Oil-induced structural change in nonionic microemulsions

Citation
K. Ozawa et al., Oil-induced structural change in nonionic microemulsions, J DISP SCI, 22(1), 2001, pp. 119-124
Citations number
25
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
ISSN journal
0193-2691 → ACNP
Volume
22
Issue
1
Year of publication
2001
Pages
119 - 124
Database
ISI
SICI code
0193-2691(2001)22:1<119:OSCINM>2.0.ZU;2-A
Abstract
Effect of added oil (heptane or squalane) on the microemulsion structures i n polyoxyethylene dodecyl ether (C12EOn) systems was investigated by means of phase behavior and NMR diffusion experiments. In the binary water-C12EOn systems, an isotropic fluid, D-2 (or L-3), and an aqueous micellar solutio n, Win, phases are successively formed with increasing the EO-chain length. Upon addition of heptane, D-2 and Wm phases are merged and a microemulsion of large solubilization is produced at a low surfactant concentration. Wit h squalane, the solubilization of oil in D-2 phase is very low or almost ze ro, whereas the oil solubilization in Win phase is relatively large. These structural changes in microemulsions are discussed based on the self-diffus ion coefficients of water, oil, and surfactant measured by the PGSE-NMR met hod. The difference in the phase behavior may be attributed to the differen ce in the penetration tendency of oil in the surfactant palisade layer.