Yoshikazu Tokuoka

Solubilization of synthetic perfumes by nonionic surfactants

Abstract The solubilization of synthetic perfumes (eugenol, linalool, benzyl acetate, α-Ionone, α-hexylcinnamaldehyde, and d -limonene) by hexadecyl polyoxyethylene ethers (C 16 POE n , n = 10, 20, 30, and 40) has been studied in terms of cloud point, maximum additive concentration, solubilizing capacities, distribution coefficient, and micellar size. The greater the hydrophilic properties of synthetic perfumes, the more the cloud points of C 16 POE 10 solution are decreased. The maximum additive concentration and solubilizing power are increased with decreasing polyoxyethylene chain length, except for eugenol and linalool. The distribution coefficients of eugenol, linalool, and benzyl acetate between micelle and bulk phase are increased as the number of ethylene oxides in C 16 POE n decreases. The diameters of micelles containing solubilized synthetic perfumes are increased with increasing concentration of synthetic perfumes dissolved. Furthermore, for C 16 POE 10 solution, the diameters of micelles solubilizing eugenol and linalool are increased substantially in the vicinity of each maximum additive concentration.

Phase diagrams of surfactant/water/synthetic perfume ternary systems

The phase diagrams of hexadecyl polyoxyethylene ether (C16POE10)/water/synthetic perfume, and sodium dodecyl sulfate (SDS)/water/synthetic perfume ternary systems were prepared. The synthetic perfumes used are, d-limonene, α-hexylcinnamaldehyde, α-ionone, benzyl acetate, linalool, and eugenol. In a series of C16POE10/water/synthetic perfume ternary systems, as the hydrophilicity of synthetic perfume increases, the regions of normal and inverse micellar solution phases were found to be extended, while that of the lamellar liquid crystal phase was reduced. Moreover, every region of normal micellar solutions, inverse micellar solutions, and lamellar liquid crystal phases in SDS/water/synthetic perfume ternary systems was found to be smaller than those in C16POE10/water/synthetic perfume systems.

VOLATILITY AND SOLUBILIZATION OF SYNTHETIC FRAGRANCES BY PLURONIC P-85

ABSTRACT The volatility of synthetic fragrances (benzyl formate, benzyl acetate, benzyl propionate) from pluronic P-85 aqueous solution has been investigated by the dynamic headspace method The experimental results showed that the volatility of a more hydrophobic fragrance was strongly controlled by pluronic P-85. This volatile behavior was explained by the solubilization constants of fragrances between the micelle and bulk phase by semiequilibrium dialysis method.

Solubilization of oil—soluble azo dye by anionic—nonionic mixed surfactants in aqueous solutions, II

Abstract The solubilization of oil-soluble azo dyes by anionic—ninionic mixed surfactants was studied by spectrophotometric methods: these systems are sodium dodecyl sulfate (SDS)—alkyl polyoxyethylene ethers (C m POE n ; m = 10 and 18 at n = 10 and 40 m = 16). This maximum additive concentration and solubilizing capacity of pure C m POE n solutions exceeded those of pure SDS solutions. The influence on the maximum additive concentration and solubilizing capacity was due to a greater difference in hydrophobic groups in nonionic surfactants than in hydrophilic groups. In the mixed surfactant systems, the maximum additive concentrations are made larger by nonionic surfactants including longer alkyl chains and/or longer polyoxyethylene chains. The amount of increase was larger in the system in which two kinds of micelles, one rich in anionic surfactant and the other rich in nonionic surfactant, exist than in system of mixed micelles. The presence of the oil-soluble azo dye asissts the mixed micelle formation.

Expansion of mixed anionic—non-ionic micelles caused by solubilization of organic solutes

Abstract The micelle size was determined by dynamic light scattering for mixed anionic—non-ionic micelles containing solubilized organics. The surfactants used were sodium dodecyl sulfate and hexadecyl polyoxyethylene ethers (C 16 POE n where n = 10, 20, 30 or 40). For pure or mixed surfactant systems, the diameters of micelles which contain solubilized n -octane are almost independent of solute concentration, while micelles containing solubilized 1-octanol increase in size with increasing solute content. The change in micellar size for systems containing 1-octanol is influenced by hydrophilic group interactions between anionic and non-ionic surfactants in the mixed system.