کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
613580 | 880724 | 2006 | 4 صفحه PDF | دانلود رایگان |

The critical reverse micelle concentrations of C12-s-C12⋅2Br (s=2,3,4,5,6,8,12)(s=2,3,4,5,6,8,12) in n-heptane/n-hexanol solutions, cmcI s, have been determined by absorption spectrum method using iodine as probe. The values of cmcI s are smaller than those of the critical micelle concentrations (cmcaq s ) in aqueous solution and reach a maximum at s=4s=4, which is similar to the variation of cmcaq with s. The variation of cmcI with s is attributed to the alteration in the spacer chain conformation, i.e. when the spacer is short enough, it may adopt stretch configuration and when the spacer is long, it tends to bend towards the continuous oil phase to achieve a more densely packing of the quaternary ammonium heads on the surface of the core.
The gemini surfactants C12-s-C12⋅2Br (s=2,3,4,5,6,8,12)(s=2,3,4,5,6,8,12) form reverse micelles in n-heptane with the assistance of n-hexanol. The variation of the critical reverse concentration (cmcI) with s is attributed to the change of folded conformation of the spacer chain.Figure optionsDownload as PowerPoint slide
Journal: Journal of Colloid and Interface Science - Volume 300, Issue 1, 1 August 2006, Pages 310–313