This fiver layer model (with smooth SLD/volume fraction profiles) was therefore used for further fitting of all polymer brushes, in D2O, H2O and silicon matched medium (0.60/0.40 D2O/H2O, with an SLD of 2.07 × 10 -6 Å -2 ). This model represents a smooth structural profile for the solvated brushes extending toward the bulk solutions. For each brush, optimisation of the fits was carried out by iteration of fitting in different media (Supplementary Figures ), until systematically reduced correlation coefficients could be obtained, and fringes observed in D2O (in particular, but not exclusively) were satisfactorily captured by the profile of the fits. This resulted in optimised fits that were used for analysis of the morphology of swollen architectures in deionised water (Figure ). Inspection of the scattering length density profiles (Figures and) qualitatively confirmed expected swollen thicknesses extracted from in situ ellipsometry data (Figure ).