J. Phys. IV France 03 (1993) C8-169-C8-172
Structure and aggregation of lithium dodecyl sulfate micelles in the presence of a macrocyclic cage : a SANS studyP. BAGLIONI1, Y.C. LIU2, S.H. CHEN3 and J. TEIXEIRA4
1 Department of Chemistry, University of Florence, Italy
2 Department of Materials Science and Engineering, MIT, Cambridge, MA 02139, USA.
3 Department of Nuclear Engineering, MIT, Cambridge, MA 02139, U.S.A.
4 Laboratoire Léon Brillouin, Saclay, 91191 Gif-sur-Yvette, France
At pH=12, a macrocyclic cage CESTO is a neutral molecule known to complex Li+ in aqueous solution. We study the effect of addition of CESTO on the aggregation behavior of lithium dodecyl sulfate (LDS) by small angle neutron scattering. In aqueous solutions the LDS molecules form micelles of quasi-spherical shape with aggregation number of 90 and fractional ionization of 18%. Upon addition of 0.5 to 1 and 1 to 1 molar ratios of CESTO to the solutions, the aggregation number increases but the ionization reduces due to the complexation of lithium ions by CESTO. This is also accompanied by the decrease of hydration number on the micellar surface.
© EDP Sciences 1993