Study of the micelle formation and the effect of additives on this process in reversed micellar systems by positron annihilation techniques

Journal Article · Wed Sep 27 00:00:00 EDT 1978 · J. Am. Chem. Soc.; (United States)

OSTI ID:6827325

Ache, H J; Jean, Y

The positron annihilation technique was applied to the study of the micelle formation process in reversed micellar systems, aerosol and dodecylammonium propionate in solvents, such as benzene, isooctane, and cyclohexane. The results indicate that the positronium formation probability responds very sensitively to microphase changes in reversed micellar solutions. The abrupt changes in positronium formation probability observed at certain surfactant concentrations appear to coincide with variations in the aggregation state of the surfactant molecules in solution, as postulated by the modified pseudophase model which considers the possibility of conformational changes between premicellar aggregates, and the surfactant concentrations at which they occur may be interpreted as operational critical micelle concentrations. Additives or probe molecules can affect these changes and shift them to lower surfactant concentrations. The additions of H/sub 2/ and its solubilization in the form of clusters inside the reverse micelle leads to microphase changes also detectable by the positron annihilation technique. 51 references.

• OSTI ID: 6827325
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 100:20; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
ADDITIVES
ANNIHILATION OPERATORS
ANTILEPTONS
ANTIMATTER
ANTIPARTICLES
CHEMICAL PREPARATION
ELEMENTARY PARTICLES
ELEMENTS
FERMIONS
HYDROGEN
LEPTONS
MATHEMATICAL OPERATORS
MICELLAR SYSTEMS
NONMETALS
POSITRONIUM
POSITRONS
QUANTITY RATIO
QUANTUM OPERATORS
SURFACTANTS
SYNTHESIS