ISSN:
1435-1536
Keywords:
Key words Small vesicles
;
Phase behaviour
;
Small-angle neutron scattering
;
Charged surfactants
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The phase behaviour and properties of the tetradecyldimethylamine oxide/HCl/hexanol/water quaternary surfactant system have been studied by means of electric conductivity, rheology, freeze-fracture transmission electron microscopy (FF-TEM) and small-angle neutron scattering (SANS). In this system the originally zwitterionic surfactant can become increasingly charged by protonation through the addition of HCl, i.e. the degree of charging can be changed continuously. An interesting, isotropic phase (L1 * phase) of low viscosity was observed for intermediate degrees of charging. From viscosity and conductivity measurements this phase can clearly be distinguished from the conventional L1 phase that is composed of micelles. Investigation of the structures present by means of FF-TEM and SANS showed that the L1 * phase is made up of unilamellar vesicles of extremely small diameter of 8–10 nm. Evidently such highly curved structures are stabilized by the electrostatic conditions in this system.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s003960050023
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