Phase behavior and properties of reverse vesicles in salt-free catanionic surfactant mixtures Article

Li, H, Hao, J, Wu, Z. (2008). Phase behavior and properties of reverse vesicles in salt-free catanionic surfactant mixtures . 112(12), 3705-3710. 10.1021/jp7112329



cited authors

  • Li, H; Hao, J; Wu, Z

fiu authors

abstract

  • Salt-free 1:1 cationic/anionic (catanionic) surfactant mixture tetradecyltrimethylammonium laurate (TTAL) could be prepared by mixing equimolar tetradecyltrimethylammonium hydroxide (TTAOH) and lauric acid (LA) in water. Given the condition of suitable range of weight fraction of TTAL in total surfactant, p = WTTAL/(WTTAL + WLA), and at existence of a small amount of water, it was found that the mixtures of soobtained TTAL and LA could spontaneously form stable reverse vesicles in various organic solvents including toluene, tert-butylbenzene, and cyclohexane. The reverse vesicle phase shows a blue color against room light and exhibits strong birefringence under polarized microscope. The reverse vesicles are very sensitive to temperature change. Increasing temperature could make the p values within which reverse vesicles were constructed move to higher values. In organic solvents of alkanes such as n-heptane, reverse vesicles could still form but become unstable upon time and centrifugation. Increasing temperature could accelerate phase separation, and finally a gel-like bottom phase was usually observed. Interestingly, the stable reverse vesicles formed by so-called salt-free catanionic surfactant mixtures still show some resistance against adding inorganic salts. They can trap inorganic ions such as Zn2+ and S2- into their hydrophilic layers. This opens the door for template applications of reverse vesicles to prepare inorganic nanoparticles. © 2008 American Chemical Society.

publication date

  • March 27, 2008

Digital Object Identifier (DOI)

start page

  • 3705

end page

  • 3710

volume

  • 112

issue

  • 12