Gelation of <em>n</em>-Butanol by a Catanionic Surfactant System

Abstract

the gelation of n-butanol was realized by a mixture of cationic and anionic surfactants (referred to as surfactant). in this study, we used sodium laurate/cetyltrimethylammonium bromide (sl/ctab) as the catanionic surfactant. the rheological properties and microstructures of the n-butanol gel were studied using a rheometer and scanning electron microscopy (sem). we found that the concentration and mole ratio of the catanionic surfactant affected the formation of the gel and n-butanol was only efficiently gelled in the presence of the catanionic surfactant at a suitable concentration and mole ratio. when we fixed the concentration of one component in the catanionic surfactant system, the gel viscosity increased with the concentration of the other component on the basis of gel formation. this gel was a non-newtonian fluid and showed a shear-thinning property in rheological experiments. in addition, sem results showed that the gel had a representative three-dimensional network structure, which was composed of zonal fibers with uniform thickness. further investigation indicates that the hydrophobic effect between the hydrocarbon chains, the electrostatic attraction between the polar headgroups, and the hydrogen bond interaction between the surfactants and n-butanol play an important role in gel formation.