出典:Wikipedia
出典:『Wikipedia』 (2011/02/10 01:06 UTC 版)
Dioctadecyldimethylammonium bromide (DODAB) is a doublechained quaternary ammonium surfactant that forms unilamellar vesicles (ULVs) in water. Among various preparation methods, the ‘‘hot-water” method offers a simple procedure to prepare DODAB cationic vesicles by simply dissolving the DODAB in hot water above 50 °C, i.e., chain melting (main) transition, Tm. In general, the DSC thermograms of the unsonicated DODAB dispersions are dominated by two endotherms; the pre- (35–36 °C) and main transition (42.7–45 °C) peaks. Moreover, in literature reported the presence of a third endotherm (post transition) at 52.2 °C. The main transition (Tm) is ascribed to gel to liquid-crystalline phase transition in which the alkyl chains transform from solidlike to liquid-like state.