title: Micelle-Vesicle Transition by Cleavage of Disulfide Spacer Chain for Gemini Surfactant in Didodecyldimethylammonium Chloride Aqueous Solutions.
abstract: We examined the "micelle-vesicle transition" through the mixing effect of single-tailed thiol surfactants produced by the cleavage of gemini surfactants, [C12H25N(CH3)2CH2CH2SSCH2CH2N(CH3)2C12H25] 2Cl (C12SSC12), which have a disulfide bond in the spacer chain. Phase diagrams of C12H25N(CH3)2CH2CH2SHCl-didodecyldimethylammonium chloride (C12SH-DDAC) and C12SSC12-DDAC were determined by conductivity and pyrene fluorescence probe methods. The aggregate diameters were evaluated by dynamic light scattering (DLS). The critical vesicle concentration (CVC) was confirmed by the abrupt increase in the intensity of light scattering with excitation at 335 nm. Vesicle formation was confined to the DDAC-rich region of the C12SSC12-DDAC system, while the vesicle formation region for the C12SH-DDAC system spread out with the addition of dithiothreitol (DTT) to C12SSC12-DDAC. This implies that single-tailed surfactants can induce a more favorable environment for molecular packing of the vesicular surface. The micelle-vesicle transition occurs with disulfide spacer chain cleavage of gemini surfactants at a particular specific concentration range.
authors.affiliation: School of Chemistry, College of Science and Engineering, Kanazawa University.
authors.forename: Toshinari
authors.initials: T
authors.lastname: Mizuhashi
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Asakawa
authors.forename: Akio
authors.initials: A
authors.lastname: Ohta
mesh_terms: D004220:Disulfides / Q000737:chemistry*; D008823:Micelles; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D012996:Solutions; D013500:Surface Tension; D013501:Surface-Active Agents / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D004220:Disulfides; D008823:Micelles; D000644:Quaternary Ammonium Compounds; D012996:Solutions; D013501:Surface-Active Agents; D014867:Water; C046112:didodecyldimethylammonium