A-pBuOx-A In contrast to A-pBuOzi-A, neat A-pBuOx-A micelles have a coreshell structure and are significantly larger than the A-pBuOzi-A assemblies at the same concentration with a total radius of approximately 75-80 Å (Figure ). However, the SLDs of the core and this shell are also very similar (Figure and). Again, the size of the second shell is negligible, resulting in an overall core-shell structure (Figure ). This seems inconsistent as BuOzi should be more hydrophobic than BuOx, and thus, a stronger core-shell contrast would be expected. However, preliminary comparison of 1 H-NMR spectra in CDCl 3 and D 2 O indeed suggest a highly hydrated and thus mobile BuOzi core, but this will have to be studied separately in more detail.