Location of Butanol in Mixed Micelles with Alkyl Glucosides Studied by SANS

Aqueous micellar solutions of β- d -octyl glucopyranoside (β-C 8 G 1 ), β- d -decyl maltopyranoside (β-C 10 G 2 ), and β- d -dodecyl maltopyranoside (β-C 12 G 2 ) containing 5 wt % of butanol have been studied by small angle-neutron scattering using contrast matching techniques in order to determine the location of the alcohol molecules in the micelles. At the chosen alcohol content the micelles of all three surfactants take on prolate ellipsoidal shape. Using deuterated butanol in combination with fully protonated surfactants dissolved in an appropriate mixture of H 2 O/D 2 O, it was possible to obtain a scattering signal solely due to the alcohol. For all three systems under investigation, it was found that butanol is incorporated into the amphiphile film and is not solubilized into the hydrophobic core of the micelles.