• Journal of the Korean Chemical Society
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• v.13 no.1
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• pp.1-4
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• 1969

Temperature effect on the critical micelle concentration of hexadecyl trimetyl ammonium bromide over the range of $2^{\circ}-50^{\circ}C$ has been investigated by the method of electrical conductivity. The values obtained have been formulated as a power series in T. Several thermodynamic parameters have been calculated for the temparature range examined and their values have been discussed in the light of current theories on the participation of solvent in micelle formation.

• Macromolecular Research
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• v.15 no.1
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• pp.39-43
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• 2007

The amphiphilic block copolymer (PEtOz-PCL) of poly(2-ethyl-2-oxazoline) (PEtOz) and poly(${\varepsilon}$-caprolactone) (PCL) formed spherical micellar structures with an average diameter of 26 nm in aqueous phase. Au and Pd nanoparticles with an average diameter of $2{\sim}3nm$ were prepared by using the PEtOz-PCL micelle consisting of a PEtOz shell and PCL core. The Au nanoparticles of PEtOz-PCL micelles in aqueous phase could be transferred into organic phase by using n-dodecanethiol. The use of the Pd-NP/PEtOz-PCL micelle as a nanoreactor for Suzuki cross-coupling reaction was investigated.

• Rapid Communication in Photoscience
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• v.4 no.3
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• pp.73-75
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• 2015

Cr(VI) reduction was successfully achieved in the presence of cationic micelles (CMs) under visible light illumination. Micelle formation of cationic surfactants seems to be critical in Cr(VI) reduction. Cr(VI) was reduced very fast above the critical micelle concentration (cmc) of CTAB solutions, but was not reduced at all either below or around the cmc of CTAB. The reduction rate of Cr(VI) was enhanced in the absence of dissolved oxygen, supporting that the removal of Cr(VI) should be achieved via a reductive pathway. When CTAB was substituted by Brij 35 or SDS, the reduction of Cr(VI) was negligible. This indicates that the electrostatic interaction between Cr(VI) and headgroups of surfactants is important in the visible light-induced Cr(VI) reduction in micellar solutions.

• Macromolecular Research
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• v.16 no.5
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• pp.418-423
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• 2008

Poly[(R)-3-hydroxy butyrate] (PHB) and methoxy poly(ethylene glycol) (mPEG) were conjugated by the transesterification reaction with tin(II)-ethylhexanoate (Sn(Oct)-II) as a catalyst. Hydrophobic PHB and hydrophilic mPEG formed an amphiphilic block copolymer which was formed with the self-assembled polymeric micelle in aqueous solution. In this study, we tried to determine the optimum ratio of hydrophobic/hydrophilic segments for controlled drug delivery. The particle size and shape of the polymeric micelle were measured by atomic force microscopy (AFM) and transmission electron microscopy (TEM). Their size were 61-102 nm with various block ratios. Griseofulvin was loaded in the polymeric micelle as a hydrophobic model drug. The loading efficiency and release profile were measured by high performance liquid chromatography (HPLC). The model drug in our system was constantly released for 48 h.

• Food Science of Animal Resources
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• v.24 no.3
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• pp.273-276
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• 2004

The objective of this study was to investigate the microstructure of folic acid-contained yogurt. Folic acids (25 and 50%) were added to milk preparation prior to pasteurization, then starter culture was added. The microstructure of yogurt containing folic acid was determined by the size of cluster of casein micelle using scanning electron microscopy and transmission electron microscopy. The cluster of casein micelle in yogurt containing folic acid were showed larger size than in control (p<0.05). In addition of 50% of folic acid, cluster of casein micelle per unit area was exhibited the highest number among tested yogurts. From these results, folic acid concentration of yogurt may be affected by mouth-feel of yogurt texture as well as the aggregation of casein micelle.

• Journal of the Korean Applied Science and Technology
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• v.18 no.4
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• pp.249-253
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• 2001

A proposed method of determining the composition of mixed micelles in equilibrium with monomer of known composition is described. The systems were sodium ${\alpha}-sulfonated$ dodecanoyl ethyl esther (${\alpha}-SR_{12}Et$) or sodium dodecyl sulfate(SDS)-polyoxyethylene 23 lauryl ether (Brij 35) un water and in 0.1M sodium chloride solution at $25^{\circ}C$. This technique applies the Gibbs-Duhem equation to the mixed micelles, which is treated as a pseudophase. This proposed methodology, which needs only critical micelle concentration data as a function of monomer composition, is applied to an anionic/nonionic surfactant pair. The calculated monomer-micelle equilibrium is found to be very similar to the much-used regular solution for nonideal systems.

• Bulletin of the Korean Chemical Society
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• v.24 no.1
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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.

• Bulletin of the Korean Chemical Society
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• v.25 no.9
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• pp.1392-1396
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• 2004

The micellization of dodecylpyridinum chloride (DPC) assembled on aqueous gold nanoparticles has been studied as a function of concentration using Surface-Enhanced Raman Scattering (SERS). At the low concentration, the strong SERS band of the benzene ring moiety was observed at 1025 $cm^{-1}$, and assigned to “trigonal ring breathing”. According to high concentration of DPC, a new strong band was also appeared at 1012 $cm^{-1}$, which was assigned to “totally symmetry ring breathing”. The difference of two spectra seems to ascribe to the geometry of polar head group, i.e., pyridinium cation. These geometry exist flat-down at low concentration, whereas standing-up or tilted geometry at high concentration. The critical micelle concentration (CMC) was first obtained from the ratio of intensities of the two bands related to the benzene ring moiety by vibrational spectroscopy, and was about 28 mM. After the CMC, the benzene ring moiety in the micelle state was more restricted than in monomer state because there is no more change of intensities at 1012 $cm^{-1}$. In addition, the size of gold-assembled micelle was estimated using light scattering and it was about 328.3 nm.

• Journal of Environmental Science International
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• v.1 no.1
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• pp.69-76
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• 1992

The effects of $Ca_{2+}$ ion on the formation of micelle colloid of nonionic surfactants, nonylphenol-(ethylene oxide)n [NP-(EO)n: n= 11, 40, 100) were investigated by the iodine solubilization method. The characteristics of spectra depended on the concentration of $Ca_{2+}$ ion and the number of EO unit. Above CMC(critical micelle concentration), the intensity of the CT (charge transfer) band by the addition of $Ca_{2+}$ ion for the NP-(EO)11 and NP-(EO)40 increased and when decreased and for the NP-(EO)In continuously increased. The increase in the intensity of CT band were attributed to the compactness of micelle in the presence of $Ca_{2+}$ ion. These phenomena may be explained by the fact that the linear ethylene oxide (EO) chain, relatively free to assume various configuration in aqueous solution, could form a pseudo-crown ether structures capable of forming complexes with $Ca_{2+}$ ion.

• Journal of the Korean Magnetic Resonance Society
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• v.9 no.2
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• pp.155-162
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• 2005

The interaction of poly(ethylene glycol)(PEG) with cationic dodecyl trimethyl ammonium bromide (DTAB)micelle was studied with electron spin resonance (ESR) by determining line widths of the ESR spectra and coupling constant of nitrogen($A_N$). The degree of ESR line shape change such as line widths and coupling constant indicated that PEG mixes well with DTAB micelle due to a great hydrophobic interaction with surfactant alkyl chains. This suggests that the PEG can be used as non-ionic surfactant to disperse the exposed oil in the ocean.