J. Phys. IV France 03 (1993) C8-149-C8-152
Small-angle neutron scattering (SANS) determination of the volume occupied by a single water molecule in the inverted micellar systems AOT + X(H, D)2 O + C10D22 by internal contrast variation techniqueN. GORSKI and Y.M. OSTANEVICH
Laboratory of Neutron Physics, Joint Institute for Nuclear Research, 141980 Dubna, Moscow Reg., Russia
we performed the small-angle neutron scattering measurements on the AOT + X(H, D)2O + C10D22 reverse micellar solution over a wide range of water molar ratios X = 3 - 40. We determined the match - point bc, the aggregation numbers N, the radii of the spherical water nuclei rw, the area per head group of surfactant ao and the volumes of single water molecules in micelles Vw. In detail we obtained vw = 143 Å3 for X = 3, vw = 53 Å3 for X = 7, vw = 45 Å3 for X = 14, vw = 31 Å3 for X = 20 and vw = 27 Å3 for X = 40. All these data show that with increasing water nucleus size the volume per water molecule decreases and reaches the volume of the water molecule in bulk at x ≥ 20.
© EDP Sciences 1993