Equilibrium structural properties of polymer brushes formed by dendrons grafted via the root segment onto spherical surfaces (dendritic spherical polymer brushes, DSPB) are studied by means of the Scheutjens–Fleer self-consistent field (SF-SCF) numerical approach and scaling analysis. In particular, we focus on the effects of the variable curvature of the surface on the polymer volume fraction distribution and extension of the individual dendrons in DSPB. A systematic comparison with spherical polymer brushes formed by linear polymer chains (LSPB) end-grafted to the surfaces of the same curvature radii is performed. We demonstrate that the difference in internal structural organization of DSPB and LSPB is most pronounced at small curvature radius of the grafting surface. In particular, the radial distribution of polymer volume fraction in DSPB is close to uniform, whereas in LSPB it decays in the radial direction following a power law. The quasi-plateau polymer volume fraction distribution in DSPB is ensured by wide radial distribution of the end segments. In contrast, in LSPB the end segments of the chains are localized preferentially close to the periphery of the brush. An increase in the curvature radius of the surface is accompanied by emerging segregation into two (or more, for larger number of generations) populations of dendrons: the less extended and the more extended ones. The former ones fill the space in the central region of the DSPB, and the latter bring the majority of the monomer units closer to the periphery of the DSPB. The theoretical results are in line with experimental findings on hydrodynamic radii of linear and dendritic poly(ethylene glycol) brushes end-grafted onto Fe3O4 nanoparticles.
- polyelectrolyte brushes
- scaling theory