Feitosa, E.Jansson, J.Lindman, B.2014-05-202014-05-202006-07-01Chemistry and Physics of Lipids. Clare: Elsevier B.V., v. 142, n. 1-2, p. 128-132, 2006.0009-3084http://hdl.handle.net/11449/22003Differential scanning calorimetry (DSc) and dynamic light scattering (DLS) were used to obtain the gel to liquid-crystalline phase transition temperature (T-m) and the apparent hydrodynamic radius (R-h) of spontaneously formed cationic vesicles of dialkyldimethylammonium bromide salts (CnH2n+1)(2)(CH3)(2)N+center dot Br-, with varying chain lengths. The preparation of cationic vesicles from aqueous solution of these surfactants, for n = 12, 14, 16 and 18 (DDAB, DTDAB, DHDAB and DODAB, respectively), requires the knowledge of the surfactant gel to liquid-crystalline phase transition temperature, or melting temperature (T-m) since below this temperature these surfactants are poorly or not soluble in water. That series of cationic surfactants has been widely investigated as vesicle-forming surfactants, although C-12 and C-18, DDAB and DODAB are by far the most investigated from this series. The dependence of T-m of these surfactants on the number n of carbons in the surfactant tails is reported. The T-m obtained by DSC increases non-linearly with n, and the vesicle apparent radius R-h is about the same for DHDAB and DODAB, but much smaller for DDAB. (c) 2006 Elsevier B.V.. All rights reserved.128-132engdialkyldimethylammonium saltsCationic vesiclecationic surfactantsDODABDHDABDTDABDDABphase behaviordifferential scanning calorimetrydynamic light scatteringmelting temperaturehydrodynamic radiusArtigo10.1016/j.chemphyslip.2006.02.001WOS:000238797000013Acesso restrito