Conductivity study of microemulsions. Dependence of structural behavior of water/oil systems on surfactant, cosurfactant, oil, and temperature

Journal Article · Wed Jan 10 23:00:00 EST 1990 · Journal of Physical Chemistry; (USA)

DOI:https://doi.org/10.1021/j100364a060· OSTI ID:6946691

Bisal, S; Bhattacharya, P K; Moulik, S P ^[1]

---

1. Jadavpur Univ., Calcutta (India)

Structural features of w/o microemulsions have been conductometrically evaluated. The radius of the water pool, the effective radius of the droplets, their number per unit volume, the effective surface area of the water pool, and the aggregation number of the surfactant and cosurfactant molecules per droplet in the oil/water interphase have been estimated. Three oils (n-heptane, n-decane, and xylene), three surfactants (CTAB, SDS, and AOT) and two cosurfactants (1-butanol and n-hexylamine) have been used; their effects on the structural properties of microemulsions have been studied at two different temperatures, 293 and 303 K, at two weight ratios of surfactant/cosurfactant, 0.33 and 0.50. The droplet radius has been found to be oil dependent and follows the order n-heptane < n-decane < xylene. The values at 293 K are greater than those at 303 K. The dependence of the radius on the surfactant is in the order SDS > AOT > CTAB. 1-Butanol yields greater radius than n-hexylamine with SDS and AOT, and the order is reversed with CTAB. The aggregation number of the surfactant and cosurfactant per droplet increases and decreases, respectively, with elevation of temperature. The R{sub e}/R{sub W} (ratio of the effective radius of the droplet and the radius of its water core) remains fairly constant under all situations, the average value being 1.15 {plus minus} 0.10.

• OSTI ID: 6946691
• Journal Information: Journal of Physical Chemistry; (USA), Journal Name: Journal of Physical Chemistry; (USA) Vol. 94:1; ISSN 0022-3654; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603 -- Materials-- Properties
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400400* -- Electrochemistry
ALKANES
CALCULATION METHODS
COLLOIDS
DATA
DATA ANALYSIS
DISPERSIONS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
EMULSIONS
EXPERIMENTAL DATA
HYDROCARBONS
HYDROGEN COMPOUNDS
INFORMATION
MEASURING INSTRUMENTS
MEASURING METHODS
MICROEMULSIONS
NUMERICAL DATA
OILS
ORGANIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SURFACTANTS
TEMPERATURE EFFECTS
WATER