title: Concentration and pH-dependent aggregation behavior of an l-histidine based amphiphile in aqueous solution.
abstract: The surface activity and self-assembly behavior of zwitterionic amphiphile N-(2-hydroxydodecyl)-l-histidine (C(12)HHis) were studied in phosphate buffers of pH 2 and 13 using surface tension and fluorescence probe techniques, respectively. Transmission electron microscopic images of the aggregates have revealed existence of nano-size vesicles in dilute solutions of both acidic and basic pH. In basic medium, the vesicles are converted to tubular aggregates upon increase of surfactant concentration. The nanotubes undergo phase transition to form elongated or small rod-like micelles at a much higher concentration of the amphiphile. The vesicles and nanotubes were found to become more stable upon addition of 10mol% of cholesterol.
authors.affiliation: Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India.
authors.forename: Arjun
authors.initials: A
authors.lastname: Ghosh
authors.forename: Saurabh
authors.initials: S
authors.lastname: Shrivastava
authors.forename: Joykrishna
authors.initials: J
authors.lastname: Dey
mesh_terms: D002784:Cholesterol / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry; D006639:Histidine / Q000031:analogs & derivatives* / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D043942:Nanotubes / Q000737:chemistry; D044367:Phase Transition; D013500:Surface Tension; D013501:Surface-Active Agents / Q000737:chemistry; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D005456:Fluorescent Dyes; C552879:N-(2-hydroxydodecyl)histidine; D013501:Surface-Active Agents; D014867:Water; D006639:Histidine; D002784:Cholesterol