Publications


Title : Small-angle neutron scattering study of droplet density dependence of the water-in-oil droplet structure in a ternary microemulsion

Language: English
Type: Article
Authors: Michihiro Nagao, Hideki Seto, Mitsuhiro Shibayama and Norifumi L. Yamada
Journal: Journal of Applied Crystallography
ISSN: 0021-8898
Volume: 36
Number: 3
Month: 6
Year: 2003
Actual year: 2003
Pages: 602-606
doi:   10.1107/s0021889803006174
Abstract: Droplet density, phi, dependence of the water-in-oil droplet structure of microemulsion was investigated by means of small-angle neutron scattering ( SANS) at room temperature in a ternary system consisting of AOT (Aerosol-OT; dioctyl sulfosuccinate sodium salt), water, and n-decane. SANS profiles from 2 different contrast samples of the bulk contrast (AOT/D2O/C10H22) and of the film contrast (AOT/D2O/C10D22) were collected. By introducing a relative form factor as the ratio of scattering functions of the bulk and film contrast samples, we evaluated the phi dependence of the shape and size of droplets without the influence of the structure factor, S ( Q). The mean radii of droplet core and shell were constant, while the polydispersity index decreased for phi less than or equal to phi* similar or equal to 0.62. The evaluated structure factors S (Q) from the bulk-contrast samples were in good agreement with those from the film contrast. From the phi dependence of S ( Q), we confirmed that the droplet density fluctuations were dominant at low-phi regime and the inter-droplet correlations at high-phi regime. The crossover concentration of these two regimes was estimated to be about 0.25. It is demonstrated that this relative form factor method is quite useful for SANS experiments.

"Small-angle neutron scattering study of droplet density dependence of the water-in-oil droplet structure in a ternary microemulsion"

Michihiro Nagao, Hideki Seto, Mitsuhiro Shibayama and Norifumi L. Yamada, Journal of Applied Crystallography, 36, 602-606 (2003)