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Characterization of Microemulsion Systems Formed by a Mixed 1,3‐Dioxolane Ethoxylate/Octyl Glucoside Surfactant System
Author(s) -
Alkhatib Mayson H.,
Hayes Douglas G.,
Urban Volker S.
Publication year - 2009
Publication title -
journal of surfactants and detergents
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.349
H-Index - 48
eISSN - 1558-9293
pISSN - 1097-3958
DOI - 10.1007/s11743-009-1122-x
Subject(s) - microemulsion , chemistry , pulmonary surfactant , phase (matter) , salting out , chromatography , salt (chemistry) , analytical chemistry (journal) , organic chemistry , aqueous solution , biochemistry
The phase behavior of microemulsion systems containing water (or 1.0 wt% NaCl aq ), isooctane, and the binary surfactant system consisting of n ‐octyl‐β‐ d ‐glucopyranoside, C 8 βG 1 , and the acid‐cleavable alkyl ethoxylate, 4‐CH 3 O (CH 2 CH 2 O) 7.2 , 2‐(CH 2 ) 12 CH 3 , 2‐(CH 2 )CH 3 , 1,3‐dioxolane, or “cyclic ketal” (“CK‐2,13”), was determined. Large temperature‐insensitive one, two, and three‐phase microemulsion‐phase regions were obtained when equal masses of the two surfactants were employed, suggesting that C 8 βG 1 reduces the temperature sensitivity of CK‐2,13's ethoxylate group. Addition of C 8 βG 1 to CK‐2,13 greatly improves the latter's low efficiency, evidenced by the formation of a three‐phase microemulsion system for surfactant concentrations at low fractions of total surfactants for systems with equal mass ratios of water to oil and CK‐2,13 to C 8 βG 1 . Analysis of the phase diagrams also suggests that CK‐2,13 and C 8 βG 1 impart hydrophobic and hydrophilic character, respectively, to the surfactant mixture, and that addition of salt further increases the hydrophilicity of C 8 βG 1 , presumably because of the salting‐in of the latter. Analysis of small‐angle neutron scattering data revealed that the mixed surfactant system formed spherical oil‐in‐water microemulsions, and that increasing the CK‐2,13 fraction among the surfactants reduced the critical microemulsion concentration but slightly increased the nanodroplet size.