Neutron scattering study of pentanol solubilization in sodium octanoate micelles

We extend a previous small-angle neutron scattering study of sodium octanoate (NaC₈) micelles to the ternary system sodium octanoate/pentanol/water. The use of contrast variation through selective deuteration of individual components together with explicit computation of interference effects, permits us to deduce the location of pentanol (C₅OH) in the micelles. Our main conclusion is that, although the micelles grow as (C₅OH) is solubilised, there is no concomitant variation in the NaC₈ aggregation number. At low alcohol concentrations, the C₅OH is located near the NaC₈ polar heads, while at higher concentration the -OH groups are distributed throughout the micellar core.