POLYMERS END-GRAFTED ONTO A CYLINDRICAL SURFACE

Equilibrium properties of linear polymers grafted at one end onto a repulsive cylindrical surface of radius R are studied by using molecular dynamic simulation. R is varied between the limiting cases of a flat surface (R --> infinity) and a grafting line (R = 0). Polymers consisting of 50-150 monomers are grafted randomly at an average surface coverage of rho-a onto a cylindrical surface immersed in a good solvent. rho-a is taken to be large enough to induce overlap and consequent stretching of the chains. We present results for the monomer density profile and the density of the free ends. We find no evidence for the existence of a dead zone near the surface from which the free ends are excluded in any of the systems with finite R. This is in contrast with some recent predictions that such a dead zone should exist in the case of polymers in a melt state, and probably under good solvent conditions as well. Only when R --> 0 (that is, polymers grafted on a line) do we see an indication of a dead zone.