Accession Number : ADA257206


Title :   Aggregation Behavior of Mixed-Counterion Double-Chained Surfactants


Corporate Author : MINNESOTA UNIV MINNEAPOLIS


Personal Author(s) : Miller, D D ; Evans, D F


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a257206.pdf


Report Date : Jan 1991


Pagination or Media Count : 10


Abstract : The aggregation behavior of dilute solutions of the ditetradecyldimethylammonium surfactant cation with mixtures of bromide and acetate counterions was studied using video enhanced microscopy, cryo- transmission electron microscopy, and time resolved fluorescence quenching. Large liposomal aggregates of the bromide surfactant are gradually transformed into micellar aggregates by the addition of the acetate surfactant. Stable, equilibrium, unilamellar vesicles predominate at intermediate concentrations (40-60% Br-), while small, spherical micelles coexist with, and gradually replace, vesicles as the bromide content is further reduced. Similar behavior is seen with long chain-short chain phospholipid mixtures. These results are analyzed in terms of free energy minimization and bilayer asymmetry arguments.


Descriptors :   *METHYL RADICALS , *LIPOSOMES , *BROMIDES , *ACETATES , *SURFACE ACTIVE SUBSTANCES , QUENCHING , MICROSCOPY , FREE ENERGY , PHOSPHOLIPIDS , ELECTRON MICROSCOPY


Subject Categories : Biochemistry
      Microbiology


Distribution Statement : APPROVED FOR PUBLIC RELEASE