Abstract
Neutron reflectivity has allowed the measurement at nanometric resolution of the structures formed when high internal phase water/oil emulsions are in contact with hydrophobic and hydrophilic surfaces prepared at planar faces of silicon blocks. The emulsion was a dispersion of micrometer sized droplets of saltwater-in-hexadecane. Contrast variation by selective deuteration of different components of the emulsion shows that at nanometric resolution an oil-rich phase is produced at the solid-emulsion interface independent of the nature of the solid surface. There is an almost complete surfactant monolayer at the hydrophilic solid face and then a hexadecane-rich layer that persists for 150 Å. Both are less pronounced for the hydrophobic surface, but not qualitatively different. The hexadecane-aqueous interfaces are highly curved with an ∼500 Å radius-compared with the micron radius of the aqueous droplets.
Original language | English |
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Pages (from-to) | 9153-9157 |
Number of pages | 5 |
Journal | Langmuir |
Volume | 18 |
Issue number | 24 |
DOIs | |
Publication status | Published - 26 Nov 2002 |