• Journal of the Korean Chemical Society
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• v.16 no.4
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• pp.201-204
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• 1972

The critical micelle concentrations of decylpyridinium chloride in aqueous solutions have been determined by the electrical conductance measurements in the range of $10^{\circ}C$-$50^{\circ}C$. The temperature variation of the critical micelle concentrations has shown the minimum at the vicinity of $15^{\circ}C$. The Clausius-Clapeyron type equation of log (c.m.c.) versus temperature has been established. The values ${\Delta}Hm$ and the other thermodynamic properties associated with micelle formation have been determined using the above equation and compared with that of dodecylpyridinium chloride and dodecylpyridinium bromide.

• Journal of the Korean Chemical Society
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• v.9 no.3
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• pp.124-127
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• 1965

The surface tension of the solution of dodecylpridinium bromide was measured by the ring method over the range $25^{\circ}\; to\; 45^{\circ}C.$ The critical micelle concentration was determined from the change of the surface tension of solution with concentration. The temperature dependence of the critical micelle concentration was also investigated. The result was compared with Adderson and Taylor's data determined by the conductivity method.

• Journal of the Korean Chemical Society
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• v.10 no.2
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• pp.103-108
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• 1966

The effect of temperature on the critical micelle concentration of dodecylpyridinium chloride has been determined by electrical conductance method over the range from $5^{\circ}C\;to\;50^{\circ}C$. The values of the change in heat content, ${\Delta}H_m$, and the other thermodynamic parameters have been estimated using the equation of temperature dependence on the critical micelle concentration for the same temperature range. The significance of these thermodynamic quantities and their relations to the various current theories of micelle forming processes were discussed.

• Journal of the Korean Chemical Society
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• v.16 no.4
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• pp.205-207
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• 1972

Dodecylquinolinium bromide has been synthesized and the critical micelle concentrations of it in the aqueous solution have been determined by the measurement of the surface tension and the electrical conductance. The values are $3.34 {\times} 10^{-3}mole/l$ and 3.41 {\times} $10^{-3}$mole/l, respectively. Since dodecylquinolinium bromide has the larger hydrophobic group than dodecylpyridinium bromide, it is considered that the former has the smaller critical micelle concentration than the latter.

• 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.

• Archives of Pharmacal Research
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• v.4 no.2
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• pp.75-84
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• 1981

As the cetyltrimenthy ammonium bromide (CTAB) concentration increases to $2{\times}10^{-4}$/M the absorption maximum of ethyl orange (EO) makes a blue shift from 475 mm to 395 mm. At higher concentration of CTAB than $2{\times}10^{-4}$ / M the absorption maximum shifts to higher wavelength than 395 nm. A new peak at 395 nm is shown to result from the mixed micelle due to dye stacking interaction rather than from a change in dye geometry. Because Raman spectra of EO on interaction with varying amount of CTAB are similar to that of EO in water. EO retains trans azo type on interaction with CTAB. There is a change of c.m.c.s. of CTAB for the mixed micelle in the presence of salt. The effect of added salt on C. M. C. of CTAB for the mixed micelle is given that the logarithm of the c. m. c. is a linear function of the logarithm of the sum of the c. m. c. and the concentration of added salt.

• Journal of the Korean Applied Science and Technology
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• v.27 no.4
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• pp.545-551
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• 2010

Hydrophobically monoendcapped poly(sodium acrylate)s formed hydrophobic microdomains in water. This was concluded on poly(sodium acrylate)s with a linear $C_{12}$-alkyl chain attached specifically at the end of the polymer. There was no well defined CMC (critical micelle concentration), but rather a gradual transition from a micelle free solution to a micelle solution. Steady state fluorescence spectroscopy indicates that the micro domains are rather hydrophobic. At pH 5 in the abscence of salt and at pH 9 in the prescence of 1 M sodium citrate the CAC (critical aggregation concentration) was in the range of 0.1 to 2.4 mM. However at pH 5 there was a linear increase in the transition concentration with a head-group size due to an increase in steric and electrostatic repulsions between polymer main chains. At pH 9 in the abscence of salt the transition concentration was in the range of 1 to 80 mM. For the larger polymers there was a effect which consisted of a concentration gradient of sodium counterion toward the hydrophobic domain. The effect was larger for the larger polymers because of the higher total sodium concentration and the less steep counterion concentration gradient.

• Journal of the Korean Applied Science and Technology
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• v.23 no.2
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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.

• Journal of the Korean Chemical Society
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• v.55 no.2
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• pp.163-168
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• 2011

The variations of molar conductivity of various surfactants such as sodium caprylate, sodium laurate, sodium palmitate, sodium stearate, sodium oleate, sodium dodecyl sulphate, and lithium dodecyl sulphate with concentrations of the surfactants for each of the solutions consisting of mixtures of varying concentrations of N-methyl acetamide in water at constant temperature of $30{\pm}0.2^{\circ}C$ were studied. The critical micelle concentration (CMC) for each surfactant is measured. It is found that the CMC values in mixtures of N-methyl acetamide and water solutions of various surfactants are lower than the CMC values in water, and the driving force for micelle formation correlates with solvophobicity. The surfactant-solvent interactions that drive amphiphilic self-organization in N-methyl acetamide in water are discussed. Thermodynamic parameters were evaluated for micellar system to explain the results.

• 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.