Ternary water in oil microemulsions made of cationic surfactants, water, and aromatic solvents. 2. Droplet sizes and interactions and exchange of material between droplets

Journal Article · Thu Jan 11 00:00:00 EST 1990 · Journal of Physical Chemistry; (USA)

DOI:https://doi.org/10.1021/j100364a066· OSTI ID:6666453

Jada, A; Lang, J; Zana, R ^[1]; Makhloufi, R; Hirsch, E; Candau, S J ^[2]

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1. CNRS-ULP, Strasbourg (France)
2. Laboratoire de Spectrometrie et d'Imagerie Ultrasonores, Strasbourg (France)

Ternary water in oil microemulsions made of cationic surfactants, water, and aromatic solvents have been investigated by means of time-resolved fluorescence quenching, quasi-elastic light scattering, and electrical conductivity in order to determine the surfactant aggregation number N per water droplet, the rate constant k{sub e} for the exchange of material between droplets through collisions with temporary merging, the droplet diffusion coefficient D, and the coefficient of interaction between droplets {alpha} and to study the occurrence of electrical percolation as a function of the surfactant chain length, head-group size, and water content of system (expressed as the molar concentration ratio {omega} = (water)/(surfactant)). Most measurements were performed with chlorobenzene as solvent. In one instance, chlorobenzene was substituted by benzene in order to investigate the effect of the nature of the solvent. For a given surfactant, N and k{sub e} increased with {omega} and upon substituting chlorobenzene by benzene. Also, at a given {omega}, N and k{sub e} increased when the surfactant chain length was decreased. The increases of k{sub e} were always extremely large. The droplet hydrodynamic radii from quasi-elastic light scattering were found to agree with the droplet sizes calculated with the N values from fluorescence quenching. The droplet interaction coefficient {alpha} became more negative as the surfactant chain length decreased, indicating increasingly attractive interdroplet interactions. Finally, electrical percolation was found to occur in all systems where interdroplet interactions were sufficiently attractive. The percolation threshold {omega}-values increased with surfactant chain length.

• OSTI ID: 6666453
• Journal Information: Journal of Physical Chemistry; (USA), Vol. 94:1; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
MICROEMULSIONS
PHASE STUDIES
DATA ANALYSIS
DROPLETS
ELECTRIC CONDUCTIVITY
EXPERIMENTAL DATA
MEASURING INSTRUMENTS
MEASURING METHODS
OILS
QUENCHING
REACTION KINETICS
SURFACTANTS
WATER
COLLOIDS
DATA
DISPERSIONS
ELECTRICAL PROPERTIES
EMULSIONS
HYDROGEN COMPOUNDS
INFORMATION
KINETICS
NUMERICAL DATA
ORGANIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PARTICLES
PHYSICAL PROPERTIES
360603* - Materials- Properties
400201 - Chemical & Physicochemical Properties