl) stearic acid (AS) and 2-p-toluidinylnaphthalene-6-sulfonate (TNS) which are incorporated in the interior of the micelle and attaced to its surface, respectively. As these two probes were effectively quenched by aniline and its surface, respectively. As these two probes were effectively quenched by aniline and its derivatives, the modified Stern-Volmer relationship in micellar system could be applicable to estimate the partition coefficient, $K_{p}$ of the solubilizate between aqueous and micellar phase. Because $K_{p}$ derived by this method reflects the relative proximity of the fluorophore to the quencher, the ratio of $K_{p}$ in the surface area to that in the interior of the micelle is interpreted in terms of the relative location of the solubilizate in micellar aggregate. The results show that the solubilizates are not located in a definite position but distributed in the multiple-sites of the micelle. The solubilization sites of the solubilizates in the icelle are dependent on their structures. As the solubilizate has more numbers of N-substituents of aniline and more numbers, of carbon in the substituent, it tends to incorporate in the interior of the micelle more effectively.

• 한국응용과학기술학회지
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• 제23권2호
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• pp.160-168
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• 2006

The conductances of trimethyltetradecylammonium bromide (TTAB) plus triphenyltetradecyl phosphonium bromide (TTPB) and TTAB plus trimethylhexadecylammonium bromide (HTAB) over the entire mole fraction range of TTAB were measured in water and in cyclodextrin plus water mixtures at fixed 4 and 8 mM of cyclodextrin at $30^{\circ}C$. The conductivity plot for both binary mixtures shows a single break from which the mixed critical micelle concentration and degree of micelle ionization were computed. From the slope of the conductivity curve, the equivalent ionic conductivities of the monomeric, associated, and the micelle states were calculated and discussed with respect to the surfactant-cyclodextrin complexation in the whole mole fraction range of both surfactant binary mixtures. The association constant K between the respective monomeric surfactant and cyclodextrin cavity of fixed 4 mM cyclodextrin was computed by considering 1:1 association from the surface tension measurement. A comparison among the K values for HTAB-cyclodetrin, TTAB-cyclodextrin, and TTPB-cyclodextrin shows that the former complexation is significantly stronger in comparison to the other ones due to the longer hydrophobic tail.

• 대한화학회지
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• 제18권5호
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• pp.354-357
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• 1974

모노스테아르산설탕의 critical micelle concentration(CMC)를 $20^{\circ}C$와 $40^{\circ}C$사이의 여러 온도에서 측정하였고 이어서 디에스테르가 첨가 되었을 때의 CMC를 측정하였다. 디에스테르가 포함된 모노에스테르의 용액에서는 용액의 표면장력이 약 40dyne $cm^{-1}$가 될 때 표면장력 대 농도 곡선이 불연속을 나타내는데 이것은 모노에스테르와 디에스테르와의 회합체가 이 영역에서 표면배열을 갑자기 바꾸기 때문이라고 생각된다.