The structures of salicylate surfactants with long alkyl chains in non-aqueous media.
The self-assembled structures formed by alkyl salicylate surfactants, as a function of metal headgroup counterion, in dodecane and toluene have been investigated. Results from optical microscopy are combined with small angle neutron scattering to show that moisture in the organic phase can have a dramatic effect on the observed structures. A simple acidic cation produces a cluster of surfactant chains irrespective of the oil type or presence of water. However, systems with an alkali metal counterion (potassium or sodium) result in cylindrical micelles in dry dodecane changing to lamellar structures in the wet case and fuzzy spheres in dry toluene changing to bidisperse emulsions with the presence of water. However, if magnesium or calcium counterions are used, this leads to different structures, depending on the oil type and the presence of moisture.
Department of Chemical Engineering & Biotechnology, University of Cambridge , New Museums Site, Pembroke Street, Cambridge, CB2 3RA, United Kingdom.
Chern Leing
CL
Lee
Peter J
PJ
Dowding
Allyson R
AR
Doyle
Katrina M
KM
Bakker
Su Shiung
SS
Lam
Sarah E
SE
Rogers
Alexander F
AF
Routh