Unilamellar vesicles obtained by simply mixing dioctadecyldimethylammonium chloride and bromide with water.
Optically clear dispersions of dioctadecyldimethylammonium bromide and chloride (DODAX, X = Br-, Cl-) in water can be obtained by simply mixing the amphiphiles at low concentrations (1 mM) and at a temperature safely above the gel to liquid crystalline phase transition temperature (Tm approximately 45-48 degrees C) of DODAX in water. Under these conditions, dynamic light scattering shows that, at room temperature, the dispersions contain two well-defined populations of large vesicles with average hydrodynamic radii (R(H)) of 80 and 337 nm for DODAB and of 69 and 247 nm for DODAC. Cryo-transmission electron microscopy (cryo-TEM) micrographs show that DODAX vesicles are unilamellar and polydisperse with apparent radius up to 800 nm. The vesicles are stable for at least 1 month according to the ageing time-dependence of the turbidity and molar absorption coefficient.
Departamento de Física, IBILCE/UNESP, Rua Cristóvão Colombo 2265, 15054-000, São José do Rio Preto, SP, CEP: 15054-000, Brazil. eloi@ibilce.unesp.br
Eloi
E
Feitosa
Göran
G
Karlsson
Katarina
K
Edwards
D000042:Absorption; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D008027:Light; D008567:Membranes, Artificial; D046529:Microscopy, Electron, Transmission / Q000379:methods; D044367:Phase Transition; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity; D013696:Temperature; D014867:Water / Q000737:chemistry
D008567:Membranes, Artificial; D000644:Quaternary Ammonium Compounds; D014867:Water; C015831:dimethyldioctadecylammonium