Characteristics of wormlike pentaoxyethylene decyl ether C(10)E(5) micelles containing n-dodecanol.
ABSTRACT The wormlike micelles formed with the surfactant pentaoxyethylene decyl ether C10E5 containing n-dodecanol were characterized by static (SLS) and dynamic light scattering (DLS) experiments. The SLS results have been analyzed with the aid of the light scattering theory for micelle solutions, thereby yielding the molar mass Mw(c) as a function of concentration c along with the cross-sectional diameter d of the micelle. The observed Kc/DeltaR0 as a function of c and the hydrodynamic radius RH as functions of Mw have been well described by the theories for the wormlike spherocylinder model. It has also been demonstrated that the apparent hydrodynamic radius RH,app(c) as a function of c is well described by a fuzzy cylinder theory which takes into account the hydrodynamic and direct collision interactions among micelles. Our previous results for the hexaoxyethylene dodecyl ether C12E6 micelles containing n-dodecanol were reanalyzed in the same scheme. It has been found that the micellar length increases with increasing concentration c or with raising temperature T irrespective of the composition of the C10E5 + n-dodecanol and C12E6 + n-dodecanol systems. The length of the micelles at fixed c and T steeply increases with increasing weight fraction wd of n-dodecanol in both systems. The growth of the micelles accompanies the increase of the cross-sectional diameter d of the micelles and the results that the surfactant molecules are more densely assembled with increasing wd in order to keep n-dodecanol molecules inside the micelles.
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ABSTRACT: The values of critical micelle concentration (CMC) and counter ion binding constants (B) in a micellar state of CPC (1-hexadecylpyridinium chloride) with Brij 35 (polyoxyethylene(23) lauryl ether) in water were determined as a function of (the overall mole fraction of CPC) by the use of electric conductivity method. Various thermodynamic parameters () were calculated and analyzed by means of the equations derived from the non-ideal mixed micellar model. And thermodynamic parameters () for the micellization of CPC/Brij 35 mixtures were also calculated from the temperature dependence of the CMC values. The values of are all negative, but the values of and are positive or negative, depending on the measured temperature and .Journal of the Korean Chemical Society 01/2009; 53(2).