SMALL-ANGLE NEUTRON-SCATTERING STUDY OF CONCENTRATED NONIONIC-AMPHIPHILE SOLUTIONS

The structure of aqueous solutions of two polyoxyethylene non-ionic amphiphiles, C10E5 and C8E4, is studied by small-angle neutron-scattering along isothermal paths crossing the isotropic single-phase region from 0% to 100% amphiphile volume fractions. The scattered intensity I (k) shows a peak at a value k(m), which grows monotonically as the amphiphile volume fraction phi-increases. The interpretation of the scattering data leads to the following conclusion: as PHI increases the micellar structure becomes less and less sharp, but orientational correlations between neighboring amphiphile molecules are preserved even in the pure amphiphile phase.