J. Phys. IV France 03 (1993) C8-133-C8-136
Etude par diffusion centrale des neutrons de la formation et de la structure des micelles de tensioactifs cationiques dans le formamideT. PERCHE1, X. AUVRAY1, C. PETIPAS1, R. ANTHORE1, S. MELIANI2, E. PEREZ2, I. RICO2 and A. LATTES2
1 U.R.A./C.N.R.S. 808, U.F.R. des Sciences, 76821 Mont-Saint-Aignan cedex, France
2 U.R.A./C.N.R.S. 470, Université Paul Sabatier, 31062 Toulouse cedex, France
We report here a study of the micellization of different surfactants to observe the effects of the chain length, counterions and headgroups in a non-aqueous polar solvent-formamide. Small-angle neutron scattering measurements were performed in a PACE spectrometer in L.L.B. The solvent used was a 2/3 deuterated formamide. The aggregation number and the spontaneity of the association depend on the chain length ; but, in formamide, micelles always are smaller and more ionized than in water. Their growth is much more low in formamide than in water where "rod-like micelles" form especially with Br". Cl- in formamide leads preferentially to the formation of small micelles as it does in water. The micellar ordered phase is observed in the binary C16 Py Cl/formamide system at high concentration. With regard to the headgroup N+(CH3)3, the pyridinium ring encouraged the micellization in formamide close to 20°C.
© EDP Sciences 1993