Fading phenomena of azo oil dye in anionic-nonionic surfactant solutions III. The effect of solubilizates on the fading behavior of azo oil dye in mixed surfactant systems

Abstract

Abstract:The effects of solubilizates on the fading behavior of 4-phenylazo-l-naphthol O-OH) in aqueous solutions of anionic-nonionic mixed surfactant systems are described; the systems studied are sodium dodecyl sulfate (SDS) -octadecyl poly(oxyethylene) ethers (C18POE20). The fading rate of 4-OH in the mixed solution was independent of the addition of octane. By adding octanoic acid, the rate became faster. On the other hand, the 1-octanol slowed the rate. The fading speed of 4-OH decreased as the concentration of the alcohol and the number of carbon atoms in the alcohol molecule, used as a solubilizate, increased. The sizes of mixed micelles penetrated by the solubilizate were dependent on the kind of oily materials and on the alkyl chain lengths in the molecules of normal higher alcohols. Relative viscosities and effective specific volumes in the mixed micellar solutions increased with the increase in the concentration of 1-octanol and octanoic acid, and with increasing the number of alkyl groups in the alcohol molecule. The effect of solubilizates on the fading behavior of 4-OH was found to be dependent on the differences in their solubilization sites in mixed micelles. A solubilizate with a strong polar group supported a hydrophilic-hydrophilic interaction, whereas one including a weak polar group did not.

Effect of Temperature and Concentration on Density, Apparent Molar Volume, Ultrasound Velocity, Isoentropic Compressibility, Viscosity, and Conductivity of Hexadecyldimethylethylammonium Bromide

“…The values of reduced viscosity were observed to be more or less constant in the investigated concentration range, indicating that the size and shape of micelle remain constant. 32,33 The intrinsic viscosity values of surfactant solutions are given in Table 4. The intrinsic viscosity values were observed to decrease with increase in temperature, which may be due to the dehydration of head groups and consequent decrease in size of micelles.…”

Solubilization of oleyl alcohol by pure and mixtures of surfactants

“…It can be speculated that, in solutions containing mixtures of surfactants, the tendency to form aggregated structures would be substantially different from in solutions having only the pure surfactants. In fact, the protonation and the fading phenomena occur in aqueous solutions containing mixtures of surfactants [4][5][6][7]. Many recent papers have been published on solution properties of mixed surfactant systems [8][9][10][11].…”