Sliding grafted polymer layers


V.A. Baulin, A. Johner, C.M. Marques

Macromolecules, 38(4), 1434 – 1441 (2005)

We study theoretically the structure of sliding grafted polymer layers, or SGP layers. These interfacial structures are built by attaching each polymer to the substrate with a ringlike molecule such as cyclodextrins. Such a topological grafting mode allows the chains to freely slide along the attachment point. Escape from the sliding link is prevented by bulky capping groups. We show that grafts in the mushroom regime adopt mainly symmetric configurations (with comparable branch sizes), while grafts in dense layers are highly dissymmetric so that only one branch per graft participates in the layer. Sliding layers on small colloids or starlike sliding micelles exhibit an intermediate behavior, where the number of longer branches participating in the corona is independent of the total number of branches. This regime also exists for sliding surface micelles comprising less chains, but it is narrower.